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Wairarapa Water Use Project: Prefeasibility Summary Report June 2015

Report prepared by: WWUP Working Group, Greater Wellington Regional Council

Author: Michael Bassett-Foss, Project Director

Contents

1. Introduction ................................................................................................................................. 1

2. The purpose of the WWUP .......................................................................................................... 1

2.1 Building economic prosperity ...................................................................................................... 2

2.2 Allocating and using water efficiently .......................................................................................... 2

2.2.1 National Policy Statement for Freshwater Management (NPS) .................................................. 3

2.2.2 Integrated catchment management ............................................................................................ 3

3. Project vision and objectives ....................................................................................................... 5

4. Stakeholder engagement ............................................................................................................. 5

5. Previous investigations ................................................................................................................ 7

5.1 Options Identification and Analysis (October 2011 - April 2013) ................................................ 7

5.2 Options Refinement (April 2013 - September 2013) ................................................................... 8

6. The Prefeasibility phase (March 2014 – May 2015) .................................................................... 9

6.1 Scheme option descriptions....................................................................................................... 11

6.2 Scope of Prefeasibility ................................................................................................................ 13

6.3 Assumptions and limitations ...................................................................................................... 16

6.4 Factors not yet investigated....................................................................................................... 16

7. Scheme comparison using Multi-Criteria Analysis (MCA) ......................................................... 17

7.1 The MCA process ....................................................................................................................... 17

7.2 Financial theme .......................................................................................................................... 20

7.2.1 Scheme capital and operating costs .......................................................................................... 20

7.2.2 Peer review - scheme capital and operating costs .................................................................... 26

7.2.3 Regional economic return .......................................................................................................... 26

7.2.4 On-farm economics .................................................................................................................... 27

7.2.5 Scheme economics..................................................................................................................... 29

7.2.6 Overall financial theme – summary ........................................................................................... 30

7.3 Social theme ............................................................................................................................... 31

7.3.1 Community dislocation in inundated areas ............................................................................... 32

7.3.2 Loss of employment in inundated areas .................................................................................... 32

7.3.3 Temporary construction effects................................................................................................. 33

7.3.4 Recreation implications and opportunities ............................................................................... 34

7.3.5 Overall social theme - summary ................................................................................................ 35

7.4 Environmental theme ................................................................................................................ 36

7.4.1 Terrestrial Ecology ..................................................................................................................... 37

7.4.2 Aquatic Ecology .......................................................................................................................... 38

7.5 Māori cultural theme ................................................................................................................. 40

7.6 Risks & Opportunities (scheme-specific) ................................................................................... 41

7.6.1 Financial ..................................................................................................................................... 41

7.6.2 National Policy Statement for Freshwater Management (NPS) ................................................ 44

7.7 Other risks and opportunities (general)..................................................................................... 44

8. Summary of results – comparisons of schemes ......................................................................... 44

8.1 Summary table – MCA ............................................................................................................... 44

8.2 Sensitivity analysis – overall ....................................................................................................... 45

9. Other storage opportunities ...................................................................................................... 46

9.1 On-plains storage ....................................................................................................................... 46

9.2 Reserve scheme options ............................................................................................................ 47

Glossary

Abbreviations (T&T, June 2015)

GWRC Greater Wellington Regional Council

GG Governance Group for the Wairarapa Water Use Project

IAF Irrigation Acceleration Fund, managed by the Ministry for Primary

Industries, is a fund set aside to support investigation into regional rural

water harvesting, storage and distribution infrastructure

LG Leadership Group for the Wairarapa Water Use Project

MCA Multi-Criteria Analysis, a basis for ranking and comparing scheme

options

MCM Million Cubic Metres

NIWA National Institute of Water and Atmospheric Research

PwC PricewaterhouseCoopers

QEII Queen Elizabeth II National Trust open space covenants. A National Trust

open space covenant is a legally binding protection agreement, which is

registered on the title of the land. It is voluntary but once in place binds

the current and all subsequent landowners. Each covenant is unique. It

can apply to the whole property or just part of the property. There can

be different management areas within a covenant with varying

applicable conditions. Conditions can be stringent where rare or

vulnerable natural features or habitats are being protected.

RMA Resource Management Act

RPS Regional Policy Statement for the Wellington Region, April 2013 (GWRC)

SAG Stakeholder Advisory Group for the Wairarapa Water Use Project

T&T Tonkin & Taylor Limited

WG Working Group for the Wairarapa Water Use Project

WRIT Wairarapa Regional Irrigation Trust

WWUP Wairarapa Water Use Project

Terminology

(T&T, June 2015)

90th percentile The value, derived from a statistical analysis, below which 90% of

observations may be found e.g. the value that has a 1 in 10 chance of

being exceeded

Command area The gross area that could be supplied with water from a scheme.

