northland regional council · penstock intake clear of weed and debris (see figure 2). penstocks...

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31 October 2018 Attention: Stuart Savill/Glenn Mortimer Northland Regional Council ref. 14119.blh Email: [email protected] [email protected] Dear Stuart/Glenn RE: WAIRUA HEPS – RESPONSE TO REQUEST FOR FURTHER INFORMATION – APP.004845.01.02 This is a response to the request for further information contained in your letter dated 10 September 2018. Each of the items is addressed as follows: 1. The infrastructural elements of the HEPS as it now exists are well explained in the Assessment of Environmental Effects (AEE) but it is understood that several structural changes have occurred since the current consents were issued, e.g. canal widening, automated penstock grid weed clearance and, possibly, weir height raising by 700mm. For the sake of completeness, please list and explain the purpose of any water use-related structural changes made to the HEPS since 1993 when the station was purchased by Northpower. Answer: Table 1 lists and explains the purpose of the water use-related structural changes made to the HEPS since 1993 when the HEPS was purchased by Northpower. Table 1 Structural changes made to HEPS since 1993 Component Description Auxiliary Spillway Northpower installed the Auxiliary Spillway in 1995 in accordance with Permit 00.004845.01.01. No structural changes have been made to the auxiliary spillway since its construction (see Figure 1). Diversion Weir (Consisting of the flap gates and vertical gate) Changes were made to the diversion weir structure (consisting of the flap gates and vertical sluice gate) between 1995 and 2008 to improve the ability of Northpower to control water levels. The HEPS was fully automated by 1995. The installation of hydraulic actuators and the removal of the counter weight was also undertaken and completed in 2008. The flap gates were replaced in 2008. The dimensions of the flap gates were unchanged and were fitted into the existing concrete weir structure. This change had no effect on the capacity of the scheme or the river storage (see Figure 1). Canal Intake and Canal Maintenance Following the installation of a fourth generator and a storm event in 2007, canal maintenance works were undertaken during 2008 and 2009 to address erosion and seepage issues. Approximately 15m of the canal (beginning at the intake structure) was lined with concrete and the canal wing walls were repaired (see Figure 1). Headpond Northpower raised the headpond wall 75mm in 2013. The purpose of this change was to accommodate the height of the existing penstock intake wall. The existing fish migration facility was installed at the same time. A siphon pipe was installed between the Headpond and the trough to allow for migrating eels to enter when

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Page 1: Northland Regional Council · penstock intake clear of weed and debris (see Figure 2). Penstocks & Generator Generator 4 (G4) was installed by Northpower and completed in 2007. At

31 October 2018

Attention: Stuart Savill/Glenn Mortimer

Northland Regional Council

ref. 14119.blh

Email: [email protected]

[email protected]

Dear Stuart/Glenn

RE: WAIRUA HEPS – RESPONSE TO REQUEST FOR FURTHER INFORMATION – APP.004845.01.02

This is a response to the request for further information contained in your letter dated 10

September 2018.

Each of the items is addressed as follows:

1. The infrastructural elements of the HEPS as it now exists are well explained in the

Assessment of Environmental Effects (AEE) but it is understood that several structural

changes have occurred since the current consents were issued, e.g. canal widening,

automated penstock grid weed clearance and, possibly, weir height raising by

700mm. For the sake of completeness, please list and explain the purpose of any water

use-related structural changes made to the HEPS since 1993 when the station was

purchased by Northpower.

Answer:

Table 1 lists and explains the purpose of the water use-related structural changes made to the

HEPS since 1993 when the HEPS was purchased by Northpower.

Table 1 Structural changes made to HEPS since 1993

Component Description

Auxiliary Spillway Northpower installed the Auxiliary Spillway in 1995 in accordance with Permit

00.004845.01.01.

No structural changes have been made to the auxiliary spillway since its construction (see

Figure 1).

Diversion Weir

(Consisting of the flap

gates and vertical

gate)

Changes were made to the diversion weir structure (consisting of the flap gates and

vertical sluice gate) between 1995 and 2008 to improve the ability of Northpower to control

water levels. The HEPS was fully automated by 1995.

