c958 5_final bar_010914

DEA&DP ref: 16/3/1/1/E4/5/2031/14

FINAL COMBINED BASIC ASSESSMENT REPORT

PROPOSED FLOOD DAMAGE REPAIR PROJECTS

IN THE WESTERN OVERBERG

CONTRACT C958.5

Prepared for:

Department of Environmental Affairs and Development Planning

On behalf of:

BERGSTAN South Africa (Pty) Ltd

for

The Western Cape Government:

Department of Transport and Public Works

JUNE 2014

Environmental assessment

Charl de Villiers

Environmental Consulting

[email protected]

Public participation:

[email protected]

Specialist aquatic assessment

Dr Liz Day

Freshwater Consulting

[email protected]

Aspects of this report may reflect material produced by Charl de Villiers Environmental Consulting on behalf of CCA

Environmental (Pty) Ltd in 2012-2013. In such instances, CCA Environmental (Pty) Ltd and, where relevant, Aurecon, are

acknowledged as the co-authors of such content.

OB1: Botrivier (Kanaan) OB2: Botrivier (Doringkloof)

OB3: Elandskloofrivier (Meerlustkloof)

OB4: Elandskloofrivier secondary flood

channel (Meerlustkloof)

OB5: Unnamed watercourse

(Tarentaalkraal)

OB6: Unnamed watercourse

(Nooitgedacht)

Fig 1: Flood repair sites, western Overberg – Contract C958.5

Proposed flood damage repair projects in the western Overberg (C958.5)

Draft Combined BAR i

Fig 2: Project locations


CCA Environmental (Pty) Ltd Draft BAR ii

DEA&DP ref: 16/3/1/1/E4/5/2031/14

Combined Basic Assessment Report in terms of the NEMA Environmental Impact Assessment Regulations, 2010

JULY 2014

DEPARTMENTAL REFERENCE NUMBER(S)

File reference number (EIA):

File reference number (Waste): N/A

File reference number (Other): N/A

PROJECT TITLE

Repairs and maintenance to flood-damaged bridges in the western Overberg (Contract No C958.5)

DETAILS OF THE ENVIRONMENTAL ASSESSMENT PRACTITIONER (EAP)

Environmental Assessment

Practitioner (EAP): Charl de Villiers Environmental Consulting

Contact person: Charl de Villiers

Postal address: 14 Bradwell Road

VREDEHOEK Postal

code: 8001

Telephone: (021) 461 2477 Cell: 083 785 0776

E-mail: [email protected] Fax: 086 553 9256

EAP Qualifications Charl de Villiers – B.A. Hons (Journ), M.Phil (Environmental Management), with

distinction

EAP

Registrations/Associations Certified EAP (ICB)


CCA Environmental (Pty) Ltd Draft BAR iii

DETAILS OF THE EAP’S EXPERTISE TO CARRY OUT BASIC ASSESSMENT PROCEDURES:

NAME Charl de Villiers

RESPONSIBILITY ON PROJECT EAP

DEGREE BA Hons (Journ) (Stellenbosch)

MPhil (Environmental Management), with distinction (Cape Town)

PROFESSIONAL REGISTRATION Certified EAP (ICB)

EXPERIENCE in years 12

EXPERIENCE

Charl de Villiers has worked as an environmental assessment

practitioner since 2002. He has managed environmental processes –

including combined applications – relating to flood repairs, river

maintenance and soil conservation works on behalf of private clients as

well as the Western Cape departments of agriculture and transport and

public works. He specialises in agro-ecosystem governance and

biodiversity mainstreaming and was contributing editor to the Fynbos

Forum Ecosystem Guidelines for Environmental Assessment in the

Western Cape (De Villiers et al., 2005), SANBI's Grassland Ecosystem

Guidelines and Fynbos: Ecology and Management (Esler et al. eds, In

Press). Charl was awarded the IAIA President's Bursary in 2008 and serves

as a part-time lecture on biodiversity and IEM at the universities of Cape

Town, Stellenbosch and the Western Cape. He became a Certified

Environmental Assessment Practitioner in December 2010.


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EXECUTIVE SUMMARY

1. Introduction

This application has been undertaken as a combined application in terms of Regulation 14 of the July 2010 NEMA EIA

regulations.

This Executive Summary incorporates the main findings of the Draft Basic Assessment Report (DBAR) prepared for

proposed repairs to flood-damaged bridges at six sites in the western Overberg (Theewaterkloof Municipality). Two of the

sites are located on District Road (DR) 1288, which follows the course of the Bot River between the Theewaterskloof Dam

and the N2 to the south. The remainder of the sites are on the DR1313 where it crosses northern tributaries of the

Riviersonderend, along the southern base of the Riviersonderend Mountains.

The projects are:

DR1288

OB1 This project entails the complete replacement of a damaged bridge (C10765) over the Bot River at the

farm Kanaan. The site is about 10 km north of the Bot River village. The new bridge would be repositioned

approximately 15 m upstream of the existing crossing, which requires realignment of the DR1288. The

bridge consist of a single span portal concrete structure with an opening of c. 12 m wide x 4.5 m high with

concrete invert slabs. The upstream and downstream banks will receive gabion mattress protection.

OB2 This project is located about 3 km north of OB1, on the DR1288, where the southern approaches to

structure C10768 are vulnerable to wash-aways. The site is at the confluence of the Bot River and a

seasonal tributary that flows in from the east, via the farm Doringkloof. New concrete slabs required on the

road approaches which will also be equipped with side slope protection.

DR1313

NOTE The repairs relating to the four damaged structures over the northern tributaries of the Riviersonderend (OB3 -OB6)

are particularly urgent, because these crossings on the DR1313 provide the only road access to the Helderstroom

Maximum Security Prison when the Riviersondernd is in flood and cuts off the prison from the DR1311 (the main road

linking the R43 (Caledon-Villiersdorp) with Greyton. This has potentially grave security and humanitarian consequences

and interferes with the effective functioning of the justice system.

OB3 This site is located on the DR1313 where it spans the Elandskloof River by means of a severely damaged

pipe culvert crossing adjacent to the farm 'Meerlustkloof'. A new two-lane causeway is required,

comprising six 3.0 m wide x 1.6 m high openings along a new alignment approximately 12 m downstream

of the existing crossing. Road slabs will be provided. The Western Cape Department of Agriculture is due to

construct groynes in the Elandskloof River, which are designed to control the severe destabilisation and

erosion that periodically contributes to damage of the bridge at this site.

OB4 This project entails constructing short concrete aprons upstream and downstream of a small pipe culvert

crossing about 140 m to the east of OB3. The main object of this work is to control the growth of reeds that

trap sediment and cause the pipes underneath the road to become blocked. Flood water is then forced

upwards on to the road surface where it causes damage. This small side channel of the Elandskloof River

also skirts the farm 'Meerlustkloof'.

OB5 This project entails repairing a box culvert at Tarentaalkraal, some 700 m east of OB4 on the DR1313. An

apron slab at the culvert outlet has become undermined and needs to be repaired and under-pinned. An

additional secondary outlet slab, plus a cut-off wall, will also be constructed downstream. Rock will be

dumped in the plunge pool to limit further scour.

OB6 This project at Nooitgedacht entails construction of an additional box culvert next to an existing one so

that larger flows can be passed through the structure, rather than over-topping the road and causing

wash-aways and erosion. The existing culvert will be extended on the on upstream side and there will be a

slight realignment of the existing road to improve road safety at the crossing. Embankment protection will

be provided upstream and downstream. Heavy stone rip-rap will be emplaced at the end of downstream

apron slab to prevent scouring.


v

2. Invitation to comment

The Draft BAR has been distributed for a 40-day review / comment period from xyz to xyz 2012 in order to provide

Interested and Affected Parties (I&APs) and authorities with an opportunity to comment on any aspect of the Basic

Assessment process and the proposed project. Copies of the full report have been made available at the following

locations:

1. Plek A

2. Plek B

3. Plek C.

Any written comments on the Draft BAR must be submitted to:

BolandEnviro cc

Attn: Marizanne Vos

PO Box 250

WORCESTER

6849

Ph 023 347-0336

Fax 023 347-5336

[email protected]

Please ensure that you have included the DEA&DP reference number in your comment: 16/3/1/1/E4/5/2031/14

3. Legislation

A Basic Assessment is required in accordance with the 2010 Environmental Impact Assessment (EIA) 2010 Regulations

promulgated in terms of Sections 24(5), 24M and 44 of the National Environmental Management Act (No. 107 of 1998)

(NEMA), as amended (Government Notice (GN) No. R.543).

Water Use Licences may be necessary in terms of subsections 21(c) and (i) of the National Water Act 36 of 1998 (to be

clarified with the Breede-Gouritz Catchment Management Agency). A 'Notice of Intent to Develop' has been submitted

to Heritage Western Cape in order to determine if the proposed projects are subject to the heritage assessment

requirements of the National Heritage Resources Act 25 of 1999.

The proposed projects triggers the following activities listed in GN No. R544 and R546:

Listing Notice 1 (GN R. 544) Aspects of the road repairs that relate to the

applicable listed activity.

11(xi) Construction of infrastructure ≥50 m2 in size within 32

m of a watercourse

This activity applies to sites OB1 and OB3 where

damaged bridges are to be replaced with new

structures.

18 (i) In-filling, removal etc of any material >5 m3 in a

watercourse …

This activity relates to all earth-moving and

excavation that may be necessary during

construction or, in the case of site OB6, to build a

temporary bypass.

39(iii) Expansion of bridges within a watercourse or within

32 m of a watercourse

This activity applies to the proposed works at sites

OB5 and OB6. It is triggered by the addition of

concrete approaches, outlets and scour protection

to existing bridges. .

40(iv) Expansion of infrastructure by >50 m2 within a

watercourse or within 32 m of a watercourse

This activity also applies to sites OB5 and OB6. It

relates to the provision of additional or redesigned

elements, e.g. wing walls, scour protection and

culverts that may increase the extent of existing

structures.


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16(d)(ii)(hh) Construction of infrastructure ≥10 m2 within 32 of a

watercourse outside urban areas within 5 km from

any other protected area identified i.t.o. NEMA

Protected Areas Act 57/2003

Two of the sites where 'construction'-related

activities are triggered (OB1 and OB3), are located

within 5 km of proclaimed Mountain Catchment

Areas or provincial nature reserves managed by

CapeNature.

24(d)(ii)

and (iii)(gg)

Expansion of infrastructure by ≥10 m2 in or within 32

m of a watercourse in all watercourses in the

Western Cape, and outside urban areas in the

Western Cape within 5 km from any protected

areas (other than a National Park or World Heritage

Site) proclaimed in terms of the NEM: Protected

Areas Act 57 of 2003

Three of the projects, at OB4, OB5 and OB6, entail

'expansion' as defined in LN3.

4. The environmental context

The study domain is in the Western Overberg, an agricultural region that support cereal and deciduous fruit production,

as well as sheep farming. The sites lie at the base of the Groenlandberge, between Bot River and the Theewaterskloof

Dam, and the Riviersonderend Mountains respectively. The sites are within a 20 km radius of Caledon; OB1 and OB3 to

the north-west of the town, and the remainder to the north. The closest settlement to any of the sites is a Bereaville,

which is about 5.5 km by road from OB6.

The Helderstroom Maximum Security Prison is about 8.5 km west of site OB3. The Moravian mission settlement at

Genadendal and Greyton are located some six and 13 km respectively from the easternmost site, OB6.

There are two regionally important rivers in the study area: the Bot River and the Riviersonderend. Sites OB1 and OB2 are

located on the former, whereas OB3 to OB6 are located on watercourses that drain from the Riviersondernend

Mountains into the Riviersonderend itself.

All the sites in question fall within mapped Crtiical Biodiversity Areas or Ecological Support Areas. The Ecological

Importance and Sensitivity (EIS), Present Ecological State (PES) of each river or wetland and condition of terrestrial

habitat are also provided (cf. Day, 2014). Sites OB3 to OB6 were ground-truthed as valley bottom wetland FEPAs

(Freshwater Water Ecosystem Priority Areas).

Site CBA ESA Condition and importance of

aquatic ecosystems (rivers, wetlands)

Condition of terrestrial habitat

within a c. 100 m radius of each

site** Ecological

Importance and

Sensitivity (EIS)

Present

Ecological State

(PES*)

OB1 Yes Yes Moderate D D = 80; T = 20

OB2 Yes Yes Moderate D NN = 10; D = 60; T = 30

OB3 Yes Yes Low E D = 80; T = 20

OB4 No Yes Low C NN = 60; D = 40

OB5 No Yes Moderate C NN = 30; D = 50; T = 20

OB6 No Yes Low D/E NN = 20; D = 50; T = 30

*A = Unmodified/natural B = Largely natural C = Moderately modified D =

Largely Modified E = Seriously modified F = Critically/extremely modified

** NN = Near Natural D =

Degraded T = Transformed


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The basic assessment, supported by a specialist aquatic assessment undertaken by Dr Liz Day, provisionally concluded

that the following aspects of the receiving environment could be affected by the proposed projects and related

activities:

Hydrological aspects

− Flow regimes

− Water quality

Hydro-geomorphological aspects

− Scouring, erosion and sediment movement

− Physical structures and stability of watercourse

Biodiversity aspects

− In-stream and riparian habitat

Biodiversity conservation priorities

− Critical Biodiversity Areas and Ecological Support Areas

− Freshwater Ecosystem Priority Areas

− Listed threatened ecosystems

Socio-economic aspects

− Employment opportunities

− Sense of place and wellbeing

− Integrity of road network (safety and reliability)

The overall significance of impacts during the construction phase was evaluated as follows:

Table 1: Impacts during the construction phase Potential (negative) significance of impacts

Before mitigation After mitigation

Biophysical environment

Erosion and sedimentation Low to Very Low Very Low

Water quality (turbidity) Low to Very Low Very Low

Water quality (contamination) Medium to Very Low Very Low

Channel stability Low to Very Low Very Low

Critical Biodiversity Areas Medium Very Low

Socio-economic environment

Inconvenience to road users Low Low

Sense of wellbeing

Noise Medium to Very Low Very Low

Dust Medium to Very Low Very Low

Socio-cultural environment

Sense of place Medium Very Low

The overall significance of impacts during the post-construction, operational phase was evaluated as follows:

Table 2: Impacts during the operational phase:

Potential (negative) significance of impacts



Improved hydraulic capacity Medium Low (positive)

Erosion and sedimentation High to Low Very Low (positive)

Aquatic CBAs Medium to High Very Low

Terrestrial CBAs Low to Very Low Very Low


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Improved road safety High to Medium High (positive)

No negative cumulative impacts were conclusively identified a site-specific scale. Generally, it is assumed that improved

culvert design, particularly by the introduction of increased flow space and/or scour protection, could be expected to

reduce flow concentration and the risk of downstream erosion and habitat degradation, which would be a positive

impact. Conversely, if erosion is allowed to persist, it will almost certainly result in further damage to agricultural land and

road infrastructure, as well as having a cumulative, negative, impact on aquatic habitats, biota and ecological

processes.

However, as with other flood repair projects in the Overberg area, any environmental benefits issuing from the new or

upgraded structures would largely be annulled by the impacts of intense floods and heavy sediment burdens that are

directly linked to the degraded and destabilised condition of most of the affected catchments in this intensively-farmed

region. Similarly, failure to keep channels clear of invasive alien plants will mean that the structures remain vulnerable to

the impacts of down-cutting, erosion and enhanced sediment transport.

One of the most evident positive cumulative impacts relates to the improvement and maintenance of a high quality

rural road network which holds manifest benefits across the socio-economic spectrum.

From a socio-economic point of view, the road repairs would be both necessary and desirable. Any long-term

environmental benefit would, however, be contingent upon the degree to which these highly degraded and

destabilised watercourses can be rehabilitated. It is for the latter reason that mitigation has to be addressed

strategically, at an ecosystem or catchment scale, if the environmental benefits of the repaired and rebuilt structures are

to materialise.

5. Recommendations

The Draft Basic Assessment Report recommends that environmental authorisation be granted for all six projects, subject

to the following conditions that apply:

(A) Generically to all construction;

(B) To ecological mitigation and post-construction rehabilitation and maintenance at each of the respective sites;

and

(C) To farm and catchment-scale interventions.

(A) GENERIC, CONSTRUCTION-RELATED MITIGATION THAT APPLIES TO ALL SITES

The key mitigation measure is impact avoidance, failing which disturbance of watercourses and other wetlands must be

minimised and remedied.

Where adverse impacts cannot reasonably be prevented, construction should be managed through the effective

implementation of the Construction Environmental Management and Maintenance Programme (EMP) with a strong

emphasis on post-construction rehabilitation and channel maintenance.

Construction-related impact avoidance and mitigation must address activities that may:

− Cause disturbance to river banks;

− Result in potential pollution of the water course as a result of allowing the passage (direct, or by seepage,

surface spillage or overflow) of pollutants such as sediment, cement, fuels, litter or other waste into

watercourses;

− Increase the likelihood of invasion by alien plants;

− Increase disturbance as a result of human access to river / wetland areas; and/or

− Negatively affect the success of planned river bank rehabilitation activities.

Timing of construction


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− Construction activities within watercourses should not take place during the wet season (i.e. any activities

requiring the diversion of flows should take place between October and April only), and construction schedules

should preferably be managed within these time frames.

Delineation of construction sites and access to watercourses

− Obtain the landowner's written permission if sites must be accessed across farmland

− Only use existing access roads to undertake the proposed activities

− The physical extent of construction-related impacts must be minimised and securely contained within an area

demarcated by RoadQuip® 'Express Net' or a similar highly visible and durable barrier device. This particularly

applies to those points where vehicles obtain access into watercourses.

− Limiting activities and vehicle movement to disturbed sections of river channels

− Clearly mark vegetation that may not be damaged

− All areas outside of the demarcated construction zone should, within reason, be regarded as no-go areas

during construction, with the exception of personnel engaged in required alien clearing and bank

rehabilitation activities outside of construction disturbance zones.

Removal of indigenous vegetation

− Only remove reeds and other riparian vegetation in the channel and along river banks if access to structures or

construction areas would otherwise be impeded by indigenous vegetation – this applies specifically to Site OB5,

which still retains natural in-stream vegetation and habitat types.

De-watering of construction sites

− Where de-watering is required as part of construction activities, provision must be made for the settlement of

sediment in temporary sediment ponds or other areas of containment. These must be managed so as to

prevent the passage of sediment-rich water into the watercourse

− De-watering systems must be designed so that they do not result in the passage of concentrated flow into

watercourses, thereby promoting erosion.

− Ensure that flows that are routed around or discharged downstream of construction areas do not result in scour

downstream of construction sites

− Ensure that the impact of pumped water that is discharged under pressure is dissipated by placing pipe outlets

in rocky parts of the stream bed that are not susceptible to scour.

Removal and stockpiling of topsoil for post-construction rehabilitation

− Fill sourced for construction purposes must be free of alien seed.

− Remove topsoil to a depth of 150 mm and stockpile it locally for re-vegetation.

− Grade banks to a slope of at least 1:4, but preferably flatter, between the repaired structures and the

boundary of the road reserve.

− Grade slopes downwards, towards the watercourses, with reducing the width or depth of the channel

− Re-plant disturbed areas directly upstream and downstream of each structure with indigenous, locally-

occurring pioneer species at the level of base flow.

− Using bagged plants rather than seeds or cuttings to achieve rapid stabilisation of particularly lower banks.

Storage and preparation of construction materials

− Construction sites must be managed so that construction material (especially cement and fuel products) is not

washed or blown into watercourses during storm events or strong winds.

− Store and contain all materials on the construction sites at least 40 m from the nearest water resource.

− Concrete batching must take place at least 40 m from the edge of channel in a secure, bunded area (e.g.

wooden boards placed over heavy plastic sheeting within a bund of sandbags).

− Keeping stockpiled spoil and recently disturbed areas moist.


x

Refuelling of vehicles and other machinery

− Vehicles must be refuelled at least 40 m away from rivers, in securely bunded areas

− Fuel bowsers and other forms of fuel storage must be kept at least 40 m away from any watercourse

− Check vehicles daily for oil leaks and repair leaks immediately

− Maintain all construction machinery and vehicles in good working order.

General site maintenance

− Inspect sites daily for litter and remove all rubble and waste material from the river channels and riparian zones

after construction is completed.

− No open fires are permitted at any of the construction sites – fires for cooking or heating purposes must be

made in 'konkas' within a cleared area within the construction site

− Provide and regularly service ablution facilities for construction staff on site.

− Toilets must be located at least 40 m from watercourses.

− No tools, packaging, empty containers or other construction materials may be washed in watercourses

− Water used for washing must be managed such that it does not contaminate any watercourse;

Noise abatement

− Ensure construction machinery and especially silencers are in good working order.

− Limit construction to the hours of daylight, on weekdays only.

Dust abatement

− Vehicles must not exceed 40 km/hr on gravel roads in the vicinity of human habitation or vineyards or

orchards with ripening fruit.

Road safety

− Provide sufficient signage to warn motorists of the presence of construction works and detours.

Post-construction rehabilitation

− Rehabilitation activities specified in mitigation measures, including rehabilitation of temporary bypasses or

defunct structures should take place outside of the wet season, and immediately after the completion of

construction activities.

− All waste generated by construction activities (including rubble, litter etc.) is to be removed from the site and

disposed of at an appropriate approved site.

− Remove invasive species such as black wattle Acacia mearnsii and beefwood Casuarina sp as they contribute

to channel restriction, down-cutting and erosion, and displace indigenous biodiversity.

− Post-construction alien management must be ongoing at all sites.

− Alien clearing procedures should be carried out in accordance with species-specific guidelines outlined by

Working for Water documentation, or as recommended by an experienced alien clearing specialist;

− Bank rehabilitation activities should make provision for input by a river ecologist or the Western Cape Department of Agriculture into the final shaping and planting of these areas.

− Any area accidentally disturbed during construction should be rehabilitated after construction, with input from

a riverine specialist ecologist or the Western Cape Department of Agriculture where such areas lie within a

watercourse or other wetland.

Post-construction channel maintenance

− Keeping watercourses upstream of the structures (at least as far as the edge of the road reserve) clear of flood

debris (particularly ‘spoelklippe’, branches and uprooted bushes and trees) to prevent premature over-topping

and back-flooding in floods ≤1:5-year return period.


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− Keeping channels downstream, at least as far as the fenced edge of the road reserve, clear of branches and

other obstacles that may deflect flows into the banks of watercourses.

− Where excavations have taken place upstream of structures, ensure that potential nick-points and benches in

the channel are removed so as to prevent head-cut erosion from developing upstream of these locations.

− Monitor the first reach/first 150 m of the watercourse downstream for signs of new erosion.

− Monitor changes to sediment patterns (deposition and erosion) up- and downstream of repaired structures to

assess recovery and reinstatement of the general slope of the watercourse.

− Obtaining timeous ecological advice on how best to repair and, if feasible, provide additional venting, to

gravel approaches that may be washed away as a result of floods.

− Maintain roads to reduce the concentration and/or intensity of run-off so as to dissipate energy and erosion

potential.

(B) Measures relating to site-specific mitigation and ecological rehabilitation

OB1: Kanaan The following measures need to be implemented upon completion of construction:

− All concrete and other debris associated with the present road crossing should be removed from the river bed and banks as

soon as the requirement for a construction-phase bypass road is over, and disposed of outside of the 1:50 year flood line for the river;

− The existing road, which will be replaced by a new alignment, should be ripped, all artificial debris removed, and the river bank and riparian zone thus created should be shaped to resemble a natural system, in a band at least 15m wide on either side of the river – a river ecologist should oversee / sign off on this aspect of mitigation;

− The river bank must be rehabilitated according to Environmental Specification C1008; and − The small tributary directly to the east should be addressed as part of the latter process, and re-shaped as a broad open

channel, planted in destabilised areas to prevent erosion;

OB3: Meerlustkloof

− Additional pipes must be installed in the existing causeway to improve its capacity to accommodate high flows during construction, after which this structure must be demolished and its disturbed footprint rehabilitated as specified below. The installation of the extra pipes must be supervised by the project engineer and an aquatic ecologist.

− All concrete and other debris associated with the present road crossing should be removed from the river bed and banks as soon as the requirement for a construction-phase bypass road is over, and disposed of outside of the 1:50 year flood line for the river; and

− The existing road, which will be replaced by a new alignment, should be ripped, all artificial debris removed, and the river bank rehabilitated according to Environmental Specification C1008.

Site OB6: Nooitgedacht

− The wetland head-cut must be addressed, as a matter of great urgency, and prior to the start of any construction activities on this overall project, through the installation of a gabion weir, located at the head-cut point, and appropriately designed to prevent further erosion caused by a change in gradient between the wetland channel and the excavated channel upstream of the low-lying culvert.

(C) General, post-construction ecological rehabilitation

These recommendations relate to long-term rehabilitation and channel maintenance and do NOT apply to construction

phase activities as specified in the Construction Environmental Management Programme for project C958.5

Alien clearance and monitoring − Keep channels upstream and downstream – and at least as far as the first bend and/or for 150 m – clear of large branches

and other debris that may deflect flows into the banks of watercourses. − Clear invasive alien plants from river banks and the floodplain at least 200 m downstream of the structures, in a corridor at

least 30 m wide and replant with locally-occurring indigenous pioneer plant species.


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− Species-appropriate alien clearing methods should be employed – Working for Water guidelines should be used in this regard;

− Cleared areas should be stabilised by a combination (as appropriate) of bank shaping and planting with locally indigenous plant species

− Monitor the first reach/first 150 m of the watercourse downstream on an annual basis for signs of new erosion. − Maintain a photographic record of the monitored reaches. − In all cases, alien clearance needs to be co-ordinated by an authority such as the Western Cape Department of Agriculture

and local landowners should be encouraged to participate in such clearance programmes.

Site OB1: Kanaan

− The eroding bank upstream of the bend must be addressed, through removal of alien vegetation, reshaping of the bank and

replanting; hard stabilisation techniques (e.g. bank lining with gabions) should not be used, although it is understood that gabions will be used immediately up- and possibly downstream of the new structures.

Site OB2: Doringkloof

− All invasive woody alien vegetation and the seedlings of such species should be cleared from a zone extending at least 30 m upstream and 30 m downstream of the present crossing point, as well as 30m upstream along the inflowing minor stream, in a swathe at least 15m wide on either side of the river channel, or less if alien invasion is within a narrower zone – the final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner;

− The design for this structure must include an additional or extended culvert or other ecologically cognisant measure that allows for the free flow of the minor stream through the structure, without being diverted along the road edge. The mechanism for this would need to address the fact that the stream appears to enter the system at a higher level than the existing culvert.

Site OB3: Meerlustkloof

− The DTPW should liaise with the Western Cape Department of Agriculture regarding the proposed installation of a groyne field in the Elandskloof River, and ensure that bank erosion and channel migration in the reaches at least 50 m upstream and downstream of the crossing are controlled by groynes, designed in keeping with the objectives of the broader WCDA flood and erosion control programme.

− Such structures ideally need to be in place before the start of the present proposed activities – in the event that delays in their authorization through WCDA are considered likely, it is recommended that the DTPW either work with WCDA to prioritise approval and construction of the structures that would affect the present road, or design and obtain authorization for such structures separately.

− Note that the proposed design at OB3 already assumes implementation of the groyne field, and allows for a lower invert level in the crossing than that required at present, given that the river would be down-cut by concentration of flood flows.

− The extensive eroded area to the east of the existing bermed river channel downstream of OB3 must be addressed, and returned to a vegetated floodplain condition.

− This rehabilitation measure, which should only take place after construction of the groynes and new road and bridge, would require:

o Liaison with the WCDA regarding the implications of the proposed groyne field for this area – ideally, the groyne field itself should allow for widening of the river in these disturbed reaches

o Removal of the berm (berm material may be spread on the eroded floodplain)

o Removal of the beefwood trees lining the channel downstream of the road

o Landscaping / shaping the floodplain area such that it comprises a mosaic of depressions and raised areas, mirroring natural conditions;

o Establishment of indigenous floodplain vegetation on the rehabilitated area – note that while planting or seeding of the area would be positive, it is likely that appropriate plants will establish themselves in the rehabilitated area over time, provided that weeding is allowed for in the establishment phase. This has been the case with disturbed areas upstream (Day 2013).

− Allowance must be made for the establishment of a continuous swathe of appropriate, locally indigenous vegetation along


xiii

at least the wetted bottom of the bank of the river, but ideally up the bank as well, for a distance of 30m up- and downstream of the proposed structure, to prevent erosion. It is strongly recommended that dense stands of Palmiet reeds (Prionium serratum) should be utilised for this purpose. Other plant species used should be selected in consultation with a botanist and/or river ecologist, to ensure they meet the required criteria of being hardy, locally indigenous and suited to the conditions in which they are planted;

− The final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner;

Site OB5: Tarentaalkraal

In order to address the issue of concentrated flows and at times the passage of large debris through the road culvert, exacerbating the problems experienced in the scour hole: − The alien-invaded channel upstream of the road must be cleared of all woody aliens and the seedlings of such species,

across the entire riverine zone, extending upstream for a distance of at least 40 m upstream of the road – the final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner


− Cleared areas should be stabilised by a combination (as appropriate) of bank shaping and planting with locally indigenous plant species;

− Local landowners should ideally be required to participate in long-term alien maintenance clearing activities in the cleared reach and upstream;

− Branches and other material that become entangled in the fence across the culvert should be cleared before the onset of winter in order to prevent debris-build-up;

− Consideration should be given to the creation of attenuation depressions / wetlands in the area to the west of the channel, upstream of the road, to manage flood velocities and volumes; and

− Also, alien vegetation should be cleared to a distance of 30 m downstream of the road (i.e. to just past the riffle at the end of the pool).

OB6: Nooitgedacht

− The eroding banks downstream of the culvert must be addressed as a matter of urgency, bearing in mind their proximity to the Riviersonderend wetlands downstream. The following measures are regarded as minimum requirements:

o The need for the installation of energy-control weirs in the channel should be considered, to prevent further

down-cutting and allow the re-establishment over time of wetland vegetation – where considered necessary by an engineer, working with a river ecologist, such weirs should be constructed;

o The river banks must be graded (during low flow periods) to establish banks that have slopes no steeper than 1:5 and preferably less steep;

o Allowance must be made for the planting of at least the lower bank with hardy locally indigenous plant species, approved by a botanist or river ecologist, that will play a role ion lower bank stabilisation; the use of Palmiet in this regard would be encouraged;

o The passage of flows into the channel from the west must be investigated and addressed, such that it does not

constitute a threat to the long-term rehabilitation of the channel.


Charl de Villiers Environmental Consulting & BolandEnviro Draft BAR xiv

TABLE OF CONTENTS

PROJECT INFORMATION i

DEPARTMENTAL REFERENCE NUMBERS ii

PROJECT TITLE ii

DETAILS OF THE ENVIRONMENTAL ASSESSMENT PRACTITIONER (EAP) ii

DETAILS OF EAP'S EXPERTISE TO CARRY OUT BASIC ASSESSMENT PROCEDURES iii

EXECUTIVE SUMMARY iv

TABLE OF CONTENTS x

A. ACTIVITY INFORMATION 1

1. Project description 1

2. Physical size of the activity 4

3. Site access 5

4. Description of the property on which the activity is to be undertaken 5

5. Site photographs 7

B. DESCRIPTION OF RECEIVING ENVIRONMENT 8

1. Gradient of the site 8

2. Location in landscape 8

3. Groundwater, soil and geological stability of the site 9

4. Surface water 10

5. Biodiversity 11

6. Land use of the site 13

7. Land use character of surrounding area 14

8. Socio-economic aspects 16

9. Historical and cultural aspects 16

10. Applicable legislation, policies and/or guidelines 17

C. PUBLIC PARTICIPATION 19

D. NEED AND DESIRABILITY 21

E. ALTERNATIVES 24

F. IMPACT ASSESSMENT, MANAGEMENT, MITIGATION AND MONITORING MEASURES 27

1. Manner in which the development will impact on various aspects 27

2. Waste and emissions 28

3. Water use 29

4. Power supply 30

5. Energy efficiency 30

6. Description and assessment of the significance of impacts prior to and after mitigation 30

7. Specialist inputs/studies and recommendations 41

8. Impact summary 42

9. Other management, mitigation and monitoring measures 43


Charl de Villiers Environmental Consulting & BolandEnviro Draft BAR xv

G. ASSESSMENT METHODOLOGIES AND CRITERIA, GAPS IN KNOWLEDGE, UNDERLYING ASSUMPTIONS

AND UNCERTAINTIES 44

H. RECOMMENDATION OF THE EAP 45

I. APPENDICES 47

DECLARATIONS 48


Charl de Villiers Environmental Consulting & BolandEnviro Draft BAR 16

SECTION A: ACTIVITY INFORMATION

1. PROJECT DESCRIPTION

2.1 Is the project a new development? See below

All projects relates to the repair or replacement of existing culverts and related infrastructure on public roads in the north-

western Overberg. In two cases, flood-damaged bridges are to be replaced with equivalent structures (OB1 and OB3). In

one case (OB6), an additional box culvert is to be added to a crossing. A small gabion weir would also have to be installed

in the eroding channel upstream of Site OB6 in order to prevent a head-cut from forming. Activities at the remainder of the

sites will be limited to the repair and/or refurbishment of existing infrastructure (OB2, OB4 and OB6) within their current

alignment (i.e. April 2014).

(b) Provide a detailed description of the development project and associated infrastructure.

Essential repairs to flood-damaged rural road infrastructure in the Theewaterskloof Municipality

The Western Cape Government: Department of Transport and Public Works (DTPW) proposes to undertake essential flood

damage repairs to road infrastructure at various locations in the western parts of the Overberg, in an area spanned by

Villiersdorp, Bot River, Caledon and Greyton in the Theewaterskloof Municipality (cf. Fig 1). The work entails two contracts:

− C958.5 (Bergstan) – To which this application for environmental authorisation applies; and

− C960.4 (Hatch Goba) – This contract is subject to a separate but parallel application for environmental

authorisation.