Distribution system/network Conveyance structures located downstream of the reservoir, comprising

existing rivers, canals, races and pipework that transfer flow from the

reservoirs to the command areas

Flushing flows High river flows, usually associated with rainfall, which flush out the river

system

Harvesting Transferring water to storage from a nearby stream/river located in a

different catchment. This definition is different from the Regional Policy

Statement, which uses harvesting to refer to on-river storage also.

Headworks Storage reservoir, dam structures required to impound the reservoir,

and any intakes, conveyances and pump stations (if required) to

‘harvest’ water to fill the reservoir

Net supplied area The portion of the command area expected to actually be

irrigated/supplied, after accounting for buildings, tracks, hedges etc.

Reservoir A natural or artificial pond or lake used for the storage and regulation of

water.

Scheme Headworks and associated distribution network to transfer water from

reservoirs to a command area

Uptake The commitment of water users to use (buy) water from the scheme

Executive Summary

The Wairarapa Water Use Project (WWUP) is investigating a multi-purpose water scheme for Wairarapa

to collect and store water, then distribute it for a variety of economic and community uses. Any eventual

scheme would improve regional prosperity while promoting sustainable management of land and water.

More specifically, WWUP aims to:

• Provide an affordable, economically efficient and resilient water supply to support rural and/or urban

demand, and thereby enable broader economic benefits;

• Manage effects on the natural and social environment in a way that, as far as is practicable, minimises

potential adverse effects through sound scheme selection, project design/operation and mitigation;

• Enable the integration of cultural values and opportunities through consultation and collaboration

with iwi;

• Contribute to wider initiatives to improve the resilience, efficiency and reliability of the Ruamāhanga

catchment water resource.

Water could be used for irrigation, environmental uses, power generation, municipal water supply,

recreation and cultural uses.

Conversations with all parts of the community with an interest in water have been a priority for the

WWUP since it began. A wide range of community interests have been involved in the development of

the project and its investigations through the WWUP Governance, Leadership and Stakeholder Advisory

Groups who provide feedback and input into project design and decisions.

Separately from the WWUP, the Ruamāhanga Whaitua committee is currently working to determine

community values and needs and set the vision for the catchment as part of the Regional Plan review. It

will then create policies and rules for how land and water resources are managed. Any water scheme

developed would need to operate within the Regional Plan’s water quality and quantity limits.

The question of how to increase the reliable supply of water through storage has been considered in

Wairarapa for several decades. In September 2013, following preliminary investigations led by Greater

Wellington Regional Council with support from the Ministry for Primary Industries, five possible water

schemes were selected for further investigation - Tividale, White Rock Road, Te Mara, Black Creek and

Mangatarere. A sixth scheme, Wakamoekau, a smaller variant of the Black Creek option, was also

considered in its own right.

The aim of the Prefeasibility investigations conducted between March 2014 and May 2015 was to

determine which scheme options, if any, showed enough feasibility to proceed to the Feasibility phase.

Early assessment of any possible ‘fatal flaws’ that could be used to eliminate schemes was favoured.

The six schemes, comprising headworks (including water storage reservoirs) and water distribution

systems were investigated as stand-alone options.

White Rock Road and Tividale options would supply water to essentially independent areas, except for

some minor overlap of Tividale and Black Creek. Te Mara, Wakamoekau, Black Creek and Mangatarere

would supply water to areas that overlap substantially.

The six scheme options were compared against each other and ranked using multi-criteria analysis (MCA)

that evaluates and weighs multiple criteria to help compare options against each other for the purpose

of decision-making.

Prefeasibility investigations were categorised into four main themes – financial, environmental, social

and cultural which were divided into a series of sub-themes. For each theme and sub-theme, the scheme

options were ranked against each other on a 1-5 scale with 1 as the least favourable and 5 as the most

favourable. While this work was more detailed than the preliminary investigations, it was still at a

relatively broad level.

Sensitivity analysis was undertaken to determine at what point the altered weightings significantly

affected the outcomes.

Criteria, weightings and scores were largely decided by the nominated professional experts employed by

the project e.g. geologists, hydrologists, ecologists, engineers and economists. Expert consultants, other

specialists, peer reviewers, and representatives of the Irrigation Acceleration Fund (IAF) also provided

input at key points.