The installation of hydraulic actuators and the removal of the counter weight was also

undertaken and completed in 2008.

The flap gates were replaced in 2008. The dimensions of the flap gates were unchanged

and were fitted into the existing concrete weir structure. This change had no effect on the

capacity of the scheme or the river storage (see Figure 1).

Canal Intake and

Canal Maintenance

Following the installation of a fourth generator and a storm event in 2007, canal

maintenance works were undertaken during 2008 and 2009 to address erosion and

seepage issues. Approximately 15m of the canal (beginning at the intake structure) was

lined with concrete and the canal wing walls were repaired (see Figure 1).

Headpond Northpower raised the headpond wall 75mm in 2013. The purpose of this change was to

accommodate the height of the existing penstock intake wall.

The existing fish migration facility was installed at the same time. A siphon pipe was installed

between the Headpond and the trough to allow for migrating eels to enter when

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operated. This facility provides for the capture and transfer of eels past the HEPS and for

cultural harvest (see Figure 2).

Headpond Spillway As a result of rock slippage at the Headpond, spillway chutes and the cliff face were

reinforced in 2003. Northpower also installed a plunge pool to provide for migrating eels at

the same time (see Figure 2).

Penstock Intake Repairs to the automatic weed rake at the penstock intake were completed in 2008. The

purpose of the automatic weed rake is to ensure the penstock intake is kept clear of weed

and debris. The weed rake is triggered by a differential pressure sensor at the penstock

intake screens. The sensor is activated by the differential water level across the intake

screens. The automation of the weed rake replaced the manual requirement to keep the

penstock intake clear of weed and debris (see Figure 2).

Penstocks & Generator Generator 4 (G4) was installed by Northpower and completed in 2007. At the same time

the Generator (G3) penstock was also replaced and repositioned to allow for the

installation of G4 (see Figure 3).

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Figure 1 - An aerial view of the HEPS. In view is the diversion weir, canal intake, the canal and auxiliary spillway. Structural changes made to these

HEPS scheme components between 1993 and present are also noted above.

Canal Intake Structure

Canal – 15m concrete lining,

canal wing walls repaired.

Diversion Weir Structure – Flap Gates

replaced and automated along with the

Vertical Sluice Gate.

Flap Gates

Auxillary Spillway

Vertical Sluice Gate

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Figure 2 - An aerial view of the HEPS. In view is the Headpond, Penstock Intake, Fish Migration Facilities.

Weed Dump Penstock Intake

Penstock Intake Screens &

Automatic weed rake

Penstock Trough & Fish Migration Facilities

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Figure 3 - An aerial view of the HEPS. In view is the Headpond, Penstock Intake, Fish Migration Facilities and Penstock Pipes.

Weed Dump

Fourth Penstock & Generator installed

Penstock Intake & Automatic weed rake

Penstock Trough & Fish Migration Facilities

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2. Details of the actual day-to-day operation of the river diversion elements (as

opposed to the power generation elements) are not made clear in the AEE. In

particular:

a. please explain the differing purpose(s) and use of the vertical sluice gate versus

the diversion weir gates.

b. please explain how operational decisions are made with respect to raising or

lowering the vertical sluice gate and/or the diversion weir flap gates during:

i) medium to high flows;

ii) low flow periods including droughts.

Answer:

The layout of the diversion weir structure (consisting of the flap gates and the vertical sluice

gate) is shown below in Figure 4. Figure 4 also indicates the location of the auxiliary spillway.

Figure 4 - An aerial view of the HEPS. In view is the diversion weir, canal intake and auxiliary spillway.

Diversion Weir - Vertical Sluice Gate

The vertical sluice gate is a flushing gate for the purpose of allowing water to flow past the

diversion weir at the lowest point in the river. The vertical sluice gate will stop or regulate flow

when required. Prior to the automation and replacement of the flap gates, the vertical sluice

gate was the primary water level control. The current operation of the vertical sluice gate

allows for maintenance of the flap gates and full river flow during periods of high flow.