Contact C958.5

The proposed works entail repairs and/or maintenance to flood-damaged causeways, culverts and drifts at six different sites

in the Theewaterskloof Municipality. The sites are located on the Bot River (OB1 and OB2) and northerly tributaries of the

Riviersonderend (OB3-OB6). The damage – which originally stemmed from floods in August 2012 – has been exacerbated by

subsequent floods in October 2012 and November 2013.

Two of the structures (OB1 at Kanaan, and OB3 at Meerlustkloof) will be replaced with new crossings. These bridges need to

be rebuilt owing to the extent of damage and the adverse implications this holds for road safety and maintaining

serviceable public road infrastructure. Redundant structures will be demolished and their former footprints rehabilitated.

Rubble is to be conveyed to municipal waste dumps. The redundant structures will serve as bypasses during construction of

the new bridges.

*** Access to the Helderstroom Prison: High priority ***

The repairs relating to the four damaged structures over the northern tributaries of the Riviersonderend (OB3-OB6) are

particularly urgent, because these crossings on the DR1313 provide the only road access to the Helderstroom Prison when

the Riviersondernd is in flood and cuts off the prison from the DR1311 (the main road linking the R43 (Caledon-Villiersdorp)

with Greyton. This has potentially grave security and humanitarian consequences and interferes with the effective

functioning of the justice system.

Environmental factors influencing repairs

All the structures, barring those at OB3 and OB4 (which are both vented by pipes; the rebuilt bridge at OB3 is to be equipped

with box culverts), constitute concrete box culverts of various dimensions that carry either single or double lane decks. The

use of precast box culverts is generally recommended where riverbeds carry a high boulder load and high energy flood

events are common in winter and early summer. All the rivers in question are degraded as a result of alien infestation, and

cultivation and development in former floodplains and the surrounding catchments that, cumulatively, promote channel

confinement, down-cutting, lateral erosion and mobilisation of large quantities of sediment during floods. Boulders are less

likely to block rectangular portal units than pipe culverts, which are prone to being clogged by uprooted or felled trees and

high loads of debris that are generated as a result of chronic channel destabilisation. Box culverts are also more easily

cleared than pipe culverts. In the light of the boulder load in the affected systems, gabions have been largely avoided.

Flood capacity of structures

The structures are designed to cater at least for a one-in-two-year design flood and in most cases entail increasing the



hydraulic capacity of the portals, which also has the effect of improving sediment movement underneath the crossings. The

structures would be designed to be over-topped by larger floods. Where deemed necessary, protection works such as cut-

off walls, apron slabs and approach slabs have been designed to cater for larger flow volumes. In this way, structural

damage during large floods should be reduced even if the road becomes temporarily unpassable. In some cases, splash

aprons would be extended to prevent scouring at outlets which, if not controlled, can undermine the structure and

contribute to erosion of the downstream channel. See Appendix B1 for an overview of the proposed repairs and

maintenance-related activities.

(c) List all the activities assessed during the Basic Assessment process:



11(xi) Construction of infrastructure ≥50 m2 in size within 32

m of a watercourse

This activity applies to sites OB1 and OB3 where

damaged bridges are to be replaced with new

structures.

18 (i) In-filling, removal etc of any material >5 m3 in a

watercourse …

This activity relates to all earth-moving and

excavation that may be necessary during

construction or, in the case of site OB6, to build a

temporary bypass.

39(iii) Expansion of bridges within a watercourse or within

32 m of a watercourse

This activity applies to the proposed works at sites

OB5 and OB6. It is triggered by the addition of

concrete approaches, outlets and scour protection

to existing bridges. .

40(iv) Expansion of infrastructure by >50 m2 within a

watercourse or within 32 m of a watercourse

This activity also applies to sites OB5 and OB6. It

relates to the provision of additional or redesigned

elements, e.g. wing walls, scour protection and

culverts that may increase the extent of existing

structures.



16(d)(ii)(hh) Construction of infrastructure ≥10 m2 within 32 of a

watercourse outside urban areas within 5 km from

any other protected area identified i.t.o. NEMA

Protected Areas Act 57/2003

Two of the sites where 'construction'-related

activities are triggered (OB1 and OB3), are located

within 5 km of proclaimed Mountain Catchment

Areas or provincial nature reserves managed by

CapeNature.

24(d)(ii)

and (iii)(gg)

Expansion of infrastructure by ≥10 m2 in or within 32

m of a watercourse in all watercourses in the

Western Cape, and outside urban areas in the

Western Cape within 5 km from any protected

areas (other than a National Park or World Heritage

Site) proclaimed in terms of the NEM: Protected

Areas Act 57 of 2003

Three of the projects, at OB4, OB5 and OB6, entail

'expansion' as defined in LN3.

If the application is also for activities as per Listing Notice 2 and permission was granted to subject the application to

Basic Assessment, also indicate the applicable Listing Notice 2 activities:

GN No. R. 545

Activity No(s):

If permission was granted in terms of Regulation

20, describe the relevant Scoping and EIA

Activity(ies) in writing as per Listing Notice 2 (GN

No. R. 545)

Describe the portion of the development as per the

project description that relates to the applicable

listed activity.

N/A

Waste management activities in terms of the NEM: WA (Government Gazette No. 32368):

GN No. 718 - Category A Activity

No(s): Describe the relevant Category A waste management activity in writing.



N/A

If the application is also for waste management activities as per Category B and permission was granted to subject the

application to Basic Assessment, also indicate the applicable Category B activities:

GN No. 718 – Category B Activity No(s): Describe the relevant Category B waste management activity in writing.

N/A

Atmospheric emission activities in terms of the NEM: AQA (Government Gazette No. 33064):

GN No. 248 Activity No(s): Describe the relevant atmospheric emission activity in writing.

N/A

(d) Please provide details of all components of the proposed project and attach diagrams (e.g. architectural

drawings or perspectives, engineering drawings, process flow charts etc.).

Buildings YES NO �

Provide brief description:

N/A

Infrastructure (e.g. roads, power and water supply/ storage) YES � NO


See Section 1(b) above for an overview of the projects, as well as the plans and project descriptions in Appendices B and

C.

Two of the projects (OB1 and OB3) will entail building new bridges in close proximity to the alignment of the damaged

structures (<20 m will separate the new structures from the old ones, which are to be demolished and removed upon

completion of the works).

The remainder of the projects entail repairing and upgrading existing bridges on public thoroughfares. Only OB6 requires a

bypass. It also entails installation of an additional box culvert to double the hydraulic capacity of the culvert.

In all cases, structures are to be equipped with either new or additional anti-scour protection and road surfaces may be

sealed with concrete to protect approaches against erosion.

Most of this work will take place within the existing road prism or with minimal expansion within watercourses. Only one

temporary bypass is required, namely at site OB6.

More detailed descriptions follow below.

3.1 OB1 This project entails the complete replacement of a damaged bridge (C10765) over the Bot River at the

farm Kanaan. The site is about 10 km north of the Bot River village. The new bridge would be repositioned

approximately 15 m upstream of the existing crossing, which requires realignment of the DR1288. The bridge

consist of a single span portal concrete structure with an opening of c. 12 m wide x 4.5 m high with

concrete invert slabs. The upstream and downstream banks will receive gabion mattress protection.

3.2 OB2 This project is located about 3 km north of OB1, on the DR1288, where the southern approaches to structure

C10768 are vulnerable to wash-aways. The site is at the confluence of the Bot River and a seasonal tributary

that flows in from the east, via the farm Doringkloof. New concrete slabs are required on the road

approaches which will also be equipped with side slope protection.

3.3 OB3 This site is located on the DR1313 where it spans the Elandskloof River by means of a severely damaged

pipe culvert crossing adjacent to the farm 'Meerlustkloof'. A new two-lane causeway is required,

comprising six 3.0 m wide x 1.6 m high openings along a new alignment approximately 12 m downstream of

the existing crossing. Road slabs will be provided. The Western Cape Department of Agriculture is due to

construct groynes in the Elandskloof River, which are designed to control the severe destabilisation and

erosion that periodically contributes to damage of the bridge at this site.

3.4 OB4 This project entails placing gabion 'mattresses', each about 12 m2 in extent, upstream and downstream of a

small pipe culvert crossing about 140 m to the east of OB3. The top surface of the mattresses will receive a

thin concrete slab. The main object of this work is to control the growth of reeds that trap sediment and

cause the pipes underneath the road to become blocked. Flood water is then forced upwards on to the

road surface where it causes damage. The mattresses will contain the growth of reeds while permitting low

flows through the gabions, thereby maintaining the hydraulic functioning of this minor flood channel. This



small side channel of the Elandskloof River also skirts the farm 'Meerlustkloof'.

3.5 OB5 This project entails providing new scour protection downstream of a box culvert at Tarentaalkraal, some 700

m east of OB4 on the DR1313. An apron slab at the culvert outlet has become undermined and needs to

be repaired and under-pinned. The damaged apron slab will be replaced with a stepped structure of three

gabions that are designed to break the fall of water. The base of the latter 'cascade' will be extended into

a reinforced gabion 'mattress' that will prevent scour downstream of the culvert. The gabion 'mattress' will

be 14.84 m wide, and the entire protective structure will extend 8 m from the culvert outet into the

watercourse below. The difference in height between the base of the culvert outlet and the base of the

gabion 'mattress' is 2.7 m. The top surfaces of the stepped gabions and the gabion 'mattress' will be

protected with concrete screed panels which allow water to infiltrate the structures and permit some

flexibility to accommodate settling of the scour protection.

3.6 OB6 This project at Nooitgedacht entails construction of an additional box culvert next to an existing one so that

larger flows can be passed through the structure, rather than over-topping the road and causing wash-

aways and erosion. The additional culvert will be 12.68 m long, by 1.8 m wide and 1.2 m high. The existing

culvert will be extended by 3.68 m on the upstream side and there will be a slight realignment of the

existing road to improve road safety at the crossing. Embankment protection will be provided upstream

and downstream. A gabion 'mattress' will be placed downstream of the outlet. It will have a width of 12 m

extend 4 m downstream. As with the scour protection at OB5, the surface of this gabion 'mattress' will also

protected with concrete screed panels.

Processing activities (e.g. manufacturing, storage, distribution) YES NO �


N/A

Storage facilities for raw materials and products (e.g. volume and substances to be stored)

Provide brief description YES NO �

N/A

Storage and treatment facilities for solid waste and effluent generated by the project YES NO �

Provide brief description

N/A

Other activities (e.g. water abstraction activities, crop planting activities) YES NO �

Provide brief description

N/A

2. PHYSICAL SIZE OF THE ACTIVITY

Size of the property

(a) Indicate the size of the property (cadastral unit) on which the activity

is to be undertaken.

The new causeways at OB1 and OB3, and the rebuilt scour protection at

OB5, will extend beyond the boundaries of the road reserve. The gabion

check-weir at OB6 and the temporary by-pass at this site will also be built

outside the road reserve. All other work will be confined to the road

reserve.

OB1

Farm 246/1 CALEDON

435.7770 ha

OB3

Farm 59/4 CALEDON

408.5953 ha

OB5

Farm 59/2 CALEDON

368.617 ha

OB6

Farm 58/6 CALEDON

85.3723 ha



Size of the completed structures (m2)

(extent of expansion relative to existing extent of

structure in brackets)

(b) Indicate the size of the facility (development area) on which

the activity is to be undertaken.

See Appendix B2 for the physical surface area of the respective

works in terms of their existing extent, the area of expansion and,

in the case of OB6, the footprint of the temporary by-pass (280

m2).

OB1 1 050 (600)

OB2 245

OB3 750 (250)

OB4 83 (32)

OB5 367 (112)

OB6 522 (322)

Site number (c) Indicate the physical size

(footprint) of the activity

together with its associated

infrastructure

Total extent of repairs plus by-

passes

(m2)

(d) Indicate the physical size

(footprint) of the activity

This represents the extent to

which structures may be

extended as a result of the

repairs and refurbished scour

protection and approach slabs

(m2)

(e) Indicate the physical size

(footprint) of the associated

infrastructure

This relates to the bypasses that

will be in place for the duration

of the repairs

(m2)

OB1 1050 600 0

OB2 245 0 0

OB3 750 250 0

OB4 82 32 0

OB5 367 112 0

OB6 522 322 280

and, for linear activities:

(f) Indicate the length of the activity: Length of the activity:

N/A m

3. SITE ACCESS

(a) Is there an existing access road? YES � NO

(b) If no, what is the distance over which a new access road will be built? m

(c) Describe the type of access road planned:

N/A

4. DESCRIPTION OF THE PROPERTY ON WHICH THE ACTIVITY IS TO BE UNDERTAKEN AND THE LOCATION OF THE

ACTIVITY ON THE PROPERTY

(a) Provide a description of the property on which the activity is to be undertaken and the location of the activity on

the property.



All the sites in question are located on relatively isolated gravel rounds in rural landscapes in which farming (intensive and

extensive) is the predominant land use. The DR1288 carries, on average, fewer than 100 vehicles per day, and the DR1313

fewer than 200 vehicles per day (Bergstan South Africa, 2013).

(b) Please provide a location map (see below) as Appendix A to this report which shows the location of the property

and the location of the activity on the property; as well as a site map (see below) as Appendix A1 to this report; and

if applicable all alternative properties and locations.

Locality map:

The following GoogleEarth images and locality maps are included in Appendix A. The location map

is based on the 1:250 000 topocadastral sheet 3319 WORCESTER (Chief Directorate: Surveys and

Mapping, 1997). It is not to scale.

− Location map for sites OB1-OB6

− GoogleEarth image: OB1, Kanaan

− GoogleEarth image: OB2, Doringkloof

− GoogleEarth image: OB3, Meerlustkloof

− GoogleEarth image: OB4, Meerlustkloof

− GoogleEarth image: OB5, Tarentaalkraal

− GoogleEarth image: OB6, Nooitgedacht

Site Plans: See Appendix A1

(c) For a linear activity, please also provide a description of the route.

N/A

Indicate the position of the activity using the latitude and

longitude of the centre point of the site. Latitude (S): Longitude (E):

N/A

(d) Location of sites (degrees-minutes-seconds)

Site reference Lat Long 1:50 000 sheet Place reference

OB1

34° 9'3.83"S

19°14'9.29"E

3419AA

Kanaan

OB2

34° 7'27.84"S

19°14'21.78"E

3419AA

Doringkloof

OB3

34° 3'44.29"S

19°26'10.56"E

3419AB

Meerlustkloof (1)

OB4

34° 3'44.26"S

19°26'16.51"E

3419AB

Meerlustkloof (2)

OB5

34° 3'43.33"S

19°26'43.34"E

3419AB

Tarentaalkraal

OB6

34° 3'31.66"S

19°27'50.85"E

3419AB

Nooitgedacht

5. SITE PHOTOGRAPHS



Interpreted photographs of all the sites are represented in Appendix C. Depending on local circumstances and the

availability of vantage points, the photographic record depicts the condition of watercourses up- and downstream of

the respective causeways, surrounding land uses and the general state of riparian vegetation. Observations that are

relevant to the environmental assessment are also provided in summary.



SECTION B: DESCRIPTION OF RECEIVING ENVIRONMENT

Site/Area Description

1. GRADIENT OF THE SITE

Indicate the general gradient of the site (highlight the appropriate box). NOTE Gradients represent slope profiles.

Sites Flat Flatter than 1:10 1:10 – 1:4 Steeper than 1:4

OB1 �

OB2 �

OB3 �

OB4 �

OB5 �

OB6 �

2. LOCATION IN LANDSCAPE

For ease of reference, the sites are clustered into two geographical groups, broadly arranged from west to east, namely:

The Bot River sites

The Riviersonderend sites

OB1 and OB2

OB3, OB4, OB5 and OB6

(a) Indicate the landform(s) that best describes the site (highlight the appropriate box(es).

NB: All sites lie inland of the coast, and references to coastal landforms or locations are therefore omitted.

The Bot River sites

Sites Ridge-

line Plateau

Side slope of hill,

mountain and/or

foothill

Closed

valley

Open

valley Plain

Undulating

plain/low hills

OB1 � �

OB2 � �


Sites Ridge-

line Plateau

Side slope of hill,

mountain and/or

foothill

Closed

valley

Open

valley Plain

Undulating

plain/low hills



OB3 � �

OB4 � �

OB5 � � �

OB6 � � �

(b) Please provide a description of the location in the landscape.

The Bot River sites

OB1 This site is located on the Bot River, about 10 km north of the Bot River village and some 18 km from Caledon,

and just over 100 m south of out-buildings on the farm 'Kanaan', to the north-west. The river channel

upstream of the damaged bridge is densely infested with black wattle Acacia mearnsii.

Downstream of the bridge, the channel widens into a highly disturbed area denuded of vegetation, except

for black wattle along the fringes of the main channel and a smaller stream that enters the Bot River directly

downstream of the bridge, from the south-east.

The topography is dominated by the Groenlandsberg, directly west (Mount Lebanon: 1 201 mamsl), and hilly

terrain to the east. The site is about 200 m due west of the main connector between the R45 and R43 routes

south of the Theewaterskloof Dam. The landscape is intensively farmed with wheat and sheep.

OB2 The bridge at 'Doringkloof' is also located on the Bot River, about 4 km north of OB1, on the DR1288. The

damaged (southerly) approaches to the bridge skirt a minor seasonal watercourse, the Doringkloof River,

which joins the Bot River directly upstream of the bridge from the east.

An informal turn-off to 'Quaggaskloof' veers off the DR1288 to the east, about 50 m from the confluence of

the two watercourses. The latter track crosses the Doringkloof River directly upstream of the DR1288.

Upstream of the bridge, the Bot River is heavily infested with black wattle which continues downstream

along the banks of the channel. There is a dense stand of black wattle in the channel.

Downstream, the channel traverses a broad expanse of exposed shale with heaped piles of woody debris

against both banks, and in the channel itself. The flatter, low-lying areas in the vicinity of this site are

cultivated, and two dams lie to the south-east, alongside the DR1288. The terrain is similar to that at OB1.

The Riviersonderend sites (NOTE that all these sites are located on tributaries that join the Riviesonderend from the north,

i.e. these sites are not located on the main stream of the latter river).



OB3 This site is located on the lower reaches of the Elandskloof River, where the DR1313 skirts the farm

'Meerlustkloof'.

The damaged bridge is located in a cultivated floodplain about 500 m upstream of the

Riviersonderend. The Elandskloof River runs through a relatively open valley, after dropping sharply

from the Riviersonderend Mountains into foothill reaches that start about 5 km upstream of the

damaged bridge. An extensive berm has been bulldozed between the left bank of Elandskloof River,

directly downstream of the bridge, and an eroded salient that intrudes into the floodplain, east of the

channel.

The DR1313 makes a wide bend to the north at the damaged bridge. Upstream of the structure, the

cobble-dominated channel is massively disturbed and denuded of vegetation, except for black

wattle along its edge. There is an extensive patch of kikuyu grass and ’fluitjiesriet' Phragmites australis

on the left bank of the river, upstream of the bridge. The latter area appears to mark the point at

which a minor flood channel branches off the Elandskloof River to the east (site OB4 is located on this

channel).

Downstream of the bridge, the Elandskloof River is separated from the DR1313 by a grassed meadow

that makes way for orchards directly to the south. The only infrastructure in this meadow is a former

evaporation tank, which is fenced but no longer in use.

A major irrigation pipe crosses the Elandskloof River just north of the point where it enters the

orchards, en route to the Riviersonderend (it has been suggested that this pipeline, which links the

remainder of the farm with two pump stations near the Riviersonderend, be routed via the new road

bridge to protect it from flood damage).

The floodplain extends east of the river, and is also occupied by orchards to the south. The area

directly north of the road is currently not cultivated and hosts scattered stands of alien acacias. A

row of six cottages extends along the northern side of the DR1313, to the west of the bridge. The

nearest cottage is about 70 m from the Elandskloof River.

The Helderstroom Prison is located on the DR1313, about 9 km to the west. This is primarily a fruit-

producing area, and the farm 'Meerlustkloof' (which is owned by Agrisouth Orchards SA (Pty) Ltd),

exports about 60% of its produce.

OB4 This minor pipe culvert lies about midway between the damaged bridge over the Elandskloof River

(site OB3) and the main entrance to 'Meerlustkloof', north of the DR1313. The distance between OB3

and OB4 is about 140 m. The channel at OB4 hosts 'fluitjiesriet' and dense stands of acacia north of

the DR1313. The surrounds are very similar to those described for OB3.

OB5 Sites OB4 and OB5 are separated by about 700 m. OB5 is a box culvert on an unnamed tributary of

the Riversonderend which drains through the farm 'Elandskloof' 59/2, directly east of 'Meerlusktloof'.

The 'Tarentaalkraal' recreational camp is situated directly north-west of OB5. It constitutes an

expansive grassed area, some 2 000 m2 in extent, that grades gently uphill towards the

Riviersonderend Mountains.

The watercourse in question is densely infested with black wattle upstream of the culvert, and

marginally less so downstream of structure, which drains into a wide open pool fringed by palmiet

Prionium serratum against its left bank. There is a depression upstream and west of the culvert that

seems to be considerably damper than the adjacent lawn on 'Tarentaalkraal'; this may serve as a

flood channel during elevated flows.

The only buildings in the vicinity of the site are a shed in a ploughed field to the north-west, and an

unoccupied building at the northern edge of the 'Tarentaalkraal' lawn. Otherwise, there do not

appear to be any permanently occupied buildings within a 500 m radius of the site.



OB6 This site is located just east of the apex of a relatively tight northern bend in the DR1313, about 1 km

before it joins the DR1298. The Riviersonderend is about 600 m to the south.

This is open countryside with a rolling topography dominated by the Riviersonderend Mountains to

the north and typical 'Rûens'-type hills to the south. A homestead lies directly south of the DR1313, on

the right bank of the unnamed channel that is spanned by a single box culvert at this point. Besides

the farmhouse, the most distinctive built feature in the landscape is an earth dam that is situated

west of the homestead, between the DR1313 and the Riviersonderend.

Facing upstream from the culvert, there is a steep clay bank to the right (east), topped by indigenous

thicket-type vegetation, whereas the area west of the channel is occupied by bulrush Typha

capensis. There is an elevated bench in the channel several meters upstream of the culvert, which

may indicate a head-cut precipitated by excavations between this point and the culvert inlet. A

fence spans the channel here, and appears to trap debris, which may exacerbate plunge-induced

scour downstream of the obstruction during elevated flows.

The homestead is roughly equidistant from the road and the channel (about 70 m). Several mature

willows grow in and around the channel, directly below the road crossing. The banks of the channel

downstream of the culvert appear to be actively eroding, and flood overflow from the west has

scoured a donga between the road and a fenced-off orchard about 20 or 30 m to the south.

3. GROUNDWATER, SOIL AND GEOLOGICAL STABILITY OF THE SITE

(a) Is the site(s) located on or near any of the following (highlight the appropriate boxes)?

Bot River sites

Site Water

table <

1.5 m

deep

Season-

ally wet

soils

Un-

stable

rocky

slopes or

steep

slopes

with

loose

soil

Dis-

persive

soils

Soils with

high

clay

content1

Any

other un-

stable

soil or

geo-

logical

feature

An area

sensitive

to

erosion

An area

next to

or above

an

aquifer

An area

≤ 100m

of a

source

of sur-

face

water

OB1 No Yes No No Yes No No Unsure Yes

OB2 No Yes No No Yes No No Unsure Yes

Riviersonderend sites

Site Water

table <

1.5 m

deep

Season-

ally wet

soils

Un-

stable

rocky

slopes or

steep

slopes

with

loose

soil

Dis-

persive

soils

Soils with

high

clay

content

Any

other un-

stable

soil or

geo-

logical

feature

An area

sensi-

tive to

erosion

An area

next to

or above

an

aquifer

An area

≤ 100m

of a

source

of sur-

face

water

OB3 Potent-

ially

Yes No No Clays

overlaid

with

sand

No Yes Unsure Yes

OB4 Potent-

ially

Yes No No Clays

overlaid

No Yes Unsure Yes

1 Soil types derived from Mucina and Rutherford (Eds)(2006)



with

sand

OB5 Potent-

ially

Yes No No Clays

overlaid

with

sand

No Yes Unsure Yes

OB6 Potent-

ially

Yes No No Humic

soils,

clays

overlaid

with

sand

No Yes Unsure Yes

(b) If any of the answers to the above are “YES” or “unsure”, specialist input may be requested by the Department.

(Information in respect of the above will often be available at the planning sections of local authorities. Where it

exists, the 1:50 000 scale Regional Geotechnical Maps prepared by Geological Survey may also be used).

NOTE that the 'Groundwater Vulnerability Map of South Africa' (Council for Geoscience, 2011) describes groundwater

resources in the study area as being of 'Moderate' to 'Insignificant' vulnerability, with depth to groundwater ranging

from five to 30 m.

http://www.geohazard.org.za/images/docs/subsection_downloads/Groundwater_vulnerability.pdf

(accessed 5 April 2014).

(c) Please indicate the type of geological formation underlying the site.

Granite Shale � Sandstone � Quartzite � Dolomite Dolerite Other

(describe) �

Please provide a description

The rocks of the Groenlandberg and Riviersonderend Mountains are composed of auartzitic sandstones associated with

the formations of the Table Mountain Group. The more rolling, lower-lying relief between the sandstone ranges (i.e. the

Western Rûens that extend from Bot River towards Swellendam) is explained by the presence of shales within the

Bokkeveld Group. These formations consist of thick shale bands that alternate with sandstone units and are therefore

more susceptible to erosion than rocks in the underlying TMG sequence (Rebelo et al., 2006).

The type of parent material is reflected in the sediment that occurs in the different watercourses. The Bot River appears

to carry a relatively higher proportion of finer sediments (gravels and clay-rich silt) than the rivers that drain the

Riviersonderend Mountains to the east. Alluvial deposits in the high energy reaches of the latter channels are generally

coarser, with bed load being dominated by sandstone cobbles and rocks upstream of the DR1313. However, as the

vertical profile of channels flattens towards the Riviersonderend, hydrogeomorphologial sorting results in generally finer,

sand or gravel-dominated deposits as would be expected from dissipated flows.

There is no evidence of dispersive, soluble soils at any of the sites.

4. SURFACE WATER2

(a) Indicate the surface water present on and or adjacent to the site and alternative sites (highlight the appropriate

boxes)?

NB The following has bearing on reporting with respect to surface water and associated ecosystems:

− No coastal wetlands are presents as all the sites are inland of the Cape Fold Belt.

2 (cf Day, 2014; Table 3.2, and pp 15-26)



− The classification of river and wetland types follows the definitions provided by the National Wetland

Classification System (Ollis et al., 2013).

− Please see Section 5 ('Biodiversity') for a summary of freshwater features, their status as biodiversity conservation

priorities, and condition as observed during a site visit on 3 February 2014.

Bot River sites

Site River type Wetland type

OB1 Lower foothill river None present

OB2 Lower foothill river None present

Riviersonderend sites

Site River type Wetland type

OB3 Lower foothill river Channelled valley bottom wetland

OB4 Floodplain channel Channelled valley bottom wetland

OB5 Channelled valley bottom wetland

OB6 Channelled valley bottom wetland

(b) Please provide a description.

See Day (2014) for a comprehensive description of the types and condition of aquatic ecosystems at each site.

Department of Water Affairs 'ecoregions'

Sites OB1 and OB2 are located in the Bot River, which falls in Ecoregion 19 (Southern Folded Mountains), which is

characterised as follows:

− Closed hills and mountains, of moderate and high relief;

− A range of highly diverse vegetation types;

− Includes sections of the Riviersonderend, and Breede and Bot rivers – along which sites OB1 and OB2 are

located;

− Varied annual precipitation, between 100 and 1 500 mm MAP with a moderate to high Coefficient of

variation of annual precipitation;

− Rainfall falling mainly in very late summer to winter;

− Mean annual temperature of 10 to 20°C; and

− The Bot River is classified as a lower foothill river at sites OB1 and OB2.

Sites OB3-OB6 are located in Ecoregion 22 (Southern Coastal Belt Ecoregion). This ecoregion encompasses the rivers

in the southern portion of the Breede River Basin, and is characterised by:

− Terrain comprising low plains, closed hills with moderate relief, open hills with high relief, and low mountains

with high relief;

− Altitude that varies from 0 to 600 mamsl;

− Rock types include quartzitic sandstone, shale, sand and biotite granite overlain by sand-clay, sand-clay-

loam, loam-sand, clay-loam and sand-loam soils;

− Natural terrestrial vegetation that is dominated by a variety of thicket, fynbos and renosterveld, with patches

of forest in the Riversonderend range (in the present study area, NEFEPA vegetation data, based on the

Vegetation Map of South Africa, Lesotho and Swaziland (Mucina et al. (eds), 2005) classifies natural wetland

vegetation at the sites as Southwest Shale Fynbos); and

− Moderate rainfall (400 to >1 200 mamsl) and mean annual temperatures between 18 and 22 °C. Rainfall

ranges from winter to all year; heavy downpours associated with cut-off lows can be expected between

September and November.

− In terms of the NWCS (Ollis et al., 2013),

o the Elandskloof River at OB3 is a lower foothill river, associated with a valley bottom wetland

o the watercourse at OB4 is a floodplain channel, associated with a valley bottom wetland

o OB5 and OB6 are located in channelled valley bottom wetlands.

5. BIODIVERSITY



Refer to Appendix D1 for the Critical Biodiversity Area and NFEPA maps of the study domain.

This section requires that information be provided with respect to;

a) The applicable biodiversity planning categories of all areas on site and the reasons for their selection;

b) The condition of habitat on site, and the percentage natural, near natural, degraded and transformed habitat

present;

c) (i) The type of vegetation present, and its ecosystem status

(ii) Whether an aquatic ecosystem is present on site; and

d) A description of the vegetation type and/or aquatic ecosystem present on site, including any important

biodiversity features/information identified on site (e.g. threatened species and special habitats)

Note: Appendix D2 provides a tabulated summary of all the required biodiversity features, as well as a brief synopsis of

their implications for the proposed repairs. These aspects are considered in more depth in the impact assessment

(Section F). See Appendix G for a comprehensive ecological assessment of the proposed repairs (Day, 2014).

The biodiversity implications of the proposed repairs are presented below. The concluding section discusses how these

findings would inform the combined basic assessment.

(a) Critical Biodiversity Areas and Ecological Support Areas

The biodiversity plan for the Overberg District Municipality (Holness and Bradshaw, 2010) depicts Critical Biodiversity

Areas (CBAs) and Ecological Support Areas (ESAs) that represent the most spatially efficient network of sites for achieving

biodiversity conservation targets, maintaining ecosystem function and securing ecological connectivity across the

landscape in terms of ‘best design’ principles.

As indicated by the table below, all the sites in question fall within mapped CBAs or ESAs. The Ecological Importance

and Sensitivity (EIS), Present Ecological State (PES) of each river or wetland and condition of terrestrial habitat are also

provided (cf. Day, 2014). These findings are based on a site visit on 3 February 2014, i.e. in mid-summer.

Site CBA ESA Condition and importance of

aquatic ecosystems (rivers, wetlands)

Condition of terrestrial habitat

within a c. 100 m radius of each

site** EIS PES*

OB1 Yes Yes Moderate D D = 80; T = 20

OB2 Yes Yes Moderate D NN = 10; D = 60; T = 30

OB3 Yes Yes Low E D = 80; T = 20

OB4 No Yes Low C NN = 60; D = 40

OB5 No Yes Moderate C NN = 30; D = 50; T = 20

OB6 No Yes Low D/E NN = 20; D = 50; T = 30

*A = Unmodified/natural B = Largely natural C = Moderately modified D =

Largely Modified E = Seriously modified F = Critically/extremely modified

** NN = Near Natural D =

Degraded T = Transformed

See Appendix Dfor maps of the CBA status of the respective sites.

All the ESAs have been selected as being important supporting areas for maintaining hydrological processes. The CBAs,

in turn, have been selected with regard to the following criteria (cf Holness and Bradshaw, 2010; http://bgis.sanbi.org):

− Habitat required as part of the CBA network (i.e. critical for maintaining corridors, linkages and ecological

processes);

− Critical areas for maintaining hydrological processes;

− Areas with potential occurrences of (unspecified) threatened species or habitat;

− Potential occurrence of CR or EN habitat; and



− Areas important for protected habitats, such as wetlands and forests.

Loss of habitat and ecological functioning in CBAs must, as a first principle, be avoided. Alternatively, if degradation has

already occurred and may be perpetuated, steps must be taken to stem and rehabilitate the affected habitat to a

'natural' or 'near-natural' condition. Habitat loss can be contemplated with respect to ESAs, but without compromising

ecological processes, which would include maintaining a desired standard of water quality and the appropriate flow

regimes (in terms of volumes and seasonality) for the affected watercourses. Similarly, degradation or loss of both

terrestrial and aquatic habitats should not compromise the effective functioning of ecological and hydrological

processes.

(b) Freshwater Priority Ecosystem Areas

Maps produced for South Africa’s National Freshwater Ecosystem Priority Areas (NFEPA) project depict areas that have

been prioritised for conserving freshwater ecosystems and supporting sustainable use of water resources (Nel et al., 2011;

Day, 2014).