In addition, risks and opportunities associated with each scheme option were identified and considered.

The findings from the MCA are an important part of the decision as to which scheme/s, if any, should

advance to the WWUP’s Feasibility phase.

Overall MCA rankings

A summary of the MCA rankings and weightings for each of the four main themes; financial, social,

environmental and cultural, considered during the Prefeasibility phase are presented in Table A below.

When combined and weighted, the four main themes provide an overall score for each scheme option

which is then translated into a ranking.

Table A: Combined themes - MCA rankings1

(Barnett, 2015; Boffa Miskell 2015; Steer, 2014; Opus, 2014; T&T, 2015; WWUP, 2015)

From an overall perspective, Wakamoekau appears to be the most favourable scheme, followed by Black

Creek with a ranking of 4. Mangatarere is moderately favourable with an overall ranking of 3. Tividale

and Te Mara are next with an equal ranking of 2. White Rock Road is the least favourable scheme option

with a ranking of 1.

1 Rankings are comparative; 5 most favourable - 1 least favourable. Raw scores are the weighted sum of the themes.

Combined Themes MCA

Rankings

Weightings are based on Options Refinement

MCA pre-sensitivity testing weighting

Theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wak

amo

eka

u

21

0 -

Bla

ck C

reek

21

5 -

Ma

ng

ata

rere

Financial 70% 3.0 1.0 3.0 5.0 4.0 4.0

Social 10% 4.0 3.0 5.0 5.0 2.0 1.0

Environmental 10% 1.0 3.0 3.0 5.0 4.0 1.0

Cultural 10% 3.5 4.0 1.0 5.0 5.0 4.0

Raw Combined Score 3.0 1.7 3.0 5.0 3.9 3.4

MCA Ranking 2 1 2 5 4 3

Overall sensitivity testing

Sensitivity analysis was undertaken to determine at what point the altered weightings of the four main

themes significantly affected the outcomes.

As Table B below indicates, four of the scheme options are relatively insensitive to varying the financial

and combined social/environmental/cultural weightings.

No matter what weighting is applied, Wakamoekau is consistently the most favourable scheme from an

overall perspective, followed by Black Creek which is also insensitive to weightings. Te Mara and Tividale

are relatively insensitive. When more weight is given to combined social/environmental/cultural factors,

Mangatarere is highly sensitive and becomes the least favourable. When more weight is given to financial

factors, White Rock is highly sensitive and becomes the least favourable of the scheme options.

Table B: Sensitivity testing on combined themes - MCA rankings2 (WWUP, April 2015)

Sensitivity Testing on

Combined Themes MCA

Rankings 1

0 -

Tiv

ida

le

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

kam

oe

kau

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

0% Env/Cult/Soc, 100% Financial 3 1 3 5 4 4










Opportunities and risks

Tonkin & Taylor developed risk and opportunity scores for each scheme option relating primarily to

engineering components. Risk scores focused on potential cost increases or technical risks. The focus of

opportunity scores was on potential cost savings (T&T, June 2015).

With respect to engineering, in terms of opportunities for cost savings, Te Mara is clearly the most

favourable, followed by Black Creek, and then Mangatarere. Tividale and Wakamoekau are similarly

moderately favourable. White Rock Road is clearly the least favourable of the six schemes in terms of

opportunities (T&T, June 2015).

2 Rankings are comparative; 5 most favourable - 1 least favourable.

In terms of risks of cost increases and technical constraints from an engineering perspective, Te Mara is

clearly the most favourable, very closely followed by Wakamoekau and Mangatarere. Black Creek is less

favourable to moderately favourable in terms of risk. Tividale is the least favourable of the six schemes,

though White Rock Road only slightly more favourable than Tividale (T&T, June 2015).

Next steps

The information contained in this summary report and the numerous expert reports that fed into it will

be used by the WWUP Governance Group to make a decision on which scheme or schemes, if any, should

advance to the next, Feasibility’ phase of investigation.

All reports completed during Prefeasibility that are not commercially sensitive are referenced in this

report and available on the ‘Reports’ page of the WWUP website at www.wairarapawater.org.nz

1

1. Introduction The Wairarapa Water Use Project (WWUP) is investigating a multi-purpose water scheme for

Wairarapa to collect and store water then distribute it for a variety of economic and community

uses. Any eventual scheme would improve regional prosperity while promoting sustainable

management of land and water.

WWUP aims to maximise the productive capacity of the Wairarapa valley through water storage

and distribution infrastructure for irrigation and also to meet a range of other environmental

and community needs such as power generation, municipal water supply, recreational and

cultural purposes.