Diversion Weir – Flap Gates

During operation the flap gates control the water level at the diversion weir to provide water

flow down the canal intake. During floods, the flap gates are down to allow river flow past

the diversion weir.

The flap gates are operated automatically and rise or drop in order to maintain a certain

flow at the canal intake. The flow is based on an operating river level set point of 2.2m

Flap Gates

Canal Intake Structure

Vertical Sluice Gate Auxillary Spillway

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measured at the canal intake by Northpower’s Supervisory Control and Data Acquisition

(SCADA) system1.

Figure 5 - Diversion Weir Structure consisting of Vertical Sluice Gate and Flap Gates

Operational monitoring and decision making - medium to high flows

Northpower’s SCADA and security systems monitor the HEPS, including diversion weir water

levels, tail water level, canal flow, gate positions and generation output. In addition,

Northpower considers national and regional rain fall, river levels and weather forecasts.

Northpower also considers communications from neighbouring landowners and community

relating to high water levels.

Northpower undertakes monitoring and responds accordingly during medium to high flows

as set out below:

1. Northpower regularly monitors forecasts provided by MetService (including the Severe

Weather Outlook, Severe Weather Watch, Coastal Warnings and Oceanic Warnings)

and is in regular communication with Civil Defence Northland and local lifelines

colleagues. In the event of a MetService Severe Weather Warning, Northpower staff or

contractors are dispatched to the HEPS to “man” the station during the anticipated

flood event.

2. Northpower also monitors pre-storm event river levels at the diversion weir and station tail

water levels. Those levels are compared to the river level and flow rate on the Wairua

River at the Northland Regional Council’s Purua Monitoring Station. This monitoring

particularly considers the rate of increase in flow and river level rise. In the event of high

river levels (exceeding 50.2m RL), Northpower will override the automatic controls and

manually lift the vertical sluice gate if it is considered that the river level is rising too

quickly and/or debris is collecting at the diversion weir and needs flushing past the weir;

3. In the event of an emergency, at the request of the District or Regional Councils, Civil

Defence Northland or emergency services, Northpower can override the HEPS

automatic controls.

1 (see Attachment 1 for a screen shot SCADA system)

Vertical Sluice Gate Flap Gates

Diversion Weir Structure

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Operational monitoring and decision making - low flows

Northpower undertakes the following monitoring and responds accordingly during periods of

low flows:

1. Northpower’s SCADA and security systems monitor the HEPS;

2. During periods of low flows, Northpower monitors MetService Severe Drought weather

warnings;

3. If there is not enough flow to efficiently run a generator, Northpower will pond the river

to keep it at a consistent level of 2.0m at the canal intake. Northpower can raise the

vertical gate and allow flow past the diversion weir. The continuation flow of 30L/s is

maintained via the vertical sluice gate orifice;

4. If the water level at the canal intake reduces below 1.0m, Northpower will reduce

generation to ensure the continuation flow of 30L/s is maintained through the vertical

sluice gate orifice.

5. If the water level at the canal intake is likely to reduce below 0.9m, Northpower

suspends generation to ensure that the continuation flow of 30 L/s is maintained

through the vertical sluice gate orifice.

3. Please explain the basis for the 30 cumec diversion rate applied for when the

combined turbine outflow with all four units operating is apparently

16 cumec (Hawthorn and Geddes Report s4.1 Table 1) and it is indicated in AEE

Appendix 11 Consultation Information that a 20 cumec rate has been actively

considered.

Answer:

Northpower approached consultation openly and actively and considered both a reduced

diversion rate based on generation output and an unchanged diversion rate. Following

consultation and further technical assessment Northpower have applied for an unchanged

diversion rate on the basis of the following considerations:

• Northpower is continually maintaining and repairing its assets, indeed, the

maintenance of operational technology and repairs to penstock equipment is one of

the reasons for this application (see AEE, section 2.1.2). Such maintenance and repairs

may in the future include installation of new technology generators. It is likely that such

generators would require higher inflows (potentially up to 20 cumecs). So as not to

preclude such future upgrades, Northpower decided to maintain the existing diversion

rate;

• The results of the assessment of environmental effects determined that the effects of

the HEPS operating with an unchanged diversion rate would be no more than minor

and can be adequately managed by proposed mitigation measures and proposed

conditions of consent;

• The continued operation of the HEPS and the continued benefits it provides to the

Northland community and the Northpower Trust relies on the HEPS being economically

viable. Lower diversion rates will ultimately reduce the amount of renewable electricity

generated by the HEPS and threaten its future viability.

