tennyson dunes coast park concept...

Prepared for: DEWNR Document: 15048 Date: January 2016

Tennyson Dunes Coast Park Concept Report

ASPECT Studios Pty Ltd ABN 11 120 219 561

Trail Solutions Australia | T & M Ecologists | Prepared for DEWNR02

TENNYSON DUNES COAST PARK CONCEPT PLAN REPORT

Contents

Introduction 3

Design Principles 4

Site Attributes 5

Coast Park Shared-Use Path Requirements 6

Concept Options 7

Concept Options Plan 01 8

Concept Options Plan 02 9

Treatment Options - Visualisations 10

Treatment Options - Detail Plans 11

Discovery Trail Node/East West Link 12

Treatment Options - Detail Sections 13

Construction Methodology 14

Revision Description By DATEA Draft for review CG 23.12.2015B Final Draft CG 08.01.2016

C Revision to page 9 CG 12.01.2016D Final for Consultation TC 18.01.2016E Revision for Consultation TC 19.01.2016F Revised Final for Consultation TC 25.01.2016



Background The Tennyson Dunes are a destination of regional significance and the only remnant tertiary dune system along the South Australian Metropolitan Coastline. As an important link (approximately 1.5km in length) in the Coast Park strategy, the need for a path that caters for all users including the young, the old, pedestrians, joggers and cyclists, wheelchairs and prams, while enhancing the environment and encouraging visitors to stay on the path, is key to the success of this component of the Coast Park plan.

Introduction

Walking the site on numerous occasions to confirm opportunities and issues

Significant remnant plants persist throughout the dunes

A ‘Discovery Trail’ for Coast Park Through a series of ‘walking workshops’, where detailed investigations of path alignment options revealed the significance of dunes to the design team, it was apparent that a consciously different approach to path design was required. Branding the trail as a ‘Discovery Trail’ is important in terms of understanding the distinct qualities this section of the Coast Park path has to offer in relation to other sections of the Coast Park shared-use path link along the metropolitan coast.The ‘Discovery Trail’ offers an opportunity to rouse public awareness of the importance of the dunes, allowing more people to experience this important ecological asset. There are opportunities for education and interpretation within a low speed shared-use path environment. This report summarises the key site attributes, opportunities and path alignment options and has been prepared in close collaboration between the design team, officers of the Department for Environment, Water and Natural Resources (DEWNR) and key members of the Tennyson Dunes Group.



Design Principles

It is vital that the trail is designed and constructed in a way that ensures the long term benefits for both the trail users and the environment. Above all, the conservation and protection of the environment, maintaining the integrity of the dunes and reinforcing these values are the driving force behind this enterprise.It is important that the trail is well-connected and provides sustainable linkages to other recreational facilities and amenities. To ensure the highest quality of shared-use path, the core principles of sustainable trail development should be adopted. A sustainable trail;

• Conserves and protects the environment • Meets the needs of the users • Minimises conflict between different user

groups (eg. pedestrians, wheelchairs and cyclists)

These values are key to the design approach and underpin the concepts presented in this report.

New trail through sensitive environment at Banrock Station, SA



Dune EcologyTennyson Dune Reserve is the most ecologically significant strip of dunes on the Adelaide metropolitan coastline. The mature, well-established and largely intact native vegetation at Tennyson is one of the last reminders of the original dune system that was once prominent along the Adelaide metropolitan coastline and the area provides connection between coastal vegetation to the south (Grange) and Semaphore Park to the north, with Tennyson Dunes as the ‘hub’.

Flora and FaunaSignificant plants found at Tennyson include Coast Bitter-bush (Adriana quadripartita) which is crucial habitat for the rare Bitterbush Blue Butterfly (Theclinesthes albocincta) and Hawkweed Picris (Picris squarrosa), a small daisy which has a conservation rating of ‘Rare’ in South Australia.The rare Cynone Grass Skipper (Anisynta cynone cynone) has been reported in tussock grass at Tennyson and the dunes provide habitat for a high number of reptile species, including the Painted Dragon (Ctenophorus pictus), a small coastal lizard which is classed as ‘Endangered’ and in probable decline due to fragmentation of the dune vegetation which is its preferred habitat. Recent survey has indicated that Painted Dragons seem to be most abundant in shrubland vegetation in swales and hind-dune areas, with a combination of a medium to large size shrub layer and open areas likely to be important as habitat .1

Paths, fences and other infrastructure and network of paths, allow reasonably good access throughout the dunes however the quality of the path surface differs greatly due mainly to coastal sand movement processes. Fencing

consisting of coppice log and wire edge both sides of the paths, create a dominant and somewhat obtrusive visual appearance. Other infrastructure in the dunes include; interpretive signage, a lookout deck structure and seating.

Tennyson Dunes GroupOne of Tennyson’s greatest assets is the Tennyson Dunes Group, a dedicated volunteer conservation group whose prime objective is to provide a safe sanctuary for native flora and fauna and to improve and share this valuable asset with the community. Their tireless work over the last 20 years has included animal and plant surveys, collection and propagation of locally native plant seed, revegetation, weed and feral animal control, erosion control and community education through designing interpretive signs and conducting tours and presentations.

1 Milne, T. (2015). Surveys to determine the current distribution of small

coastal dragon-lizards of the Adelaide Coastline. Prepared for Natural

Resources Adelaide and Mount Lofty Ranges, December 2015.