Work to date has focused at a high level on how water could be provided to irrigate an

additional 30,000 hectares of the Wairarapa valley through a range of scheme options.

Currently, about 12,000 hectares are irrigated using surface and ground water, most of which

is fully allocated.

WWUP is sponsored and funded by the Greater Wellington Regional Council (GWRC). It has co-

funding from the Ministry for Primary Industries’ Irrigation Acceleration Fund (IAF) which

primarily supports investigation into regional rural water harvesting, storage, and distribution

infrastructure.

The project involves wide sections of the community through its Governance Group, Leadership

Group and Stakeholder Advisory Group, Farmer Group and Rural Bankers Group. This is

described further in Section 4 below.

This report summarises the results of the project’s Prefeasibility investigations on five scheme

options carried out between March 2014 and May 2015. These investigations follow

preliminary work by the project which is described in Section 5 below.

The process of assessing options is a critical part of the consideration by decision makers. The

requirement for adequate consideration of alternatives for major infrastructure projects is well-

recognised under the Resource Management Act 1991 (RMA).

This summary report and the numerous expert reports that fed into it form the basis of a

decision on which scheme or schemes, if any, should advance to a Feasibility investigation. This

report outlines the project’s purpose and background, then summarises a multi-criteria analysis

(MCA) process that compares the scheme options on financial, social, environmental and

cultural criteria. Known risks and opportunities associated with each scheme option are also

presented.

All reports completed during Prefeasibility that are not commercially or personally sensitive are

referenced in this report and available on the ‘Reports’ page of the WWUP website at

www.wairarapawater.org.nz.

2. The purpose of the WWUP The question of how to increase the reliable supply of water through storage has been

considered in Wairarapa for several decades. The opportunity for regional economic

development and resilience has and continues to be a key driver for the project.

More recently, a second question; how the region’s existing scarce water resource could most

efficiently be used for a range of purposes, has driven the project investigations.

2

2.1 Building economic prosperity

Primary production is the biggest single contributor to Wairarapa’s GDP at 17 percent. Water

storage for irrigation would provide the reliability needed for new crops, horticulture, pastoral

farming and processing of primary produce, while insulating farm production against dry years.

This presents the opportunity to achieve significant economic growth for the entire Wellington

region.

A greater, more reliable water supply in Wairarapa would grow the primary production base,

creating long-term and inter-generational economic and social development. Benefits could

include:

• increased farming productivity and returns

• a more diverse and higher-value range of agricultural and horticultural outputs

• creation of new jobs and increased regional GDP

• retention of younger people in the region through greater job prospects

• local processing of primary produce made possible through more reliable production

• new and expanded service industries e.g. transport

• social spin-offs – community facilities, population-based services, strong school rolls.

2.2 Allocating and using water efficiently

The current resource consents to take surface water account for nearly all of the available ‘core

allocation’ from the rivers in the Wairarapa valley. Limited additional groundwater is available,

especially now that investigations have confirmed that there is strong interconnection between

surface water and groundwater in Wairarapa.

Therefore, to reliably meet increased water demand in a sustainable manner, water would have

to be supplied from storage. GWRC’s over-arching environmental policy directive, the Regional

Policy Statement (RPS), requires the Regional Plan to promote efficient use of water and ‘water

harvesting’; i.e. taking and storing water when the availability is high and using it when needed.

With this comes the environmental challenges of more intensive land use and managing

changing land use; both key considerations. This requires an integrated discussion about

efficient use of water in a way that maintains or enhances the overall environment and provides

for community values.

3

2.2.1 National Policy Statement for Freshwater Management (NPS)

The Government’s freshwater management reforms resulted in the introduction of the National

Policy Statement for Freshwater Management (NPS) in 2011, which was updated in 2014.

The NPS specifically sets out:

“… objectives and policies that direct local government to manage water in an

integrated and sustainable way, while providing for economic growth within set

water quantity and water quality limits” (NPS, 2014)”

and must be considered in terms of progressing water storage and reticulation options.

While water quantity and allocation regimes have been in place for some time, there is now a

new requirement for local government to set and meet water quality limits. In a catchment-

wide approach to land and water management, GWRC has divided the greater Wellington

region into five ‘Whaitua’ or management areas. In each area, including Wairarapa, a

community-led vision for land and water use is being developed as part of the Regional Plan

review.

2.2.2 Integrated catchment management

GWRC is moving from an individual water take approach to looking holistically at a catchment

scale at how to most efficiently aggregate, distribute and use water to achieve environmental

sustainability and economic growth. This requires cohesive planning for water allocation and

distribution for individual use and public good environmental, recreational, social, cultural and

economic purposes.