The NFEPA project has produced maps for seven types of priority freshwater ecosystems:

− River FEPAs and associated sub-quaternary catchments: Areas that are essential for achieving targets for river

ecosystems and threatened or near-threatened fishes and in a ‘natural’ (A) or ‘largely natural’ (B) ecological

condition; the sub-catchment must be managed to maintain an A or B condition;

− Wetland or estuary FEPAs:;

− Wetland clusters: These are groups of wetlands in relatively natural landscapes that must be managed in

support of maintaining ecological processes;

− Fish sanctuaries and associated sub-catchments: Rivers in an A or B condition that are essential for protecting

threatened and near-threatened indigenous freshwater species;

− Fish support areas and associated sub-catchments: Rivers with an ecological condition lower than A and B that

are important for conserving and supporting the migration of threatened or near-threatened indigenous fish

species

− Upstream management areas: These are sub-quaternary catchments that need to be managed to prevent

degradation of downstream FEPAs and fish support areas

− Free-flowing rivers: These are represented by 19 rivers nationally that, due to their rarity as unimipounded

systems, should never be dammed.

The following findings were made regarding the FEPA status of rivers and wetlands at each site (cf Day, 2014, Table 3.2):

River FEPAs or

Associated sub-

quaternary catchments

None of the sites are located in Phase 2 FEPAs, or mapped as River FEPAs or Associated sub-

quaternary catchments

Wetland FEPAs All of the sites are depicted as Wetland FEPAs (note, however, that no wetlands were

identified by aquatic ecologist with respect to sites OB1 and OB2).

FEPA attributes Threatened crane species have been sited at wetlands in the respective sub-quaternary

catchments

As with CBA maps, FEPA maps promote an ecosystem perspective in environmental assessment in that they introduce a

broader scale to impact identification than is often the case with site or property-specific impact assessment. These

maps emphasise the functional attributes of biodiversity by providing spatial or geographic surrogates for ecological

processes that may otherwise not be readily evident if an assessment were limited to a particular site or property

(Cadman et al., 2013).

FEPAs are often tributaries or rivers that support “hard working” rivers downstream (that is, rivers that are heavily utilised or

impacted by agricultural, industrial or other human activities) (Driver et al., 2011; Day, 2014). They need to stay (or get

into) good condition to manage and conserve freshwater ecosystems and to protect downstream water resources for

human use. Driver et al (2011) stress however that FEPAs do not necessarily need to be protected from all human use.

Rather, they should be supported by good planning, decision-making and management to ensure that human use does

not impact on their condition or on the important resources they may protect downstream.



The extent of degradation of wetlands and rivers in South Africa means that even systems considered in the best relative

condition for a particular ecosystem type may be highly degraded. Nevertheless, the recommended condition for all

river and wetland FEPAs is an Ecological Category A or B, indicative of a system that is in an unmodified/natural to

largely natural condition respectively (Driver et al 2011).

None of the affected rivers have been identified as FEPAs. Sites OB3 to OB6 are located in channelled valley bottom

wetlands mapped as wetland FEPAs. From an NFEPA perspective, mitigation and rehabilitation at the latter four sites

should aim to guide recovery towards a PES of A or B.

(c) Wetland types

Following the South African Wetland Classification System (Ollis et al., 2013), the respective sites have been found to

occur in proximity to the following river and wetland types (Day, 2014, Table 3.2, pp 15-26):

Sites River/watercourse River/wetland type

(Ollis et al., 2013)

Findings

(Day 2014, Table 3.2)

OB1 & OB2 Bot

Valley floor floodplain wetlands

No wetlands identified at OB1 and

OB2

OB3 Elandskloof

All other sites ground-truthed as

channelled valley bottom wetlands

OB4 Elandskloof (flood channel)

OB5 Unnamed watercourse

OB6 Unnamed watercourse

(d) Vegetation types and ecosystem status

According to the Vegetation Map of South Africa, Lesotho and Swaziland (Mucina et al. (eds), 2005): the sites may

correspond with the following vegetation types (the 2011 ecosystem status of each is also provided):

Sites Vegetation type

Ecosystem status

(CR = Critically

Endangered EN =

Endangered)

OB1 Western Rûens Shale Renosterveld (FRs 11) CR

OB2 Western Rûens Shale Renosterveld (FRs 11) CR

OB3 North of DR1313: Greyton Shale Fynbos (FFh 7) EN

South of DR1313: Central Rûens Shale Renosterveld (FRs 12) CR


South of DR1313: Central Rûens Shale Renosterveld (FRs 12) CR


South of DR1313: Central Rûens Shale Renosterveld (FRs 12 CR

OB6 Greyton Shale Fynbos (FFh 7) EN

(e) Habitat condition at the respective sites

The table at 5(a) provides three measures of ecosystem or habitat condition, two of which directly address the

ecological importance and condition of aquatic ecosystems (Ecological Importance and Sensitivity, and Present

Ecological State respectively) and, more broadly, the condition of terrestrial habitat within a roughly 100 m radius of

each site (cf Day (2014, pp 11-14) for a comprehensive explanation of methods for ascertaining the importance and

condition of aquatic ecosystems). To this must be added the evaluation of habitat condition reflected in the Critical

Biodiversity Areas Map for the Overberg District Municipality (Holness and Bradshaw, 2010).



Ecological Importance and Sensitivity (EIS) defines the ecological importance of a river as an expression of its

importance to the maintenance of ecological diversity and functioning on local and wider scales, while ecological

sensitivity refers to the system’s ability to resist disturbance, as well as its resilience. Both abiotic and biotic components of

the system are taken into consideration in the assessment of ecological importance and sensitivity. EIS ratings are

strongly biased towards the potential importance and sensitivity of particular system under unimpaired conditions. This

means that the present ecological status or condition (PES) is generally not considered in determining the ecological

importance and sensitivity per se (Day, 2014).

Present Ecological State (PES) describes a river according to its ecological status or health compared to natural or

'reference' conditions. Determining the PES of a river constitutes one of three components of the EcoClassification

process recommended by the Department of Water Affairs (the other two components of EcoClassification are the EIS

and reference condition of a river). PES is expressed by a scale ranging from 'A' (i.e. a river or reach is in a natural,

unmodified condition) to 'F' (which reflects critical or extreme modification), relative to the 'reference' or natural

condition of the river or reach subject to assessment.

The condition of terrestrial habitat was estimated visually, on site.

None of the aquatic features of the respective sites is in a natural or near-natural condition and their PES is either

'moderately', 'largely' or 'seriously modified'. This is attributed inter alia to:

− Infestation of channels and riparian areas by woody alien plants (specifically black wattle) (sites OB1, OB2, OB3

and OB6);

− Erosion and/or sedimentation (OB1, OB2, OB3 and OB6);

− Loss of indigenous vegetation (OB1, OB2, OB3 and OB6); and

− Channel constriction and confinement of flows (OB1, OB2, OB3 and OB4) (Day, 2014).

Only two sites – OB4 and OB5 – have a PES of 'C' (moderately modified); the remainder are 'largely' to 'seriously'

modified. OB5 has the highest overall rating in terms of its EIS and PES (Moderate, and 'C' respectively).

Woody alien plants contribute significantly to poor PES scores and habitat degradation beyond the immediate channel

margins of the respective watercourses. This is reflected in the condition of terrestrial habitat which has been

fundamentally transformed by cultivation (as would be expected in this particular region of the Western Cape where

shale-based soils have supported cereal cultivation for many decades). Greyton Shale Fynbos, an EN vegetation type, is

almost exclusively restricted to the foothills of the Riviersonderend Mountains. No occurrences of CR Western and Central

Rûens Shale Renosterveld were evident at any of the sites. The road reserves in the immediate vicinity of all of the sites

are in a highly disturbed condition and do not, at least locally, appear to serve as vegetation refugia or ecological

corridors in what is a highly transformed and fragmented landscape (cf. Esler and Milton, 2006).

The respective, freshwater and terrestrial, assessments of terrestrial habitat quality are supported by the CBA Map for the

Overberg District Municipality (Holness and Bradshaw, 2010) which described all the CBAs and ESAs at the six sites as

being either degraded or transformed (chiefly by road infrastructures and farmland).

(f) Potential biodiversity significance of the respective sites and related ecosystems

As indicated above at Section B(5)(a), (b) and (d), all of the sites in question have been mapped as coinciding with

priority features for biodiversity conservation and the potential occurrence of habitat in threatened ecosystems. All the

sites are either within CBAs or ESAs, or both, FEPA wetlands (excluding sites OB1 and OB2), and Critically Endangered or

Endangered ecosystems. Contextually, therefore, all these sites and their environs must be viewed as having high

biodiversity significance.

At the same time, however, all the sites and their associated catchments are moderately to seriously modified as a result

of channel constriction, alien infestation, erosion, infrastructure development and cultivation. Only two sites (OB4 and

OB5) have an observed (current) PES of 'C' or 'moderately modified'; the observed PES of the remainder of site ranges

from 'D' ('largely modified' to 'E' or 'seriously' modified. This not to say that the sites are not conservation-worthy; that is

clearly not the case. However, if the ecological condition of the sites remains unchanged – or worsens – their current

contribution to the achievement of the Overberg CBA network and national targets for wetland conservation is limited.



6. LAND USE OF THE SITE

(a) Land use

All the sites constitute integral, established components of the provincial rural road network. The proposed works entail

repairing established road infrastructure that was damaged by floods in August 2012. All the roads involved in this

application (the DR1288 and DR1313) are gravelled.

The structures in question (bridges and box or pipe culverts) are per definition located within watercourses. In some

cases, approaches are shored up or supported by raised embankments. All sites are rural in character with agriculture

(both intensive and extensive) and privately-owned conservation areas being the dominant land uses. Most of the sites

are within 5 to 10 km of mountains. One site (OB3) is located 3 km from a provincial nature reserve and another (OB1)

within 3 km of a Mountain Catchment Area. In neither case would the proposed repairs have any impact on the values

that assign significance to mountain catchment areas or the integrity of provincial nature reserves.

The Groenlandberg and Riviersonderend Mountains in the west and north respectively provide a bold topographical

backdrop to the study domain, which is located between the latter features and the wheat lands of the Western Rûens.

The Bot River and Riviersonderend are important regional rivers which, owing to dense infestations by particularly black

wattle Acacia mearnsii are largely hidden from view. Other than being associated with rural landscapes and farms,

none of the sites has particular heritage value. See Appendices A and B for locality maps and photographs of the sites

respectively.

(b) Description.

All six sites form part of the existing provincial road network at the specified locations and adjacent to specified rivers.

7. LAND USE CHARACTER OF SURROUNDING AREA

(a) Highlight the current land uses and/or prominent features that occur within +/- 500m radius of the site and

neighbouring properties if these are located beyond 500m of the site.

The Bot River sites

Untransformed area Low density residential Medium density

residential High density residential Informal residential

Retail Commercial &

warehousing Light industrial Medium industrial Heavy industrial

Power station Office/consulting room

Military or police

base/station/com-

pound �

Casino/entertainment

complex

Tourism & Hospitality

facility �

Open cast mine Underground mine Spoil heap or slimes

dam

Quarry, sand or borrow

pit Dam or reservoir �

Hospital/medical

centre School

Tertiary education

facility Church Old age home

Sewage treatment

plant

Train station or shunting

yard Railway line

Major road (4 lanes or

more) Airport

Harbour Sport facilities Golf course Polo fields Filling station

Landfill or waste Plantation Agriculture � River, stream or Nature conservation



treatment site wetland � area �

Mountain, koppie or

ridge � Museum Historical building Graveyard Archaeological site

Other land uses

(describe):

Sites OB1 and OB2 are situated in the Vanderstel Pass, about 4 km apart by road. They are both

surrounded by farmland. The 'Porcupine Hills Guest Farm' (Ph 028 284 9066) is located about 1 km

north of OB2, on the far side of a ridge. OB1 is situated about 3 km from the Hottenots Holland MCA,

to the west. There are two earth dams that lie parallel to the DR1288, immediately to the south-east

of the approaches to the site.


Untransformed area Low density residential Medium density

residential High density residential Informal residential

Retail Commercial &

warehousing Light industrial Medium industrial Heavy industrial

Power station Office/consulting room Prison � Casino/entertain-ment

complex

Tourism & Hospitality

facility �

Open cast mine Underground mine Spoil heap or slimes

dam

Quarry, sand or borrow

pit Dam or reservoir �

Hospital/medical

centre School

Tertiary education

facility Church Old age home

Sewage treatment

plant

Train station or shunting

yard Railway line

Major road (4 lanes or

more) Airport

Harbour Sport facilities Golf course Polo fields Filling station

Landfill or waste

treatment site Plantation Agriculture �

River, stream or

wetland �

Nature conservation

area �

Mountain, koppie or

ridge � Museum Historical building Graveyard Archaeological site

Other land uses

(describe):

As with the Bot River sites, the four bridges/culverts on the DR1313 traverse an agricultural landscape

in a corridor between the Riviersonderend and the mountains that bear its name. The Helderstroom

Maximum Security Prison (Tel 028 215 1000) is situated about 9 km to the west of OB3, just north of the

Riviersonderend. This correctional services facility is entirely dependent on the DR1313 for access to

the outside world when the main road bridge over the Riviersonderend is flooded – and when the

bridge at OB3 has been put out of action owing to flood damage (as in October 2012), staff and

prisoners have had to be routed to and from the prison via an emergency crossing over the

Elandskloof River on the farm 'Meerslustkloof'. There is a campsite at 'Tarentkraal', directly north-west

of OB5 and an earth dam about 100 m west of the 'Nooitgedacht' site, OB6.

(b) Please provide a description, including the distance and direction to the nearest residential area and industrial area.

There are no residential areas within 5 km of any of the sites. The nearest settlement to OB1 and OB2 is Bot River, next to

the N2 and about 10 km to the south by road. The other sites are roughly 20 km due north of Caledon, but further by

road. OB6 is some 15 km by road from Greyton, which lies to the east.

8. SOCIO-ECONOMIC ASPECTS

Describe the existing social and economic characteristics of the community in order to provide baseline information.

All the sites are located within the Theewaterskloof (TWK) Local Municipality, which falls under the Overberg District

Municipality. The TWK Municipality spans the N2 national road between Grabouw and Stormsvlei. Its northern boundary

coincides with the Riviersonderend Mountains, while the Kleinrivierberge and the northern exent of the Agulhas Plain



broadly delineate its southern aspects. The TWK Local Municipality is based in Caledon, and the Oberberg District

Municipality in Bredasdorp.

The total population of the TWK Municipality was about 106 000 in 2009, representing some 44% of the total population of

the Overberg District Municipality. The official unemployment rate (using the broader definition) in the TWK Municipality was

just under 40%. Local estimates of out-of-season unemployment are even higher. There is extensive poverty in the area, with

20% of households registered as indigent.

Agricultural production generates 36.47% of the local economy, making this the predominant economic activity???? in the

TWK Municipality.

The TWK Municipality is responsible for local roads which lie within the boundaries of the towns. Roads outside the town area

are the responsibility of the Overberg District but TWK acts on an agency basis for the District. Other than the pass through

freight on the N2, the road based freight transport in the region is almost entirely related to agricultural activity. Roads

Division receives grant-funding from the Provincial Department of Transport and Public Works and acts as a Provincial Agent

for the maintenance of the network of main, divisional and minor roads. This includes all activities relating to the

maintenance of 3 685 km of proclaimed roads in the Overberg District, of which more than 70% are unpaved.

The functions of the Road Division of the Overberg District Municipality include:

− Maintaining, repairing, protecting and managing the proclaimed Provincial Roads in the Overberg area;

− Resealing of surfaced roads;

− Regravelling of gravel roads; and

− Effecting initial repairs of flood damage to road infrastructure.

Sources:

Theewaterskloof Municipality, Third Generation IDP (2012-2017)

Overberg District Municipality, Third Generation IDP (2012-2016).

9. HISTORICAL AND CULTURAL ASPECTS

Is section 38 of the National Heritage Resources Act, 1999, applicable to the development? YES NO �

UNCERTAIN

If YES, explain: N/A. None of the projects trigger any of the thresholds prescribed in s 38 of the NHRA, 25 of1999.

Will the development impact on any national estate referred to in section 3(2) of the National

Heritage Resources Act, 1999?

YES NO �

UNCERTAIN

If YES, explain: N/A

Will any building or structure older than 60 years be affected in any way? YES NO � UNCERTAIN

If YES, explain: N/A

10. APPLICABLE LEGISLATION, POLICIES AND/OR GUIDELINES

(a) Please list all legislation, policies and/or guidelines that have been considered in the preparation of this Basic

Assessment Report.

LEGISLATION ADMINISTERING

AUTHORITY

TYPE

Permit / license / authorisation /

comment / relevant consideration

DATE

(if already obtained):

National

Environmental

Management Act

Department of

Environmental Affairs

& Development

Environmental Authorisation Pending



(107 of 1998) (NEMA),

as amended

Planning (DEA&DP)

EIA Regulations 2010

promulgated in terms

of Section 24(5) of

NEMA as amended

DEA&DP Environmental Authorisation Pending

National Water Act

(No. 36 of 1998)

Department of Water

Affairs (DWA)

The General Authorisation that

potentially exempts water users

from having to obtain a water use

licence in terms of sections 21(c)

and (i) of the National Water Act

may be applicable. Such

‘permissible use' does, however,

have to be registered (cf. GN

1199 of 18 Dec 2009), unless works

constitute an existing lawful use.

The Draft Combined BAR will be

sent to the Breede-Overberg

CMA and the Department of

Water Affairs for this

consideration.

POLICY/ GUIDELINES ADMINISTERING AUTHORITY

Guideline on interpretation of listed activities (June 2010) Department of Environmental Affairs (DEA)

Guideline on public participation (October 2013) DEA&DP

Guideline on alternatives (October 2013) DEA&DP

Guidelines for involving specialists in EIA processes (2005) DEA&DP

Guideline on need and desirability (October 2013) DEA&DP

CBA Map for the Overberg District Municipality (2010)

Atlas of National Freshwater Ecosystem Priority Areas (2011)

DEA&DP/CapeNature

SANBI

(b) Please describe how the legislation, policies and/or guidelines were taken into account in the preparation of this

Basic Assessment Report.

LEGISLATION / POLICY /

GUIDELINE

DESCRIBE HOW THE LEGISLATION / POLICY / GUIDELINE WERE TAKEN INTO ACCOUNT

(e.g. describe the extent to which it was adhered to, or deviated from, etc).

NEMA, EIA Regulations 2010

This Draft Combined Basic Assessment Report (BAR) was compiled in terms of Reg 14 of

the NEMA EIA Regulations 2010 (Government Notice No. R543). The applicable

requirements of the EIA Regulations 2010 were adhered to during the compilation of this

report.

National Water Act (No 36 of

1998)

The Draft Combined BAR will be submitted to BOCMA and the DWA for consideration in

accordance with the National Water Act. Also see Section 10(a) above.

National Heritage Resources

Act (No. 25 of 1999)

The Draft Combined BAR will be sent to HWC for consideration. Also see Section 10(a)

above.

Guidelines associated with

2010 NEMA EIA Regulations as

listed under 10 (a) above

These guidelines were consulted in the undertaking of the Basic Assessment process

(including public participation) and the preparation of the Draft Combined BAR and

associated specialist studies

CBA map (2010)and NFEPA

atlas (2011)

The CBA Map for the Overberg District Municipality and Atlas of Freshwater Ecosystem

Priority Areas were consulted to determine the strategic biodiversity importance of the

respective sites, the reasons for their selection as CBAs or ESAs, and whether the proposed

projects would have a significant detrimental effect on the achievement of biodiversity

conservation objectives in these areas.



SECTION C: PUBLIC PARTICIPATION

Please highlight the appropriate box to indicate whether the specific requirement was undertaken or whether there was

a deviation that was agreed to by the Department.

1. Were all potential interested and affected parties notified of the application by –

(a) fixing a notice board at a place conspicuous to the public at the boundary or on the fence of -

(i) the site where the activity to which the application relates is to be

undertaken; and YES � DEVIATED

(ii) any alternative site mentioned in the application; N/A* YES DEVIATED

(b) giving written notice to –

(i) the owner or person in control of that land if the applicant is not the owner or

person in control of the land; YES N/A �

(ii) the occupiers of the site where the activity is to be undertaken and to any

alternative site where the activity is to be undertaken; YES � DEVIATED

(iii) owners and occupiers of land adjacent to the site where the activity is to be

undertaken and to any alternative site where the activity is to be undertaken; YES � DEVIATED

(iv) the municipal councillor of the ward in which the site and alternative site is

situated and any organisation of ratepayers that represent the community in

the area;

YES � DEVIATED

(v) the municipality which has jurisdiction in the area; YES � DEVIATED

(vi) any organ of state having jurisdiction in respect of any aspect of the activity;

and YES � DEVIATED

(vii) any other party as required by the competent authority; YES � DEVIATED

(c) placing an advertisement in -

(i) one local newspaper; and YES � DEVIATED

(ii) any official Gazette that is published specifically for the purpose of providing

public notice of applications or other submissions made in terms of these

Regulations;

YES DEVIATED N/A �

(d) placing an advertisement in at least one provincial newspaper or national

newspaper, if the activity has or may have an impact that extends beyond

the boundaries of the metropolitan or local municipality in which it is or will

be undertaken.

YES DEVIATED N/A �

* No alternative sites are available as the activity entails upgrading and repairs to existing road infrastructure.

2. Provide a list of all the state departments that are to be consulted:

• Breede-Overberg Catchment Management Agency

• CapeNature

• Department of Agriculture, Forestry and Fisheries

• Department of Correctional Services

• Department of Water Affairs;

• Heritage Western Cape;

• Overberg District Municipality.

• Theewaterskloof Local Municipality; and

• Western Cape Department of Agriculture



3. Please provide an overall summary of the Public Participation Process that was followed. (The detailed outcomes of

this process must be included in a comments and response report to be attached to the final Basic Assessment Report

(see note below) as Appendix F).

A list of steps undertaken as part of the public participation process is presented below. All supporting information is

presented in Appendix F.

• A preliminary list of I&APs was compiled consisting of landowners of properties adjacent to road infrastructure,

authorities (local and regional), ward councillors, agricultural associations and other key stakeholders (see

Appendix F1).

• Site notices (in Afrikaans and English) were erected at each site on 11 April 2014. Interested and affected parties

were invited to register as I&APs before 10 May 2014. Photographs of the site notices in situ have been included as

an appendix.

• The Draft BAR was released for a 40-day period of public comment (which included an additional day to

compensate for a public holiday) from xxx to xxxx

• A notice announcing the availability of the DBAR for public comment was published in xyz on xyz (see Appendix

F3).

• Copies of the DBAR were made available at the following locations:

1. xxx

2. Offices of BolandEnviro cc;

3. On the BolandEnviro website, www.bolandenviro.co.za;

• Copies of the Draft BAR were also sent to: CapeNature; the Western Cape Department of Agriculture; the

Department of Agriculture, Forestry and Fisheries; the Department of Water Affairs; the Theewaterskloof

Municipality and the Overberg District Municipality for comment.

• I&APs have been requested to submit comment on the Draft BAR by.

• All comment received by BolandEnviro from I&APs will be captured in a comments and responses report to be

circulated with the Final Combined BAR. The latter and I&AP comment will be be forwarded directly to DEA&DP

for consideration.

• After DEA&DP has reached a decision, all I&APs on the project database will be notified of the outcome of the

application, the reasons for the decision and the associated appeal process.



SECTION D: NEED AND DESIRABILITY

1. Is the activity permitted in terms of the property’s existing land use rights? YES � NO Please explain

The proposed projects would entail upgrading and maintenance of existing infrastructure as part of a provincial road network.

2. Will the activity be in line with the following?

(a) Provincial Spatial Development Framework (PSDF) YES � NO Please explain

The PSDF refers to the provision of well-maintained and safe road networks, which matches the Basic Services and

Infrastructure KPA of the Overberg District Municipality, insofar as it commits the district municipality to "(keeping) the

proclaimed Provincial Roads in a safe and reliable condition within the legal framework of the various Ordinances, Acts and

Regulations..."

Source:

Overberg District Municipality, Third Generation IDP (2012-2016).

(b) Urban edge / Edge of Built environment for the area YES � NO Please explain

All the projects are outside the urban edge.

(c) Integrated Development Plan (IDP) and Spatial Development Framework of

the Local Municipality (e.g. would the approval of this application

compromise the integrity of the existing approved and credible municipal

IDP and SDF?).

YES � NO Please explain

The proposed project entails road maintenance and upgrading of existing road infrastructure, which is compatible with the

IDP of the Overberg District Municipality.

(d) Approved Structure Plan of the Municipality YES � NO Please explain

The proposed project entails essential maintenance and upgrading of existing road infrastructure which does not require any

decisions pertaining to changes in land use rights, departures or zoning.

(e) An Environmental Management Framework (EMF) adopted by the

Department

(e.g. Would the approval of this application compromise the integrity of the

existing environmental management priorities for the area and if so, can it

be justified in terms of sustainability considerations?)

YES NO Please explain

N/A. There is no approved Environmental Management Framework for the study area.

(f) Any other Plans (e.g. Guide Plan) YES NO � Please explain

No other plans are applicable to the respective projects or the decisions that is the object of this application.

3. Is the land use (associated with the activity being applied for) considered

within the timeframe intended by the existing approved Spatial Development

Framework (SDF) agreed to by the relevant environmental authority (i.e. is

the proposed development in line with the projects and programmes

identified as priorities within the credible IDP)?


N/A. The proposed project entails essential maintenance and upgrading of existing provincial road infrastructure.

4. Should development, or if applicable, expansion of the town/area

concerned in terms of this land use (associated with the activity being

applied for) occur here at this point in time?


The repairs and maintenance work have been prioritised to improve the safety of the affected public roads, to prevent

potential further damage to this infrastructure, and to curb further degradation of the affected watercourses. Repairs to the

bridge over the Elandskloof River (OB3) are particularly urgent owing to its crucial strategic importance to the Helderstroom

Maximum Security Prison.

5. Does the community/area need the activity and the associated land use

concerned (is it a societal priority)? (This refers to the strategic as well as local

level (e.g. development is a national priority, but within a specific local

context it could be inappropriate.)




The structures on the DR1288 provide a direct link, via Bot River, between the N2 and the Vyebom-Villiersdorp areas, and from

Vyeboom to Caledon via the R43. South-bound traffic diverted at OB2 will have to drive an additional 33 km if headed for the

N2 via the DR1288 and R43. The structures on the DR1313, in turn, provide an important route for farms and communities north

of the Riviersonderend River, but at certain times of the year are also of great importance to the Helderstroom Maximum

Security Prison. This is because the prison’s primary access (via the tarred section of DR1313 south of the prison) is sometimes

impassable for several weeks as a result of flooding. During such periods, the gravel portion of DR1313 serves as the prison’s

only access (and, when the bridge over the Elandskloof River is out of order, an emergency drift on the farm 'Meerlustkloof'

provides the only connection with the prison and the outside world).

Source:

Bergstan, 2013

6. Are the necessary services with adequate capacity currently available (at

the time of application), or must additional capacity be created to cater for

the development? (Confirmation by the relevant Municipality in this regard

must be attached to the final Basic Assessment Report as Appendix E.)


N/A: The repairs fall within the exclusive legislative mandate and powers of the Provincial Government of the Western Cape,

which is responsible for designing, managing and repairing provincial roads. The Executive Manager: Provincial Roads and

Transport Management Branch in the Department of Transport and Public Works has the authority and capacity to undertake

the works that are the subject of this application for environmental authorisation.

7. Is this development provided for in the infrastructure planning of the

municipality, and if not what will the implication be on the infrastructure

planning of the municipality (priority and placement of services and

opportunity costs)? (Comment by the relevant Municipality in this regard

must be attached to the final Basic Assessment Report as Appendix E.)


N/A. The relevant road sections form part of the existing provincial road infrastructure under the management control of the

Provincial Department of Transport and Public Works: Roads Infrastructure Branch and fall outside of the urban edge of the

local municipalities. The Overberg DM manages these roads on behalf of the provincial transport department on an agency

basis.

8. Is this project part of a national programme to address an issue of national

concern or importance? YES NO Please explain

N/A. The proposed projects entail either rebuilding or repairing and refurbishing existing provincial road infrastructure.

9. Do location factors favour this land use (associated with the activity applied

for) at this place? (This relates to the contextualisation of the proposed land

use on this site within its broader context.)


The proposed projects entail rebuilding, repairing and refurbishing existing public transport infrastructure.

10. How will the activity or the land use associated with the activity applied for, impact on sensitive natural and cultural areas

(built and rural/natural environment)?

There are six projects of which two entail rebuilding damaged bridges (OB1 and OB3), and variously repairing and refurbishing

the remainder of the structures. Anticipated biophysical and other impacts are addressed in the impact assessment (Section

F). Enhanced flow capacity, improved sediment throughput and additional scour protection will have the effect of preventing

or at least mitigating the type and extent of environmental degradation that may have been associated with the structures

prior to their repair and/or refurbishment.

11. How will the development impact on people’s health and well-being (e.g. in terms of noise, odours, visual character and

sense of place, etc)?

The proposed projects would, overall, result in a positive impact on people’s health and well-being as they would contribute

to the safety and utility of road infrastructure at all the proposed project sites. In the short term (during construction), there may

be some inconvenience to traffic, and noise and dust levels may increase locally (it may be necessary to temporarily close

the crossing at OB2 for up to three weeks to accommodate construction activities at the site). The temporary disruption of

traffic would be offset by the fact that none of these roads is a major thoroughfare, and that the repairs would probably be

viewed favourably by most motorists (and especially local residents). The total annual average daily traffic at sites OB1 and O2

is less than 100 vehicles per day, and that at sites OB3 to OB6 less than 200 vehicles per day (Bergstan, 2013).



14. Is the development the best practicable environmental option for this

land/site? YES � NO Please explain

The 'best practicable environmental option' is the option or alternative that provides the most benefit or causes the least

damage to the environment as a whole, at a cost acceptable to society, in the long term as well as the short term (cf s 1(1)(iii)

of NEMA 107/1998).

The proposed projects would entail repairing and maintaining existing infrastructure as part of the provincial road network. In

the case of OB1, the new, single-span culvert is designed to pass the 1:10-year flood. At OB3, significantly enlarged culvert

openings, embankment slope protection and scour aprons have been designed to accommodate 1:2-year floods with

frequent over-topping. Besides reducing the vulnerability of these structures to flood damage, increased hydraulic capacity

will allow larger flows and debris loads to move through the structures which will help to promote the stability of the affected

channels.

Although adverse, long-term impacts on aquatic ecosystems in the direct vicinity of the structures cannot be conclusively

discounted, the repaired and refurbished structures represent a significant improvement on their predecessors in terms of

minimising adverse impacts on flows and erosion and, over time, should contribute to measurable improvements to the

condition and stability of in-stream habitats.

Overall, the proposed road repairs would bring about a reduction in long-term environmental damage that, even if were

residual negative impacts to persist, would be of considerably less significance than had prevailed previously at the respective

sites. The repairs represent an indisputable contribution to public wellbeing that can be achieved and maintained at a

minimal detrimental cost to the environment.

12. Will the proposed activity or the land use associated with the activity applied

for, result in unacceptable opportunity costs? YES NO � Please explain

The proposed projects entail repairing and maintaining existing provincial road infrastructure to improve the safety and

lifespan of the structures, and to prevent further degradation to the affected aquatic ecosystems. The public participation

process is aimed at inter alia identifying such opportunity costs, if raised as concerns by interested and affected parties.

13. What will the cumulative impacts (positive and negative) of the proposed land use associated with the activity applied for

be?

No negative cumulative impacts related to the proposed activities have been conclusively identified a site-specific scale.

Generally, it is assumed that improved culvert design, particularly by the introduction of increased flow space and/or scour

protection, is expected to reduce flow concentration and the risk of downstream erosion and habitat degradation, which

would be a positive impact.

Conversely, if erosion is allowed to persist, it will almost certainly result in further damage to agricultural land and infrastructure,

as well as having a cumulative, negative, impact on aquatic habitats, biota and ecological processes.

As with other flood repair projects in the Overberg area, any environmental benefits issuing from the new or upgraded

structures will largely be annulled by the impacts of intense floods and heavy sediment burdens that are directly linked to the

degraded and destabilised condition of most of the affected catchments in this intensively-farmed region. Similarly, failure to

keep channels clear of invasive alien plants will mean that the structures remain vulnerable to the impacts of down-cutting,

erosion and enhanced sediment transport.

One of the most evident positive cumulative impacts relates to the improvement and maintenance of a high quality rural

road network which holds manifest benefits across the socio-economic spectrum.



15. What will the benefits be to society in general and to the local communities? Please explain

The proposed projects would improve road safety and prevent potential further damage or eventual collapse of the road

infrastructure in future flood events (which is potentially imminent in the case of the damaged structures at OB1 and OB3). As

explained above, the DR1313 represents the only link between the maximum security Heldestroom Prison and the outside

world when the bridge across the Riviersonderend is made impassable by floods.

The maintenance of robust rural transport infrastructure is essential to ensure the continued viability of particularly agricultural

activities, which represent the mainstay of the rural economy. A safe and effective road network is also exceedingly important

for farming and rural communities who rely on health and welfare facilities in local towns such as Villiersdorp and Caledon.

It is anticipated that employment opportunities would be available to a limited number of people from the local communities

during the construction phase. The Contractor would also contribute to the local economy for the duration of the contract

period.

16. Any other need and desirability considerations related to the proposed activity? Please explain

None.

17. Please describe how the general objectives of Integrated Environmental Management as set out in section 23 of NEMA

have been taken into account.

The general objectives of IEM have been given effect as follows:

− The National Environmental Management Principles (specifically those relating to the primacy of human need in

environmental management and the prevention of environmental degradation) are key informants to this application;

− The impact assessment has been informed by the consideration of feasible and reasonable alternatives in support of

selecting the best practicable environmental option for each of the repaired structures;

− The combined basic assessment process has aimed to inform, where feasible, amendments to the engineering designs

so as to proactively accommodate and respond to particularly ecological concerns. Construction-related impacts have

been anticipated and would be mitigated by means of an Environmental Management Programme, which also

doubles as a management plan for post-construction maintenance of the immediate environs of the respective

structures;

− Interested and affected parties have been involved in the environmental assessment by means of a robust consultation

process;

− The environmental assessment has sought, inasmuch as it is reasonably possible to do so, to identify and analyse all

significant environmental factors that are relative to the decision that is being sought; and

− Established techniques for identifying, assessing and avoiding significant residual environmental harm and promoting

environmental and societal benefits arising from the project have been pursued throughout.