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4. Similarly, please provide comment on why a higher continuation flow than the current

30 L/s has not been actively considered within the AEE.

Answer:

The continuation flow is derived from three sources being:

1. An orifice located within the diversion weir gates; and

2. Leakage from around the diversion weir gate structures; and

3. Tributary inflows between the Wairua Falls and the point of discharge from the HEPS.

The orifice allows Northpower to ensure that a 30 L/s continuation flow is maintained at all

times. It is not possible to accurately measure the contributions in flow from the latter two

sources. However, their influence means the continuation flow is greater than 30 L/s at all

times.

The application seeks all necessary resource consents to continue the status quo operation

of the Wairua HEPS without making physical alterations to the gates/orifice. With current

operational behaviour, the continuation flow is likely to be in the order of 150 L/s or more for

much of the time. However, Northpower cannot currently ensure that a continuation flow

above 30 L/s is achieved at all times without physically altering the gates/orifice.

As set out in section 2.1.2 of the AEE, critical repairs and maintenance of the HEPS are

immediately required, including the maintenance of operational technology and repairs to

penstock equipment to the life span of the scheme components.

5. In AEE s8.1 (second bullet point), it is stated that concerns of one landowner about effects

of flooding were allayed. Who was the landowner and how were their concerns

specifically allayed?

Answer:

The concerned landowner was Richard Booth. Mr Booth owns a farm which is predominantly

located on the western side of Tokiri Road. Mr Booth also owns land immediately adjacent to

the penstocks on the northern side of the canal.

Mr Booth had queried whether the diversion weir was causing the Wairua River to overtop its

western bank in extreme rain events, spilling across Wairua Falls Road, and ultimately flooding

properties further to the west (including his own).

Northpower representatives and an engineer from Hawthorn Geddes (Conal Summers) met

with Mr Booth at his property on 10 August 2017. Mr Summers explained that the modelling

carried out by Hawthorn Geddes, supported by detailed survey information, showed that the

diversion weir was having no influence on the flooding experienced to the west of the HEPS

during extreme rain events.

6. In AEE s8.3, there is a brief discussion of the relationship between the HEPS operation

and the WDC 'emergency' water take from the Wairua River (using the Maungatapere

water take infrastructure) during drought situations. What management arrangements

have been agreed between the parties?

Answer:

The arrangements between Northpower and the Whangarei District Council (WDC) are

informal. Northpower provided support in principle for WDC’s Water Permit application for

extraction from the Wairua River upstream of the HEPS on 3 October 2017.

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Northpower recognise the regional significance of WDC’s water supply and the need to

maintain that in the event of a drought or Civil Defence Emergency scenario. In the past

Northpower and WDC have collaborated on this aspect of the HEPS’s operation and WDC’s

‘emergency’ water take, and will continue to do so, as follows:

Northpower is prepared to work with WDC to ensure that, if required, sufficient flow is

available for the community water supply;

1. In the event of drought circumstances occurring and coinciding with water levels in the

Whau Valley Dam reducing to less than 55% of its full capacity, WDC may contact

Northpower to advise it of the situation and request support;

2. Northpower will then operate the diversion weir to control the water level and hold

water back to allow WDC to take water. Northpower will suspend generation operations

if necessary during this time.

Northpower is aware that previous modelling undertaken has indicated that WDC will require

the ‘emergency water take’ approximately once every 12 years.

7. In the Kessel Ecology report, at s3.6, the gauging results for the Downstream A and B

sites are presented with the recorded flow at the Downstream B site roughly double

that of the Downstream A site. Please provide comment on the likely contribution of

the Motukutuku Stream outflow to this difference, as the stream mouth is between Sites

A and B.