In Wairarapa, this holistic approach has three key parts supported by an extensive programme

of science modelling;

a. The Regional Plan review (to become the Natural Resources Plan)

b. The community-led Whaitua process, and

c. The Wairarapa Water Use Project.

The key task now is establishing limits for allocation and limits for quality through the new

Regional Plan. Each of these inter-related projects has a role to play in how water resources are

used and how the community makes decisions about the balance of environmental, cultural,

economic and social uses.

Briefly described below, the Regional Plan, Ruamāhanga Whaitua and WWUP are all

underpinned by a substantial scientific programme developed by GWRC and involving national

partners. This is building a repository of evidence on what to base decisions.

Regional Plan review

The current Regional Plan review process, is considering amongst other things, how to allocate

water and set minimum flows to recognise the importance of in-stream ecosystems, while

managing potential land-use impacts in an environmentally and economically sustainable way.

One of the drivers for the review was how water is allocated and for what purposes; for

example, irrigation, water races, flushing flows and municipal supply.

The new Regional Plan, to be known as the ‘Natural Resources Plan’, is likely to be proposed in

August 2015 with some provisions likely to have immediate effect. The plan will become fully

operative after going through a process of submissions, hearings and possible appeals.

4

Ruamāhanga Whaitua (catchment) committee

Throughout the greater Wellington region, the complex question of how to manage the limit-

setting process, particularly with regard to quality, is being considered through community-led

Whaitua (catchment) committees.

In Wairarapa the Ruamāhanga Whaitua is working to determine community values and needs

and set the vision for the catchment. It will then create policies and rules for how land and

water resources are managed that suit the needs of local people. These will be incorporated

into the new Regional Plan through the ‘Ruamāhanga Whaitua chapter’. This section will be

read alongside the regional policies and regulations and will control how resources are

managed in the wider GWRC area. Any water scheme developed in the region would need to

operate within the Regional Plan framework.

Wairarapa Water Use Project

The third part of considering the catchment in an integrated/holistic way is the question of

harvesting water and storing it in order to create long-term security of supply for a variety of

purposes.

Ultimately a large-scale water scheme is an infrastructure tool that could assist the efficient use

and allocation of water for current and new users and the management of land and water in

the catchment.

To this end, WWUP is investigating the feasibility of a water scheme that contributes to

economic growth and to wider initiatives to improve the resilience, efficiency and reliability of

the Ruamāhanga catchment water resource. Any effects on the natural and social environment

would need to be managed in a way that, as far as is practicable, minimises potential adverse

effects.

Increased irrigation is likely to bring environmental challenges, particularly those associated

with more intensive land use. Understanding potential land use change and its effects is a key

consideration for WWUP and the community and will be assisted by the GWRC science

modelling work. At the same time, water storage can present opportunities for the environment

by increasing minimum stream flows and providing flushing flows in summer, and assisting with

efficient use and allocation of water. Opportunities exist to improve farm practices, use new

technology and use irrigation water more efficiently.

The NPS/Regional Plan framework will have a significant impact on any water scheme that

might eventuate. It is difficult at this stage to quantify the extent of this until limits are set by

the Ruamāhanga Whaitua and the results of GWRC’s science modelling work are known.

Therefore, the potential impact on possible water schemes is presented as risks and

opportunities in Section 7.6.2 of this report.

5

3. Project vision and objectives The Wairarapa Water Use Project vision, developed in 2012 is:

“To provide one or more multi-purpose water scheme for Wairarapa to collect

and store water then distribute it for a variety of economic and community uses.

This will be done in a way that promotes sustainable management of land and

water and creates regional prosperity.”

Following on from the vision, the project objectives are to:

• Provide an affordable, economically efficient and resilient water supply to support rural

and/or urban demand, and thereby enable broader economic benefits;

• Managing effects on the natural and social environment in a way that, as far as is

practicable, minimises potential adverse effects through sound scheme selection,

project design/operation and mitigation;

• Enable the integration of cultural values and opportunities through consultation and

collaboration with iwi;

• Contribute to wider initiatives to improve the resilience, efficiency and reliability of the

Ruamāhanga catchment water resource.

These objectives are a revision of the original project objectives first formulated in November

2012 at the early stage of investigations. The changes take into account advancement in the

knowledge gained and decisions made during the intervening period.

Revision of the objectives has also taken into account decisions from recent applicable RMA

decisions including those relating to water irrigation projects.