18 Please describe how the principles of environmental management as set out in section 2 of NEMA have been taken into

account



The proposed projects would contribute to the maintenance of essential provincial road infrastructure and have a positive

impact on road safety and the security of the rural road network in the western Overberg. This directly addresses reasonable

human needs.

Adverse impacts associated with the current, damaged, crossings at OB1 and OB3 included road approaches being washed

away, major erosion downstream, physical damage to the causeway in the case of the pipe culvert crossing at OB3, and

disrupted road transport. The repaired and refurbished bridges and culverts would contribute substantially to reducing

environmental degradation by improving the hydraulic capacity of the structures and the unimpeded passage of high

volumes of sediment during floods. Although a residual element of degradation to aquatic habitats and ecosystems can

never be entirely dispelled, reasonable measures have been pursued to anticipate and prevent negative impacts from arising

in the first place and, where such impacts cannot be avoided by positive planning, to ensure that environmental change that

may be associated with post-construction lifespan of the repaired structures is monitored and responded to.

In summary, it is believed that the proposed projects would be sustainable in terms of socio-economic and environmental

(primarily ecological) considerations and where negative effects may persist, these would – provided that all recommended

mitigation measures are implemented – be within limits that are acceptable to society at large as well as in terms of the

management objectives for CBAs, ESAs and FEPAs.



SECTION E: ALTERNATIVES

NOTE that the Department of Transport and Public Works has agreed to adapt the initial engineering designs to

accommodate concerns raised by the specialist aquatic ecologist, Dr Liz Day (Day, 2014). Agreement on these changes

was obtained at a meeting between Mr Harry Viljoen, representing the DTPW, Mr Mick Latimer of Bergstan South Africa

(consulting engineers), and the project EAP, Mr Charl de Villiers, on 25 April 2014. The engineering drawings appended to

this Draft BAR (Appendix A2) incorporate these changes, which are recorded below.

1. In the sections below, please provide a description of any identified and considered alternatives and alternatives

that were found to be feasible and reasonable.

(a) Property and location/site alternatives to avoid negative impacts, mitigate unavoidable negative impacts and

maximise positive impacts, or detailed motivation if no reasonable or feasible alternatives exist:

The proposed project entails either re-building, repairing or refurbishing flood-damaged provincial road infrastructure at

six sites in the western parts of the Overberg, in the Theewaterskloof Municipality.

No location or site alternatives are available or necessary with regard to the works at OB2, OB4, OB5 and OB6. In the

case of the damaged bridges that are to be rebuilt with larger openings – and, therefore, increased hydraulic capacity

and less long-term environmental impact –, the structures at sites OB1 and OB3 will be parallel to their predecessors.

The centre lines of the new bridges at OB1 and OB3 will be about 12 m from the centre lines of the current, damaged,

structures, which are to be demolished once the new structures have been built. At OB1, the new bridge is to be placed

upstream from the current crossing, whereas at OB3 the new structure will span the watercourse downstream of the

current pipe culvert.

Site OB6 is the only one that will require a by-pass, primarily because the road at this point is too narrow to simultaneously

accommodate construction work and traffic (i.e. 'half-width construction'). Owing to difficult terrain upstream of the

works (including a wetland, a deeply cut channel, and a heavily bushed clay outcrop), traffic will have to be routed via

by-pass around the downstream aspect of the construction site. This would necessitate removing one or more willow

trees. Owing to the restrictions imposed by the terrain, this by-pass cannot be placed anywhere else.

(b) Activity alternatives to avoid negative impacts, mitigate unavoidable negative impacts and maximise positive

impacts, or detailed motivation if no reasonable or feasible alternatives exist:

Activity alternatives refer to different means of achieving a particular objective (such as different response to flood

hazards, waste disposal or mass transit of commuters) (cf. Preston et al., 1996; DEADP, 2013). Knowing the purpose or

desired outcome of the activity is therefore crucial when considering the feasibility and reasonableness of different

activity alternatives.

In this regard, changes to designs that would meet the objectives of the proposed activities have been addressed under

this head.

The objectives of the activities

Overall, the objective that guides the activities that must be undertaken to execute the proposed projects relate to the

repair, reinstate or maintain flood-damaged provincial road infrastructure according to prescribed design specifications.

The 'do nothing' option, insofar as it implies abandoning the damage infrastructure, would be unconscionable unless the

Provincial Government of the Western Cape intends de-proclaiming the DR1288 and DR1313 as public roads and

divesting itself and its agents of any responsibility towards the upkeep of the affected road infrastructure and its safe use

by the motoring public. This is patently not the case and therefore does not merit further consideration

Activity alternatives to the proposed flood-related repairs

− There is no reasonable or feasible alternative to replacing the badly damaged bridges at OB1 and OB3 and

equipping the new structures with sufficient hydraulic capacity to prevent over-topping in a 1:2-year flood and

allowing sediment to pass unimpeded through the structures (Bergstan 2013).



− Originally, it was proposed that concrete scour protection be provided upstream and downstream of the pipe

culvert at OB4 in order to control the growth of reeds that contributed to blockages, over-topping of the road

during floods, and subsequent erosion. The freshwater specialist (Day, 2014) instead recommended that gabion

mattresses be used as an alternative to concrete slabs as this would allow low flows to seep through the gabion

mattresses. There would still be some opportunity for reeds to be established, but at far low densities than is currently

the case. At higher volumes of flow, water would simply pass over the gabion mattresses. This alternative has been

implemented in the designs for the works at OB4.

− Originally, it was proposed that the undermined scour apron at OB5 be under-pinned, equipped with a secondary

outlet slab and cut-off wall, and protected on its downstream aspect by placing rocks in the plunge pool to

prevent further scour. These plans have been amended on Dr Day's advice. Instead, the damaged apron slab is to

be replaced with three tiers of gabions, founded on a gabion 'mattress'. This design will still allow the velocity of

water to be broken, and the structure to be protected against scour and undermining, while permitting vegetation

to be gradually re-established in and around the gabions. The roughed surface and cavities provided by the

gabions also contribute to the establishment of micro-habitats that can be occupied by aquatic organisms.

− The works at OB6 entail adding a second box culvert to this crossing as the existing structure does not have

sufficient capacity to carry 1:2-year flows. Ongoing over-topping and wash-aways can be expected at this site if

the flood conveyance capacity of the structure cannot be improved. The freshwater ecologist (Day 2014) has also

recommended that a weir be constructed to control a head-cut a short distance upstream of the crossing, and

that the eroding banks downstream of the crossing be addressed as a matter of urgency. The DTPW has agreed to

include the construction of a gabion check-weir and 'mattress' as recommended by Dr Day. Erosion downstream of

the expanded culvert at OB6 would be countered by the addition of more lateral flow space, which will prevent

down-cutting and erosion around the edges of the outlet structures.

Activity alternatives: Construction of bypasses

In order to maintain functionality of roads during repairs and maintenance work, traffic must, where possible, be allowed

to pass through sites under construction. Activity alternatives with respect to bypasses are as follows:

− Only one site, OB6, will have to be equipped with a temporary bypass outside of the current road alignment as the

road width here is inadequate to accommodate half-width construction. The by-pass would have to be placed

immediately downstream of the structure (i.e. to the south) as the northern option would be impracticable owing to

the depth of the channel and steepness of its sides. Installing a bypass upstream of the construction sites would also

mean having to destroy a substantial stand of indigenous vegetation and, potentially, intrude into a valley bottom

wetland north-west of the road. A bypass at the latter location would also entail considerably more excavation

than would the case with regard to the preferred alignment, which would run through a seriously disturbed section

of channel that needs to be stabilised. The bypass will have a low profile and be laid as close to the existing shape

of the bed of the watercourse as possible. It will be built with commercially-sourced material. The bypass will be

demolished and the disturbed footprint rehabilitated immediately after construction. The residue of the

decommissioned bypass will be used to ‘tie in’ the expanded box culvert crossing with the adjacent gravel road

approaches.

− The narrowness of the road and difficult terrain at OB2 precludes half-width construction and laying of a bypass,

which means that this road will have to be closed to traffic for an estimated three weeks while construction takes

place.

− The existing bridges at sites OB1 and OB3 will be used to route traffic past the latter construction sites. The old,

damaged, bridges are to be demolished and all debris is to be removed. The sites will be rehabilitated.

(c) Design or layout alternatives to avoid negative impacts, mitigate unavoidable negative impacts and maximise

positive impacts, or detailed motivation if no reasonable or feasible alternatives exist:

The basis of the design brief set by the DTPW is that all the repaired structures must be trafficable, with no over-topping

for a 1:2-year flood, except for the structure at OB1 which is designed to pass the 10-year flood. Designs are based on



two specifications: the PGWC Standard Drawings and Details for Culverts and Causeways and the South African

National Roads Agency Drainage Manual (5th edition).

In three instances, road crossings are to be equipped with substantially improved hydraulic capacity, namely OB1, OB3

and OB6. The new bridges that are planned for the Botrivier and Elandskloofrivier will replace the existing structures,

which have experienced repeated wash-aways to their approaches because of blocked pipes or culverts which

deflects high flows to the side and into the gravel road embankments. The single culvert at OB6 is too small to convey

floods underneath the road, which are either deflected into the upstream embankments or over the road surface, which

causes erosion to the embankment on the southern side of the road. A narrow outlet structure at this site has also

apparently contributed to significant down-cutting of the channel below this point.

Besides reducing blockages and scour, and the ensuing risk of damage to the structures, less erosion means that less

sediment would enter the affected watercourses. This holds benefits with respect to reducing the overall hydrological

instability of these systems, and lessening undesirable impacts on in-stream habitat.

The most significant changes to the proposed engineering designs that have been recommended by the specialist

aquatic ecologist (Day, 2014) are summarised below. The responses by the DTWP are also recorded.

Design-related questions raised by the aquatic ecologist: OB1

At the farm 'Kanaan' (site OB1), blockages caused by trees and debris have periodically caused flood waters to back up

to such an extent that fields upstream of the bridge have been eroded when the floods subside (pers comm., Mr Kobus

van Zyl, owner of 'Kanaan', 11.04.2014). The channel of the Botrivier downstream of the bridge at 'Kanaan' is massively

eroded and has cut so deeply into the peat substrate that large 'blocks' within the embankment of the DR1288 have

slumped towards the base of the channel. The banks of the river are also heavily infested with black wattle.

The new bridge at 'Kanaan' is to consist of a single span portal structure, some 12 m wide and 4.5 m high. In comparison,

the current, damaged, bridge consists of two portals, each of which is 4 m wide and 1.8 m high. This structure is

supported on a former drift equipped with six 600 mm pipes. The new bridge is designed to accommodate 10-year

floods without over-topping and will substantially reduce the build-up of debris during floods. It will also be protected by

wing walls and gabion 'mattresses'.

The aquatic ecologist (Day, 2014, pp 29-31) supported the assertion that the new bridge at OB1 would be better able to

reduce the frequency of significant flood disturbance. Ecological recovery would, however, depend on removing alien

trees both upstream and downstream of the structure.

The aquatic ecologist raised the following concerns about the new bridge at OB1:

− Failure to address the present constricted alignment of the small stream that enters the river on its left bank

downstream of the existing structure means that this system will probably play a long-term role in disturbance of the

downstream channel and banks. The small stream has been directly impacted by the existing road alignment.

− Medium to long-term likelihood of structural failure, as a result of erosion and bank collapse at the bend some 20 m

upstream of the proposed structure. If this erosion (triggered by constriction of alien trees along the channel, and

blockage of flows in the channel by fallen trees) is left unchecked, it is likely to result in significant widening of the

channel over time, and potential bypassing of the bridge structure on the left hand bank.

The DTPW has indicated that, in response to the first concern regarding the tributary that enters the Botrivier from the

east, downstream of the crossing, the problem of restricted flow space will be resolved once the damaged bridge is

demolished, and alien trees are removed from the site. The eroding left bank of the Botrivier upstream of the crossing will

be evaluated by the project engineers. It is, however, outside the road reserve and its stabilisation has not been factored

into the contract for the repairs in question (pers comm., Mr Harry Viljoen, DTPW, 25.04.2014).

Design-related questions raised by the aquatic ecologist: OB2

The specific practical challenges that arise at this site on the Botrivier include:



− The skew alignment of the existing culvert relative to the course of the Botrivier, which is forced into an 'S'-bend

where it passes through the structure;

− The seasonal Doringkloof stream which joins the Botrivier at a sharp angle, directly at the upstream edge of the

culvert, from the east;

− An informal track that crosses the Doringkloof stream just above its confluence with the Botrivier; and

− Heavily infested river banks up- and downstream of the DR1288 which contribute to channel constriction and

erosion.

One of the effects of this state of affairs is that the southern approach to the existing crossing are highly vulnerable to

erosion damage that occurs when the road is over-topped by floods.

Currently, the repairs planned for OB2 would entail installing concrete road slabs on the approaches to the existing

culvert over the Botrivier, namely a 7 m slab on the northern approach, and another one of about 30 m on the southern

approach. The latter, longer slab, would taper from an initial width of 6 m to about 4.1 m where it abuts the southern

facie of the culvert. The latter design would have the purpose of protecting the road surface against flood-related scour

on the upstream side of the structure, as well compelling motorists to slow down when approaching the single-lane

crossing. The works would also include repairing or extending existing masonry walls to protect the sides of the road.

New, concrete, side cut-off walls would be built along the upstream aspect of the southern approaches. Eroded fill at

the south-eastern edge of the culvert, where it meets the upstream edge of the concrete road slag, will be replaced

with compacted material.

The aquatic ecologist (Day, 2014, pp 31 and 32), raised the following concerns about the proposed repairs at site OB2:

− The proposed construction measures at OB2 did not attempt to address the problem of the small tributary (which

issues from Doringkloof, to the south-east of the main culvert) that was currently diverted along the upstream edge

of the concrete structure, increasing flood pressure and erosion damage on the right hand side of the Bot River

channel, and contributing to the high levels of erosion damage observed in the river downstream of the structure.

− Contextually, invasion of the riparian zone and banks by woody aliens, which constricted the channel and

contributed to high levels of disturbance (erosion) during floods, with felled or fallen aliens blocking the bridge and

causing high levels of scour even in relatively small flood events, increased the frequency of disturbance;

− The existing culverts were inadequately sized for the unstable river, characterised in floods by sediment and tree

debris; furthermore, the small stream is not catered for at all by the culverts, with the result that flows from the

stream were deflected off the structure, flowed parallel with the road, and then passed under the culvert with the

main Bot River. This system was likely to have contributed to erosion and undercutting of the right hand river bank

downstream of the road. As with all the other structures, however, it deserves noting that the adequacy of the

culverts may have been compromised over the years as a result of long-term changes to run-off patterns in

catchments, channel modification and the invasion of riparian areas by woody alien plants.

− The existing access road off DR1288 interrupted flows along the minor stream. However, this informal road crossing

was less damaging than the bridge structure, because it did not result in debris dams and associated bank erosion.

− These impacts would be perpetuated by repairs to the new structure, which did not take the foregoing factors into

account.

The aquatic specialist recommended that the designs for the repairs at OB2 be amended to:

− Make provision for an additional or extended culvert or other ecologically cognisant measure that allowed for the

free flow of the minor stream through the structure, without being diverted along the road edge; and

− The mechanism for this would need to address the fact that the small stream appeared to enter the system at a

higher level than the existing culvert.

These issues were raised in discussion with the DTWP, its consulting engineers and EAP on 25.04.2014.

In short, Mr Harry Viljoen (DTPW) indicated that Dr Day's observations and concerns were valid. However, contract

C960.4 only provided for essential repairs to flood-damaged road infrastructure or, where crossings had been so badly

damaged, that they needed to be replaced (e.g. at OB1 and OB3). The interventions proposed by Dr Day were

extensive, had not been budgeted for, and could not be implemented in the 2104/2015 financial year. Dr Day's

recommendations would, however, be seriously considered if the crossing at OB2 had to be replaced. Planning to this



end would probably necessitate specialist input by a fluvial geomorphologist and hydrological surveys to better

understand flow dynamics at this point, and how engineering designs could best respond to this complex state of affairs.

The upshot is that the current designs for the refurbishment of the damaged road and crossing at OB2 will not be

amended in the course of the contract in questionC960.5????

The Applicant has implemented recommended amendments to the initial designs at the following sites:

OB4: See above, 'Activity alternatives';

OB5: See above, 'Activity alternatives; and

OB6: See above, 'Activity alternatives'.

(d) Technology alternatives (e.g. to reduce resource demand and resource use efficiency) to avoid negative impacts,

mitigate unavoidable negative impacts and maximise positive impacts, or detailed motivation if no reasonable or

feasible alternatives exist:

N/A.

(e) Operational alternatives to avoid negative impacts, mitigate unavoidable negative impacts and maximise positive


N/A. The most critical operational alternatives would relate to (a) post-construction maintenance of the channels

upstream of and downstream of the structures, combined with (b) the removal of invasive plants and stabilisation of

degraded watercourses with groynes (as in the case of the Elandskloofrivier), controlling excavations in the affected

watercourses, and landscaping and revegetation of river banks with appropriate indigenous plants. The latter

alternatives are beyond the object or scope of this application for environmental authorisation.

(f) The option of not implementing the activity (the No-Go Option):

In all cases, pursuit of the ‘no go option’ would be counter to the Duty of Care with respect to road safety, ensuring the

integrity and availability of well-functioning regional road transport infrastructure, and prevention of environmental

degradation in highly dynamic and important ecosystems. Where such the integrity and safety of provincial roads are at

stake, failure to undertake the planned repairs is not a credible or desirable alternative and would hold no benefits to

society or the environment and is therefore not considered to be a feasible or reasonable option deserving of further

assessment.

(g) Other alternatives to avoid negative impacts, mitigate unavoidable negative impacts and maximise positive


The freshwater assessment (Day 2014) includes specific management recommendations that represent key elements in

an integrated 'package of measures' to prevent erosion and destabilisation that may expose the respective structures

for future flood damage. These are addressed in detail in Section H, which deals with mitigation measures.

Because the recommendations are, in effect, integral to the long-term ecological sustainability and structural viability of

the structures, they are also presented as crucial, 'high-level' means to prevent ongoing degradation and destabilisation

of the affected watercourses and their associated road infrastructure.

In the case of the new crossing over the Elandskloofrivier at OB3, the proposed construction of groynes by the Western

Cape Department of Agriculture was an essential intervention to stabilise the high rates of erosion and sedimentation in

this system. If these soil conservation works were not to be erected, the damage associated with even a new, better-

designed causeway at OB3 would persist, compounding an already "ecologically catastrophic situation" (Day, 2014, p

34).



In all cases, invasive alien vegetation had to be removed from channels as this infestation was a major driver of structural

failure of the affected watercourses (Day, 2014, p 42) and, by implication, damage to provincial road infrastructure.

(h) Please provide a summary of the alternatives investigated and the outcomes of such investigation:

− The ‘no go’ alternative is regarded as neither feasible nor reasonable with regard to any of the projects, and is

therefore not subject to further consideration or assessment.

− Activity or design-related concerns that could be remedied by adapting engineering designs have been

addressed in the course of this environmental assessment, through interactions with the aquatic ecologist, the

DTPW, its consulting engineers and the project EAP.

− The projects where these concerns could be positively addressed by means of amendments to the respective

engineering designs, are the proposed works at OB4, OB5 and OB6 (see above). No alternatives will therefore be

assessed with regards to activities at the latter sites.

− At OB1, on the Botrivier, the most important additional intervention, which does not form part of the current

contract, would be to investigate methods for stabilising the left bank of the Botrivier upstream of the crossing. If the

DTPW were, at a later stage, to proceed with stabilising the river bank at this point, this would require environmental

authorisation and a basic assessment that should inter alia consider various options for preventing erosion at this

point.

− At OB2, major investigations and expenditure would be needed to address the concerns raised by the ecological

assessment. The DTPW has indicated its readiness to take these recommendations into account in the event of this

crossing having to be replaced. This work cannot, however, be implemented in the course of the current contract.

No alternatives will be investigated at this site.

− At OB3, the potential environmental advantages of the new causeway are contingent upon the stabilisation of the

Elandskloof River by means of soil conservation works that are in the process of being planned by the Western

Cape Department of Agriculture. Execution of the latter project is beyond the responsibilities or powers of the

DTPW. It has, however, been emphasised that the ecological benefits of the new causeway at this site will not be

realised unless extensive erosion and sedimentation in this system are addressed, failing which the new crossing will

perpetuate an unstable system that has resulted in catastrophic degradation. No major issues were identified with

regard to the alignment and design of the new causeway, and it is therefore not necessary to consider any other

options for a crossing at this site.

− At OB6, there is only one feasible route to accommodate a by-pass around the construction site, namely

downstream of the DR1313. Short of retaining a single, under-capacitated culvert at this crossing, there is no

feasible alternative available to improve the flood conveyance of this structure besides adding an extra box

culvert as proposed. No alternatives will therefore be investigated. The same applies to the proposed construction

of a small gabion weir to restrain the development of a head-cut upstream from site OB6. This is viewed as essential

and urgent from a wetland and river management perspective, and failure to address erosion at this point would

perpetuate degradation of the channelled valley bottom wetlands upstream of the culvert.



SECTION F: IMPACT ASSESSMENT, MANAGEMENT, MITIGATION AND MONITORING MEASURES

N O T E

PROBLEMS ARISING FROM THE IDENTIFICATION AND ASSESSSMENT OF MULTIPLE, SYNERGISTIC IMPACTS

AND HOW TO FORMULATE MANAGEMENT RESPONSES AT A FUNCTIONAL OR ECOSYSEM SCALE

1) It is a fundamental, internationally-recognised precept that environmental assessment and management must

(a) focus on the functional relationships and processes within ecosystems and (b) carry out management

actions at the scale appropriate for the issues being addressed (cf. Annex B and C, Decision V/6 'Ecosystem

Approach', Sixth meeting of the Conference of Parties of the Convention on Biodiversity, 15-26 May, 2000,

Nairobi).

2) It is also common cause that activity-specific environmental impact assessment is generally poorly suited to

predicting and assessing cumulative impacts on ecosystems and ecological functioning, and often fails to

situate project-specific impacts within a broader landscape, regional or functional – ecological – perspective

(cf. Le Maitre et al., 1998; Treweek, 1998; Brownlie et al., 2005; Treweek et al., 2005; DEA, 2005).

3) The assessment of impacts resulting from listed activities is required by law, and represents a non-negotiable

mandatory cornerstone of the prescribed environmental assessment process (cf. sections 24(2)(a) and (b) of

NEMA, and Regulation 22 of the NEMA EIA regulations). Competent authorities, when reviewing applications for

environmental authorisation, must among others take into account any environmental or environmental

degradation likely to be caused if the application were to be authorised or refused (NEMA s 24O). Likewise, the

authorities must take into account measures to protect the environment from harm as a result of the activity

(ies) being applied for, as well as measures to prevent or mitigate substantially detrimental environmental

impacts, or degradation of the environment.

4) It is less clear, however, if the potential impacts of activities subject to compulsory environmental authorisation

must be analysed and understood in relation to the effects of environmental degradation and ecosystem

instability that may, in origin, be entirely independent to the activities subject to environmental scrutiny but,

unless prevented or mitigated, could substantially and negatively amplify what would otherwise be relatively

benign or acceptable impacts if these are defined in isolation of broader contextual factors.

5) Such an approach to environmental assessment, which is attuned to the condition and changed dynamics of

surrounding ecosystems, and how these may influence the impacts generated by a particular project at a

particular site, can certainly be motivated on the basis of EIA best practice. Its legal foundations can be readily

inferred from particularly those national environmental management principles that require that environmental

management must avoid disturbance to ecosystems, or pay specific attention to planning and management

in vulnerable or stressed ecosystems that are subject to specific human resource usage and development

pressure.

6) The difficulty faced by this environmental assessment (and, potentially the decision maker), is that the

environmental impacts associated with the listed activities subject to this application would, from a strict

activity and site-specific perspective, be relatively insignificant. In some cases, the impacts on the affected

watercourses may even be positive.

7) However, this state of affairs is effectively turned on its head if the environmental implications of the proposed

projects are recast in relation to their interaction with the highly modified flood and erosion dynamics that have

resulted from intensive agricultural use of the surrounding catchments and floodplains which, in turn, have

been compounded by alien infestation and, in the case of the Meulrivier at Site OB1, extensive bulldozing of

the river channel.

8) The specialist aquatic assessment (Day, 2014) undertaken in support of this combined application for the

environmental authorisation of activities 'triggered' by repairs, refurbishment of rebuilding of flood-damaged

provincial road infrastructure has been closely guided by a functional, scale-sensitive approach to biodiversity

assessment. The latter assessment has considered construction-related impacts, and post-construction

management/maintenance of the immediate environs of the respective structures. In addition, the specialist

aquatic assessment has also highlighted the mutually-reinforcing and environmentally damaging interactions

between destabilised aquatic ecosystems and the impacts of the affected river crossings.



9) Of crucial importance, however, is the finding by the aquatic specialist assessment that the environmental

advantages of the proposed works will effectively be annulled if erosion, channel instability and alien

infestation – which, synergistically, are driving negative environmental change in the affected catchments,

outside the proclaimed road reserve – are not actively addressed and remedied by the responsible

landowners.

10) As indicated, this state of affairs poses a serious conundrum to both the applicant, as well as the competent

authority, as the impacts of the proposed works could, if analytically divorced from any extraneous factors, be

mitigated to environmentally (specifically ecologically) acceptable levels. In fact, construction of new bridges

at OB1 and OB3 would potentially represent a significant improvement upon the poor environmental

performance of its predecessor. The specialist ecological assessment has, however, found that the

management of potential impacts arising from the proposed works cannot be divorced from the synergistic

and cumulative effects of land use practices in the respective catchments – which means that this suite of

problems needs to be addressed in an integrated and co-ordinated manner at a catchment or ecosystem

scale. Failure to do so would perpetuate the continued degradation and destabilisation of especially the

Elandskloofrivier, and effectively obliterate most of the environmental advantages that would be achieved by

implementing the proposed repairs.

11) It is recognised, however, that environmental decision-making in terms of section 24 of NEMA is primarily

concerned with controlling listed or specified activities which applicants (i.e. project proponents) may not

commence with without environmental authorisation. In this respect, individual project proponents cannot be

held accountable for managing or mitigating the impacts of listed activities that are pursued, independently,

by other persons or parties. Likewise, it is difficult to see how an individual or entity can be expected to exercise

the 'duty of care' towards preventing or remedying environmental degradation that is entirely the making of

someone else. This line of reasoning is less clear-cut, however, in the context of ecosystem management where

multiple independent actors may, through a variety of pressures and land uses, have a combined impact on

the condition and functioning of the affected ecosystem, such as a foothill river and its floodplains and

wetlands on the southern slopes of the Riviersonderend Mountains. This, in fact, is the situation that prevails with

regard to all of the projects in question – the environmental concerns associated with the proposed repairs are

relatively trivial compared to those arising from the highly modified condition of the affected catchments and

watercourses, but the latter has a direct, negative, effect on the significance of the former. The only realistic

method for addressing this state of affairs requires defining the environmental degradation in question as a

case of ecosystem failure, and responding at an equivalent scale. Exclusively focusing on controlling individual

listed activities and their impacts will not, unfortunately, yield sustainable outcomes for the affected rivers.

12) Given this complexity, and the activity-specific focus of the environmental regulatory system, impact

identification and assessment will be presented as two distinct but inter-related components:

a) The first will focus exclusively on impacts attributable to the proposed activities for which authorisation is

being sought; whereas

b) The second component will situate and analyse the potential consequences of the proposed works in a

broader, ecosystem context.

13) This is an artificial device designed to assist the decision making process by distinguishing between:

a) Impacts that are clearly activity-related, and therefore within the ambit of authority and responsibility of

the Western Cape Department of Transport and Public Works, its duty of care towards the environment,

and obligations under environmental legislation and the EIA regulations – as the applicant; and

B) Broader problems of environmental management that need to be addressed in conformity with the

national environmental management principles, the objectives of integrated environmental

management, and the duty of care, but are not the responsibility of the Department of Transport and

Public Works and therefore fall outside the ambit of this application.



1. PLEASE DESCRIBE THE MANNER IN WHICH THE DEVELOPMENT WILL IMPACT ON THE FOLLOWING ASPECTS:

The draft basic assessment has provisionally concluded that the proposed projects will have an impact on the following

aspects of the affected environment (which are discussed in detail below):

ENVIRONMENTAL ASPECTS THAT MAY BE AFFECTED BY THE P ROPOSED PROJECTS AND RELATED ACTIVITIES

Phase of project when environmental aspects may be

affected by impacts

A–D = Biophysical aspects

E = Biodiversity conservation priorities

F = Socio-economic aspects

Construction Operation

A. Hydrological aspects − Flow regimes − Water quality

� �

B. Hydro-geomorphological aspects

− Scouring, erosion and sediment movement − Physical structures and stability of watercourse

� �

C. Biodiversity aspects

− In-stream and riparian habitat � �

D. Biodiversity conservation priorities

− Critical Biodiversity Areas and Ecological Support

Areas − Freshwater Ecosystem Priority Areas − Listed threatened ecosystems

� �

E. Socio-economic aspects

− Employment opportunities − Sense of place and wellbeing − Integrity of road network (safety and reliability)

� �

(1)(a) The biophysical context, biophysical impacts and evaluation criteria

The biophysical context and definition of biophysical impacts

The impacts identified by this Draft Combined Basic Assessment relate virtually exclusively to the biophysical environment

which, to recapitulate, is broadly characterised by:

− The Southern Folded Mountains (late summer to winter rainfall) and Southern Coastal Belt Ecoregions (winter

rainfall), both of which form part of the Cape Floristic Region, a global biodiversity hotspot;

− Threatened shale fynbos and shale renosterveld ecosystems, which are reduced to a fraction of their original

extent with respect to the latter vegetation types;

− Lower foothill rivers and valley bottom wetlands (the former are either CBAs or ESAs, and the latter are wetland

FEPAs which as with CBAs, should be managed in support of an unmodified or largely natural condition).

Two of the sites have a PES of 'C' ('moderately modified'); the remainder are 'largely' to 'seriously' modified. Half of the

rivers are rated as having 'moderate' ecological importance and sensitivity; the EIA of the remainder is 'low'. Rivers with

an EIS of 'moderate' are usually not sensitive (in terms of habitat and biota) to flow modifications, and may have a

substantial capacity for use (Day 2014, p 12). Sites OB3 to OB6 are associated with wetland FEPAs.

Classification of biophysical impacts

The classification of biophysical impacts distinguishes between:

− Construction-related impacts, including those arising from the proposed by-pass at OB6 (which are generic to

all sites); and



− Impacts that may persist after construction, into the operational lifespan of the structures, at a site-specific and

ecosystem scale.

Impacts that may result if specific aspects of the affected environment are not adequately managed will be dealt with

separately as these considerations fall outside the scope of this application (see 'Note' above).

This section is, unless otherwise indicated, exclusively based on the findings of the specialist freshwater ecological

assessment (Day, 2014).

Aspects of the biophysical environment to undergo review and impact assessment

As indicated above, each of the projects will be assessed for impacts on:

− Hydrological aspects, i.e. flow regimes and water quality;

− Hydro-geomorphological aspects, i.e. scour, erosion and sediment movement;

− The physical structure and stability of the watercourse; and

− Biodiversity aspects, i.e. aquatic CBAs as surrogates for biodiversity pattern (in -stream and riparian habitats)

and ecosystem function (flows and sediment dynamics).

The projects will be assessed generically against this set of impacts, using the 'extent-duration-magnitude' formula. The

method of impact evaluation (i.e. determination of impact 'significance') is explained below. Impacts that are specific

to a particular structure or situation will be highlighted and dealt with independently.

Impacts on hydrological and hydro-geomorphological aspects (flow regimes and erosion)

Whereas the impact assessment in Section F will allow for a focused scrutiny of the environmental implications of the

proposed works, relative to the ecological management objectives of foothill rivers as summarised above, it also needs

to be recognised that the new or repaired and refurbished structures may represent a net improvement on the condition

of affected ecosystems that is more usefully expressed in the language of 'need and desirability' than impact

significance.

The latter statement must, however, be qualified by the caveat that such improvements in the ecological condition of

the respective watercourses are virtually entirely contingent upon implementing mitigation measures in the reaches

directly up- and downstream of all the sites, except OB4, and, in the case of OB3, at the scale that it would take in order

to stabilise the seriously degraded Elandskloof River (cf. Day, 2014).

Nonetheless, it must be recognised that the proposed works also represent a deliberate attempt on the part of the

project engineers to design structures to standard specification that are not only capable of withstanding floods of a

specified magnitude, but are also equipped to prevent flow restriction and minimise scour and erosion which would

otherwise result in loss of agricultural land, channel destabilisation and degradation of in-channel habitats.

The bridges at OB1 and OB3 are to be rebuilt. In both cases, the new structures will be equipped with significantly

improved hydraulic capacity that will permit 1:2-year floods to pass through the structures without being impeded by

blockages caused by driftwood or sediment.

The new bridge at OB1 will be vented by a single opening, 12 m wide x 4.5 m high and the directly abutting

embankments will be secured with gabion 'mattresses'. The bridge spans a relatively deep channel and has therefore

not been designed for over-topping.