Answer: (provided by Tonkin & Taylor Limited, previously Kessels & Associates Limited):

It is presumed that the question is intended to refer to the Matukutuku Stream (rather than

the Motukutuku Stream). As far as we are aware, flow gauging has not been undertaken

within the Matukutuku Stream. We have therefore relied on modelled data from the NZ Rivers

Maps website, which is run by NIWA and based on published literature. Several sites are in

proximity to the HEPS and Matukutuku Stream (Error! Reference source not found.).

Based on modelled data, the Matukutuku Stream has a catchment area of 4.06 km2

compared to the 726 km2 catchment for the Wairua River (at the Downstream point as

shown on Figure 6). That is equivalent to ~0.6% of the total contributing catchment.

The data reported in section 3.6 of the Kessels report was collected in March 2016, and is

therefore considered to be representative of lower in-stream flows. We have therefore

considered the proportion of flow that the Matukutuku Stream contributes under mean

annual low flow (MALF) and 5 year low flow conditions. Using this information, we can then

estimate what proportion of the measured 155.3 L/s (at Downstream B in March 2016) came

from the Matukutuku Stream as requested in the question above.

During MALF conditions, the Matukutuku Stream is estimated to contribute 10 L/s to the

Wairua Stream, and during 5 year low flow conditions, 5 L/s. This contribution comprises 33%

and 17% (for each flow measure) of the flow between the upstream and downstream points

(Table 1). Using those percentages, it is estimated that 39 L/s of the measured 155.3 L/s is

contributed by the Matukutuku Stream assuming the MALF scenario or 22 L/s of the

measured 155.3 L/s is contributed by the Matukutuku Stream assuming the 5 year low flow

scenario.

These figures further support the conclusion at section 3.6 of the Kessels report that the 72.4

L/s recorded at the Downstream A site is an inaccurate representation of the flow

downstream of the Omiru Falls.

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Table 1: Summarised results from modelled flow assessment. A

Upstream

B

Downstream

C

Difference

D

Matukutuku Stream

(L/s and % of

difference)

E

Flow before

Matukutuku Stream

contributions

F Contribution to 155

L/s from Matukutuku

Stream

MALF 2330 L/s 2360 L/s 30 L/s 10 L/s (33%) 116 L/s 39 L/s

5 year low

flow

1240 L/s 1270 L/s 30 L/s 5 L/s (17 %) 133 L/s 22L/s

A and B = modelled flow data from Figure 6

C = difference between A and B

D = proportion (L/s and %) that Matukutuku Stream contributes to the difference (C).

E = flow in diversion reach before the Matukutuku Stream enters it (based on the measured flow of 155 L/s divided by (1 + % of difference)).

F = the contribution from the Matukutuku Stream to the 155 L/s measured flow reported by Kessels (based on the formula of 155 L/s minus E).

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Figure 6 - Modelled flow data for the HEPS area. Data sourced from

https://shiny.niwa.co.nz/nzrivermaps/

8 Please provide electronic copies of:

a. Williams, E. et al. 2013. Tuna Populations in the Wairua and Mangakāhia Rivers. Prepared

for Ngā Kaitiaki o Ngā Wai Māori, Northland Regional Council, Northpower & Ministry of

Primary Industries. NIWA Report HAM 2013 - 109.

b. Williams, E. et. al, 2018. Understanding Elver Populations in the Wairua River Catchment –

Year 1: 2017 Elver Survey Results. Prepared for Ngā Kaitiaki o Ngā Wai Māori Incorporated

Society. NIWA Report.

Answer:

These documents are attached.

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9. The Kessels Ecology report deals in some detail with potential effects on eels and eel

migration upstream and downstream but does not expressly evaluate effects on other

native climbing fish species, e.g. Banded Kokopu and Koaro. Please provide comment

on how the NEPS may affect migration of these species, including whether or not the

eel capture system provides some mitigation (if needed), i.e. also captures these other

species?

Answer: (provided by Tonkin & Taylor Limited, previously Kessels & Associates Limited).