4. Stakeholder engagement Conversations with all parts of the community with an interest in water have been a priority for

the project since it began. A wide range of community interests have been involved in the

development of the project and its investigations through several groups. Their membership

(see Appendix A) reflects the magnitude of the opportunities and challenges the project

presents to the region.

The WWUP Governance Group, established in 2014 comprises members of the community,

local iwi, local government, and the Wairarapa Regional Irrigation Trust. The Governance Group

is the key project decision-maker and an advisory group to the GWRC as the project funder.

Following initial community engagement by the project late in 2009, the WWUP Stakeholder

Advisory Group (SAG) was formally established in 2011. Made up of 19 community

organisations, it acts as an advisory body to the project. The SAG meets approximately six-

weekly, receives all project information, and provides feedback and input into project design

and decisions.

Established in 2009, the WWUP Leadership Group comprises regional leaders and acts in an

advisory capacity. The project is managed by the WWUP Working Group. Structural

relationships and committee functions are outlined in Figure 1 below.

6

Figure 1: WWUP stakeholder structural relationships and committee functions

7

5. Previous investigations Investigations of possible water storage schemes in Wairarapa have been carried out by several

organisations and date back to 2001. In 1997 a significant drought attracted a Central

Government-funded research project.

Between 2001 and 2003 local economic development agencies commissioned several studies

that showed that a water storage option(s) was both feasible and advantageous for Wairarapa.

In 2007 the Wairarapa Regional Irrigation Trust (WRIT) was established by members of

Wairarapa’s business community to promote irrigation within the region and provide farmers

and interested parties with information on how irrigation could work for them.

In its early years WRIT built on initial investigative work carried out since 2001. Working with

Meridian Energy, it commissioned preliminary studies that indicate strong potential for

irrigating land that currently does not have access to water for that purpose.

In 2011 an independent expert review of all previous investigations found that the water

scheme project is potentially feasible in hydrology, engineering and economic terms.

Against this backdrop, GWRC decided to conduct a thorough and open investigation of how

water in Wairarapa could be stored and distributed in a way that contributed to both economic

growth and overall environmental sustainability. This was part of an integrated catchment

management approach as described in Section 2.2 of this report.

To date, the GWRC-funded investigations have included an initial Scoping Study, an Options

Identification and Analysis Phase, an Options Refinement Phase, and the Prefeasibility Phase,

the subject of this report, which considered and built on the previous studies by other

organisations.

Key constraints and exclusions were agreed at the beginning of the Options Identification and

Analysis Phase, and have been retained for the Options Refinement Phase and current

Prefeasibility Phase. In particular, dam sites in the Tararua Forest Park and on the main stems

of the Ruamāhanga, Tauherenikau, Waiohine and Waingawa Rivers were excluded from

consideration for recreational and environmental reasons principally.

5.1 Options Identification and Analysis (October 2011 - April 2013)

The broad study of Options Identification and Analysis, identified 243 storage options based on

an initial sweep, accounting for all possible sites with topography suitable for storing more than

3 million cubic metres of water. The large number of storage options was progressively and

systematically refined to a short-list of nine, based on a preliminary understanding of cost-

effectiveness, geology and active faults, water availability, environmental impacts and risks,

impacts on infrastructure and towns, land tenure constraints, and a range of social, cultural,

environmental and financial opportunity/risk factors.

Nine scheme options were then developed to a concept level suitable for comparison, each

comprising one of the short-listed reservoirs and an associated indicative command area. The

nine single storage schemes were assessed on their merits as independent options. A command

area was selected for each scheme on the basis of the area that could be supplied most cost-

effectively from the relevant reservoir. As the locations of the reservoirs were not evenly

distributed around the Wairarapa valley, the associated indicative command areas tended to

overlap, and significant areas of the valley were not covered. (T&T Executive Summary, 2015)

8

5.2 Options Refinement (April 2013 - September 2013)

The decision to undertake an Options Refinement Phase emerged from recommendations set

out in the Scheme Options Identification and Analysis Report, feedback on that report from

GWRC’s peer reviewers, the WWUP Stakeholder Advisory Group (SAG), Leadership Group (LG)

and Working Group (WG), and the key findings presented at meetings with the SAG and LG

during March 2013.

The Options Refinement work developed a concept for an integrated valley scheme comprising

multiple reservoirs supplying an indicative command area. This provided coverage of the high

and medium priority demand areas in the Wairarapa valley study area i.e. a ‘multi-storage’

scheme rather than ‘single storage’ scheme.