Site Attributes

Existing dune vegetation in good condition

Threatened species of Tennyson Dunes: Painted Dragon Residential properties overlooking the existing native vegetation of the dunes

5 lined Earless Dragon ‐ Tympanocryptis lineata lineata

Endangered in the Metropolitan Region Where does it like to live?

We do not know much about the habitat of the 5 lined Earless Dragon along the Adelaide coastline, but think they are most likely where there is limestone rock and low shrubs present.

Where has it been most recently seen?

They were last seen in 1993 in Moana Sands Conservation Park, just south of Port Noarlunga.

How to recognise it

Max. Size: Body 7cm, tail 12cm, total length 19cm

Five‐lined Earless Dragons are generally a mottled grey brown colour, but have five paler coloured lines that run down their back and flanks. Scattered spiny scales give them a rough appearance, which helps distinguish them from skinks and the Painted Dragon.

Painted Dragon ‐ Ctenophorus pictus

Uncommon in the Metropolitan Region Where does it like to live?

Painted dragons like sandy soils, so the typical sand dunes of the Adelaide coastline are highly suited, especially where there is a good 30‐50% cover of native shrubs.

Where has it been most recently seen?

They still occur in the Tennyson dunes, but would once have been widespread through dune systems along the Adelaide coastline. Most of these dunes are now gone.

How to recognise it

Max. Size: Body 5cm, tail 7.5cm, total 12.5cm

Male painted dragons in spring are easy to recognise due to their spectacular yellow and blue coloration like in the photograph. Females lack the bright colours, generally being a tan brown with white and black spotting, as on the front cover. They differ from the other two dragons in this area by being relatively smooth skinned.



Austroads Guide to Road Design Part 6A: Pedestrian and Cyclist Paths states that the acceptable range for a shared-use recreational path is 3.0-4.0 meters wide, with a desirable width of 3.5 metres. The width of the Coast Park shared-use path recently built in other areas such as Semaphore, Grange and Henley Beach is 3.5m wide. Given the environmental constraints of the Tennyson Dunes site, and the fact that the trail moves through a highly significant and sensitive ecosystem, a much narrower width will be adopted. Popularity and visitation to the dunes will more than likely increase as the trail is upgraded and thus provides an enhanced visitor experience and therefore the path must be built to a standard that caters for this increased usage. It is important that the aesthetics of the trail is complementary with the surrounding sand dunes and vegetation, but it is also important for the surface material to be smooth enough to cater for recreational bikes of all varieties. The proposed path width and materials are further discussed below.

An Appropriate Path Width for the Coast Park Tennyson DunesThe ‘tread’ is defined by the finished surface that users will walk or ride on. In summary, the following strategies will be adopted for the Coast Park shared-use path:

• The minimum path tread will be 1.5m at choke points, where undulating terrain occurs or in areas where there is high quality vegetation, and only where sightlines permit.

Coast Park Shared-Use Path Requirements

• Path tread will range from 1.8m-2.4m typically. - 1.8m width in medium undulating terrain

with high quality/ sensitive vegetation. - Up to 2.4m in passing areas

• 2.5m-3m wide path tread in degraded/modified sites or road reserves/council verges.

• Passing/ pullover areas will be at distances of 30-50m centres. They will be approximately 10m long and allow for a total width including the path of 3.5m. These may include a seat and interpretation where applicable.

• Infrastructure (i.e. signage/ seating) to be limited and minimal in design and materiality.

• Seating nodes are to be rationalised and occur only in already cleared/ degraded zones.

• Low vegetation only next to paths and curved sections to maintain sightlines. Revegetation to consider set-backs and allow for mature growth of species (without pruning).

• Tread texturing at intersections to create slow points.

For path durability, it will be necessary to build a basecourse for the path tread that extends beyond the surface tread by anywhere from 200mm (if using rock edge), to 500mm (where no defined edge to the path is proposed). Typically, the hardstand basecourse will be covered with sand and allow planting to grow over the surface. In some cases, eg. where there are tight curves, the basecourse will function as a ‘run-off’ safety zone.

Materials and FeaturesWhile typically the guidelines for shared-use paths dictate a hard stand surface finish

such as either asphalt or concrete, due to the requirements to achieve a low impact integrated trail, the preferred finish is a ‘natural surface finish The proposed surface finish for this section of Coast Park is a cement stabilised compacted crushed limestone.

Path Alignments The alignment of the path is key to minimising the impact on the native environment first and foremost while minimising the need for on-going maintenance. The tread itself needs to have a robust surface in order to withstand regular sweeping/ blowing of sand that may be required. A cement treated, compacted crushed limestone is light in colour and therefore maintains an appearance close to the colour of the sand.Trail anchors, such as rocks or timber posts, will help to define the alignment and will be placed on the inside of a curved section on of path to help define and maintain the edge. Slow points including rest stops with seating (where appropriate) will be incorporated into the alignment.

Other Infrastructure Other infrastructure will include:

Fences Post and wire fences are proposed for the length of the trail. Timber posts which will have a weathered look and wire in between will provide protection to the dune vegetation while being aesthetically in-keeping with the surrounding materials. The alignment of the fence will be offset from the path, and will be generally straighter sections while the path will meander. The proximity of the fence to the edge of the path will vary from a minimum of 0.7m to 3m as a maximum. This will give visitors a feeling that they are not hemmed in, and is a safer offset

for bicycles. Native dune vegetation, existing or revegetated, will provide a physical and visual barrier, and soften the edge of the path.

Seating Seating will be minimal and located at strategic locations along the trail to maximise the user experience in places where there are important views or interpretive elements, while also providing a rest stop for users.