Advice has also been sought from Jacques Boubee (formerly of NIWA) in the preparation of

this response as he is most familiar with the trap and transfer systems at the HEPS. During his

time with NIWA, Jacques was instrumental in improving the trap and transfer system at the

HEPS shown in Figure 7.

Figure 7 - Location of elver traps at HEPS. Figure provided by Jacques Boubee, 12 October 2018.

All climbing fish species, including banded kokopu, giant kokopu, short jawed kokopu and

kōaro as well as shrimps, are able to use Trap 1 set up at the tailrace (if they are present in the

tailrace). Other species including some bullies and koura may also be able to use Trap 1.

Trap 2 at the penstock was installed after the discovery that a large number of elvers were

being trapped in this location. It is unclear how elvers reach this location although it is

possible that there is an underground drainage channel. Regardless, the installation of Trap 2

has been very successful and now catches more elvers than Trap 1.

It is rather difficult to determine let alone enumerate how many fish other than eels are in a

trap when large number of elvers are present. As such, the number of species other than eel

has not been quantified to date.

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It is not possible for non-climbing fish species such as smelt and Inanga to use the existing

traps. This approach is deliberate as the Omiru Falls are a natural barrier to ‘non-climbers’

and these species would never have made it over the Omiru Falls in its natural state.

In respect of downstream migration, the only species of concern at this site is eels as they

migrate downstream as adults. Larval fish, such as kōaro and banded kokopu, will pass

through the turbine. Mechanical strike impact is not a concern with these small fish.

In summary, it is considered that the HEPS does not adversely affect migration of non-eel

species as upstream passage is provided for by the trap and transfer system or naturally

limited by the Omiru Falls, and larval fish are small enough to pass downstream without

mechanical strike impact.

10. Table 16 of the Kessel Ecology report refers to 'missed fish' of differing species, which

make up the majority of those recorded during the fish survey. However, the meaning

of the term is not explained in the text. Please explain.

Answer:

‘Missed fish’ are those that were observed, but not captured and identified during electric

fishing surveys. The site is bouldery and some areas had a high coverage of filamentous

algae, making it difficult to successfully capture all fish. It is best practice to record their

presence but, without a confident identification, they are just included as ‘missed fish’.

11. Section 5.1.1 of the Kessel Ecology report sets out proposed offset mitigation (riparian

planting) but notes that potential mitigation sites have yet to be identified. However,

please provide a general indication of the types of sites to be considered and an

evaluation of where within the Wairua River catchment these are known to be, or likely

to be, located.

Answer: (provided by Tonkin & Taylor Limited (T+T), previously Kessels & Associates Limited):

Northpower has reviewed the parcels of land in the immediate vicinity of the HEPS and

prepared the attached indicative map2 showing the extent and ownership of parcels of land

that may be appropriate for offset planting to be undertaken. T+T has reviewed aerial

photographs of these parcels to assess whether there is benefit in undertaken ecological

restoration.

A combination of road reserve and Department of Conservation (DOC) land could provide

approximately 2 km of available planting upstream of the diversion canal. Planting could be

undertaken on the true right bank (TRB) and would provide shading to the river, as well as

inputs of woody debris. This land is road reserve and so additional water quality benefits

could be achieved as road runoff would filter through the riparian planting. The true left bank

(TLB) is reserve land administered by DOC, which would also benefit from planting.

Some infill planting and enhancement could be undertaken within DOC reserve land

located between the diversion canal and the outflow. Given the existing planting, this option

is likely to be less beneficial to the enhancement of aquatic biodiversity values and

ecosystem function compared to other sites.

Approximately 3 km downstream of the outflow, further road reserve area is available for

planting (in the order of 3 km). Multiple benefits could be achieved by planting along this

section, however planting would be limited to one side of the river.

2 Refer to Attachment 2

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Northpower has approached both Whangarei District Council (WDC) and Kaipara District

Council (KDC) to gauge their interest in Northpower undertaking planting of land in the road

reserve and both WDC and KDC agreed in principle that such planting could be feasible.

Northpower is also meeting with DOC to discuss planting on its land.