In addition, two additional storage options in the Taueru Valley catchment and a smaller version

of the Black Creek reservoir was developed as three independent schemes to a concept level

suitable for comparison with the nine schemes developed during Options Identification and

Analysis. Two of the original nine scheme options were eliminated as unrealistically expensive

compared with the other schemes under consideration, resulting in a ‘top ten’ list of possible

schemes.

The ‘top ten’ schemes were compared through a multi-criteria analysis (MCA), accounting for

environmental, financial, social, cultural and opportunity/risk themes. Overall MCA scores

showed relatively little difference between the top ten schemes, especially if only the top nine

were considered.

In order to ensure coverage of the medium and high priority areas in the Wairarapa valley, the

study area was divided into zones, and a priority reservoir and back-up reservoir was identified

for each zone. The priority schemes selected for further investigation were:

1. Tividale (Scheme 10)

2. White Rock Road (Scheme 135)

3. Te Mara (Scheme 197)

4. Black Creek (Scheme 210) including a smaller variant option called ‘Wakamoekau’

(Scheme 206)

5. Mangatarere (Scheme 215)

In addition, substantial flexibility for considering alternative arrangements and cost savings for

the multi-storage scheme was identified. Understanding how multiple reservoirs could fit

together in a cost-effective arrangement to cover the medium and high priority areas was

considered important for ensuring a long-term cost-effective strategy to water management in

the study area.

Therefore, further development of the distribution aspects of the multi-storage scheme was

recommended for investigation along with further work on the specific storage sites. These

recommendations were endorsed by the project and its stakeholders and the Options

Refinement report was published in September 2013.

9

6. The Prefeasibility phase (March 2014 – May 2015) In September 2013, following preliminary investigations, five possible water schemes were

selected as priorities for further investigation. Three other schemes were identified as reserve

options, should any of the five prove unviable during the Prefeasibility phase.

The following five single storage schemes were advanced through the Prefeasibility phase of

work:

• Tividale (Scheme 10)

• White Rock Road (Scheme 135)

• Te Mara (Scheme 197)

• Black Creek (Scheme 210)

• Mangatarere (Scheme 215)

A sixth scheme, Wakamoekau (Scheme 206), a smaller variant of the Black Creek option, was

also considered in its own right. Figure 2 (T&T) shows the location of the five reservoir storage

sites and the indicative irrigable area associated with each.

Further details on key attributes of each scheme option are detailed in WWUP Prefeasibility

Phase Engineering Report (T&T, June 2015).

10

Figure 2: Location of short-listed reservoirs and command areas assumed for evaluation as independent, alternative scheme options (T&T, June 2015)

11

6.1 Scheme option descriptions

Tividale (Scheme no. 10)

The Tividale water storage option is located approximately 23km northeast of Masterton off Te

Ore Ore Bideford Road in the vicinity of Mangapurupuru Road. It is situated on the Taueru River

just downstream of the confluence with Mangapurupuru Stream. The water would be sourced

from its own catchments the Taueru River and Mangapurupuru Stream.

With a capacity of 29.2million cubic metres (MCM) of water, the reservoir could supply

30.2MCM of water to its irrigable area in a drought year.

The indicative command area associated with the Tividale scheme is a long, narrow area along

the Taueru and Ruamāhanga Rivers that extends from around Bideford at its northern end to

southwest of Greytown and to the northern end of Lake Wairarapa. The total net supplied area

would be approximately 9,800ha, of which approximately 3,200ha would be riparian users

along the Taueru and Ruamāhanga Rivers (existing and new users with direct takes from the

river). The remaining 6,600ha would be supplied from a centralised scheme intake, pump

station and pumped pipe network comprising approximately 24km of pipe (T&T, June 2015).

White Rock Road (Scheme no. 135)

The White Rock Road water storage option is located approximately 10km south of

Martinborough immediately west of White Rock Road. It is situated on the Makara River a few

hundred metres downstream of the confluence with the Mangapari Stream and approximately

3km upstream of the confluence with the Huangarua River. The reservoir would be filled by

own catchment infill i.e. runoff and river flows from the Makara River and Mangapari Stream

catchments, upstream of the dam.

With a capacity of 23.2MCM of water, the reservoir could supply 27.4MCM of water to its

irrigable area in a drought year.

The indicative command area associated with the White Rock Road scheme extends from the

Huangarua River valley (north of White Rock Road) to around Martinborough, and southwest

towards Lake Wairarapa. The total net supplied area would be approximately 7,600ha, of which

approximately 1,100ha would be riparian users along the Huangarua River (existing and new

users with direct takes from the river). The remaining 6,500ha would be supplied from a

centralised scheme intake, pump station and a pumped pipe network comprising approximately

26km of pipe (T&T, June 2015).