Wayfinding and interpretationSignage will be located at nodes directing users to key linkages, destinations and amenities. Wayfinding will be minimal and use timber and other natural materials. Graphics will be small and etched into the timber or on stainless steel panels incorporated onto posts. Interpretation, in-keeping with the character of the surrounding dunes, will also be implemented where appropriate.



Discovery Trail ConceptThe Discovery Trail concept for the Coast Park Tennyson Dunes is based on the following key strategies:

• Acknowledging distinct character and ecology; • Intention of slow speed meandering shared

trail similar to National Parks trail experiences; • Promoting education and ecotourism and

incorporating interpretation; • Creating logical and safe linkages north and

south to the proposed future extensions of Coast Park path to link Semaphore Park to Grange.

Concept OptionsThe following plans describe the preferred concept options for the alignment of the dunes. Each section is clearly illustrated and referenced with the identified positive and negative attributes of that section.

Concept Options

Sustainable trail with rock anchors at Banrock Station

Meandering trail at Craigburn Farm



SHEET 01Coast Park Tennyson Dunes | DRAFT - FOR DISCUSSION 18 January 2016 REV: B

Trail Alignment Options

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Trail option reference

Trail junction marker No.

Trail alignment option


Existing trail not required for Coast Park path link

Node - Locations TBC on fi nal on-site alignment

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Existingcar park

Existingcar park

Existingcar park

Existingcar park

Important Alyxia buxifolia patch

Extensive patches of Leucopogon parvifl orus present

Area of rare native nettles

Good views to water

9 Alignment has minor impacts on native shrubs. Most larger shrubs can be avoided or trimmed to accommodate path

9 Weedy/ degraded zone 9 Avoids high quality dune vegetation

2 Proximity to residents

This section of path will be removed and revegetated to reconsolidate dune vegetation - not an option

9 Enables decommissioning of long section of existing track to be returned to dunes.

9 Negligible impacts on dune vegetation in this area

2 Moderate impacts on dune through semi-degraded swale area

9 Follows existing track alignment

2 Need for increased clearance to open up corners of path. This will offset any benefits to be gained from this alignment.

9 Follows existing track alignment 9 Provides linkage


9 Enables decommissioning of existing track to be returned to dunes

9 Minimises dune fragmentation 9 Increased safety for cyclists

2 Traverses intact hind dune vegetation and will result in some disturbance

2 This section of trail take longer to construct in order to minimise disturbance to the sensitive habitat

9 Follows existing track alignment 9 Allows for potential interpretation of very old, remnant Leucopogan parviflorus species

2 Will require widening at node points

9 Follows existing track alignment 9 Allows visitors experience within the dunes

2 Fragmentation of dune



9 Minor (if any) impact on native vegetation

9 Allows decommissioning of track that fragments dune

9 Defragments dune vegetation


2 Existing alignment difficult to maintain due to coastal erosion/ deposition and sand movement

9 Very minor (if any) impact on native vegetation

9 Improved visitor experience. Unique opportunity for rest points and seating overlooking dunes and taking in views to beach.

9 Utilises change in level/ elevation 9 Decommissioning of existing North-South alignment will provide an environmental gain as the dune vegetation will readily regenerate and result in a less fragmented area of dune vegetation

9 Utilises an existing and well-used pedestrian path in front of dwellings

2 Proximity to residents 2 Balustrade required on side of steep

embankment

9 Avoids cutting through mounded area 9 Avoids heavy engineering solution 9 Minimises impact on dune vegetation

2 Requires trimming back and selective removal of native vegetation

9 Avoids good revegetation by resident 9 Avoids good fauna habit

2 Cuts through mounded area 2 Requires heavy engineered solution

which will widen construction footprint 2 Greater impact on dune vegetation

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Concept Options Plan 01 (Bournemouth Street to Estcourt Road)

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Node - Locations TBC on final on-site alignment

Existing trail (not required for Coast Path link)

Remnant/ highly significant existing vegetation

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SHEET 02Coast Park Tennyson Dunes | DRAFT - FOR DISCUSSION 18 January 2016 REV: B


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Important Helichrysum patch

Good Scaevola crassifolia patch

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Good Lepidosperma gladiatum Patch

Good Lepidosperma gladiatum patch

Good reveg maintained by resident

Norfolk island pine

Good native grasses

Good native grasses

Area where Leucopogon parviflorus present

KEY






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9 Negligible impact on dune 9 Alignment through degraded area 9 Defragmentation of dune 9 Avoids sensitive swale area


2 More difficult to construct and maintain 2 Impact on dune vegetation (esp. patch

of Lepidosperma gladiatum 2 Fragmentation of dune

9 Environmental gain due to larger and less fragmented area of dune

9 Avoids area of Lepidosperma gladiatum






2 Major sand drift issues and undulating path requires fill and modification to existing levels

2 Maintenance issues and reduced trail sustainability



2 Avoids area of revegetation


9 Ease of construction, therefore reduced impact


9 Defragmentation of dune 9 Ease of construction

2 Dissects area of high quality revegetation by adjacent resident


9 Defragmentation of dune 9 Ease of construction

2 Alignment through some good patches of native vegetation

2 Dissects area of high quality revegetation by adjacent resident



2 Major sand drift issues and undulating and winding track requires fill and modification to existing levels

2 Maintenance issues 2 Reduced trail sustainability


9 Through weedier area that supports less intact dune vegetation

9 Ease of construction, therefore reduced impact





2 Major sand drift issues and undulating track requires fill and modification to existing levels

2 Maintenance issues 2 Reduced trail sustainability 2 Fragmentation of dune



2 Maintenance issues and reduced trail sustainability




2 Maintenance issues 2 Reduced trail sustainability 2 Fragmentation of dune

9 Alignment through weedy area with less intact dune vegetation.

9 Ease of construction, so reduced impact on dunes

9 Less fragmentation of dune

2 Fragmentation of dune 2 Impact on Lepidosperma gladiatum 2 Proximity to residents

9 Alignment through weedy area

2 Path alignment constrained by proximity to property boundary and requirement to avoid Bushland Condition Monitoring (BCM)