At OB3, where the DR1313 crosses the Elandskloof River, the new causeway is designed to be over-topped by floods

exceeding the 1:2-year return period. The new causeway will have three twin box culverts, each consisting of cells 3 m

wide x 2.05 m high. The approaches at either end will be protected by concrete road slabs, and the embankments by

gabion 'mattresses'.

From an environmental perspective, the major design shortcomings of river crossings in the study area relate to culverts

or pipes that cannot accommodate the passage of floods through the structures, especially when insufficiently-sized



openings are blocked by waterborne debris. This has the effect of causing water to back up, upstream, and to break

around the edge of structures which often causes approaches to be washed away. This undesirable deflection of flows

away from active channel can also result in significant lateral erosion into cultivated floodplains, as evident at OB3.

These physical shortcomings can be exacerbated when culverts are not aligned perpendicular to flows. Culverts that do

not have adequate scour protection at their outlets may also be vulnerable to undermining due to the development of

plunge pools that erode the underside of outlets slabs and aprons. Concrete wing walls and/or gabion protection at

inlets may be absent or damaged, which also contributes to erosion and eventual instability of the crossings.

There may be some disruption of flows down the watercourses in question during the establishment of temporary

diversions or coffer structures to route water around the construction sites. 'Local' impacts may arise during the initial

establishment of diversionary structures (such as sandbagged coffers) and flows (depending on water levels) are

temporarily prevented from reaching the Riviersonderend.

Impacts on flows in the Bot River cannot be altogether avoided as the works will be taking place either within or in close

proximity to this watercourse.

Overall, these will be short-lived interruptions, not lasting more than a few minutes in any instance. Flows may be

interrupted intermittently during construction which, except for the construction of the bridges at OB1 and OB3, is not

expected to exceed more than five months in toto. The aim of mitigation would be to maintain natural flow regimes

during the full period of construction. Overall, the drier the watercourse at the time of construction, the less impact there

will be on flows.

The site at 'Nooitgedacht' (OB6) is the only one where a temporary by-pass will be required owing to the narrowness of

the road at the point. Impacts that may typically be associated with by-passes include:

− Changes to the structure and condition of the bed and banks of watercourses;

− A potential increase in local scour and erosion caused by the passage of water over the by-pass, or as a result

of channel constriction;

− Impeded flows if water cannot pass through over the by-pass;

− Flow diversion if bypasses are vented by pipes;

− An increase in downstream turbidity and sedimentation; and

− Development of eroding head-cuts at the downstream edge of the by-pass and which thereafter may migrate

upstream.

These impacts can be effectively countered by ensuring that the by-pass has a low profile, laid as close to the existing

shape of the bed of the watercourse as possible.. It will be necessary to lay pipes through the by-pass in order to

accommodate low flows. The by-passes will be demolished and the disturbed footprint rehabilitated immediately after

construction. Close attention needs to be given to evening out any residual 'benches' across the watercourse that may

precipitate head-cut erosion after the by-pass has been demolished. The residue of the decommissioned by-pass will be

used to ‘tie in’ the enlarged culvert structure with the adjacent gravel road approaches.

Changes to flows, especially in terms of the availability and quality of water, can have a deleterious effect on aquatic

organisms and riparian vegetation in the lower, wetted zone of the watercourses. Where flows have to be disrupted for

operational reasons, interruptions must be kept as short as possible. High flows during winter, or as a result of cut-off low

pressure events in early summer can swamp construction sites, exacerbate erosion, damage works and lead to

contamination of water by building materials and fuel. These are all factors that need to be taken into account by the

Construction Environmental Management Programme and Maintenance Plan for these works.

Unless prevented or mitigated to acceptable levels, erosion and sedimentation can reduce in-stream habitat diversity,

contribute to turbidity and, cumulatively, result in simplification and destabilisation of aquatic ecosystems and their biotic

communities. The prevention and control of erosion and sediment release into watercourses is therefore a key

consideration in the design of watercourse crossings.

Engineering best practice w.r.t. bridge and culvert design in rural conditions

In this regard see, for example, the DTPW‘s Standard Drawings and Details for Culverts and Causeways (2012), DEA&DP

guideline on planning off-road routes (2006), the KwaZulu Natal Department of Transport’s design standards for local



roads (1997) and the US Environmental Protection Agency (EPA) manual on best practice for low-volume roads’

engineering (2003). The EPA recommends that vented crossings must be designed to occasionally be over-topped by

floods and have an erosion-resistant deck and approaches. Outlet structures must be equipped with scour protection

(‘splash aprons’).

According to a major Australian manufacturer of concrete box culverts, 'Humes', box culverts are "ideal" for flows where

hydraulic head is limited. For an equivalent waterway, box culverts can be configured to have less impact on upstream

water levels and downstream flow velocities than equivalent pipe structures (http://www.humes.com.au accessed 23

April 2014).

These best practice requirements have been met with regard to the majority of the proposed projects. The exception is

OB2, where time and cost constraints do not permit a fundamental review and re-assessment of the effectiveness of the

culvert crossing over the Botrivier at 'Doringkloof'.

Impacts on CBAs and ESAs

All of the structures are located in either CBAs or ESA, or combinations thereof, and will have an impact on the

achievement of the ecological management objectives for these features. These impacts can be either positive or

negative, depending on the scale at which impacts are assessed. This is explained below.

Potential impacts on CBAs and ESAs can be defined as:

− Impact on biodiversity pattern thresholds or targets (chiefly relating to focal species, priority catchments,

important aquatic habitats and threatened ecosystems); and/or

− Impacts that may result in the degradation of areas or features that are important for maintaining ecological

processes (i.e. areas selected on the basis of ‘best design’ considerations).

CBAs can be selected for their contribution to both pattern and process targets or thresholds, whereas ESAs mostly only

apply to areas or features that are important for maintaining ecosystem function (such as ecological corridors or

hydrological processes).

CBAs and ESAs are treated as a surrogate for biodiversity pattern and process at a site-specific scale, i.e. representing

localised impacts on flows, sediment processes and habitat within approximately 100 m up-and downstream of each

structure. CBAs and ESAs will also be used to evaluate the potential significance of impacts by:

− Defining the 'magnitude' of impacts in relation to loss of habitat in CBAs and ESAs; and

− Contextualising the overall environmental benefits or costs of the projects in relation to the extent to which the

repairs may either contribute to, or detract from, the achievement of the management objectives for CBAs

and ESAs.

Potential impacts on FEPAs

'Wetland FEPAs' refer to wetlands that must be maintained or rehabilitated to a good ecological condition (i.e. 'A' or 'B'

ecological category). The aquatic ecologist has confirmed that Sites OB3-OB6 coincide with channelled valley bottom

wetlands that have been identified as Wetland FEPAs (cf. Driver et al., 2011). None of the wetlands at the four sites in

question are in a 'good', 'natural' or 'near-natural' condition (Day 2014, p 14).

The specialist aquatic assessment has summarised the present ecological state (PES) and ecological importance and

sensitivity (EIS) of these respective Wetland FEPAs as follows (Day, 2014, p 14):

Site PES Explanation EIS

OB3 E River severely degraded – no associated wetland habitat. Very high levels of disturbance,

extensive sedimentation, loss of indigenous vegetation, alien invasion.

Low



OB4 C River degraded – but large areas of floodplain wetland upstream of road. Confined

downstream and channelised

Low

OB5 C River degraded – but areas of floodplain wetland upstream of road. High levels of alien

invasion but river channel retains good quality instream habitat including palmiet

vegetation.

Moderate

OB6 D/E River highly degraded – but areas of valley bottom wetland upstream of road. Very high

levels of erosion; loss of indigenous vegetation; channelisation.

Low

A = Unmodified/natural B = Largely natural C = Moderately modified D = Largely Modified E = Seriously

modified F = Critically/extremely modified

SANBI's Implementation Manual for Freshwater Ecosystem Priority Areas (Driver et al., 2011, p 46) recommends that

potential impacts on FEPAs must be dealt with as follows in the course of environmental assessments:

− Anticipated impacts on FEPAs that may result in an ecological condition lower than A or B should be ranked as

having medium to high significance.

− Any activity that will have an overall residual impact on wetland or river FEPAs and their immediate surrounds

greater than a low negative significance, is not acceptable from the point of view of managing and

conserving freshwater ecosystems, and must be avoided.

− Unavoidable development must require special mitigation measures that would reduce the overall impact of

the activity or development to low negative significance, or must require a biodiversity offset....

If the potential impacts on wetland FEPAs at sites OB3-OB6 are reviewed in terms of the preceding considerations, the

following emerges:

− None of the wetlands in question is in a natural (A) or near-natural (B) condition. In all instances, however, the

proposed works would contribute to local or at least site-specific improvements to flood conveyance and

lower levels of erosion and sediment transport. However, improvements to the ecological condition of the

affected watercourses would only be accomplished if the full suite of 'high level' mitigation measures were to

be implemented (Day, 2014, p 38). Even so, the specialist aquatic assessment predicted that "full mitigation"

(i.e. on-, and off-site) would have a very limited positive effect on the PES of the affected watercourses as

illustrated below:

Site

Pre-

construction

PES (February

2014)

Estimated post-construction PES

With full

mitgation

Without

mitigation

OB3 E D/E E A = Unmodified/natural

B = Largely natural

C = Moderately modified

D = Largely Modified

E = Seriously modified

F = Critically/extremely

modified

OB4 C C C

OB5 C C C

OB6 D/E C E

Given the 'moderately' to 'seriously' modified condition of these watercourses, which is a culmination of land

use practices in the adjacent catchments and upstream reaches, alien invasion and the local effects of the

respective structures on the aquatic environment, the impacts of the works will be relatively trivial – even if a

comprehensive programme of ecosystem rehabilitation were to take place at the appropriate functional and

geographical scales. In the circumstances, it is understood that the proposed activities will have a negligible

impact on the condition of FEPA wetlands. Also, there appears to be little prospect that any of these

watercourses, wetlands and catchments can be restored to the desired ecological condition for FEPAs. Small,

incremental improvements may be possible, but can certainly not be initiated or registered at the scale of

individual sites and their immediate environs. Impacts on FEPAs will therefore not be assessed.



− There are two basic ways in which impacts on FEPAs and CBAs can be assessed: assessing impacts on

surrogates for the biodiversity that is represented by FEPAs and by means of which FEPAs are maintained (e.g.

habitats, flows, erosion and channel stability), or by assessing the consistency of predicted impacts with the

management objectives for FEPAs (or CBAs). The results of these two assessments are reported at Sections

F(8(a) and (c) respectively. With regards to site-specific impacts on biodiversity pattern and process, none of

the impacts would, provided that mitigation takes place as recommended, exceed 'Low' negative

significance, and most would be of 'Very Low' negative significance. The section below assesses the impacts of

the proposed works for consistency with the management objectives for FEPAs, CBAs and ESAs.

− Following from the latter point, there are no impacts that are directly associated with the proposed activities

that cannot be mitigated to at least 'Low' negative significance. However, if the works are re-evaluated in a

broader spatial and functional context, it is recognised that site-specific mitigation cannot have its desired

effect unless causes of widespread ecological degradation and instability of the respective watercourses are

addressed at source, and at the appropriate scale. The uncontested environmental benefits of the works will,

unfortunately, come to nought as long as they are undermined by the cumulative damage that arises from the

structural instability of the affected ecosystems. That is not, however, a problem that can be addressed by the

DTPW. Answers to these issues lie elsewhere, and will certainly not be found in the course of project-specific

environmental assessments relating to the repair of flood-damaged road bridges.

Evaluating the compatibility of projects with respect to the management objectives for CBAs, FEPAs and Phase 2 FEPAs

In terms of general practice and approaches, environmental assessment sets out to identify, assess and evaluate

impacts against criteria of magnitude, duration and extent, with the view of determining if impacts can be mitigated to

acceptable environmental levels, in which case projects should or should not be allowed to proceed.

Here, an attempt is made to establish if the proposed projects can be reconciled with the ecological management

objectives of CBAs and FEPAs which, if so, can indicate that a project may be able to make a substantial contribution to

ecosystem resilience and the maintenance of functionally viable and spatially efficient network of priority conservation

sites.

The conservation management objectives for CBAs are, in summary, to maintain natural areas in a natural condition or,

where habitat in CBAs may have become degraded, to prevent further deterioration and rehabilitate the CBA to a

near-natural or natural condition (cf. Holness and Bradshaw, 2010). Management in Ecological Support Areas, in turn,

must be aimed at maintaining ecological processes.

The management objectives for foothill rivers designated as aquatic CBAs (Job et al., 2008) provide a clear standard

against which to evaluate the ecological implications of proposed activities in such systems. Ideally, management of

foothill rivers and channelled valley bottom wetlands (where these are present) should:

− Aim to maintain flow regimes as natural as possible in terms of magnitude, frequency and variability of flow;

and

− Not result in modification to the bed and banks of watercourses or constriction of flow through pipes and

culverts as this can promote erosion, excessive mobilisation of sediments, habitat destruction and

destabilisation of the affected channel.

It can also be presumed that, historically, the damaged structures would have individually and cumulatively contributed

to environmental degradation owing to designs that did not necessarily take the abovementioned management

considerations into account. Added to this, the structures were possible designed in response to physical conditions that

have subsequently changed and now exceed the capacity of the pipe and culvert crossings to convey floods and high

sediment burdens.

Such change can be attributed to catchment 'hardening', accelerated run-off, loss of wetlands, floodplains and flood

attenuation capacity, down-cutting and alien encroachment that accelerates flows and erosion. In fact, flood damage

in the study area over the past several years suggests that floods seem to be causing damage that is disproportionately

greater than what previously had been predicted for an equivalent-sized flood. Changing rainfall patterns may also be

contributing to these phenomena (King, 2012).



Where the projects may – in a site-specific context, isolated from broader catchment-related problems -- contribute to

the achievement of the management objectives for aquatic CBAs (and, therefore, FEPAs), this is regarded as a positive,

site-specific impact. Viewed from a local or regional scale, the impacts of the projects will, at best, be neutral owing to

the overall, negative, cumulative impacts arising from intensive agricultural modification of the respective catchments

(which is most severe in the case of the Elandskloofrivier).

The remainder of this section is, unless otherwise indicated, exclusively based on the findings of the specialist freshwater

ecological assessment (Day, 2014).

(1)(b) Impacts on hydrological (flow regimes and water quality) and hydro-geomorphological aspects (scouring,

erosion and sediment movement; and physical structure and stability of watercourses)

NOTE

Excavations in river beds, vehicle movements in and out of watercourses, and the type of trampling and compaction that

can be expected with construction sites anywhere will, to a lesser or greater extent, occur at all sites – and, added to this,

disturbances to flow regimes that can contribute to erosion and sediment transport which, in turn, may affect the stability

of channels, compromise water quality, degrade aquatic habitats and amplify flood-related risks to the structures in

question. All these impacts, as are their causes, inter-related. In the context of managing human interactions with

dynamic watercourses, it is critical to understand the causes of adverse environmental change, and to know at what

scale the ensuing instability and degradation take place and, therefore, at what scale they need to be addressed.

Will the development have an impact on flow regimes? YES

� NO

If yes, please describe:

OB1 During construction, flows may be temporarily diverted around the construction area to keep it dry. This will

be a temporary disturbance, largely confined to the construction footprint. Alternatively, flows may be fed

through the construction area. There will be no impoundment.

In the long-term, the single, larger culvert will assumingly reduce the frequency of significant flood

disturbance, with an enhanced likelihood of ecological recovery between flood events. The new structure

should also improve ecological connectivity by passing flows through a large portal instead of narrow

pipes as is currently the case. The new bridge over the Bot River should pose no impediment to base flows

provided that the base of the culverts is low enough to convey water under low conditions.

OB2 As previously noted, the proposed construction measures do not attempt to address the problem of the

small, seasonal tributary that joins the Botrivier from Doringkloof. The latter tributary is diverted along the

edge of the concrete structure, increasing flood pressure and erosion damage on the right hand side of

the Bot River channel, and contributing to the high levels of erosion damage observed in the river

downstream of the structure. These impacts will thus be perpetuated by repairs to the new structure.

The aquatic ecologist (Day, 2014) has recommended that structure must include an additional or

extended culvert or other ecologically cognisant measure that allows for the free flow of the minor stream

through the structure, without being diverted along the road edge. The mechanism for this would need to

address the fact that the stream appears to enter the system at a higher level than the existing culvert.

Amendment of the proposed design to address the issue of diversion of flows from the small tributary into

the Bot River is considered essential mitigation. Assuming that this and the other recommended mitigation

measures are implemented at this site, the proposed activities would be considered to have a net positive

ecological impact. In the absence of this aspect being addressed, it is likely that erosion and disturbance

will remain significant sources of disturbance to the river. Further expenditure on perpetuating these

conditions is not considered ecologically sustainable, and thus approval of this project without the

specified mitigation measures would not be recommended.

NOTE that these concerns raised by Dr Day have been discussed with the DTPW and its consulting

engineers, and that the DTPW's responses are recorded in the discussion of alternatives at Section E(1)(c)..



OB3 Widening of the existing culverts and their extension across the full width of the (now bermed and

channelised) river in these reaches as proposed, so as to allow the passage of cobbles and sand beneath

the structure and to allow the passage of flows up to a 1:2 year flood through the structure is regarded as a

positive impact, likely to promote longer-term stability of the river channel.

Provision to cater for the irrigation pipelines at the outlet to the bridge structure is also considered a

positive impact, as its relocation away from the river bed will reduce the ongoing disturbance to the river,

resulting in the past from the frequent need to repair infrastructure, subject to frequent flood damage.

However, in the absence of ensuring control over erosion at the level of the river or at least the upstream

reach, it is very unlikely that such positive outcomes will be achieved, with significant damage occurring on

a 1:2 year basis considered a disturbance regime too great to allow for ecological recovery between

disturbance events.

Flows may also have to be diverted temporarily in order to allow work to take place in the active channel.

Any disruption to flows will be of short duration and localised in extent.

Owing to the disturbed state of the river and the level of damage to the existing river crossing structure

means that there is some likelihood that further flooding will result in the current road being unusable as a

bypass without intervention during construction, resulting in the need for additional earthworks and

probable diversion of flows.

In the event of damage to the existing crossing being such that it cannot be used as a bypass during

construction, it is recommended that construction phase mitigation measures include allowance for the

short-term repair of the existing bridge, using pipe culverts if necessary to minimize disruptions to flows.

OB4 Installation of gabion 'mattresses' at the inlet and outlet structures along this secondary flood channel of

the Elandskloofrivier would, at most, have an impact of 'Very Low' negative significance on the hydraulic

functioning of this watercourse. There would consequently be no reason to motivate against the project

going ahead – specifically given that gabions would be used instead of concrete apron slabs.

The positive aspects of gabions are that, besides meeting the project objective to constrain the growth of

reeds that contribute to the pipe culvert being blocked, their rough surface will not accelerate flows to the

extent that concrete surfaces would, reducing erosion potential. Also, gabions would support sub-surface

seepage during the flow season which would help to prevent wetland vegetation from drying out.

As with all the other projects, flows may also have to be diverted temporarily in order to allow work to take

place in the active channel. This channel seems to be highly seasonal, only carrying water that overflows

from the Elandskloofrivier during floods. If work is confined to the dry season (January to March), there

would be minimal dispruption of flows – which, in any event, will be of short duration and highly localised in

extent.

OB5 The installation of improved scour protection downstream of this culvert will not have any influence on

flows passing through the structure. Flows may, however, be temporarily disrupted during construction,

when it may be necessary to divert water around the construction site. This will be of short duration and

localised.

OB6 The additional box culvert at this site will improve the passage and management of high flows under the

road. Flows may be disrupted during construction of the extra culvert, and a check-weir just upstream of

the crossing (see above). Such disruptions in flows may be exacerbated by the construction of a

temporary by-pass downstream of the culvert where work is to take place. Again, if work is timed to

coincide with the dry season, the management and diversion of water will be considerably less

problematic than under wetter conditions. If effectively managed, any disruptions or diversions will have a

localised and relatively short-term impact on water movement down this channel.

NOTE that in all cases, it is important to keep flows as natural as possible as the rivers at sites OB3-OB6 all drain into the

Riviersonderend, which an aquatic CBA and Wetland FEPA.

Will the development have an impact on water quality? YES

� NO




OB1 The Botrivier is already prone to sediment loading and turbidity due to the effects of high erosion. During

construction, there may be increased turbidity arising from unavoidable disturbances to the bed and

banks of the river. The river may also be contaminated by the receipt of construction-associated materials

such as cement, fuel or lubricants. These impacts, were they to occur, would be of high intensity but

localised in extent. The risk of these impacts occurring beyond the construction phase is effectively nil.

OB2 If construction takes place in late summer or autumn, there should be a negligible risk of water resources

being contaminated in the manner described above for Site OB1. The vulnerability of the resource to

contamination would, however, be less than at site OB1 because considerably less work is to take place at

the 'Doringrivier' site. Turbidity may increase under wetter conditions, when more erosion of areas disturbed

by construction may be expected. Although, the risk of contamination of water resources would cease

once construction has been concluded, erosion would probably continue with varying intensity around the

confluence of the two watercourses, across the southerly road approaches, and against the right bank of

the Botrivier downstream of the culvert. This would only be preventing by completely redesigning the river

crossings at this difficult site.

OB3 Impacts on water quality in the bottom reaches of the Elandskloof River would be as closely associated

with the proposed construction of a new bridge, as well as the large volume of unstable sediments in the

channel and along eroded reaches of river bank that become mobilised and transported downstream

during floods. The bed and banks of the Elandskloof River are actively eroding along much of its length

and the river is, overall, in a highly destabilised and degraded condition. It is therefore essential that the

destabilised river channel and its margins be stabilised by means of groynes and adequate plant cover.

The same construction phase impacts on water quality are likely as outlined for OB1. Their net effect would

however be relatively low, given the level to which the river is already disturbed. Additional sediment and

bank disturbance, for example, would probably have a negligible additional effect, given the current rates

of disturbance.

OB4 The proposed works at this minor pipe culvert are relatively far more limited in extent than those planned

for the other sites and, provided that construction takes place during dry weather, the risks of erosion,

contamination and turbidity of downstream reaches are understood to be low.

OB5 The pool below the culvert at 'Tarentaalkraal' is in a 'moderate' ecological condition and supports relatively

intact wetland vegetation along its margins (including palmiet Prionium serratum). Construction-phase

impacts may include contamination of the watercourse by construction-associated materials such as

cement and sediments, resulting in a short-term increase in turbidity and pH, in a watercourse in which

water quality is probably only mildly impacted. These impacts would all be exacerbated if construction

took place during the wet season when the water table was high, or during a period when a storm event

occurred. Great caution must be therefore be exercised in order to protect this watercourse from any

contamination and excessive disturbance or deposition of sediments.

OB6 The major source of turbidity at this site would be associated with erosion caused by disturbances to the

bed and banks of the watercourse at, respectively, the site where the check-weir has to be built, the main

construction site itself (i.e. parallel to the existing box culvert underneath the DR1313), and downstream

when the by-pass is built and de-commissioned. The erection of a temporary coffer or barrier to divert

water away from the construction site may also contribute to disturbance and turbidity, albeit of short

duration. As it is, this system is probably already vulnerable to these effects owing to existing, high levels of

disturbance and erosion. In the long-term, however, the works at OB6 would probably lead to a significant

reduction in erosion at the site and, with that, a far less severe impact on water quality downstream of the

structure. However, the active erosion and loss of river bank downstream of the crossing needs to be

controled in order to prevent ongoing deterioration of the watercourse and water quality.

NOTE that in all cases, the above impacts would be exacerbated if construction took place during the wet season when the

water table was high, or during a period when a storm event occurred.

Will the development have an impact on scouring, erosion and sediment movement?

YES

� NO



NOTE

In all cases, changes to flows coupled with disturbances to the beds and banks of the affected watercourses may

precipitate scouring, erosion and sediment transport and deposition. The proposed works at sites at OB1 and OB3 entail the

construction of two new bridges and realigning the road approaches to these structures. It would take at least six months to

complete these works, and to demolish and remove the redundant structures. Not only will there be more physical

disturbance at these sites, but it will continue for foreseeably longer than at any of the other sites with, maybe, the exception

of the extra culvert that is to be installed at OB6. With disturbance to the beds and banks of watercourses, arises the risk of

increased scour, erosion, downstream sediment transport, turbidity and even destabilisation of watercourses – particularly so

where construction may entail temporarily constricting flows around coffer structures, or flows are diverted by earthworks

(such as by-passes), excavators loosen or dislodge otherwise consolidated materials, or when water is pumped back into

rivers under pressure. These risks are generic to all sites, and need to be mitigated and managed accordingly – and

particularly so at OB1, OB3 and OB6 where disturbances are to be more sustained than elsewhere and, following from that,

would have commensurately increased prospects for erosion-related damage to the affected water resources and their

biodiversity. The proposed groynes in the Elandskloofrivier would play a critical role in mitigating the impacts of the new

causeway at OB3 as they would control bank erosion and channel migration in the reaches directly up- and downstream of

the crossing. Flows and erosion would need to controlled at least 50 m upstream and downstream of the crossing and,

ideally, the groynes should be in place before construction starts on the new causeway at OB3. Currently, however, this

seems unlikely.

OB1 As with the works at sites OB3 and OB6, major improvements to the flood conveyance capacity of this and

the structures at the latter sites will help to reduce the frequency of significant flood disturbance, ease the

passage of debris through the structure, and potentially promote more rapid ecological recovery

between floods because of the reduced rates of disturbance and erosion. However, alien trees would

have to be cleared from the channel (60 m x 15 m on each bank upstream, and 30 m x 15 m on each

bank downstream) for these improvements to have demonstrable effect. Furthermore, cleared areas

would have to be stabilised otherwise they will be vulnerable to erosion. This can be achieved by bank

shaping and planting cleared areas with indigenous plants that occur naturally in watercourses in the

western parts of the Overberg. The eroding and collapsed right bank of the Botrivier upstream of OB1 also

needs to be stabilised against further erosion. If not, the erosion may develop to the extent that it

threatens the structural stability of the new bridge. Key factors driving this erosion include dense infestation

of black wattle along the river banks, and fallen trees which block and deflect flows in the channel.

OB2 See above. This site is subject to severe erosion that appears to be caused be, among others, the

misalignment of the culvert to the direction of flow within the Botrivier, flows from a small, seasonal tributary

that are deflected across the upstream face of the culvert into the right bank of the Botrivier, and flooding

of the southern approaches to the culvert which causes road material to be scoured away and washed

into the channel. These erosive processes are exacerbated by dense stands of alien trees that need to be

cleared from the two watercourses – in swathes of 30 m x 15 m on both sides of the Botrivier, up-and

downstream of the culvert, and at least 30 m upstream along the minor stream that flows in from

Doringkloof, to the east.

OB3 See above. Little can be achieved in terms of stabilising the Elandskloofrivier in the vicinity of the crossing

at OB3 unless a comprehensive strategy of channel stabilisation is implemented along the heavily farmed

length of this severely destabilised river. The Western Cape Department of Agricultural is currently

undertaking planning to this end, with the support of national disaster relief funding. As indicated above,

the new causeway would have considerably widened culverts, extending across the full width of the

channel which would allow 1:2-year floods and their sediment load to pass unimpeded through the

structure. It will be over-topped by larger floods. Gabion protection along the approaches, and an

extensive concrete scour apron at the outlets, will help to prevent erosion of the approaches as well as

the channel downstream of the causeway.

OB4 See above. This pipe culvert on a minor flood channel of the Elandskloofrivier is to be equipped with

gabion mattress on its upstream and downstream sides. This will help to curtail the growth of reeds that

contribute to blockages and over-topping of the road during floods, as well as prevent scouring at the

outlet and when floods overtop the culvert.

OB5 See above. The stepped series of gabions and a gabion mattress at the base of the refurbished anti-scour

structure are specifically designed to prevent erosion and undermining of the culvert at 'Tarentaalkraal'.



OB6 See above. The single culvert at 'Nooitgedacht' can currently convey only 50% of flows during 1:2-year

floods, which causes the river to back up, rise and erode the gravel road embankments, over-top the

road, and inflict erosion damage on the other side of the culvert. The single culvert also causes flows to be

concentrated, which appears to have precipitated severe and active erosion of the channel bed and

banks downstrearm of this structure. A head-cut just upstream of the crossing is an additional source of

erosion and sedimentation. Besides adding a second culvert, and stabilising the head-cut, construction at

this site will also have to manage the temporary by-pass, downstream of the crossing so that it does not

precipitate erosion both during and after completion of the works.


water table was high, or during a period when a storm event occurred.

Will the development have an impact on the physical structure and stability of the watercourse? YES

� NO

OB1 The comments about the synergistic interaction between modified flows, erosion and the effects of

exacerbated sediment transport apply equally to questions of channel structure and instability. In short,

the potential environmental benefits associated with the rebuilt bridge at OB1 (improved food

conveyance capacity and sediment throughput) must be combined with measures to stabilise erosion

and slumping of the left bank of the Botrivier upstream of the new bridge, as well as the removal of alien

vegetation both upstream and downstream of the structure, as recommended above. Extra diligence is

required with regard to reshaping the channel following the removal of the now-defunct, original, bridge.

This is because residual disturbances to the bed and banks of the river may precipitate erosion at nick-

points or discontinuities (benches') in the bed of channel. All rubble must be removed for the same

reasons.

OB2 There is little prospect that the current instability and degradation of the Botrivier downstream of the

current culvert can be effectively managed and mitigated by the repairs that are proposed for this site. As

indicated above, the entire configuration of the crossing and related infrastructure at the confluence of

the minor watercourse and Botrivier needs to be revisited to resolve erosion and channel instability that

are contributing to environmental degradation as well as damage to the road.

OB3 The comments above relating to the potential impacts on channel instability at OB1 apply equally to the

works at OB3. Additional measures at this site that are necessary to forestall long-term changes to the

morphology and stability of the Elandskloofrivier include the construction of groynes to prevent rampant

erosion, as well as removing the berm along the left side of the channel downstream of the new

causeway.

OB4 Minor works are proposed at this point which, if executed as recommended and in accordance with the

Construction EMP, should not affect the structure or stability of this secondary channel.

OB5 The re-designed anti-scour measures downstream of this culvert are intended to curb erosion and under-

cutting of the outlet structure and would therefore prevent destabilisation of the channel as a result of

excessive scour.

OB6 As noted above, the current culvert at this site is a major contributor to erosion and channel instability.

With improved flow capacity, and the construction of a weir to contain the head-cut upstream of the

culvert, these problems should be largely resolved. However, as with OB1 and OB3, special care must be

taken to prevent the demolished by-pass from precipitating erosion. The aquatic ecologist has also

recommended that the severely eroded channel downstream of the culvert must be stabilised with weirs

or similar structures.


water table was high, or during a period when a storm event occurred. Achieving long-term stability for particularly the

Meulrivier can only be achieved by stemming and reversing degradation in the river's intensively farmed catchment, which

lies outside the scope of this application and the decision that must be made.

(1)(c) Biodiversity aspects:

Will the development have an impact on (a) Critical Biodiversity Areas and Ecological Support Areas,

(b) Freshwater Ecosystem Priority Areas, and (c) habitat in listed threatened ecossytems?

YES

� NO



NOTE that impacts on CBAs and ESAs are defined and assessed in relation to the criteria that informed the selection

of an area or feature for inclusion in a CBA network, as well as the implications that loss of habitat would hold for

achieving the management objectives for these two types of priority conservation areas. The CBAs and ESAs at the

respective sites were selected according to the following criteria:

− Habitat required as part of CBA network OB1 and OB2

− Potential area of important of nationally listed CR or EN habitat OB1 and OB2

− Critical area for maintaining hydrological processes All sites

− Critical area for maintaining ecological processes All sites


OB1 CBAs/ESAs

Marginally

positive to

neutral

impact

The CBA map for the Overberg District Municipality states that the ESA at this site is

transformed, and the CBA is characterised as degraded. This is reflected by the

'largely modified' PES (D) of the site as described by the aquatic ecologist (Day,

2014). Currently, habitat at this site, and the maintenance of hydrological

functioning/ecological processes in support of the affected biodiversity features,

do not contribute to keeping the affected features in their desired ecological

condition. The impacts of the proposed works, and structure, on CBAs or ESAs will

therefore be negligible owing to their degraded condition. Any ecological or

biodiversity benefits arising from the new bridge would only materialise if the full

suite of mitigation measures recommended by the aquatic ecologist were to be

implemented.

FEPAs

No impact

No FEPAs are present.

Threatened

habitat

No impact

The site is mapped as falling within Western Rûens Shale Renosterveld, a CR

ecosystem. It is severely degraded and there are no evident occurrences of

renosterveld at the site.

OB2 CBAs/ESAs

Negative

impact

The site has a PES of E, or 'seriously modified'. The CBA is also described as

'degraded' by the Overberg biodiversity plan. As with site OB1, no positive changes

can be forecast with regard to improving the ecological condition, and

biodiversity value, of the site unless the current drivers of erosion and channel

instability are conclusively addressed as recommended by the aquatic ecologist.

FEPAs

No impact

No FEPAs are present.

Threatened

habitat

No impact

The site is mapped as falling within Western Rûens Shale Renosterveld, a CR

ecosystem. Riparian vegetation is in a poor condition, with high levels of alien

infestation.

OB3 CBAs/ESAs

Marginally

positive to

neutral

impact

Habitat at the site is 'degraded', according to the Overberg biodiversity plan, and

it has a PES of 'E' or 'seriously modified'. Indigenous vegetation against the steep

western bank of the Elandskloofrivier, upstream of the current pipe culvert crossing,

will not be affected by work at the site. The remainder of the site constitutes a

grassy meadow, the severely disturbed channel and banks of the watercourse, a

bulldozed berm running downstream, left of the channel, and an area of extensive

erosion behind it. The new causeway, viewed in isolation of the heavily degraded

and destabilised condition of the Elandskloofrivier, would have a positive impact

on flood conveyance and sediment transport. However, these positive attributes

would be erased by the structural intstabiity and poor condition of habitat in the

remainder of this aquatic ecosystem.