In respect of the Guidance on Good Practice Biodiversity Offsetting in New Zealand (GBBPO)

principles, all of the sites identified to date are located along the Wairua River and are

proximate to the impact area. Therefore, the principles of proximity can be met.

The intent of the offset work is to address the HEPS’s effect of a reduction in aquatic habitat

available and modification to the dissolved oxygen and temperature within the river (Table

20 in the Kessels report). The anticipated proposed planting will address the biodiversity

values affected by the impact. It is intended that riparian planting be undertaken in one

location, rather than numerous sites. This approach is beneficial as a longer riparian margin

provides for a more connected ecosystem and in-stream effects (such as temperature

reduction) are better realised. For planting alongside road reserves, there may be additional

benefits beyond those that must be accounted for, including the potential for road runoff to

receive a level of treatment prior to it entering the Wairua River via sheetflow.

Riparian planting undertaken in conjunction with a maintenance and monitoring programme

is considered to be low risk in respect of achieving a successful outcome.

T+T considers that there is sufficient land available to plant along the Wairua River in the

immediate vicinity of the HEPS to achieve the recommended 3 ha of planting. The

preference is to have planting on both sides of the river, where possible, to provide additional

shading and availability of habitat along stream margins. However, the configuration of the

land available (i.e. the availability of one bank, or both banks) will be confirmed following

discussions and formal agreements with relevant landowners.

We trust this provides sufficient certainty that the proposed offset works can be achieved as

recommended.

12. The written comments from the Whatitiri Resource Management Unit, dated 3

September 2018, on the HEPS application place considerable emphasis on river and

diversion canal (and adjoining DoC reserve) access restrictions allegedly made in 2013

for health and safety reasons. Please provide an outline of what restrictions were

instituted and why.

Answer:

The comments from the Whatitiri Resource Management Unit (WRMU) about public access

are not relevant to the resource consents being sought from the Northland Regional Council.

However, for completeness, information on those comments is provided below.

Access to the DOC Scenic Reserve

Vehicle access to the HEPS is via Lot 7 DP 172748 (highlighted yellow in Figure 8) and through

the Scenic Reserve (highlighted green in Figure 8).

Lot 7 DP 172748 is owned by Northpower Ltd. While two private residential properties to the

south have a legal right to use Lot 7 for access (and they have been issued with a key), there

is no right of, or obligation to provide, public access across Lot 7 (see the certificate of title

attached). The gates were already in place when Northpower purchased the HEPS and

adjoining land (including what is now Lot 7). Northpower replaced the gates in 2016. These

gates enable the appropriate restriction of access to the HEPS, as is in keeping with good

health and safety practice.

Northpower’s access to the HEPS continues from Lot 7 across the Scenic Reserve by way of a

registered easement which it has the benefit of (highlighted magenta in Figure 8). That

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easement allows for right of way, electricity supply and telecommunications. Northpower has

the right to pass over this area, but does not prevent any other person from using this area.

Figure 8 - Ownership and rights to land relating to access issues raised by WRMU

Public access to the Scenic Reserve is provided by an unformed paper road (highlighted

peach in Figure 8 above). The usability of the paper road is an issue that will need to be

addressed by the Department of Conservation and/or Whangarei District Council. In

summary, Northpower has no obligation to provide public access across its private land to

the Scenic Reserve and is not restricting legitimate public access.

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Regarding public access to the head pond above the penstocks, Northpower notes that:

1. There is an unformed paper road on the western side of the head pond. This road is not

fenced (see Figure 9);

2. The head pond and canal are owned by Northpower. There is no right of public access

to these areas and they are fenced for health and safety reasons.

Figure 9 - Headpond

Yours sincerely

Brett Hood

Director

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ATTACHMENT 1 – NORTHPOWER SUPERVISORY CONTROL AND DATE ACQUISITION (SCADA) SYSTEM

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ATTACHMENT 2 – INDICATIVE MAP PUBLIC RESERCES AND ACCESS

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ATTACHMENT 3 – CERTIFICATE OF TITLE LOT 7 DP 172748

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