9 Defragmentation of dune 9 Negligible impact on biodiversity 9 Alignment through weedy area (abundance of Veldt Grass present)

2 This alignment follows the periphery of the dunes and is therefore not along desire lines for pedestrians and cyclists.

2 Risk of pedestrians traversing the dunes 2 Extra construction costs (added length)

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Concept Options Plan 02 (Estcourt Road to Shore Court)

9 Positives 2 Negatives

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Node - Locations TBC on final on-site alignment

Existing trail (not required for Coast Path link)

Remnant/ highly significant existing vegetation

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Treatment Options - Visualisations

BEFORE

• Depression through dunes

• Weed management occurring in this area

BEFORE

• Degraded area of dunes along property boundary

AFTER

• Locate path through degraded area of dunes

AFTER

• Locate path through lower part of dune system for less visual impact

BEFORE

• Sightline issues on tight corner

• Fence is visually and physically obtrusive

AFTER

• Widening of corner

• Soften by opening up angle of fence alignment



Treatment Options - Detail Plans

Widened section of trail at base of incline for safe passing

Larger rocks or timber at strategic locations along trail

Larger rocks at strategic locations along trail

Post and wire fence set back 0.6m to 3m from path edge

Flat stone edge where potential erosion occurs, or to define edge of narrow path section/ choke

Flat stone edge where potential erosion occurs, or to define edge of narrow path section

Allow planting adjacent path (revegetation and existing)

Allow planting adjacent path (revegetation and existing)

Narrower trail (1.5-1.8m) at top of incline with good sightlines

Typical trail width 1800mm - 2400mm

Post and wire fence set back 0.6m to 3m from path edge

Pullover/passing zone with interpretation material and potential limestone seating wall

Varied surface texture to define node

Edge restraint between different materials (flat stone or similar)

0.6m flat zone to edge of path

0.6m flat zone to edge of path

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Typical Path Layout (1800-2400mm)

Scale 1:50 @ A3

Seating / Passing Node

Scale 1:50 @ A3N



Discovery Trail Node/East West Link

DETAIL PLAN

Scale 1:50 @ A3

Potential seating at locations where practicable

PROPERTY BOUNDARY (INDICATIVE)

Discovery trail width 1800mm. Material to be determined

Post and wire fence set back 600-2000mm from path edge

600Mm at grade shoulder to path

Revegetate degraded area along property boundary

Allow planting adjacent path (reveg and existing) maintain as low groundcovers / sedges /grasses


Larger rocks or timber posts for signage at strategic locations along trail

East west link offset to slow movement through intersection

Existing east west path alignment

New fence to tie into existing dune fence

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SEATING NODE

Scale 1:50 @ A3

Treatment Options - Detail Sections

DUNES & VEGETATION PROTECTED




200 - 500MM

200 - 500MM

200 - 500MM





Post and wire fence

Post and wire fence

Potential for use of flat stone edge to minimise extent of bascourse

Post and wire fence

Post and wire fenceFlat stone edge to prevent potential erosion

Post and wire fence where vegetation permits

Stone or timber seating where appropriate

1500 Wide path where constrained by existing high quality vegetation and topography

Stabilization zone.

Could be narrowed to 200mm with subsurface rock. Exposed only in outside radius of a tight curve to allow for extra runoff buffer zone

Stabilization zone

1500MM WIDE PATH

PATH

1800 - 2400MM WIDE PATH

2500 - 3000MM WIDE PATH

1200

SEATING NODE

PATH AT CHOKE POINT (1500MM WIDTH)

Scale 1:50 @ A3

TYPICAL PATH (1800-2400MM WIDTH)

Scale 1:50 @ A3

PATH IN DEGRADED AREAS (2500-3000MM WIDTH)

Scale 1:50 @ A3




Construction Methodology

A variety of site responsive methods can be used for the construction of the shared-use trail ranging from using hand tools and volunteers, to having the trail constructed by professionals with small scale trail building machinery. The construction methodology below has been prepared based on the design team’s understanding of the site and construction access constraints and the needs and expectations of the Dunes Group. Due to the sensitive nature of the project, it is advised that the nominated trail constructor has within their construction team an ecologist who will be present on site at all critical setout and construction phases of the project.

Pre-Construction ActivitiesAttention to detail and true minimal impact will be paramount within this project and all works and vehicle movements will be confined to the nominated corridors. All machinery and imported products will be weed seed free and require inspection prior to entering the site. There are very few woody weeds present (most of these have been contained by the ongoing efforts of the Dune Group). All shrubs present are predominately native or endemic to the dunes and as a result it is imperative that care should be taken to avoid disturbance to all vegetation. Weed species that do exist are grasses or herbs and garden escapees closer to the adjoining residential properties.Prior to any construction activities being carried out, the following steps shall be undertaken and approved by the project Superintendent;

• Preparation of a Site Access and Management Plan

• Preparation of a Vegetation and Corridor Management Plan

• Preparation of Construction Methodology Plan. This will be mandatory as plant/ equipment (eg. micro/mini excavators, transporters and loaders) as well as a range of compaction tools and an extensive amount of hand tooling/detailing and construction that will be required.