FEPAs

Neutral

Structurally, the Elandskloofrivier coincides with a channelled valley bottom

wetland that is designated as a FEPA wetland (Day, 2014). Impacts arising from the

proposed new causeway would, if assessed locally and in isolation from the

condition of the broader system, potentially contribute to the rehabilitation of the

affected river reaches towards a less degraded ecological state. However, as with

all the other watercourses that are subject to a high degree of habitat

modification and structural instability, the full benefits of improved flood and

sediment conveyance capacity would only materialise if coupled with a

concerted programme of rehabilitation at the appropriate hydrological and

ecological scales.

Threatened

habitat

No impact

South of the DR1313, this site is mapped as coinciding with the distribution range of

Central Rûens Shale Renosterveld, a CR ecosystem. Endangered Greyton Shale

Fynbos potentially occurs north of the DR1313. As indicated above in the discussion

of impacts on CBAs and ESAs, the terrain around site OB3 is degraded and reflects

'very high' levels of disturbance. This is inter alia attributed to the massively eroded

and destabilised condition of the Elandskloofrivier, orchards and grassed areas

downstream of the damaged causeway, and severe erosion into fields to the

south-east which is currently hemmed in from the channel by a bulldozed berm.

OB4 CBAs/ESAs

Neutral

The site is mapped as an ESA which must be managed in support of maintaining

hydrological and ecological processes. It has a PES of 'C' ('moderately modified').

Provided that the recommended mitigation measures are implemented at this site,

the installation of protective gabion mattresses to contain reed growth should not

affect flows along this seasonal flood channel.

FEPAs

Neutral

Whereas the installation of gabion mattresses will not contribute to improving the

ecological condition of the affected channel, they will help to prevent blockages

that contribute to erosion damage to the road embankments and, by implication,

the condition of the small flood channel.

Threatened

habitat

No impact

The vegetation here is identical to that mapped for site OB3. The landscape south

of site OB4 is also mapped as falling within the range of Central Rûens Shale

Renosterveld, a CR ecosystem. Greyton Shale Fynbos (EN) occurs on the rounded

spurs that flank the valleys between the Riviersonderend Mountains and the

Riviersonderend. There are no vestiges of intact renosterveld or fynbos within 100 m

of the site. Upstream and downstream of the DR1313, the flood channel is choked

by 'fluitjiesriet' P. australis. Weeping willows Salix sp. occur downstream of the

culvert.

OB5 CBAs/ESAs

Neutral

Site OB5 coincides with an ESA in a channelled valley bottom wetland. It has a PES

of 'C' ('moderately modified'). The banks of this watercourse are heavily infested by

alien wattle species, but the channel retains good quality in-stream habitat,

including palmiet P. serratum. The proposed scour protection, which is to be

constructed with gabions, will intrude about 8 m into the pool below the culvert

and occupy a surface area of some 120 m2. The new measures against scour will

prevent erosion downstream of the culvert while preventing the outlet structure

from being under-mined. The gabion structure will contribute to habitat loss but, by

the same measure, will also prevent habitat degradation associated with the

culvert.

FEPAs

Neutral

The proposed works will not have a significant impact on the FEPA status of this

section of the affected watercourse. As explained above, the works will contribute

to some loss of habitat, but will also prevent erosion that would otherwise lead to

habitat degradation and potential long-term instability of the river. In the

circumstances, the refurbished anti-scour protection would represent the best

practicable option from a biodiversity and socio-economic perspective.



Threatened

habitat

No impact

As with the preceding works between the Riviersonderend and the adjacent

mountains to the north, vegetation in this area is mapped as constituting Greytone

Shale Fynbos EN north of the DR1313, and CR Central Rûens Shale Renosterveld

below the road. Neither vegetation types occur in the vicinity of the site. The works

will also not intrude into relatively intact habitat around the margins of the pool

and, in the long term, will contribute to protecting this habitat against erosion

damage.

OB6 CBAs/ESAs

Potentially

positive

This 'largely' to 'seriously' modified (PES = D/E) site spans a watercourse that has

been identified as an ESA which must be managed in support of maintaining

hydrological processes. The proposed works will represent a substantial

improvement on flood and sediment conveyance, and would therefore have a

positive impact by reducing erosion. Stabilisation of the head-cut upstream of the

culvert would also stem erosion and protect the vegetated valley bottom wetland

against degradation. A by-pass would represent a temporary source of

disturbance to the bed and banks of the channel downstream of the road.

However, the channel here is actively eroding and needs to be stabilised. The

proposed addition of another box culvert would, however, reduce the impact of

flood discharge from the culvert on the downstream environment. With stabilisation

of the channel, the proposed works may, in the long term, have a net positive

effect on riparian habitat and hydrological functioning.

FEPAs

Potentially

positive

As above.

Threatened

habitat

No impact

According to the national vegetation map, this site falls within the range of

Greyton Shale Fynbos EN. The site is substantially degraded and rates 'low' in terms

of its ecological importance and sensitivity. There is some intact vegetation on the

rise directly north-east of the culvert, as well as in the wetland to the north-west of

the road. Neither of these habitats will be affected by construction.

(c)(i) Socio-economic aspects (capital costs and employment opportunities, etc):

What is the expected capital value of the activity on completion?

What is the expected yearly income or contribution to the economy that will be generated by or

as a result of the activity?

N/A

Will the activity contribute to service infrastructure? YES � NO

How many new employment opportunities will be created in the construction phase of the

activity?

What is the expected value of the employment opportunities during the construction phase?

What percentage of this will accrue to previously disadvantaged individuals?

How will this be ensured and monitored (please explain):

The appointed main contractor would implement the applicant’s standard Procurement Policy. Specific targets have

been set in the contract documentation and will be monitored by the applicant.

How many permanent new employment opportunities will be created during the operational

phase of the activity?

None

What is the expected current value of the employment opportunities during the first 10 years? N/A

What percentage of this will accrue to previously disadvantaged individuals? N/A

How will this be ensured and monitored (please explain):

N/A.

Any other information related to the manner in which the socio-economic aspects will be impacted:

None.



(c)(ii) Socio-economic impacts

Will the development have an impact on:

− Sense of place

− Human wellbeing (noise and dust)

− The integrity and safety of the road network?

YES

� NO


Impacts on 'sense of place' (potentially applies to the construction phase at all the sites).

‘Genius loci’ or the 'spirit of place is a subjective but important consideration for individuals who attach particular

meanings or values to specific places or landscapes.

It is hard to pin down as a concern of general application, but there may be individuals who take issue with factors such

as visual or aural disturbances or detraction from perceived aesthetic qualities. Sense of place is emotionally charged,

entails idealised expectations, and can provides grounds for strong reactions to environmental change.

However, the social necessity and temporary nature of the works and rehabilitation of disturbed areas should contribute

to ameliorating people’s concerns about infringements on their sense of place and impacts on 'sense of place' will

therefore not be subject to more rigorous assessment.

− Impacts on sense of place: Marginally negative to neutral

Impacts on human wellbeing (potentially applies to the construction phase at all the sites).

Dust and noise would be generated during construction.

Particular care is needed to suppress and minimise dust near homesteads and orchards that are ready for harvesting,

specifically at OB3, which is adjacent to orchards and employee accommodation, and OB6, which is within 60 m of a

farm house. Contractors must ensure that the generation of dust is minimised and controlled in terms of the prescriptions

of the Construction EMP.

Construction-related noise may be experienced as a nuisance to people living in the vicinity of the sites. However, the

sound of heavy machinery forms part of the aural 'landscape' in farming areas and would be confined to weekdays. The

impact of noise is viewed as an unavoidable but transient nuisance and will not be assessed any further. The mitigation

of noise-related impacts is addressed in the CEMP.

− Impacts on human wellbeing: Potentially negative to neutral

The integrity and safety of the road network in the Theewaterskloof Municipality

The need and desirability of the proposed repairs and replacement of the existing bridges at sites OB1 and OB3 are

addressed favourably in detail in Section D and will not be assessed further.

Road safety has two aspects: Safety to pedestrians and motorists during construction, and the long-term contribution

that the repaired or rebuilt structures will make to safe use of the affected road network.

Whereas daily vehicle usage is heaviest on the DR1313 (annual average daily traffic count = 200 vehicles), the DR1288

negotiates a small pass with relatively tight corners and impeded visibility, and traffic control measures would therefore

be advisable at all the construction sites.

The contribution of the repaired and rebuilt structures is dealt with under the discussion of need and desirability, which

underscores the public benefits of the works and therefore will not be assessed any further.

− Impacts on the Overberg rural roadwork: Positive

2. WASTE AND EMISSIONS

(a) Waste (including effluent) management

Will the activity produce waste (including rubble) during the construction phase? YES � NO

If yes, indicate the types of waste (actual type of waste, e.g. oil, and whether hazardous or not) and

estimated quantity per type?

Rubble generated by the demolition of the damaged bridge at site OB1. The estimated volume is: 70 m3



Rubble generated by the demolition of the damaged bridge at site OB3. The estimated volume is: 65 m3

Construction waste in the form of used cement bags, broken material, etc. The estimated volume is: 6 m3

Hazardous waste in the form of spilled fuel and/or oil spills collected in drip trays and contaminated soil

resulting from accidental spills. The estimated quantity is: 2 m3

Will the activity produce waste during its operational phase? YES NO �

If yes, indicate the types of waste (actual type of waste, e.g. oil, and whether hazardous or not) and

estimated quantity per type? N/A NIL m3

Where and how will the waste be treated / disposed of (describe)?

− The demolished remains of the bridge at sites OB1 and OB3 will be removed for disposal at at the nearest license

waste collection facility.

− The Contractor would be responsible for the establishment of a solid waste control and removal system. Construction

waste would be disposed of at an approved landfill site. Hazardous waste in the form of fuel/oil and contaminated soil

would also be disposed at a registered hazardous waste site (see Construction EMP in Appendix H).

Has the municipality or relevant authority confirmed that sufficient capacity exist for treating / disposing

of the waste to be generated by this activity(ies)? If yes, provide written confirmation from Municipality or

relevant authority. N/A

YES NO

Will the activity produce waste that will be treated and/or disposed of at another facility other than into a

municipal waste stream? YES NO �

If yes, has this facility confirmed that sufficient capacity exist for treating / disposing of the waste to be

generated by this activity(ies)? Provide written confirmation from the facility and provide the following

particulars of the facility: N/A

YES NO

Does the facility have an operating license? (If yes, please attach a copy of the license.) N/A YES NO

Describe the measures that will be taken to reduce, reuse or recycle waste:

During the construction phase the Contractor shall be responsible for the establishment of a solid waste control and

removal system (see Construction EMP in Appendix H). An integrated waste management approach shall be used,

based on the principles of waste minimisation, reduction, reuse and recycling of materials.

(b) Emissions into the atmosphere

Will the activity produce emissions that will be disposed of into the atmosphere? YES � NO

If yes, does it require approval in terms of relevant legislation? YES NO �

Describe the emissions in terms of type and concentration and how it will be treated/mitigated:

Dust and noise would be generated as a result of construction activities. The Contractor shall ensure that the generation

of dust is minimised and shall implement a dust control programme (e.g. wetting of areas being disturbed) to maintain a

safe working environment and minimise nuisance to road users and residents in the area. Particular care is needed to

suppress and minimise dust near homesteads and orchards that are ready for harvesting. The Contractor shall ensure that

exposed soil and material stockpiles are adequately protected against the wind (e.g. covering of material stockpiles,

etc.).

These activities would be managed in terms of the requirements of the Construction EMP (see Appendix H).

The Contractor shall also be familiar with and adhere to any regulations and by-laws regarding the generation of noise

and hours of operation. Permits shall be required if the contractor deviates from local by-laws and/or regulations of the

local authority.



3. WATER USE

Please indicate the source(s) of water for the activity by ticking the appropriate box(es)

Municipal Water board Groundwater River, Stream,

Dam or Lake Other �

The activity will not

use water

A minimal volume of water would be required for road construction activities. The appointed Contractor would be

responsible for finding suitable water sources, which may be from local farm dams. This would be discussed with the

relevant farmers, as appropriate. Extraction of water directly from the river for construction activities is not allowed.

If water is to be extracted from a groundwater source, river, stream, dam, lake or any other natural feature,

please indicate the volume that will be extracted per month: N/A m3

Please provide proof of assurance of water supply (eg. Letter of confirmation from municipality / water user associations,

yield of borehole) N/A

Does the activity require a water use permit / license from DWA? YES NO �

A copy of the Draft BAR and freshwater assessment specialist report will be submitted to the DWA for comment and to

confirm whether the proposed project would be exempted from water use licensing in terms of GN 1199 of 18 December

2009.

If yes, please submit the necessary application to Department of Water Affairs and attach proof thereof to this application.

N/A

Describe the measures that will be taken to reduce water demand, and measures to reuse or recycle water:

Only a minimal volume of water would be required for construction activities. If water is to be used for dust suppression

measures, areas should only be wetted during windy days and/or when dust may become a nuisance to surrounding

residents and farms. All water tanks and water trucks must be maintained in a good working condition to ensure that no

unnecessary water leaks occur.

4. POWER SUPPLY

Please indicate the source of power supply e.g. Municipality / Eskom / Renewable energy source

Generators would be used at the construction sites to power drills, pumps and other machinery.

If power supply is not available, where will power be sourced from?

See above.

5. ENERGY EFFICIENCY

Describe the design measures, if any, that have been taken to ensure that the activity is energy efficient:

N/A.

Describe how alternative energy sources have been taken into account or been built into the design of the activity, if any:

N/A.



6. DESCRIPTION AND ASSESSMENT OF THE SIGNIFICANCE OF IMPACTS PRIOR TO AND AFTER MITIGATION

Note:

− All impacts are systematically assessed and presented according to the ‘Convention for assigning significance

ratings to impacts’.

− The status of all impacts should be considered to be negative unless otherwise indicated.

− Only the preferred design alternative for each project component is assessed in this section. This is in line with the

outcome of the investigation of alternatives (see Section E1(h)). The ‘no go’ option is not assessed (see Section

C1(f)).

− Owing to the common objective of the proposed repairs (repair or refurbishment of flood-damaged causeways

and culvert crossings on provincial roads), the shared functional characteristics of the affected ecosystems

(seasonal/perennial foothill rivers draining sandstone and/or shale-dominated catchments in the fynbos biome),

and generally degraded condition of most sites, impacts on the biophysical environment are assessed

generically, with specific reference to site-specific issues identified by the aquatic and terrestrial ecologists during

the initial screening process.

− Most of the sites are located within CBAs and/or ESAs. Impacts on CBAs and ESAs are assessed separately to

impacts on the actual, affected ecosystem in order to distinguish between identifiable and predictable

ecological impacts, and impacts on habitat or ecosystem functioning that may compromise the integrity of the

biodiversity features that informed the selection of the affected CBAs.

− Impacts on degraded habitat in CBAs or ESAs are treated as 'neutral'. Impacts that may hold localised, site-

specific benefits with respect to improving the condition or functioning of CBAs or ESAs are treated as having

'marginal' positive significance. The biodiversity sector plan guidelines (Holdness and Bradshaw, 2010) for

development in aquatic CBAs in the Overberg District Municipality applies a ‘restricted’ status to infrastructure

development in these features, which means that development can be entertained in these situations as long as

it is demonstrably consistent with the management objectives for CBAs. The ‘restriction’ in question would appear

to apply to new development, not repairs to existing infrastructure as is the case with the projects subject to this

Basic Assessment. The impact assessment and recommendations for impact management have nonetheless

been guided by the management objectives for CBAs.

6.1 CONSTRUCTION PHASE

Construction phase impacts are likely to be of high intensity but locally confined, and readily managed through

implementation of standard impact mitigation measures, which are provided below.

Selection of issues for impact assessment on the basis of screening

Impacts arising from the construction phase of the repairs have, for the sake of ease of analysis, been separated into

several broad environmental contexts. It is important to note, however, that this is in many respects an artificial distinction

as many of these classes of impact are integrated and mutually reinforcing. For example, a biophysical impact on

biodiversity in the form of indigenous vegetation can also be experienced as an impact on human wellbeing and sense

of place.

The following construction-phase impacts have been identified for the purpose of impact assessment and evaluation:

− Impacts on the biophysical environment, i.e.,

o Hydrological aspects, i.e. flow regimes and water quality;

o Hydro-geomorphological aspects, i.e. scour, erosion and sediment movement;

o The physical structure and stability of the watercourse; and

o Biodiversity aspects, i.e. aquatic CBAs as surrogates for biodiversity pattern (in -stream and riparian habitats)

and ecosystem function (flows and sediment dynamics).

− Impacts on the socio-economic environment, i.e.,

o Sense of place

o Human wellbeing (noise and dust)

o Inconvenience to road users



No assessment has been undertaken of potential impacts relating to cultural heritage or the national estate as this did

not emerge as an area of concern during the environmental screening process.

Impacts on employment are viewed as positive, albeit of temporary duration. Besides the benefits of direct income

generated by the projects, employment also entails a measure of capacity-building and skills’ transfer that can enhance

the future employability and livelihood prospects of beneficiaries.

NOTE that where there are inconsistencies between significance ratings reported here, and in any of the appended

specialist reports, the more conservative rating is reflected in the impact evaluation tables (Sections 6.1 and 6.2).

6.1.1 POTENTIAL IMPACTS ON BIOPHYSICAL ENVIRONMENT: HYDROLOGICAL ASPECTS AT SITES OB1, OB3, OB5 AND OB6

Flow regimes

Nature of impact:

Temporary changes to stream flows as a result of diversions and coffer

structures to de-water construction areas at sites OB1, OB3, OB5 and

OB6.


Extent of impact: Local Site-specific

Duration of impact: Short term Short term

Magnitude of impact: Low to very low Very low

Probability of occurrence: Probable Possible

Degree to which the impact can be

reversed: Fully reversible Fully reversible

Cumulative impact Low Minimal

Significance rating LOW to VERY LOW (-) VERY LOW (-)

Additional remarks

There may be some disruption of flows down the watercourses in question during the establishment of temporary

diversions or coffer structures to route water around the construction sites. 'Local' impacts may arise during the initial

establishment of diversionary structures (such as sandbagged coffers) and flows (depending on water levels) are

temporarily prevented from reaching the Riviersonderend or, in the case of the Bot River sites, the visible effects of flow

modification exceed the length of the nearest downstream reaches. These will be short-lived interruptions, not lasting

more than 48 hours in any instance. Flows may be interrupted intermittently during construction which may in toto

extend to six months at sites OB1, OB3 and OB6, i.e. where the most substantial works are to take place. Construction is

expected to be concluded more rapidly at sites OB2 and OB4. The aim of mitigation would be to maintain natural flow

regimes during the full period of construction. The risk that flows would be significantly impacted at site OB4 is viewed as

marginal owing to the seasonal character and small size of this channel. Overall, the drier the watercourse at the time of

construction, the less impact there will be on flows.

Mitigation measures

− Construction activities within watercourses must not take place during the wet season (i.e. any activities

requiring the diversion of flows must take place between October and April only), and construction schedules

should be managed within these time frames


sediment in temporary sediment ponds or other devices, managed so as to prevent the passage of sediment-

rich water into the watercourse





6.1.2 POTENTIAL IMPACTS ON BIOPHYSICAL ENVIRONMENT: HYDROLOGICAL ASPECTS AT ALL SITES

Water quality (turbidity)

Nature of impact:

− Release of sediments into watercourses may result in episodes of

increased turbidity, particularly when excavations take place to

establish foundation structures. This impact applies to all sites, but is

expected to be most significant at OB1, OB3 and OB6 owing to the

extent and duration of works arising from the construction of the

new bridge and an additional culvert and temporary by-pass in the

case of site OB6.


Extent of impact: Local (OB1, OB3 and OB6) to site-

specific (other sites) Site-specific


Magnitude of impact: Low (OB1, OB3 and OB6) to very

low (other sites) Very low





Significance rating LOW (OB1, OB3 & OB6) to VERY

LOW (-) VERY LOW (-)

Additional remarks

None.

Mitigation

− Construction activities within watercourses must not take place during the wet season, i.e. between May and

September.


sediment in temporary sediment ponds or other devices, managed so as to prevent the passage of sediment-rich

water into the watercourse;



6.1.2 POTENTIAL IMPACTS ON BIOPHYSICAL ENVIRONMENT: HYDROLOGICAL ASPECTS AT ALL SITES

Water quality (contamination by construction materials)

Nature of impact:

− De-watered material, cement and diesel may contaminate water

resources.

− Site OB5 is particularly vulnerable to excessive sediment inputs and

contamination owing to the extent and quality of habitat fringing

the pool below the culvert.


Extent of impact: Local (OB5) to site-specific (other

sites) Site-specific


Magnitude of impact: High (OB5) to very low (other sites) Very low

Probability of occurrence: Possible Possible






Significance rating MEDIUM (OB5) to VERY LOW (-) VERY LOW (-)

Additional remarks

None

Mitigation


September.


washed into watercourses during storm events. Contamination of water resources can be avoided, or where

unavoidable, mitigated by:

o Storing and containing all materials on the construction sites at least 40 m from the nearest water resource.

o Protecting cement and other water-soluble substances against rainfall and wind.

o If there is any risk that concrete or contaminated water may enter a watercourse, concrete batching must

take place at least 40 m from the edge of channel in a secure, bunded area (e.g. wooden boards placed

over heavy plastic sheeting within a bund of sandbags)

o Inspecting sites daily for litter and remove all rubble and waste material from the river channels and riparian

zones after construction is completed.

o Taking precautions to prevent soil and chemical materials, including waste cement and concrete, from being

released into downstream drainage areas.

o Refueling vehicles at least 100 m away from rivers, in securely bunded areas, preferably at sites already uses

for refueling by farmers

o Only using existing access roads to undertake the proposed activities

o Maintaining all construction machinery and vehicles in good working order.

o Provide and regularly service ablution facilities for construction staff on site; toilets must be located at least 30

m from watercourses.

6.1.3 POTENTIAL IMPACTS ON BIOPHYSICAL ENVIRONMENT: HYDRO-GEOMORPHOLOGICAL ASPECTS AT ALL SITES

Scour, erosion and sediment movement

Nature of impact:

− Construction-related disturbance (excavations, trampling, removal

of reeds, etc) may contribute to erosion of the beds and banks of

the affected watercourse.

− Restriction of flows as a result of diversions or coffer outlets may also

contribute to scouring and erosion.


Extent of impact: Local (OB1, OB3 & OB6) to site-



Magnitude of impact: Low (OB1, OB3 & OB6) to very low

(other sites) Very low







Additional remarks

Mitigation




September.




− All areas outside of this zone should, within reason, be regarded as no-go areas during construction, with the

exception of personnel engaged in required alien clearing and bank rehabilitation activities outside of

construction disturbance zones.



− Ensure that the impact of pumped water that is discharged under pressure is dissipated by placing pipe outlets in

rocky parts of the stream bed that are not susceptible to scour.

− Limiting activities and vehicle movement to disturbed sections of river channels.

− Limit the removal of reeds and other riparian vegetation in the channel and along river banks.

− Apply all the mitigatory measures relating to the prevent and mitigation of impacts on water quality.

6.1.4 POTENTIAL IMPACTS ON BIOPHYSICAL ENVIRONMENT: CHANGES TO THE PHYSICAL STRUCTURE AND STABILITY OF

WATERCOURSES

Cumulative effects of interaction between modified flows, physical disturbance and erosion

Nature of impact:

− The destabilisation of river channels is closely related to constricted

or diverted flows, physical disturbances to the bed and banks of

watercourses, scour and the ensuing transport and deposition of

sediment that may precipitate further iterative changes to patterns

of flow and erosion that undermine channel stability.

− Whereas measures can be adopted to minimise these impacts from

developing at a site-specific or local extent, the drivers of river

destabilisation must be addressed at source which means doing so

at the appropriate hydro-geomorphological and ecological scales.

− The cumulative impacts of the respective projects would be

negligible relative to the wholesale destabilisation and degradation

of the affected watercourses as a result of catchment hardening,

agricultural encroachment into floodplains, physical manipulation

of watercourses and flood processes by bulldozing, and infestation

of riparian areas by invasive alien plants.


Extent of impact: Local (OB1, OB3 & OB6) to site-



Magnitude of impact: Low (OB1, OB3 and OB6) to very

low (other sites) Very low







Additional remarks

Channel destabilisation and ensuing loss of functional resilience and riparian habitat are 'driven' and occur at physical

and geographical scales that exceed the scope of activity- and project-specific impact assessment. If effectively

mitigated (as set out above), the impacts of the respective projects on the watercourses in question can be limited to

acceptably low levels of significance. However, as previously emphasised, any environmental benefits that may be

associated with the implementation of the proposed repairs will be neutralised by the degraded and destabilised



condition of the affected ecosystems. NOTE that without 'high level' mitigation, the respective structures will have a

considerably greater impact on the affected watercourses than is predicted above.

Mitigation measures

Measures aimed at modifying agricultural land-uses that contribute to the degradation and destabilisation of aquatic

ecosystems are set out in Section G.

6.1.5 POTENTIAL IMPACTS ON BIOPHYSICAL ASPECTS: CRITICAL BIODIVERSITY AREAS

Nature of impact:

− The most severe impacts would result from loss of habitat or species

that are either irreplaceable, essential for the achievement of

biodiversity targets, or threatened. There is no evidence, however,

that any of the sites support threatened vegetation, i.e. Western

and Central Rûens Renosterved CR or Greyton Shale Fynbos EN. It is

concluded construction will not have any impacts on biodiversity

pattern that has been identified as having regional or national

conservation importance.

− Given the highly degraded condition of the immediate surrounds of

all the sites, there is little likelihood that construction-related

activities would adversely affect the functioning of ecological

corridors or any spatial surrogates of ecological processes that may

have a role in maintaining threatened ecosystems.

− Construction-related impacts may, however, temporarily affect

hydrological processes (chiefly the availability and quality of water,

and seasonal flows) maintain aquatic biodiversity and, at a regional

scale, contribute to the maintenance of biodiversity pattern and

process in the Riviersonderend.

− In conclusion, the chances that the proposed works – provided that

the stipulated mitigation measures are implemented – will

precipitate impacts that compromise the integrity of CBAs is viewed

as exceedingly remote.

− However, without addressing ecological degradation and the

instability of the affected watercourses at an effective functional

scale, site-specific mitigation will have little impact on contributing

the recovering of the affected watercourses. Impacts in the latter

regard must be viewed as of HIGH negative significance.



Duration of impact: Long term Short term

Magnitude of impact: Medium Low

Probability of occurrence: Highly probable Probable


reversed: Potentially irreversible

Partially reversible, but best

avoided.

Degree to which the impact may cause

irreplaceable loss of resources: Medium Low to medium

Cumulative impact Potentially significant if long-term

integrity of CBAs is compromised Minimal

Significance rating MEDIUM (-) VERY LOW (-)

Additional remarks

See Appendix D2 for a summary of the Critical Biodiversity Areas that apply to the respective sites, and Sections B(5)(a)

and F(1)(b) for an explanation of CBAs and their implications for project planning and impact assessment.



Impacts on the values that informed the selection of river reaches, wetlands or terrestrial habitats as CBAs and ESAs

would be a direct consequence of interactions between modified flows, physical disturbance and erosion and the

effect that this may have on in-stream and riparian habitat.

The prospects for complete ecological restoration of eroded and degraded watercourses and riparian areas are

viewed as slim but, as indicated previously, rehabilitation can aim to prevent further degradation and initiate – at least

at site level – beneficial ecological functions such as localised soil and bank stabilisation.

However, actions to prevent further degradation of aquatic and terrestrial CBAs, and to initiate their restoration to a

natural or at least near-natural state, will have to be undertaken at a far broader scale. This is beyond the scope of this

application.

Mitigation measures

Adverse impacts that may compromise the integrity of CBAs and ESAs, or where unavoidable, can be mitigated by

implementing all the mitigation measures pertaining to:

− Hydrological aspects, i.e. flow regimes and water quality;

− Hydro-geomorphological aspects, i.e. scour, erosion and sediment movement;

− The physical structure and stability of the watercourse

Adverse impacts on terrestrial habitats within CBAs and ESAs can be avoided, or where unavoidable, mitigated by:

− Implementing, insofar as these are relevant, all the mitigation measures pertaining to erosion and

sedimentation and aquatic ecosystems.


− Where possible – and definitely at Site OB5 -- actively aiming to reduce as far as practicable the removal of

existing natural vegetation in the channel and riparian zone.

− Retaining topsoil to a depth of 150 mm and stockpiling locally for revegetation.

− Grading banks to a slope of at least 1:4, but preferably flatter, between the repaired structures and the


− Grading slopes downwards, towards the watercourses.

− Revegetating disturbed areas directly upstream and downstream of each structure with indigenous, locally-

occurring pioneer species at level of base flow.


− Fast-growing pioneer plant species, and other plants that would facilitate post-construction rehabilitation (such

as xxx), should be collected beforehand, bagged and kept in good condition for replanting.

− Plant lists must be approved by CapeNature.

Degradation and loss of aquatic habitats within CBAs and ESAs can be avoided, or where unavoidable, mitigated by:

− Implementing all the mitigation measures relating to flows, erosion and sedimentation;

− Fill sourced for construction must be free of alien seed.

− The removal of invasive species such as black wattle Acacia mearnsii and beefwood Casuarina sp as they

contribute to channel restriction, down-cutting and erosion, and displace indigenous biodiversity.


6.1.9 POTENTIAL IMPACTS ON SOCIO-CULTURAL ENVIRONMENT: SENSE OF PLACE

Nature of impact:

Construction activities in relatively remote and scenically attractive

landscapes may detract from some individuals’ expectations regarding

‘sense of place’ and ‘naturalness’. This is taken to include potential

visual impacts, and impacts on valued heritage landscapes.




Extent of impact: Local Local


Magnitude of impact: Medium Low

Probability of occurrence: Probable Probable


reversed: Entirely Entirely


irreplaceable loss of resources: Low Low

Cumulative impact Negligible Negligible

Significance rating MEDIUM (-) VERY LOW (-)

Additional remarks

‘Genius loci’ or the sense of place is potentially a highly subjective but important consideration for individuals who

attach particular meanings or values to specific places or landscapes. It is hard to pin down as a concern of general

application, but there may be individuals who take issue with factors such as visual or aural disturbances or detraction

from perceived aesthetic qualities. Sense of place is emotionally charged, entails idealised expectations, and can

provides grounds for strong reactions to environmental change. The social necessity and temporary nature of the works

and rehabilitation of disturbed areas should, however, contribute to ameliorating people’s concerns about infringements

on their sense of place.

Mitigation measures

Adverse impacts that may compromise individuals’ sense of place can be avoided, or where unavoidable, potentially

mitigated by implementing all foregoing mitigation measures.

6.1.7 POTENTIAL IMPACTS ON THE SOCIAL ENVIRONMENT AND WELLBEING: NOISE

Nature of impact: Construction activities (e.g. construction vehicles, etc.) would increase

noise levels, which could be a nuisance for local residents.


Extent of impact: Local (OB3 & OB6) to site-specific Site-specific


Magnitude of impact: Medium (OB3 & OB6) to low Very low

Probability of occurrence: Highly probable Highly probable






Significance rating MEDIUM (OB3 & OB6) to

VERY LOW (-) VERY LOW (-)

Additional remarks

Noise is unlikely to be of concern at most of the sites which are located in relatively remote rural areas. Construction-

related noises could be experienced as more of a nuisance closer to farm houses and other habitation. However, if work

is limited to week days and daylight hours, this would probably not be cause for much concern, especially given that

these are primarily agricultural areas where heavy machinery (tractors, trucks and excavators) constitutes a familiar

feature of the socio-economic landscape.



Mitigation measures

Adverse impacts relating to noise can be avoided or, where unavoidable, mitigated by;

− Ensuring construction machinery is in good working order.

− Limiting construction to the hours of daylight.

− Limiting construction to weekdays.

6.1.8 POTENTIAL IMPACTS ON THE SOCIAL ENVIRONMENT AND WELLBEING: DUST

Nature of impact: Construction activities (e.g. construction vehicles, etc.) would increase

noise levels, which could be a nuisance for local residents.


Extent of impact: Local (OB3 & OB6) to site-specific Site-specific


Magnitude of impact: Medium (OB3 & OB6) to low Zero to very low

Probability of occurrence: Probable Improbable






Significance rating MEDIUM (OB3 & OB6) (-) to

VERY LOW (-) VERY LOW (-) to INSIGNIFICANT

Additional remarks

If dust suppression measures are applied (reducing vehicle speeds close to inhabited areas and crops, covering and

and sprinkling stockpiles and recently disturbed spoil), dust is unlikely to feature as an issue of concern. Specific attention

needs to be paid to suppressing the generation of dust near sensitive crops such as grapes and fruit.

Mitigation measures

Adverse impacts relating to dust can be avoided, or where unavoidable, mitigated by:

− Reducing vehicle speeds close to inhabited areas and fruit-bearing vineyards and orchards (i.e. from

November onwards, depending on the crop) – a limit of 40 km/hr is recommended for roads near homes or

settlements, and 20 km/hr adjacent to orchards or vineyards during the harvest season;

− Covering stockpiled sand and soil (especially during the dry, windy summer months); and


6.1.6 POTENTIAL IMPACTS ON SOCIO-ECONOMIC ASPECTS: INCONVENIENCE TO ROAD USERS

Nature of impact: During construction there may be delays or detours in order to route

traffic through the various sites.


Extent of impact: Local Local


Magnitude of impact: Low Low



Probability of occurrence: Highly probable Highly probable






Significance rating LOW (-) LOW (-)

Additional remarks

Temporary inconvience to road users who may be held up or required to undertake short detours around construction

sites is of little environmental consequence and would probably be viewed as a tolerable and unavoidable nuisance by

the affected public, especially given the future benefits of improved crossings.