• Highlight vegetation to be protected and retained

• Install protection/ temporary fencing where works are to be conducted to close off access while in construction and protect vegetation

• Transfer as provided documentation/drawing set out to ground via flagging of the alignment (this will be a hold point)

• Micro-design and final critique of alignment to confirm any changes required to minimise disturbance to areas of high quality vegetation

Site Access and Management Plan (SAMP)The SAMP will need to include the following items as a minimum;

• Major Transfer sites . These will require storage of approx. 100 tons of various materials able to be deposited by a 14 tonne truck and 10 tonne trailer and within several hundred meters from transfer site to installation.

• Areas for storage of skip bins, materials such as sub-base and surfacing material.

• Compound with container and an amenities block where appropriate.

• Parking for several trucks, trailers and cars will require minor sites closer to the works and be located where appropriate.

• Management of existing stockpiles of spoil and demolition material to be utilised on site where appropriate.

Use of small machinery to achieve required compaction with minimal disturbance

Hand toolsSmall scale machinery within path corridor

• Management of seed collection, plant salvaging)

• Minor transfer sites and turnarounds for small machinery in already disturbed/ degraded areasRefer to Transfer Sites Plan on page 15 for locations.

Alternative alignments for user groups to transit site while under construction will use existing corridors were practical however alternatives may be required pending final alignment selected. Adequate site signage clearly identifying access routes, use of bunting and barrier mesh and ensuring site visitors and users do not impact on undisturbed areas within the dune system will be implemented.

Vegetation and Corridor Management Plan (VCMP)A VCMP will be prepared with the assistance of the Dunes Group’s involvement ( It is noted that representatives from the group will require white cards and appropriate PPE and inductions to site along with a sign in/out policy for any access required within the construction site). The VCMP will involve the preparation of a plan that clearly illustrates the following:

• Identifying key species for protection • Vegetation to be salvaged • Seed collection as nominated • Transplanting of vegetation as nominated • Removal of vegetation as nominated



SHEET 02Coast Park Tennyson Dunes | DRAFT - FOR DISCUSSION 17 November 2015 REV: A


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MINOR SITES: Potential minor sites for transfers and small stockpiles.

MINOR SITE: Location for storage of plant and plant parking only due to restricted access.

Tight access not suitable for importing materials. Bollards and driveways adjacent laneway may also restrict access.

SHEET 01Coast Park Tennyson Dunes | DRAFT - FOR DISCUSSION 17 November 2015 REV: A


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Existingcar park

Existingcar park

Existingcar park

MINOR SITE: Minor Transfer site for small stockpiles

Services junctions 1-2, to residential/ council land boundary

MINOR SITE: Location for temporary stockpiles and staff parking

Tight access not suitable for importing materials. Bollards and driveways adjacent laneway may also restrict access.

Existing track used as transfer site, turnaround area, screening and temporary storage site, while trail in construction.

MAJOR SITE: Major transfer site for large stock piles, equipment storage and plant parking.

This site services junctions 2-6, approx 600m of trail. Services junctions 6-13, approx 1000m. Requires 3000 return trips (excluding water carting, sand/veg transfering).

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Transfer Sites Plan



• Disposal of vegetation as nominated • Final trail alignment (shown on a scaled plan

with critical dimensions where appropriate)

Path Set OutOnce the final trail alignment is documented (‘for construction’ drawings issued to contractor), the Contractor will set out the alignment of the path and node points, on the ground. This is a ‘hold point’ which means it will need sign off from the superintendent/ dunes group/ landscape architect before proceeding with the next step i.e. before any construction commences. These steps will be followed for each section of path.

Path Construction The following construction methodology shall be used for all new path works.

• After set out and alignment confirmed, remove vegetation (where required) and demolishing existing infrastructure no longer required. Items for removal will primarily be done by hand with some mechanical removal for heavier items.

• Excavate the existing ground by mini excavator to near level.

• Hand excavate where works are required within 1.0m of existing tagged specimens of major significance. (Tagging of specific specimens will occur prior to procurement).

• Soil/ material/ sand not required for the installation of surface treatment will be carefully removed, stockpiled and reused on site where appropriate.

• Excavate to final levels (final trim) • Condition and compact substrate using mini

loaders, rollers and hand compactors. • Import sub-base material and compact at

150mm intervalsPath construction Images

1 2 3

4 5 6



• Trim sub-base to level out • Condition and import selected/nominated

surface treatment • Shape and compact to 100mm min

Passive drainageNotched out areas - nicks, rolling grade dips and grade reversals will be installed regularly as part of the onsite micro design and forms part of the hold point. Anchors should be placed to enhance/reinforce passive drainage. Outward-sloping or crowning is to be installed/maintained throughout.

Junctions The outline below gives the general approach to path junction treatments. It is noted that further investigation is required for each location to ensure the most sustainable and safest design approach. The final size and location of junctions will be determined through on-site survey and setout. Treatment is required where east-west paths meet the north-south path numbered from 1 at the southern end to number 13 at the northern end. Junctions shall adhere to the following design principles;

• Alignments shall be offset to avoid direct crossings from east to west

• Junctions/ decision points shall be well-anchored using salvaged timber or limestone boulder.

• Provide textured surfaces to act as slow points. These can be either inlaid rock, reclaimed jetty timber or other suitable agreed surface finish.

• Provide directional signage/ wayfinding markers

• Widened approaches / increased view lines to minimise user conflicts

• Incorporate interpretive information and seating at key locations

• Educational signage alerting users to upcoming junction

Retaining Walls and EdgesA selection of retention treatments to stabilise steep slopes will be required in some locations along the edge of the path. Retaining heights wil be kept below 1.0m to avoid heavy engineered solutions and will be made with materials as follows;

• sand covered coir logs that can include pocket planting

• riprap walls • drystone walls • ballast walls and structures

Wall materials shall be brought to locations in small quantities to avoid the need for additional lay-down space within the construction site area.

AnchorsAnchors are structures or items utilised to help form/hold/define the intended shape and flow of the desired trail alignment.Materials considered suitable for use as anchors include selected limestone, aged timber, earthen swales/mounds and existing and planted vegetationFlatter ground may require anchors on the inside as well as the outside edge of bends in the trail alignment to define the trail and assist with keeping users on the trail. Anchors shall be carried into the site using mini loaders or by hand. Smaller rocks will be placed in a concrete or mortar haunch to ensure stability and larger rocks will be typically buried 1/3rd in ground.

Limestone rock anchor Weathered

timber log anchor

Use of either stone or timber for anchors and informal seating

Recycled jetty timber used as seat

Typical trail treatment around corner Timber seating node with edge definition

Use of hand compaction for reinforced shoulder



FencingAt the time of writing this report, it is proposed that fencing shall be provided along the length of the shared use trail to minimise access into the dunes. The proposed fencing material for the site is to be sustainably sourced timber with tensioned cable wire, however this may be subject to change in further detailed design stages of the project. The fence will be set back a minimum of 0.7m and will range up to a maximum of 3m offset from the path to ensure it blends with the coastal dune environment. The exact fence alignment requires further investigation on a site-by-site basis. New fence materials will be:

• Aged timber posts, raw (cambio), sawn, PAR • Top wire (UV stabilized plastic coated 3.15

high-tensile sighter wire) or similar, white is recommended so it can be seen by cyclist and times of low light, alternatively post at more regular intervals or timber top rail.

• Intermediate wire TBC • Height of fence TBC

A sensitive installation approach of the fence will be required due to the existing remnant vegetation, fence construction eg digging or pile-driving post holes and stringing wires through large shrubs has the potential to damage that vegetation. In some cases, where there’s no option to go around large shrubs, the fence with stop at one side of the large shrub and continue on the other side (allowing for maturing/ further growth).

Demolition/ Deconditioning/ NaturalisationConstruction of the new shared-use path will require the removal of fencing/ signage/ seating

and existing tread material where nominated. It is proposed that the demolition of existing structures will consist of careful removal by hand or machinery within the existing corridor were practical. Decommissioning of existing path surfaces will require precise and total removal of all imported products. Due to potential contaminants in the existing surface materials, all surfaces will required screening of sand from reusable mineral products and careful removal of unsuitable material from site under strict environmental management controls. It is recommended that all mineral product recovered from redundant tread be utilised on site to assist with stabilisation of new path surfaces. This will require transferring of material over extended lengths of effected corridors utilising under (light) loaded machinery to minimize/reduce the further contamination of the site.Naturalisation/ Softening of construction-affected areas and areas of redundant/rationalised trail with process and materials salvaged and stockpiled during construction.

Revegetation and Maintenance programSelective vegetation maintenance and revegetation shall be undertaken as follows;

• New revegetation on edges of the path alignment (up to 1.5m from edge of path) shall be low clumping and non-spreading planting (600mm max height)

• Older larger vegetation close to the path will need to be maintained or removed to ensure clear sightlines are retained

need for this. Specific design strategies aimed at reducing maintenance issues include;

• Appropriate path material application and alignments sized to cater for best/ low impact maintenance equipment

• Alignment of path designed to minimise maintenance (mitigating sand drift).

• Emphasis on appropriate species selection nominated and planted in selected locations to allow for it’s mature size and as a result minimise the need for pruning.

• Sand build up will occur (severity dependent on final alignment), thus trail loading will account for small maintenance vehicular access.

• Natural regeneration after completion of trail construction will need to be managed including removal/transplanting of inappropriate sized species and environmental weeds before they become problematic eg encroachment and screening of sight lines.

Trail MaintenanceCurrently, it is evident that the existing paths and infrastructure suffer from a lack of maintenance. There is evidence on-site of existing bobcat damage such as gouging of paths, damaged fencing, as well as slashing and hard pruning of shrubs adjacent path. It is intended that the new design and management will negate the

Selective vegetation removal by hand methods

Ravine des Casoars, Kangaroo Island



Appendix - 1

The following is a report prepared by T & M Ecologists which provides information and a reference guide on remnant and native plant species and the native fauna that exist in the Tennyson Dunes, along with recommendations and an analysis of the trial alignment options.



Tennyson Dunes Shared Use Path – Preferred alignment

Junction Biodiversity issues/impacts Comments 01‐02 Traverses degraded dune vegetation (Photo 1) with a groundcover dominated by grassy and

herbaceous weeds including *Bromus diandrus, *Lagurus ovatus, *Cynodon dactylon, *Brassica tournefortii and infestations of Soursob (*Oxalis pes‐caprae) which are not visible in the drier months. The patch of mature planted Grey Saltbush (Atriplex cinerea) would be impacted, and the removal or trimming of several Cushion Fanflower (Scaevola crassifolia), Ruby Saltbush (Enchylaena tomentosa), Sea‐berry Saltbush (Rhagodia candolleana), Pigface (Carpobrotus rossii) would be required.