Mitigation measures

Adverse impacts that may inconvience road resures can be mitigated by:

− Providing sufficient signage to warn motorists of the presence of construction works and detours.

− Executing individual projects as speedily and expeditiously as possible.

6.2 OPERATIONAL PHASE

Impacts that may result from the operational phase (briefly describe and compare the potential impacts (as

appropriate), significance rating of impacts, proposed mitigation and significance rating of impacts after mitigation that

are likely to occur as a result of the operational phase.

The supposition is that none of the construction-phase impacts (which, by their nature, are temporary) would persist

beyond the duration of work at the respective sites, and consequently not assessed any further.

However, three distinct sets of residual impacts that may extend into the operational phase of the respective projects

have been identified, namely:

− Impacts arising from increased hydraulic capacity, from a site to local scale (i.e. within 100 m the structures or,

alternatively, extending as far as the Riviersonderend);

− Impacts on aquatic ecosystems arising from erosion and sedimentation precipitated the structures (scale of

impacts above); and

− Impacts on road safety.

Potential residual impacts on environmental flows, erosion and sedimentation, and the effects that this potentially holds

for aquatic habitats, biota and ecological processes are closely inter-related. Erosion can contribute to turbidity, which is

both a water quality as well as an ecological concern. They are separated for the sake of ‘unpacking’ the different

types of impacts that may result from the operational lifespan of the repaired structures. In effect, however, they are

integrated and potentially mutually reinforcing.

Added to this is the over-riding problem, which has been repeatedly referred to above, of not being able to decouple

the generally localised impacts (both positive and negative) of the repaired or rebuilt structures, from the question of

broader ecosystem degradation and instability, and the implications that the latter holds for the operational phase

impacts of the respective completed works. Failure to contextualise the potential impacts of the respective projects with

reference to the condition and stability of the river systems in their totality would amount to a significant and



unacceptable 'blind spot' in this environmental assessment, and the decision that it is intended to inform. This problem is

dealt with in Section 7 below.

6.2.1 POTENTIAL POST-CONSTRUCTION IMPACTS ON BIOPHYSICAL ASPECTS: INCREASED HYDRAULIC CAPACITY

Nature of impact:

Three of the structures – at OB1, OB3 and OB6 – are to have

considerably improved hydraulic capacity over that of their

predecessors. This is predicted to substantially curtail flow concentration

downstream of these structures. Sediment movement will also be vastly

improved. Advantages include:

− Preventing sediment build-up upstream of the causeway;

− Minimising the risk of scouring and erosion downstream (thereby

preventing and mitigating impacts on aquatic habitats and

biodiversity);

− Contributing to the recovery of the longitudinal slope profile of the

affected watercourses; and

− Protecting the approaches against erosion damage.

− The benefits of the enlarged culverts will be, however, reduced if

the channels upstream of the causeways, and the culverts

themselves, are not kept clear of accumulated sediment and

debris. Mitigation refers to such maintenance.

NOTE The provision of additional hydraulic capacity is treated as a

POSITIVE impact. Mitigation equates to increased hydraulic capacity.


Extent of impact: Local Long tem

Duration of impact: Long term Long term

Magnitude of impact: Medium (-) Low (+)




Partially reversible (assuming some

flow restriction)


irreplaceable loss of resources: Medium to high Very low

Cumulative impact

Potentially significant if restriction

and concentration of flows is

allowed to persist because of

blockages.

Significantly limited if restriction

and concentration of flows is

avoided or at least minimised by

effective maintenance.

Significance rating MEDIUM (-) LOW (+)

Additional remarks

The risk of environmental degradation at sites OB1, OB3 and OB6 is proportional to the degree in which the new,

enlarged culverts either exacerbate or reduce the impact of altered flow regimes on the aquatic environment and

habitats. In general, increased flow capacity is therefore considered to be positive as it would prevent or significantly

slow down the rate of erosion that contributes to degradation of the aquatic environment. The approaches to the

crossings will also be less vulnerable to flood damage and there would less risk to lateral erosion downstream of the

structures as high flows would be conveyed through the crossing, rather than around them.

However, environmental benefits may be compromised by floods that exceed the specified conveyance capacity of

the new or refurbished structures. The bridge at OB1 has been designed to accommodate floods of up to the 1:10-year

return period without over-topping. The structures at OB3 and OB6 are designed to accommodate 1:2-year floods

without over-topping. In both cases, substantially enlarged openings will reduce the build-up of debris during floods.

Mitigation measures



Mitigation in this instance is defined by the addition of substantially improved hydraulic capacity to the crossings at OB1,

OB3 and OB6.

6.2.2 POTENTIAL IMPACTS ON BIOPHYSICAL ASPECTS: EROSION AND SEDIMENTATION

Nature of impact:

Adverse changes to environmental flows and/or erosion and

sedimentation (these impacts are linked to insufficient hydraulic

capacity that may also translate into impaired sediment transport

through the structure). If culverts and the adjacent channel are cleared

of sediments, the impact would be positive.


Extent of impact: Regional Local

Duration of impact: Medium to long term Short term

Magnitude of impact: Low to medium Low



reversed: Potentially irreversible Partially to fully avoidable

Cumulative impact

Potentially significant if long-term

integrity of Riversonderend is

compromised as a result of

erosion, sedimentation and

habitat loss

Minimal

Significance rating LOW to HIGH (-) VERY LOW (+)

Additional remarks

Potential long-term impacts associated with changes to flow restriction, erosion and the impacts that this may have on

the integrity of in-stream habitats and ecological functioning constitute the single most important area of concern

relating to the operation of the repaired and refurbished causeways.

These issues, insofar as they pose demonstrable risks to the wellbeing of the affected environment, have been addressed

‘up front’ in the design phase of the projects as degradation resulting from erosion, once it has occurred, is effectively

impossible to repair. In the case of the crossings at OB1, OB3 and OB6, the increased flood conveyance capacity of the

structures plus wing walls and scour protection will help to reduce the contribution of these structures to erosion.

The other structures are to be equipped with concrete road slabs and side protection (OB2), gabion aprons (OB4) and

improve downstream scour protection (OB5). All of these works are designed to protect the structures and immediate

aquatic environments against erosion. The aquatic ecologist (Day, 2014) has found the structural hydraulic

arrangements at OB2 to be inadequate, and has recommended that the road crossing at this site be reviewed in its

entirety.

Mitigation measures

Adverse impacts arising from erosion and sedimentation can be avoided, or where not avoidable, mitigated by:

− Keeping watercourses upstream and downstream of the structures (at least as far as the edge of the road

reserve) clear of flood debris (particularly ‘spoelklippe’, branches and uprooted bushes and trees) to prevent

premature over-topping and back-flooding in floods ≤1:5-year return period.



− Where excavations have taken place in watercourses, ensure that potential nick-points and benches in the

channel are removed so as to prevent head-cut erosion from developing upstream of these locations.

− Removing alien plants at least as far as the boundary of the road reserve, and re-planting disturbed areas with

locally-occurring indigenous pioneer plant species.



− Monitoring the first reach/first 150 m of the watercourse downstream for signs of new erosion.

− Monitoring changes to sediment patterns (deposition and erosion) up- and downstream of repaired structures

to assess recovery and reinstatement of the general slope of the watercourse.


gravel approaches that may be washed away as a result of floods; and

− Obtaining agreement with the Western Cape Department of Agriculture on how to best to manage the farm-

channel interface up- and downstream of the repaired structures on privately-owned land.


potential.

6.2.3 POTENTIAL IMPACTS ON BIOPHYSICAL ASPECTS: ECOSYSTEM FUNCTIONING AND HABITAT IN AQUATIC CBAs

Nature of impact:

Adverse, long-term changes arising from altered environmental flow

regimes, erosion and sedimentation can translate into loss of in-stream

habitats, reduced habitat and community diversity, local loss of species,

and impeded ecological processes. Impacts of 'HIGH ' magnitude are

predicted if CBAs in the Riviersonderend were to be adversely

impacted.


Extent of impact: Local to regional Local

Duration of impact: Medium to long term Short term

Magnitude of impact: High Low




Avoidance most desirable from of

mitigation


irreplaceable loss of resources: Medium to high Low

Cumulative impact Potentially significant if long-term

integrity of CBAs is compromised Minimal

Significance rating MEDIUM to HIGH (-) VERY LOW (-)

Additional remarks

See above.

Mitigation measures

In the long-term, degradation of CBAs and FEPAs can only effectively be addressed through rehabilitation of

watercourses, floodplains and wetlands an ecosystem or catchment scale.

6.2.4 POTENTIAL IMPACTS ON BIOPHYSICAL ASPECTS: ECOSYSTEM FUNCTIONING AND HABITAT IN TERRESTRIAL CBAs

Nature of impact:

Construction-related impacts (i.e. direct disturbance and degradation)

on terrestrial vegetation and habitats designed as CBAs will probably

extend into the operational phase and therefore need a measure of

management attention. Full restoration of disturbed sites is unlikely but

rehabilitation with locally occurring indigenous plants and limited

landscaping that focuses on the reinstatement of basic environmental

regulatory functions is feasible and desirable, e.g. bank stabilisation, soil

retention, and initiation of successional processes. Former construction

sites must be kept clear of aliens.





Duration of impact: Medium to long term Medium to long term

Magnitude of impact: Very low to low (-) Very low to low (+)

Probability of occurrence: Highly probable Probable


reversed: Potentially irreversible Partially reversible

Cumulative impact Insignificant at a local scale but

significant if assessed at the scale of the farming-river interface

Significance rating VERY LOW to LOW (-) VERY LOW to LOW (+)

Additional remarks

Complete restoration of the disturbed sites is unlikely and probably an unrealistic goal given the highly degraded and

even transformed condition of most of the affected sites. Post-construction rehabilitation should aim to re-establish basic

environmental regulatory functions such as bank stabilisation, soil retention and conditions that are suitable for initiating

vegetation succession. Active management of alien plants is essential.

Mitigation measures

Adverse impacts on terrestrial vegetation and habitats can be avoided, or where not avoidable, mitigated by

implementing all the above-mentioned mitigation measures. Pay specific attention to alien clearance and curtailing

erosion that may result from damage to gravel approaches during floods.

6.2.5 POTENTIAL IMPACTS ON SOCIO-ECONOMIC ASPECTS: ROAD SAFETY

Nature of impact:

The causeways and culvert crossings in question serve traffic that uses a

network of gravelled roads in the broad vicinity of Bot River,

Helderstroom, Genadendal and Greyton. Left unrepaired, these

structures are bound to deteriorate and they would potentially

represent an increasingly dangerous hazard to road users. The safety of

these structures is among others compromised by wash-aways, road

verge that cave in and general deterioration of the structures with use,

over time. One of the chief objectives of the repairs is to eliminate these

types of hazards. Securing an alternative route to the Helderstroom

Maximum Security Prison during floods is of major regional importance

and must be achieved as rapidly as possible. NOTE Improved road

safety is treated as a POSITIVE impact. Mitigation equates to such

improvement.


Extent of impact: Regional Regional

Duration of impact: Medium to long term Long-term

Magnitude of impact: High (-) High (+)



reversed: Potentially irreversible Partially to fully avoidable

Cumulative impact

Difficult to predict or quantify, but

any increase in traffic accidents

must be viewed as significant from

a cumulative perspective.

Overall positive.

Significance rating MEDIUM to HIGH (-) HIGH (+)

Additional remarks



Providing a safe and efficient integrated transport system is a key priority of the Western Cape Government: DTPW,

which aims to reduce road fatalities by 50% by the end of 2014.

Mitigation measures

Repairing the damaged drifts and causeways to a sufficiently high standard of road safety constitutes a highly significant

mitigation measure and motivation for the projects to go ahead as planned.

7. SPECIALIST INPUTS/STUDIES AND RECOMMENDATIONS

Specialist inputs/studies and recommendations:

(a) Specialist inputs/studies and recommendations:

Dr Liz Day of the Freshwater Consulting Group conducted the specialist aquatic ecological assessment (Day, 2014).

In broad, this entailed:

− Describing the condition of aquatic ecosystems in the vicinity of the respective sites, and the impacts of the

existing structures on the aquatic environment;

− Describing the affected freshwater ecosystems in terms of: distinctive environmental factors such as location,

topography, climate and vegetation (i.e. 'ecoregions'); wetland and river types; biodiversity conservation

priorities (Freshwater Ecosystem Priority Areas); the present ecological states of the respective sites; and their

ecological importance and sensitivity;

− Assessing the environmental impacts of the existing structures and the proposed works respectively, proposing

mitigation measures, and providing an overall ecological assessment and recommendation with respect to the

different works;

− Reporting on the implications of the proposed works for overall river PES;

− Making recommendations on construction-phase mitigation; and

− Assessing the proposed mitigation and management measures for consistency with the conditions specified by

the General Authorisation pertaining to sections 21(c) and (i) of the National Water Act 36 of 1998 (GN1199, 12

December 2009).

Dr Day's report is appended as Appendix G. She undertook the site visit 3 February 2014, under dry, late summer

conditions. Her findings are presented with respect to:

− Construction-related impacts, their significance and mitigation; and

− The overall effectiveness of site-specific mitigation if the degradation and destabilisation of the affected rivers is

not addressed at source, at the appropriate spatial and functional scales.

Please note that in some instances (specifically with regard to the works at sites OB4, OB5 and OB6), Dr Day revised her

initial findings on the potential significance of the long-term, operational phase impacts of the latter projects following

the implementation of some of the key mitigation measures that she had recommended in her report, dated March

2014. These revised specialist findings are recorded below.

(b) Revised specialist findings following recommended amendments to project plans

As previously indicated, the findings and recommendations of Dr Day's aquatic assessment were subsequently taken up

with the consulting engineers, Bergstan South Africa (Pty) Ltd, and Mr Harry Viljoen, of the Department of Transport and

Public Works.

It was on the basis of the latter discussions, held in Cape Town on 25 April, 2014, that the Department of Transport and

Public Works agreed – in response to some of Dr Day's recommendations – to implement a number of changes to the

plans that would contribute to further mitigating potential adverse impacts associated with, specifically, the structures at

sites OB4, OB5 and OB6. These amendments are further elucidated below, as are Dr Day's revised findings on the



potential contribution that the respective changes to the project plans would make towards mitigating adverse impacts

on the aquatic environment.

Dr Day has confirmed that the summary of her feedback on the revised plans to the project EAP accurately represents

her revised conclusions about the potential impacts of the proposed works at sites OB4, OB5 and OB6 (Appendix G1).

(c) Specialist assessment of construction-related impacts, and impact mitigation

See pages 15 of 26 of the specialist aquatic assessment (Day, 2014) for an illustrated assessment and explanation of the

current ecological condition of each site.

The findings of the specialist aquatic assessment with regard to the works at each of the six sites are summarised below.

Changes to the plans that were initiated in response to Dr Day's concerns are also recorded, plus her revised assessment

of the potential impacts that could arise from implementation of the adopted changes.

OB1: BOTRIVIER, DR1288

(Construction of a new bridge)

Positive aspects of the new structure w.r.t. flood and sediment conveyance

• A single, wider culvert (12 m wide x 4.5 m high) and slightly longer span

of the structure are proposed for this site. This would be more

appropriate to the disturbed river upstream, with its high sediment and

woody debris load, than the present system, which is to be

demolished. The new structure may therefore reduce the frequency of

significant flood disturbance, such that recovery between flood events

is likely.

• Real recovery and improved ecological function is however only likely

if invasion by woody alien plants is addressed both up- and

downstream of the crossing, and as long as alien trees dominate the

river banks, flood damage as a result of blockages to flow by debris

dams is likely to be a feature of the system.

• The new structure should improve ecologically connectivity, by passing

low flows through the wide culverts, rather than through narrow pipes,

as per the previous structure.

Construction phase impacts

Construction phase impacts are likely to be of high intensity but locally

confined, and readily managed through implementation of standard

impact mitigation measures. Impacts are likely to include:

• Increased downstream sediment and turbidity from bank and bed

disturbance (the river is however already prone to these effects as a

result of high erosion)

• Increased risk of erosion as a result of alien clearing

• Contamination of the river as a result of receipt of construction-

associated materials

• Trampling and disturbance to the (already disturbed) river bed and

banks in the vicinity of the existing and new structures.

• These impacts would all be exacerbated if construction took place

during the wet season or during a period when a storm event

occurred.

Mitigation requirements: Construction

• A Construction Phase Environmental Management Programme

Overall ecological assessment and

recommendations

• Assuming full implementation of

the mitigation measures outlined

above, the proposed change in

structural design and its

implementation is considered

likely to be a positive impact

from a freshwater ecosystems

perspective.

• However, if the requirements for

the long-term stabilisation and

management of an alien-free

river corridor immediately up-

and downstream of the

structure, and the requirement to

address concerns around

existing erosion of the river bank

upstream of the new crossing

and at the minor tributary, are

not implemented, rates of flood-

associated disturbance are still

expected to be high.

• In the event of the latter

scenario, in terms of which the

recommended mitigation

measures are not implemented,

no net positive impacts would be

expected as the existing –

destabilised – system would be

actively maintained by floods.

Without the recommendation

measures being implemented,

the impacts would therefore be

negative.

• NB The applicant has undertaken

to investigate the potential risks

associated with the eroding river

bank upstream of the structure.

If, however, this area of instability



(CEMP) must be implemented during construction (see Section H

below).

• The existing road should be ripped, all artificial debris removed, and

the river bank and riparian zone thus created should be shaped to

resemble a natural system, in a band at least 15m wide on either side

of the river – a river ecologist should oversee / sign off on this aspect of

mitigation.

• The small tributary should be addressed as part of this process, and re-

shaped as a broad open channel, planted in destabilised areas to

prevent erosion.

Residual negative aspects that need to be addressed

• Failure to address the present constricted alignment of the small

stream that enters the river on its left bank downstream of the existing

structure means that this system will probably play a long-term role in

disturbance of the downstream channel and banks. The small stream

has been directly impacted by the existing road alignment.

• Medium to long-term likelihood of structural failure, as a result of

erosion and bank collapse at the bend some 20 m upstream of the

proposed structure. If this erosion (triggered by constriction of alien

trees along the channel, and blockage of flows in the channel by

fallen trees) is left unchecked, it is likely to result in significant widening

of the channel over time, and potential bypassing of the bridge

structure on the left hand bank.

Mitigation requirements: Residual degradation

• The eroding bank upstream of the bend must be addressed, through

removal of alien vegetation reshaping of the bank and replanting;

hard stabilisation techniques (e.g. bank lining with gabions) should not

be used, although it is understood that gabions will be used

immediately up- and possibly downstream of the new structures.

is outside the road reserve, the

DTPW will not be able to readily

take any steps to secure this part

of the river bank against further

erosion and instability.

• The decommissioned bridge will

be demolished and all debris will

be removed. Demolition of the

latter structure, plus alien

clearance, would free up more

space – thereby promoting

improved stability – for the small

tributary to which Dr Day refers.

OB2: CONFLUENCE OF BOTRIVIER AND MINOR SEASONAL WATERCOURSE AT DORINGKLOOF, DR1288

(Installation of concrete road slabs and side slope protection)

Structural inadequacies of current culvert

• The proposed construction measures do not attempt to address the

problem of the small tributary that presently is diverted along the

edge of the concrete structure, increasing flood pressure and erosion

damage on the right hand side of the Bot River channel, and

contributing to the high levels of erosion damage observed in the

river downstream of the structure.

• These impacts will thus be perpetuated by repairs to the new

structure.

Need to re-assess culvert/crossing design

• The design for this structure must include an additional or extended

culvert or other ecologically cognisant measure that allows for the

free flow of the minor stream through the structure, without being

diverted along the road edge.

• The mechanism for this would need to address the fact that the

stream appears to enter the system at a higher level than the existing

culvert.

Pre-construction ecological remediation


recommendations

• Amendment of the proposed

design to address the issue of

diversion of flows from the small

tributary into the Bot River is

considered essential mitigation.

• Assuming that this and the other


measures are implemented at this

site, the proposed activities would

be considered to have a net

positive ecological impact.

• In the absence of this aspect

being addressed, it is likely that

erosion and disturbance will

remain significant sources of

disturbance to the river, i.e. have a

negative impact.

• Further expenditure on

perpetuating these conditions is



To address the significant ecological damage caused by the combined

impacts of the present road structure, inadequate control of alien

invasion and poor clearing practices, the following aspects must be

addressed at this site, prior to the start of construction:

• All invasive woody alien vegetation and the seedlings of such

species should be cleared from a zone extending at least 30 m

upstream and 30 m downstream of the present crossing point, as well

as 30 m upstream along the inflowing minor stream, in a swathe at

least 15 m wide on either side of the river channel, or less if alien

invasion is within a narrower zone;

• Species-appropriate alien clearing methods should be employed –

Working for Water guidelines should be used in this regard;

• Cleared areas should be stabilised by a combination (as

appropriate) of bank shaping and planting with locally indigenous

plant species

• Local landowners should be required to participate in long-term alien

maintenance clearing activities.


• The same construction phase impacts as outlined for OB1 would be

anticipated at OB2, albeit taking place at a lower magnitude, given

that less work is required at this site.


• As in the case of OB1, the requirements of a comprehensive CEMP

must be met during construction. Issues relevant to the reduction of

construction-associated impacts on watercourses that need to be

addressed in a CEMP are outlined in Section H.

not considered ecologically

sustainable, and thus approval of

this project without the specified

mitigation measures would not be

recommended

• NB The applicant has

acknowledged the validity of

these concerns. Its current budget

for the projects being undertaken

in terms of contract C958.5 does

not, however, provide for the

scope and technical complexity

of the interventions recommended

by Dr Day.

• The DTPW has indicated that, in the

event that the crossing at OB2 has

to be re-built owing to irreparable

damage, the new structure will be

designed to accommodate the

above-mentioned issues.

OB3: ELANDSKLOOFRIVIER, DR1313

(Construction of new causeway)

Positive aspects of the new structure w.r.t. flood and sediment

conveyance

• Widening of the existing culverts and their extension across the full

width of the (now bermed and channelized) river in these reaches

as proposed, so as to allow the passage of cobbles and sand

beneath the structure and to allow the passage of flows up to a 1:2

year flood through the structure is regarded as a positive impact,

likely to promote longer-term stability of the river channel.

• If the recommended mitigation measures are implemented, the

ecological disturbance caused by floods greater than 1:2 year

events should be much less than at present, with only large floods

likely to result in severe perturbation.

• Inclusion of the ('Meerlustkloof') irrigation pipelines in the bridge

structure is also considered a positive impact, as its relocation away

from the river bed will reduce the ongoing disturbance to the river,

resulting in the past from the frequent need to repair infrastructure,

subject to frequent flood damage.

• In the absence of ensuring control over erosion at the level of the

river or at least the upstream reach, it is very unlikely that such


recommendations

• Implementation of the proposed

structure at OB3 would, in the

absence of any mitigation

measures aimed at stabilizing the

high rates of erosion and

sedimentation taking place in the

Elandskloof River, simply

perpetuate an unstable system

and would thus, considering the

lost opportunity to rectify an

ecologically catastrophic situation,

be considered a negative impact

of at least medium-high

significance.


mitigation measures, along with the

planned improved road structure,

would be considered a positive



positive outcomes will be achieved, with significant damage

occurring on a 1:2 year basis considered a disturbance regime too

great to allow for ecological recovery between disturbance events.


• The same construction phase impacts are likely as outlined for OB1

and OB2. Their net effect would however be relatively low, given

the level to which the river is already disturbed.

• Additional sediment and bank disturbance, for example, would

probably have a negligible additional effect, given the current rates

of disturbance.

• The disturbed state of the river and the level of damage to the

existing river crossing structure means that there is some likelihood

that further flooding will result in the current road being unusable as

a bypass without intervention during construction, resulting in the

need for additional earthworks and probable diversion of flows.

Mitigation requirements

• As for of OB1 and OB2, the requirements of a comprehensive CEMP

must be met during construction (see Section H).

• The above impacts would however be exacerbated if construction

took place during the wet season when the water table was high, or

during a period when a storm event occurred.

• In the event of damage to the existing crossing being such that it

cannot be used as a bypass during construction, it is recommended

that construction phase mitigation measures include allowance for

the short-term repair of the existing bridge, using pipe culverts if

necessary to minimize disruptions to flow.

• Such measures should be considered temporary only, to ensure that

construction of the new road and crossing can proceed as fast as

possible.

Residual negative Impacts

• Ongoing erosion of the destabilised river channel and its margins, as

a result of lack of adequate plant cover;

• In the event that existing concrete and other waste associated with

the present channel is not removed, its persistence in the channel

would constitute an ongoing potential trigger for erosion as a result

of diversion of flows off the hard structure, as well as being visually

displeasing

Post-construction ecological remediation (including groyne fields)

• Allowance must be made for the establishment of a continuous

swathe of appropriate, locally indigenous vegetation along at least

the wetted bottom of the bank of the river, but ideally up the bank

as well, for a distance of 30 m up- and downstream of the proposed

structure, to prevent erosion.

• Dense stands of palmiet reeds (P. serratum) should be utilised for this

purpose. Other plant species used should be selected in

consultation with a botanist and/or river ecologist, to ensure they

meet the required criteria of being hardy, locally indigenous and

suited to the conditions in which they are planted;

• All concrete and other debris associated with the present road

crossing should be removed from the river bed and banks as soon as

the requirement for a construction-phase bypass road is over, and

impact, of low to medium

significance, with the low level of

significance reflecting the risk that

the degree of impact to date is too

high to reflect high levels of

improvement.

• NOTE that this application has been

amended to include the installation

of pipes in the existing (damaged)

bridge for the duration of

construction. This causeway is

severely damaged and there is a

high risk that the structure would

not be able to withstand even a

relatively minor flood. Additional

venting in the form of pipes may

help to secure the structure against

such failure. See figures 8 and 10,

Appendix C, for photographs of the

causeway in February 2014.



disposed of outside of the 1:50 year flood line for the river;

• The existing road, which will be replaced by a new alignment,

should be ripped, all artificial debris removed, and the river bank

treated as outlined above;

• Planted areas should be subjected to a maintenance programme

that includes where necessary, weeding, plant replacement and

irrigation, over at least one full annual cycle.

• Bank erosion and channel migration in the reaches at least 50 m

upstream and 50 m downstream of the crossing must be controlled

by groynes. Such structures should ideally be in place before

construction at OB3 commences. NOTE that the construction of river

stabilisation works falls within the purview of the Western Cape

Department of Agriculture (WCDA), and not that of the DTPW. The

WCDA is undertaking planning to construct groynes in the

Elandskloofrivier, but it is not possible to predict when this work will

commence.The groyne field should allow for widening of the river in

the disturbed reaches downstream of the crossing at OB3.

• The invert levels at the new causeway at OB3 must be designed to

account for greater channel incision than is current the case, and

which will be caused by down-cutting once the groynes are in

place and concentrate flood flows.

• The extensive eroded area to the east of the existing bermed river

channel downstream of OB3 must be returned to a vegetated

floodplain after completion of the groyne field.

• The berm east of the Elandskloofrivier must be removed. Berm

material may be spread on the eroded floodplain)

• Remove the beefwood trees lining the channel downstream of the

road

• Landscape/shape the floodplain area such that it comprises a

mosaic of depressions and raised areas, mirroring natural conditions;

• Establish indigenous floodplain vegetation on the rehabilitated area

– note that while planting or seeding of the area would be positive,

it is likely that appropriate plants will establish themselves in the

rehabilitated area over time, provided that weeding is allowed for in

the establishment phase. This has been the case with disturbed

areas upstream (Day 2013).

OB4: SECONDARY FLOOD CHANNEL OF ELANDSKLOOFRIVIER, DR 1313

(Installation of gabion mattress at in- and outlets of minor pipe culvert)

NOTE that the aquatic ecologist questioned the need for apron slabs up-

and downstream of this pipe culvert, as well as the ecological desirability

of such refurbishment (cf. Day, 2014, pp 34-35). The Applicant has

subsequently agreed to use gabion mattresses to support the concrete

apron slabs. This will help to control the proliferation of reeds that

contribute to blockages, while permitting low flows to pass unimpeded

through the porous gabion structures.


• Disturbance of the wetland

• Potential infilling of portions of wetland with excess spoil


recommendations

• The need for this specific

intervention seems unfounded as

flows over the road at this point

seem to issue from overflows of the

Elandskloofrivier, and not because

of blockages to the culvert at

OB4).

• Nonetheless, the use of concrete

apron slabs in conjunction with



• Passage of dewatered material into the watercourse

• Contamination of the watercourse by construction associated

materials such as cement.

• These impacts would all be exacerbated if construction took place

during the wet season when the water table was high, or during a

period when a storm event occurred.


• The requirements of a comprehensive CEMP must be met during

construction.

gabion mattresses would reduce

the negative significance of

impacts associated with these

works to 'low', as opposed to 'low'

to 'medium' without the proposed

mitigation.

• In this context, it would not be

necessary to motivate for the

project not to go ahead as the

negative impacts of the proposed

refurbishment of this culvert were

of limited ecological

consequence.

OB5 UNNAMED WATERCOURSE AT 'TARENTAALKRAAL', DR1313

(Addition of gabion scour protection downstream of culvert)

NOTE that the aquatic ecologist revised her initial findings about the

desirability of the proposed works at this site following revisions, on her

recommendation, to the project plans. Instead of reinforcing the outlet

structure with concrete apron slabs and the dumping of rocks to prevent

scour, the new outlet structure and scour protection will be built from

gabions. As a result, it will no longer be necessary to armour the base of

the gabion protected with rocks, as initially recommended by the project

engineers.

The revised layouts and designs

The engineering activities included in this project aim to address the

formation of a deep scour hole downstream of the road and repair an

undermined apron slab.

This is to be achieved by building a stepped (three-tier) gabion structure

and protective gabion mattress at the base of the refurbished scour

protection. The gabions will be surfaced with a protective layer of

concrete, 10cm thick. The new structure will extend 8 m into the pool,

measured from the edge of the culvert outlet to the outer edge of the

gabion mattress. The gabion mattress will be 14.84 m wide. The edge

furthest from the culvert will be sunk 0,.5 m into the river bed to stabilise

the structure. There is a 2.4 m drop between the outlet invert and the bed

of the pool. The undermined scour protection will demolished and

removed prior to the commencement of construction.

Mitigation requirements

• “Sausage gabions” or similar mechanisms should be used to allow

stabilisation of steep, deep undercut banks, and to dissipate energy

downstream of the culvert;

• In order to address the issue of concentrated flows and at times the

passage of large debris through the road culvert, exacerbating the

problems experienced in the scour hole:

o the alien-invaded channel upstream of the road must be

cleared of all woody aliens and the seedlings of such

species, across the entire riverine zone, extending upstream

for a distance of at least 40m upstream of the road

o Species-appropriate alien clearing methods should be

employed – Working for Water guidelines should be used in

this regard;

o Cleared areas should be stabilised by a combination (as

appropriate) of bank shaping and planting with locally


recommendations

• Assuming implementation of the


measures, the overall impact of

the proposed project at this site

would probably be of very low

negative significance.

• Without implementation of the


activities, the significance would

increase to at least medium

negative significance.

• Any activities taking place at this

site should however take

cognizance of the fact that the

watercourse still retains natural in-

stream vegetation and habitat

types, and should be considered

a locally sensitive habitat type, of

some value in determining local

reference conditions.



indigenous plant species

o Local landowners should ideally be required to participate

in long-term alien maintenance clearing activities in the

cleared reach and upstream

o The fence across the culvert should be removed – it

appears likely to contribute to debris-build-up;

o Consideration should be given to the creation of

attenuation depressions / wetlands in the area to the west

of the channel, upstream of the road, to manage flood

velocities and volumes;

• Alien vegetation should be cleared to a distance of 30 m

downstream of the road (i.e. to just past the riffle at the end of the

pool).

OB6 UNNAMED WATERCOURSE AT 'NOOITGEDACHT', DR1313

(Additional box culvert, inlet and outlet protection, gabion anti-scour mattress and temporary by-pass)

NOTE that the DTWP has agreed to install a gabion check-weir to stabilise

head-cut erosion upstream of the culvert at this site, as recommended by

the aquatic ecologist. It is, however, beyond the scope of this contract to

address channel erosion downstream of the culvert. The latter

interventions would be outside the road reserve, on privately-owned land.

Negative impacts

• The head-cut erosion in the wetland upstream of the existing culvert

was identfied as a matter of 'serious concern' which, if left

unaddressed, would threaten the whole valley bottom wetland

upstream.

• The DTPW has agreed to stabilise the head-cut with a gabion weir, as

part of the overall project to improve the culvert design.

• In addition, significant erosion has occurred downstream of the road,

and although the exact source of the flows from the west were not

identified in this study, the road clearly plays a pivotal causal role in

the degradation witnessed downstream.

Mitigation measures

• The wetland head-cut must be addressed, as a matter of great

urgency, and prior to the start of any construction activities on this

overall project, through the installation of a gabion weir, located at

the head-cut point, and appropriately designed to prevent further

erosion caused by a change in gradient between the wetland

channel and the excavated channel upstream of the low-lying

culvert.

• The eroding banks downstream of the culvert must be addressed as

a matter of urgency, bearing in mind their proximity to the

Riviersonderend wetlands downstream.

• The following measures are regarded as minimum requirements with

regard to stemming further erosion downstream of the culvert:

o The need for the installation of energy-control weirs in the

channel should be considered, to prevent further down-

cutting and allow the re-establishment over time of wetland

vegetation – where considered necessary by an engineer,

working with a river ecologist, such weirs should be

constructed;


recommendations


culvert designs with the

recommended, additional,

mitigation measures would result in

(limited) positive outcomes from a

freshwater ecosystem perspective.

• Importantly, this would prevent

further degradation to the

wetlands upstream of the culvert

• However, implementation of this

project without inclusion of the

specified mitigation measures

would serve only to perpetuate

the unacceptably high levels of

ecological degradation that are

occurring on an ongoing basis as

a result of the existing road culvert

and watercourse management at

OB6.

• As such, implementation without

mitigation measures would be

accorded a high level of negative

significance, form the perspective

of freshwater ecosystems.



o The river banks must be graded (during low flow periods) to

establish banks that have slopes no steeper than 1:5 and

preferably less steep;

o The passage of flows into the channel from the west must

be investigated and addressed, such that it does not

constitute a threat to the long-term rehabilitation of the

channel.

Impacts associated with layout and design

• If the mitigation measures are implement, the proposed layout and

design would have positive impacts only as the design allows for

stabilisation of the eroding toe of the road, and improved

management of flows under the road.

(d) Mitigation of high-level (supra-site) impacts on aquatic ecosystems

As previously indicated, this basic assessment is obliged to distinguish between:

(a) Impacts that can be demonstrably attributed to the proposed activities for which environmental

authorisation is being applied for, and are therefore fall within the Applicant's sphere of responsibility and

duty of care towards the environment; and

(b) Impacts that cannot be attributed to the Applicant but are nonetheless closely related to the effectiveness

of the proposed, activity-specific mitigation measures, and the overall (degraded) state of the affected

watercourses and their terrestrial margins.

Besides recommending mitigation measures that apply specifically to construction, the aquatic specialist (Day, 2014)

has identified measures to counter 'high-level' impacts that have evolved from site-specific impacts being

compounded by ecological degradation at an ecosystem scale. Poor land-use practices are the primary cause of

such broad-scale degradation – and specifically the failure by local landowners to control or properly remove,

invasive alien vegetation along watercourses.

The following 'high level' mitigation measures have been recommended with respect to the management and

rehabilitation of the Elandskloofrivier, in the broad vicinity of Site OB3:

Background to degradation associated with the existing causeway over the Meulrivier (cf. Day, 2014, pp 32-34)

Any activities planned for the Elandskloof River at OB3 need to address the significant damage that has accrued to the

river ecosystem, as a result, at least in part, of structures that have been inadequate for the flows, sediment and debris

loads passing through them. It is acknowledged that in the case of the Elandskloof River, these have changed

dramatically as a result of large-scale destabilisation in the upstream system (Day 2013), rather than because of

significant original design inadequacies at OB3. Nevertheless, without addressing the broader issues of destabilisation of

the river, at least in the reaches immediately up- and downstream of the road, it is very unlikely that sufficient stability will

be attained to prevent frequent high levels of flood damage in the vicinity of the road.

High level mitigation strategy

Following from the foregoing, it is strongly recommended that:

− The DTPW should liaise with the Western Cape Department of Agriculture regarding the proposed installation of

a groyne field in the Elandskloof River, and ensure that bank erosion and channel migration in the reaches at

least 50 m upstream and downstream of the crossing are controlled by groynes, designed in keeping with the

objectives of the broader flood and erosion control programme of the WC Department of Agriculture. Such

structures ideally need to be in place, at least 50 m up- and downstream of the alignment of the new

causeway, before the start of the present proposed activities.

− In the event that the authorisation of the groynes may be delayed, it is recommended that the DTPW either

works with the Western Cape Department of Agriculture to prioritise approval and construction of the structures



that would affect the present road, or design and obtain authorisation for such structures separately. It is noted

in this regard that the proposed design at OB3 already assumes implementation of the groyne field, and allows

for a lower invert level in the crossing than that required at present, given that the river would be downcut by

concentration of flood flows.

− The extensive eroded area to the east of the existing bermed river channel downstream of OB3, must be

addressed, and returned to a vegetated floodplain condition. This rehabilitation measure, which should only

take place after construction of the groynes and new road and bridge, would require:

o Liaison with the DA regarding the implications of the proposed groyne field for this area – ideally, the

groyne field itself should allow for widening of the river in these disturbed reaches



o Landscaping / shaping the floodplain area such that it comprises a mosaic of depressions and raised

areas, mirroring natural conditions;

o Establishment of indigenous floodplain vegetation on the rehabilitated area – note that while planting

or seeding of the area would be positive, it is likely that appropriate plants will establish themselves in

the rehabilitated area over time, provided that weeding is allowed for in the establishment phase.

This has been the case with disturbed areas upstream (Day 2013).

Dr Day's assessment concludes as follow (Day, 2014, p 42):

"With the inclusion of rehabilitation measures, none of the (activities subject to this application for

environmental authorisation) were considered unacceptable from a freshwater ecology perspective, although

the need for activities proposed at OB4 was questioned (and have been subsequently addresed – C de V).

Mitigation measures required for the rehabilitation of the crossing at OB2 require, however, that the proposed

structure be substantially reconsidered to take cognisance of a small stream.

"Included in mitigation measures at several sites is the need to address impacts resulting from the existing

structures. Such measures are considered crucial elements relating to the successful implementation of the

proposed structures, to prevent ongoing, frequent disturbance to the river channel as a result of flood damage

that is not only ecologically devastating but is financially expensive as well. It is noted however that in many

cases (particularly at OB1 and OB2) one of the major drivers of structural failure is the impact of alien invasion

along the river. It is recommended in this regard that stringent measures should be set in place to ensure that

local landowners address this issue, using best practice clearing and rehabilitation measures, to avoid ongoing

damage to the watercourses and road infrastructure, considering that while aliens appear to be kept out of

agricultural areas, they are allowed to spread (uncontrolled) along riparian zones, with the resource value of

these channels seemingly being disregarded, until severe damage accrues along access points..."

8. IMPACT SUMMARY

Please provide a summary of all the above impacts.

Significance of potential construction-phase impacts

Adverse impacts associated with construction would, if effectively mitigated, be of ‘Very Low’ significance.

Disturbances to the socio-economic and socio-cultural facets of the environment would of necessity be of limited

duration and, if effectively mitigated, would have a negligible effect on the affected public. Impacts arising from loss

of habitat and ecological function in CBAs may be of ‘Very low’ to ‘Medium‘negative significance, if not effectively

mitigated.

Significance of impacts during the operational phase

All the factors that may adversely affect socio-economic and socio-cultural facets of the receiving environment

during construction would no longer be of any consequence during the operational lifespan of the roads in question.

Residual negative impacts on CBAs would, unless timeously identified and pre-empted by appropriate engineering

designs, persist into the operational phase and cumulatively result in impacts of ‘Very Low’ to ‘Medium’ negative



significance (see above). Assuming effective, broad-scale mitigation, the provision of additional hydraulic capacity

at sites OB1, OB3 and OB6 will entail a positive impact of ‘Low’ significance. If erosion cannot be controlled at the

latter sites, it could have an impact of 'High' negative significance; if mitigation is effective, the impacts of the

structures on erosion may be marginally positive. Improved road safety will be of ‘High’ positive significance.

Table 1: Impacts during the construction phase Potential (negative) significance of impacts



Erosion and sedimentation Low to Very Low Very Low

Water quality (turbidity) Low to Very Low Very Low

Water quality (contamination) Medium to Very Low Very Low

Channel stability Low to Very Low Very Low

Critical Biodiversity Areas Medium Very Low


Inconvenience to road users Low Low

Sense of wellbeing and biophysical environment

Noise Medium to Very Low Very Low

Dust Medium to Very Low Very Low

Socio-cultural environment

Sense of place Medium Very Low

Table 2: Impacts during the operational phase:

Potential (negative) significance of impacts



Improved hydraulic capacity Medium Low (positive)

Erosion and sedimentation High to Low Very Low (positive)

Aquatic CBAs Medium to High Very Low

Terrestrial CBAs Low to Very Low Very Low


Improved road safety High to Medium High (positive)

9. OTHER MANAGEMENT, MITIGATION AND MONITORING MEASURES

(a) Over and above the mitigation measures described in Section 6 above, please indicate any additional

management, mitigation and monitoring measures.

See Section 7(d) for measures that are needed to address the instability and degraded condition of the affected

watercourses beyond the scale of the individual sites. The effectiveness of site-specific mitigation is contingent upon

these 'high level' measures being put in place.

(b) Describe the ability of the applicant to implement the management, mitigation and monitoring measures.

− The single most important mitigation strategy is impact avoidance, which has been largely achieved by the

introduction of substantially improved flow volumes with respect to the structures at OB1, OB3 and OB6.

− Furthermore, the DTPW has reacted positively to recommendations by the specialist aquatic ecologist that the

designs for the proposed works at OB4, OB5 and OB6 be amended to accommodate ecological considerations.



− Some of the recommendations by the aquatic ecologist do, however, entail interventions that are either not

catered for in the current contract, would be too expensive implement, or entail works outside the road reserve

and therefore would be beyond the official purview of the DTPW.

− All construction-related mitigation measures proposed are deemed realistic and feasible to implement (see the

Construction EMP, Appendix H).



SECTION G: ASSESSMENT METHODOLOGIES AND CRITERIA, GAPS IN KNOWLEDGE, UNDERLYING ASSUMPTIONS AND

UNCERTAINTIES

(a) Please describe adequacy of the assessment methods used.

The assessment of potential impacts related to the proposed project and compilation of this Draft BAR were undertaken

in compliance with the requirements of the NEMA EIA Regulations, 2010. The NEMA EIA Regulations Guideline Series

(DEADP, March 2013) was also consulted for guidance on the assessment and public participation process to be

followed. The identification and assessment of impacts was also informed by the IAIA best practice guideline on

‘Biodiversity in Impact Assessment’ (IAIA, 2005), and the DEADP guideline on involving biodiversity specialists in EIA

(Brownlie, 2005).

This combined basic assessment was closely informed by the principles of positive planning (cf McDonald and Brown,

1995; The World Bank, 1999; IAIA, 2005; Brownlie, 2005), in that the aquatic ecologist engaged directly with the project

engineers and the DTPW with the objective of motivating for designs to be amended to accommodate ecological

concerns. This interactive process, conducted in tandem with the basic assessment, proved to be very effective: in the

case of the projects at sites OB4, OB5 and OB6, the engineering plans were revised in response to ecological concerns

raised by Dr Day. The DTWP also indicated that, in the event that the culvert and/or approaches at OB2 being

irreparably damaged as a result of flooding, it would review the configuration of road infrastructure at this site with the

view of implementing designs that took into account the concerns raised by the specialist aquatic assessment. Bank and

anti-erosion measures recommended at sites OB1 and OB6 entailed locations outside the road reserve which would

have to be addressed in consultation with private landowners and, potentially, the Western Cape Department of

Agriculture.

Charl de Villiers Environmental Consulting is confident that all significant environmental impacts have been identified

and adequately assessed in the course of this combined basic assessment process, and that this draft report provides a

sound basis for informed public and authority comment that will be incorporated in the final BAR and environmental

management programme.

(b) Please describe the assessment criteria used.

A standard convention for assigning significance ratings to impacts was used in the assessment. A copy of this

convention is attached in Appendix J.

(c) Please describe the gaps in knowledge.

Limitations regarding the aquatic assessment

No new biophysical data were collected by the specialist aquatic ecologist. The latter report relied primarily on a visual

assessment of issues of ecological concern and existing conservation planning data (e.g. NEFEPA datasets). No floral or

faunal analysis or ground-truthing (besided a site visit in February 2014) were conducted. Nonetheless, given the extent

to which the affected sites have been disturbed, these were not considered significant limitations (Day, 2014, p 4).

Uncertainty regarding the implementation high level, ecosystem-scale mitigation

It is beyond the scope and capacity of this basic assessment process to predict whether the crucial high-level mitigation

measures that have been recommended by the aquatic specialist will, in fact, be implemented. The DTPW is equally in

the dark in this regard, and cannot reasonably be held responsible for environmentally detrimental activities on land

beyond its jurisdiction. To achieve this the level of intervention in support of river rehabilitation will require co-operation

between a variety of state agencies and the affected landowners, who are primarily farmers.

Monitoring of the long-term environmental impacts of the repaired and rebuilt structures

In view of the prevailing uncertainties about the long-term ecological effects of the repaired and refurbished structures,

it is recommended that post-construction monitoring be undertaken to determine if the structures are:



− Contributing to recovery or ongoing degradation of the river channels; or

− Simply maintaining the existing levels of degradation that have resulted from past flooding (i.e. there is no

indication that the affected watercourses in the reaches affected by the crossing are on a trajectory of

recovery from the effects of past flooding).

− Watercourses should also be monitored for build-up of sediment upstream of structures and scouring

downstream (this is necessary to test the hypothesis that improved hydraulic capacity and sediment movement

will promote recovery of the longitudinal slope profile of watercourses).

(d) Please describe the underlying assumptions.

The following assumptions apply:

− The project engineers provided the EAP with all relevant, correct and valid project description information;

− The biodiversity specialist had sufficient information on which to base a defensible assessment of the respective

sites and their local ecological context and condition, and to make recommendations on impact avoidance

and mitigation at the relevant spatial and functional scales;

− There will be no significant changes that could substantially influence findings and recommendations with

respect to mitigation and management; and − The DTPW will ensure, within the confines of its jurisdiction and resources, that all recommended mitigation

measures that apply exclusively to the activities subject to this application will be implemented.

(e) Please describe the uncertainties.

As indicated, the most over-riding uncertainty is whether the high-level mitigation measures recommended by the

aquatic specialist will be implemented. Key in this regard are the:

− Proposed bank stabilisation measures upstream of OB1

− Construction of groynes in the Elandskloofrivier, up- and downstream of OB3;

− Anti-erosion works downstream of OB6;

− Clearance of alien vegetation at sites; and

− Need to control agricultural activities that contribute to erosion, channel instability and degradation of aquatic

habitats and ecological processes.


CCA Environmental (Pty) Ltd Draft BAR 97

SECTION H: RECOMMENDATION OF THE EAP

In my view (EAP), the information contained in this application form and the documentation

attached hereto is sufficient to make a decision in respect of the activity applied for. YES � NO

If “NO”, list the aspects that should be further assessed through additional specialist input/assessment or whether this

application must be subjected to a Scoping & EIR process before a decision can be made:

No further specialist assessments are deemed necessary as the basic assessment report provides sufficient information on

which to base an informed decision about this application – subject to the proviso that operational phase impacts need

to be monitored (see recommended mitigation measures below), and high level mitigation takes place. The aquatic

ecologist will be invited to review future iterations of the basic assessment with the view of ensuring that all pertinent

biodiversity-related considerations have been identified and addressed as recommended.

If “YES”, please indicate below whether in your opinion the activity should or should not be authorised:

Activity should be authorised: YES � NO

Please provide reasons for your opinion

It is recognised that authorisation can only follow once the final basic assessment report has been submitted to the

DEA&DP. At this stage of the process, it is possible to recommend authorisation on the following grounds:

− The repairs and, in the case of the structures at OB1 and OB3, which are to be replaced with new culvert

crossings, are essential for road safety and the maintenance of an effective rural transport network in the

western Overberg.

− The DTPW has emphasised the urgency for the repairs, given the vulnerability of the Helderstroom prison to

floods that periodically cut it off from the outside world.

− Socially and economically, this basic assessment has demonstrated both the need for the repairs, as well as

their desirability.

− There are no adverse impacts at an activity or site-specific level that are sufficiently severe to warrant refusing

the authorisation of the proposed repairs.

− If all the recommended mitigation measures were to be implemented, the environmental impacts of the

repairs will range from 'very low' negative significance, to impacts of 'low' positive significance in terms of

improved flood conveyance capacity and reduced erosion and channel instability.

− However, this presupposes that all the recommended high level mitigation measures will be implemented for, if

not, the proposed activities are liable to contribute to further environmental degradation of the Bot River, and

the affected tributaries of the Riviersonderend.

− Residual uncertainties about long-term operational phase impacts must therefore be subject to monitoring and

review.

− Furthermore, it is crucial that the watercourses be kept free of invasive alien plants and that the channels at the

different crossings be cleared regularly of sediment deposits and debris that may clog culverts during floods.

If you are of the opinion that the activity should be authorised, then please provide any conditions, including mitigation

measures that should in your view be considered for inclusion in an authorisation.

NOTE that recommendations are provided for:

A. Generic mitigation of construction-related impact at all sites;

B. Measures relating to site-specific mitigation and ecological rehabilitation; and

C. General, post-construction ecological rehabilitation.

(A) Generic measures for mitigating construction-related impacts at ALL sites

− Construction activities within watercourses should not take place during the wet season (i.e. any activities

requiring the diversion of flows should take place between October and April only), and construction schedules

should preferably be managed within these time frames.

Delineation of construction sites and access to watercourses



− Obtain the landowner's written permission if sites must be accessed across farmland

− Only use existing access roads to undertake the proposed activities




− Limiting activities and vehicle movement to disturbed sections of river channels

− Clearly mark vegetation that may not be damaged

− All areas outside of the demarcated construction zone should, within reason, be regarded as no-go areas

during construction, with the exception of personnel engaged in required alien clearing and bank

rehabilitation activities outside of construction disturbance zones.

Removal of indigenous vegetation

− Only remove reeds and other riparian vegetation in the channel and along river banks if access to structures or

construction areas would otherwise be impeded by indigenous vegetation – this applies specifically to Site OB5,

which still retains natural in-stream vegetation and habitat types.

De-watering of construction sites


sediment in temporary sediment ponds or other areas of containment. These must be managed so as to

prevent the passage of sediment-rich water into the watercourse





− Ensure that the impact of pumped water that is discharged under pressure is dissipated by placing pipe outlets

in rocky parts of the stream bed that are not susceptible to scour.

Removal and stockpiling of topsoil for post-construction rehabilitation


− Remove topsoil to a depth of 150 mm and stockpile it locally for re-vegetation.

− Grade banks to a slope of at least 1:4, but preferably flatter, between the repaired structures and the


− Grade slopes downwards, towards the watercourses, with reducing the width or depth of the channel

− Re-plant disturbed areas directly upstream and downstream of each structure with indigenous, locally-

occurring pioneer species at the level of base flow.


Storage and preparation of construction materials


washed or blown into watercourses during storm events or strong winds.

− Store and contain all materials on the construction sites at least 40 m from the nearest water resource.

− Concrete batching must take place at least 40 m from the edge of channel in a secure, bunded area (e.g.

wooden boards placed over heavy plastic sheeting within a bund of sandbags).


Refuelling of vehicles and other machinery

− Vehicles must be refuelled at least 40 m away from rivers, in securely bunded areas

− Fuel bowsers and other forms of fuel storage must be kept at least 40 m away from any watercourse

− Check vehicles daily for oil leaks and repair leaks immediately



− Maintain all construction machinery and vehicles in good working order.

General site maintenance

− Inspect sites daily for litter and remove all rubble and waste material from the river channels and riparian zones

after construction is completed.

− No open fires are permitted at any of the construction sites – fires for cooking or heating purposes must be

made in 'konkas' within a cleared area within the construction site

− Provide and regularly service ablution facilities for construction staff on site.

− Toilets must be located at least 40 m from watercourses.

− No tools, packaging, empty containers or other construction materials may be washed in watercourses

− Water used for washing must be managed such that it does not contaminate any watercourse;

Noise abatement

− Ensure construction machinery and especially silencers are in good working order.

− Limit construction to the hours of daylight, on weekdays only.

Dust abatement

− Vehicles must not exceed 40 km/hr on gravel roads in the vicinity of human habitation or vineyards or

orchards with ripening fruit.

Road safety

− Provide sufficient signage to warn motorists of the presence of construction works and detours.

Post-construction rehabilitation

− Rehabilitation activities specified in mitigation measures, including rehabilitation of temporary bypasses or

defunct structures should take place outside of the wet season, and immediately after the completion of

construction activities.

− All waste generated by construction activities (including rubble, litter etc.) is to be removed from the site and

disposed of at an appropriate approved site.

− Remove invasive species such as black wattle Acacia mearnsii and beefwood Casuarina sp as they contribute

to channel restriction, down-cutting and erosion, and displace indigenous biodiversity.


− Alien clearing procedures should be carried out in accordance with species-specific guidelines outlined by

Working for Water documentation, or as recommended by an experienced alien clearing specialist;

− Bank rehabilitation activities should make provision for input by a river ecologist or the Western Cape Department of Agriculture into the final shaping and planting of these areas.

− Any area accidentally disturbed during construction should be rehabilitated after construction, with input from

a riverine specialist ecologist or the Western Cape Department of Agriculture where such areas lie within a

watercourse or other wetland.

Post-construction channel maintenance

− Keeping watercourses upstream of the structures (at least as far as the edge of the road reserve) clear of flood

debris (particularly ‘spoelklippe’, branches and uprooted bushes and trees) to prevent premature over-topping

and back-flooding in floods ≤1:5-year return period.



− Where excavations have taken place upstream of structures, ensure that potential nick-points and benches in

the channel are removed so as to prevent head-cut erosion from developing upstream of these locations.

− Monitor the first reach/first 150 m of the watercourse downstream for signs of new erosion.



− Monitor changes to sediment patterns (deposition and erosion) up- and downstream of repaired structures to

assess recovery and reinstatement of the general slope of the watercourse.


gravel approaches that may be washed away as a result of floods.


potential.

(B) Measures relating to site-specific mitigation and ecological rehabilitation

OB1: Kanaan The following measures need to be implemented upon completion of construction:

− All concrete and other debris associated with the present road crossing should be removed from the river bed and banks as

soon as the requirement for a construction-phase bypass road is over, and disposed of outside of the 1:50 year flood line for the river;

− The existing road, which will be replaced by a new alignment, should be ripped, all artificial debris removed, and the river bank and riparian zone thus created should be shaped to resemble a natural system, in a band at least 15m wide on either side of the river – a river ecologist should oversee / sign off on this aspect of mitigation;

− The river bank must be rehabilitated according to Environmental Specification C1008; and − The small tributary directly to the east should be addressed as part of the latter process, and re-shaped as a broad open

channel, planted in destabilised areas to prevent erosion;

OB3: Meerlustkloof

− Additional pipes must be installed in the existing causeway to improve its capacity to accommodate high flows during construction, after which this structure must be demolished and its disturbed footprint rehabilitated as specified below. The installation of the extra pipes must be supervised by the project engineer and an aquatic ecologist.

− All concrete and other debris associated with the present road crossing should be removed from the river bed and banks as soon as the requirement for a construction-phase bypass road is over, and disposed of outside of the 1:50 year flood line for the river; and

− The existing road, which will be replaced by a new alignment, should be ripped, all artificial debris removed, and the river bank rehabilitated according to Environmental Specification C1008.

Site OB6: Nooitgedacht

− The wetland head-cut must be addressed, as a matter of great urgency, and prior to the start of any construction activities on this overall project, through the installation of a gabion weir, located at the head-cut point, and appropriately designed to prevent further erosion caused by a change in gradient between the wetland channel and the excavated channel upstream of the low-lying culvert.

(C) General, post-construction ecological rehabilitation

T

These recommendations relate to long-term rehabilitation and channel maintenance and do NOT apply to construction phase activities as specified in the Construction Environmental Management Programme for project C958.5

Alien clearance and monitoring − Keep channels upstream and downstream – and at least as far as the first bend and/or for 150 m – clear of large branches

and other debris that may deflect flows into the banks of watercourses. − Clear invasive alien plants from river banks and the floodplain at least 200 m downstream of the structures, in a corridor at

least 30 m wide and replant with locally-occurring indigenous pioneer plant species. − Species-appropriate alien clearing methods should be employed – Working for Water guidelines should be used in this



regard; − Cleared areas should be stabilised by a combination (as appropriate) of bank shaping and planting with locally indigenous

plant species − Monitor the first reach/first 150 m of the watercourse downstream on an annual basis for signs of new erosion. − Maintain a photographic record of the monitored reaches. − In all cases, alien clearance needs to be co-ordinated by an authority such as the Western Cape Department of Agriculture

and local landowners should be encouraged to participate in such clearance programmes.

Site OB1: Kanaan

− The eroding bank upstream of the bend must be addressed, through removal of alien vegetation, reshaping of the bank and

replanting; hard stabilisation techniques (e.g. bank lining with gabions) should not be used, although it is understood that gabions will be used immediately up- and possibly downstream of the new structures.

Site OB2: Doringkloof

− All invasive woody alien vegetation and the seedlings of such species should be cleared from a zone extending at least 30 m upstream and 30 m downstream of the present crossing point, as well as 30m upstream along the inflowing minor stream, in a swathe at least 15m wide on either side of the river channel, or less if alien invasion is within a narrower zone – the final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner;

− The design for this structure must include an additional or extended culvert or other ecologically cognisant measure that allows for the free flow of the minor stream through the structure, without being diverted along the road edge. The mechanism for this would need to address the fact that the stream appears to enter the system at a higher level than the existing culvert.

Site OB3: Meerlustkloof

− The DTPW should liaise with the Western Cape Department of Agriculture regarding the proposed installation of a groyne field in the Elandskloof River, and ensure that bank erosion and channel migration in the reaches at least 50 m upstream and downstream of the crossing are controlled by groynes, designed in keeping with the objectives of the broader WCDA flood and erosion control programme.

− Such structures ideally need to be in place before the start of the present proposed activities – in the event that delays in their authorization through WCDA are considered likely, it is recommended that the DTPW either work with WCDA to prioritise approval and construction of the structures that would affect the present road, or design and obtain authorization for such structures separately.

− Note that the proposed design at OB3 already assumes implementation of the groyne field, and allows for a lower invert level in the crossing than that required at present, given that the river would be down-cut by concentration of flood flows.

− The extensive eroded area to the east of the existing bermed river channel downstream of OB3 must be addressed, and returned to a vegetated floodplain condition.

− This rehabilitation measure, which should only take place after construction of the groynes and new road and bridge, would require:

o Liaison with the WCDA regarding the implications of the proposed groyne field for this area – ideally, the groyne field itself should allow for widening of the river in these disturbed reaches



o Landscaping / shaping the floodplain area such that it comprises a mosaic of depressions and raised areas, mirroring natural conditions;

o Establishment of indigenous floodplain vegetation on the rehabilitated area – note that while planting or seeding of the area would be positive, it is likely that appropriate plants will establish themselves in the rehabilitated area over time, provided that weeding is allowed for in the establishment phase. This has been the case with disturbed areas upstream (Day 2013).

− Allowance must be made for the establishment of a continuous swathe of appropriate, locally indigenous vegetation along at least the wetted bottom of the bank of the river, but ideally up the bank as well, for a distance of 30m up- and



downstream of the proposed structure, to prevent erosion. It is strongly recommended that dense stands of Palmiet reeds (Prionium serratum) should be utilised for this purpose. Other plant species used should be selected in consultation with a botanist and/or river ecologist, to ensure they meet the required criteria of being hardy, locally indigenous and suited to the conditions in which they are planted;

− The final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner;

Site OB5: Tarentaalkraal

In order to address the issue of concentrated flows and at times the passage of large debris through the road culvert, exacerbating the problems experienced in the scour hole: − The alien-invaded channel upstream of the road must be cleared of all woody aliens and the seedlings of such species,

across the entire riverine zone, extending upstream for a distance of at least 40 m upstream of the road – the final extent of alien clearance must be clarified in consultation with the Western Cape Department of Agriculture and the responsible landowner


− Cleared areas should be stabilised by a combination (as appropriate) of bank shaping and planting with locally indigenous plant species;

− Local landowners should ideally be required to participate in long-term alien maintenance clearing activities in the cleared reach and upstream;

− Branches and other material that become entangled in the fence across the culvert should be cleared before the onset of winter in order to prevent debris-build-up;

− Consideration should be given to the creation of attenuation depressions / wetlands in the area to the west of the channel, upstream of the road, to manage flood velocities and volumes; and

− Also, alien vegetation should be cleared to a distance of 30 m downstream of the road (i.e. to just past the riffle at the end of the pool).

OB6: Nooitgedacht

− The eroding banks downstream of the culvert must be addressed as a matter of urgency, bearing in mind their proximity to the Riviersonderend wetlands downstream. The following measures are regarded as minimum requirements:

o The need for the installation of energy-control weirs in the channel should be considered, to prevent further

down-cutting and allow the re-establishment over time of wetland vegetation – where considered necessary by an engineer, working with a river ecologist, such weirs should be constructed;

o The river banks must be graded (during low flow periods) to establish banks that have slopes no steeper than 1:5 and preferably less steep;

o Allowance must be made for the planting of at least the lower bank with hardy locally indigenous plant species, approved by a botanist or river ecologist, that will play a role ion lower bank stabilisation; the use of Palmiet in this regard would be encouraged;

o The passage of flows into the channel from the west must be investigated and addressed, such that it does not constitute a threat to the long-term rehabilitation of the channel.

Duration and Validity:

Environmental authorisations are usually granted for a period of three years from the date of issue. Should a longer

period be required, the applicant/EAP is requested to provide a detailed motivation on what the period of validity

should be.

N/A



SECTION I: APPENDICES

The following appendices must be attached to this report:

Appendix

Tick the box if

Appendix is

attached

Appendix A Locality maps �

Appendix A1 Site plans

Appendix B Project summary �

Appendix C Photographs �

Appendix D1 Biodiversity overlay maps �

Appendix D2 Biodiversity summary �

Appendix E Permit(s) / license(s) from any other organ of state including service letters

from the municipality N/A

Appendix F

Public participation information including a copy of the register of interested

and affected parties, the comments and responses report, proof of notices,

advertisements and any other public participation information as required in

Section C above.

�

Appendix G1 Rapid biodiversity screening report: Mr Jan Vlok, botanist �

Appendix G2 Rapid biodiversity screening report: Dr Liz Day, aquatic ecologist �

Appendix G3 Freshwater assessment: MsToni Belcher, aquatic ecologist

Appendix H Draft Construction Environmental Management Programme �

Appendix I Application Form �

Appendix J Convention for Assigning Significance Ratings to Impacts �



DECLARATIONS

THE APPLICANT

I …………………………………., in my personal capacity or duly authorised (please circle the applicable

option) by …………….................………………… thereto hereby declare that I:

• regard the information contained in this report to be true and correct, and

• am fully aware of my responsibilities in terms of the National Environmental Management Act of 1998 (“NEMA”) (Act

No. 107 of 1998), the Environmental Impact Assessment Regulations (“EIA Regulations”) in terms of NEMA

(Government Notice No. R. 543 refers), and the relevant specific environmental management Act, and that failure

to comply with these requirements may constitute an offence in terms of the environmental legislation;

• appointed the environmental assessment practitioner as indicated above, which meet all the requirements in terms

of regulation 17 of GN No. R. 543, to act as the independent environmental assessment practitioner for this

application;

• have provided the environmental assessment practitioner and the competent authority with access to all

information at my disposal that is relevant to the application;

• will be responsible for the costs incurred in complying with the environmental legislation including but not limited to –

o costs incurred in connection with the appointment of the environmental assessment practitioner or any person

contracted by the environmental assessment practitioner;

o costs incurred in respect of the undertaking of any process required in terms of the regulations;

o costs in respect of any fee prescribed by the Minister or MEC in respect of the regulations;

o costs in respect of specialist reviews, if the competent authority decides to recover costs; and

o the provision of security to ensure compliance with the applicable management and mitigation measures;

• am responsible for complying with the conditions that might be attached to any decision(s) issued by the

competent authority;

• have the ability to implement the applicable management, mitigation and monitoring measures;

• hereby indemnify, the government of the Republic, the competent authority and all its officers, agents and

employees, from any liability arising out of, inter alia, the content of any report, any procedure or any action for

which the applicant or environmental assessment practitioner is responsible; and

• am aware that a false declaration is an offence in terms of regulation 71 of GN No. R. 543.

Please Note: If acting in a representative capacity, a certified copy of the resolution or power of attorney must

be attached.

Signature of the applicant:

Name of company:

Date:

THE INDEPENDENT ENVIRONMENTAL ASSESSMENT PRACTITIONER (EAP)

I ……………………………………, as the appointed independent environmental practitioner (“EAP”) hereby declare that I:

• act/ed as the independent EAP in this application;

• regard the information contained in this report to be true and correct, and



• do not have and will not have any financial interest in the undertaking of the activity, other than remuneration for

work performed in terms of the NEMA, the Environmental Impact Assessment Regulations, 2010 and any specific

environmental management Act;

• have and will not have no vested interest in the proposed activity proceeding;

• have disclosed, to the applicant and competent authority, any material information that have or may have the

potential to influence the decision of the competent authority or the objectivity of any report, plan or document

required in terms of the NEMA, the Environmental Impact Assessment Regulations, 2010 and any specific

environmental management Act;

• am fully aware of and meet the responsibilities in terms of NEMA, the Environmental Impact Assessment Regulations,

2010 (specifically in terms of regulation 17 of GN No. R. 543) and any specific environmental management Act, and

that failure to comply with these requirements may constitute and result in disqualification;

• have ensured that information containing all relevant facts in respect of the application was distributed or made

available to interested and affected parties and the public and that participation by interested and affected

parties was facilitated in such a manner that all interested and affected parties were provided with a reasonable

opportunity to participate and to provide comments;

• have ensured that the comments of all interested and affected parties were considered, recorded and submitted

to the competent authority in respect of the application;

• have kept a register of all interested and affected parties that participated in the public participation process;

• have provided the competent authority with access to all information at my disposal regarding the application,

whether such information is favourable to the applicant or not; and

• am aware that a false declaration is an offence in terms of regulation 71 of GN No. R. 543.

Note: The terms of reference must be attached.

Signature of the environmental assessment practitioner:

Name of company:

Date:

THE INDEPENDENT PERSON WHO COMPILED A SPECIALIST REPORT OR UNDERTOOK A SPECIALIST PROCESS

See overleaf for declarations from relevant Specialist Studies.

c958 5_final bar_010914

Documents

environmental assessment

environmental processes

western overberg c958

western overberg contract

eap qualifications charl

flood repairs

basic assessment procedures

flood repair sites