Alignment close to the property boundaries (Photo 2) avoids much of the dune vegetation. Some minor trimming may be required of 1 x Coast Daisy‐bush (Olearia axillaris), 2‐3 Sea‐berry Saltbush and several patches of Native Sarsparilla (Muehlenbeckia gunnii).

Removal of a scrambling Ruby Saltbush which is growing through the existing fence between properties and dunes will require removal.

Minor impacts. Most native shrubs can be avoided or trimmed/pruned. Many of these shrubs will happily tolerate trimming or can be readily revegetated in adjacent areas.

02‐03 First half of alignment is within a very weedy and degraded area close to the property boundaries. Native vegetation cover is estimated to be about 10%. Some minor trimming or removal of very patchy Sea‐berry Saltbush, Short‐stem Flax‐lily (Dianella brevicaulis), Coast Sword‐sedge (Lepidosperma gladiatum) and scrambling Ruby Saltbush growing through the fence may be required.

Also present are garden escapes including a Tamarisk, Bird of Paradise, Ivy Geranium, Geraniums, Aeoniums, Elephant Ears. Some of these species are considered invasive i.e. may reproduce and spread through the dunes.

Second half of alignment is through a degraded swale (Photo 3), dominated by Spinifex (Spinifex hirsutus) and Pigface. Other native species present include Sea‐berry Saltbush, Coastal Wattle (Acacia sophorae), Coast Daisy‐bush, Muntries (Kunzea pomifera), Knobby Club‐rush (Ficinia nodosa), Coast Sword‐sedge, Coast Bonefruit (Threlkeldia diffusa). Native cover estimated to be 35% and weed cover 25% with bare ground and litter comprising 40%.

Negligible impacts along property boundaries. Moderate impacts through degraded swale. Avoid patch of Seabox (Alyxia buxifolia).

03‐04 First section of alignment traverses intact hind dune vegetation and will result in some disturbance (Photo 5).

TDG’s preferred alignment would have less impact on native vegetation, although the need for increased clearance at sharp corners may offset any benefits to be gained from this alignment.

Moderate ‐ high impacts in intact hind dune may be offset by the decommissioning of the existing alignment and its return to a less fragmented dune community (Photo 4).

This area is likely to provide suitable habitat for



Junction Biodiversity issues/impacts Comments Where the alignment meets the existing trail alignment, there are scattered native plants

which are growing in the pathway, including 1 x Coast Daisy‐bush (Olearia axillaris) growing through the fence, a seedling Coastal Wattle, Austral Stork’s Bill (Pelargonium australe), Knobby Club‐rush, Spinifex and Pigface. These will require removal and/or relocation. The pathway should require little (if any) widening in this area, however some removal or minor/major trimming may be necessary.

Painted Dragons (Ctenophorus pictus). Retain and protect large Coast Beard‐heath

(Leucopogon parviflorus) (Photo 6) adjacent existing path. These shrubs are probably very old and therefore of significance.

Recommend relocation of individual plants where possible or collection of seeds, divisions and cuttings for revegetation in adjacent dunes.

Careful bunting and protection of adjacent vegetation will be necessary during trail construction.

04‐05 The pathway follows the existing alignment and should require little (if any) widening in this area. On the corner where the path will turn east it is very weedy and degraded. It may be possible to retain the larger of the 2 Coast Daisy‐bushes and the small Sea‐berry Saltbush beneath it.

Negligible impact. Careful bunting and protection of adjacent

vegetation will be necessary during trail construction.

Decommissioning of East‐West tracks to the beach will provide an environmental gain as the dune vegetation will readily regenerate in these areas.

05‐06 Alignment close to residential properties is preferred as there will be very minor (if any) impact on native vegetation.

Negligible impact Decommissioning of existing North‐South

alignment will provide an environmental gain as the dune vegetation will readily regenerate and result in a less fragmented area of dune vegetation.

06‐07 It will be possible to avoid remnant and planted vegetation in this more degraded hind‐dune area where there is high cover of weeds such as Perennial Veldt Grass (*Ehrharta calycina) and native vegetation is quite fragmented (Photo 7).

TDG’s proposed alignment would not benefit this back dune given its current condition. To avoid the Bushland Condition Monitoring (BCM) site, a 30m x 30m square quadrat which

is marked by two metal stakes to show the location of an area used to monitor change in

Negligible impact This area is described in the 2014 Biodiversity

Action Plan for Tennyson Dunes as a ‘Rehabilitation’ Zone due to its high projective foliage cover of Perennial Veldt Grass and sparse cover of natives. A broadscale revegetation



Junction Biodiversity issues/impacts Comments vegetation condition in the dunes, it may be necessary to bring the path further east . program is recommended in this area.

NOTE: It appears that Veldt Grass may have been recently slashed and sprayed in this area.

07‐08 Alignment is closer to property boundaries than the existing narrow ‘goat track’ which winds through this section of the reserve.

Vegetation in moderately good condition in this section (Photo 8). Cover of Veldt Grass estimated to be 15‐20%.

Prefer to keep the alignment as close to property boundaries as possible as these areas tend to be weedier and support less intact dune vegetation.

Impacts range from negligible – moderate – high through this section, however they are offset by the decommissioning of the existing North‐South alignment. This will provide an environmental gain as the dune vegetation will readily regenerate and/or be revegetated, resulting in a larger and less fragmented area of hind‐dune and swale vegetation.

Careful bunting and protection of adjacent vegetation will be necessary during trail construction.

08‐09 Vegetation in moderately good condition for first 10m or so of this section(Photo 9), but then deteriorates with dense Veldt Grass and an active fox den.

09‐10 Vegetation is patchy, ranging from patches with no natives to good areas of Scaevola and Coastal Sword‐sedge (Photo 10).

10‐11 Supports good patches of Scaevola at beginning of this section, then condition deteriorates. There is a well‐maintained indigenous coastal garden in front of the most northerly house in

this section which would be impacted. 11‐12 Vegetation is patchy, ranging from highly degraded with the encroachment of garden escapes to

moderately good (Photo 11). 12‐13

* Denotes introduced species

Photo 11. Junction 11‐12. Facing S. There are some reasonably good patches of native vegetation in this section which will be impacted.

REFERENCES Cordingley, SP & Petherick, CE, 2006. Vegetation Management Plan Tennyson Dunes Reserve, Urban Forest Biodiversity Program, Adelaide. EAC Ecological Evaluation, 2014. Tennyson Dunes Reserve Biodiversity Action Plan, Adelaide & Mt Lofty Ranges Natural Resources Management Board. Prescott, A, 2012. It’s Blue With Five Petals, Adelaide, South Australia.



Species Propagation/Relocation/Revegetation Notes Species Propagation/Relocation Acacia longifolia var. sophorae

Seed

Alyxia buxifolia Long‐lived. Can be grown from cuttings or seed but slow‐growing. Atriplex cinerea Readily propagated from seed, cuttings or rooted pieces. Collect seed from existing bushes at Bournemouth Street end. Carpobrotus rossii Grown easily from cuttings.

Seed Dianella brevicaulis Division of clumps.

Seed propagation can have erratic results. Enchylaena tomentosa Seed Ficinia nodosa Division of clumps – take part of plant with juvenile roots.

Seed Kunzea pomifera Cuttings are the preferred method of propagation

Difficult to propagate from seed Lepdosperma gladiatum Propagation by seed has proven to be very difficult.

Division in winter months has proved more reliable but plants often die back and are slow to recover. Trim back foliage when dividing.

Leucopogon parviflorus Can be propagated from seed but difficult and slow‐growing. Muehlenbeckia gunnii Seed Myoporum insulare Seed Olearia axillaris Seed or cuttings Pelargonium austral Seed Rhagodia candolleana Seeds propagate easily without treatment. Scaevola crassifolia Seed can take several months to germinate.

Often grown from cuttings Spinifex hirsutus Take fresh runners with 3‐4 nodes that have not quite set new roots. Bury in moist sand with a few leaves above ground. Tetragonia implexicoma Predominantly grown from cuttings Threlkeldia diffusa Seed propagation can be unreliable.

Take cuttings in late winter to early spring.



PHOTOS

Photo 1: Junction 01‐02. Facing NE from Bournemouth Street entrance. Shows weedy groundcover. Many native shrubs can be avoided or trimmed.

Photo 2: Junction 01‐02. Facing N where alignment meets the boundary fence. Very weedy and degraded.

Photo 3: Junction 02‐03. Facing S. Alignment is through a degraded swale area. Moderate impacts.

Photo 4: Junction 03‐04. Facing N. Shows track to be decommissioned and dune vegetation reinstated. Spinifex, Knobby Club‐rush, Pelargonium and Pigface are already colonising this area. Given time many other native species will readily regenerate.



Photo 5: Junction 03‐04. Facing N. First part of this section traverses a relatively intact swale which would be providing potential habitat for a range of fauna species, including the Painted Dragon.

Photo 6: Junction 03‐04. Old Coast Beard‐heath to be protected and retained

Photo 7: Junction 06‐07. Facing N. Very sparse native shrubs and trees across this area which the alignment should be able to avoid.

Photo 8. Junction 07‐08. Facing N. Vegetation in moderate condition



Photo 9: Junction 08‐09. Facing N. Vegetation in moderate condition at start of this section, but soon deteriorates. Its patchy.

Photo 10: Junction 10‐11. Facing N. Shows good patches of Scaevola.

Photo 11. Junction 11‐12. Facing S. There are some reasonably good patches of native vegetation in this section which will be impacted.

REFERENCES Cordingley, SP & Petherick, CE, 2006. Vegetation Management Plan Tennyson Dunes Reserve, Urban Forest Biodiversity Program, Adelaide. EAC Ecological Evaluation, 2014. Tennyson Dunes Reserve Biodiversity Action Plan, Adelaide & Mt Lofty Ranges Natural Resources Management Board. Prescott, A, 2012. It’s Blue With Five Petals, Adelaide, South Australia.



Appendix - 2

Glossary of Terms



Fragmentation of duneTrail alignment breaks up/ dissects colonies of vegetation

Defragmentation of dune Trail alignment allows for consolidation of dune vegetation and for plant colonies to expand and animal species to move around without interruption

Ease of Construction Trail alignment enables greater simplicity for grading and leveling of site. Trail constructed on relatively level surface and not constrained by undulations, kinks or tight bends.

Heavy engineered solution An alignment that sees more complexities such as requiring cutting or filling to enable a sustainable trail

Maintenance issuesTrail alignment subject to future sand drift/ movement or conditions that depend on continual tread sweeping

Glossary of Terms

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