Te Mara (Scheme no. 197)

The Te Mara water storage option is located approximately 15km north of Masterton, 2km west

of State Highway 2 and north of Kiriwhakapapa Road. It would be situated on the Te Mara

Stream, a tributary of the Waipoua River. The reservoir would be filled by a combination of own

catchment infill (i.e. run-off and river flows from the Te Mara Stream catchment) and water

harvested from the Ruamāhanga River.

With a capacity of 23.3MCM of water, the reservoir could supply 34MCM of water to its irrigable

area in a drought year.

The indicative command area for the Te Mara scheme encompasses three sectors; the northern

sector covering the Waipoua and Ruamāhanga River valleys north of Masterton, the eastern

sector around Te Ore Ore (east of Masterton), and the southern sector between the Waingawa

River and Carterton. The three sectors are disconnected by areas where scheme water supply

is not proposed around State Highway 2 north of Masterton, and the Waingawa River (between

the northern and southern sectors).

12

The total net supplied area would be approximately 9,700ha. The scheme would be a fully-

piped, gravity-fed system from the dam, comprising approximately 49km of pipe (T&T 2015).

Wakamoekau (Scheme no. 206)

The Wakamoekau water storage option is located northwest of Masterton near Mikimiki,

effectively at the end of Falloon Settlement Road. The dam would be situated on Wakamoekau

Creek, a tributary of the Waipoua River. A second, saddle dam would be required at the

southern end of the site. The reservoir would be filled by a combination of own catchment infill

(i.e. run-off and river flows from the Wakamoekau Creek catchment) and water harvested from

the Waingawa River.

With a capacity of 18.8MCM of water, the reservoir could supply 28.9MCM of water to its

irrigable area in a drought year.

The indicative command area for the Wakamoekau Scheme encompasses three sectors, the

northern sector covering the Waipoua and Ruamāhanga River valleys to the north of Masterton,

the eastern sector around Te Ore Ore (east of Masterton), and the southern sector between

the Waingawa River and Carterton. The three sectors are disconnected by areas where scheme

water supply is not proposed around State Highway 2 north of Masterton, and the Waingawa

River (between the northern and southern sectors).

The total net supplied area would be approximately 8,100ha. The scheme would be fully-piped

and predominantly a gravity-fed system from the Wakamoekau Creek intake, comprising

approximately 45km of pipe (T&T, June 2015).

Black Creek (Scheme no. 210)

The Black Creek water storage option is located approximately 11 km northwest of Masterton,

on Falloon Settlement Road. The main dam would be situated on Black Creek, a tributary of the

Waingawa River. A second dam would be located on Wakamoekau Creek, a tributary of the

Waipoua River. The Black Creek reservoir would be filled by a combination of its own catchment

infill (i.e. run-off and river flows from the Wakamoekau and Black Creek catchments) and water

harvested from the Waingawa River.

With a capacity of 46.2MCM of water, the reservoir could supply 67MCM of water to its irrigable


The indicative command area for the Black Creek Scheme encompasses three sectors, the

northern sector covering the Waipoua and Ruamāhanga River valleys to the north of Masterton,

the eastern sector around Te Ore Ore (east of Masterton), and the southern sector between

the Waingawa River and Carterton. The total net supplied area is approximately 19,700ha.

The scheme would be fully-piped except for a short length of river conveyance from the

Wakamoekau dam to the intake, and use of the Ruamāhanga River for riparian users. A

predominantly gravity-fed system would stem from the dams, served by two independent

outlets from the dam sites on Wakamoekau Creek and Black Creek.

The net supplied areas attributed to each outlet are roughly equal, with the northern and

eastern sectors fed by the Wakamoekau Creek outlet and the area southwest of Masterton

served by the Black Creek outlet. Approximately 89km of pipe would be required for the full

distribution network (T&T, June 2015).

13

Mangatarere (Scheme no. 215)

The Mangatarere water storage option is located approximately 10km northwest of Carterton,

on Mangatarere Valley Road. The dam would be situated on the Mangatarere Stream, a

tributary of the Waiohine River. The reservoir would be filled by own catchment infill i.e. run-

off and river flows from the Mangatarere Stream catchment upstream of the dam. With a

capacity of 29.3MCM of water, the reservoir could supply 33.6MCM of water to its irrigable


The indicative command area for the Mangatarere Scheme encompasses the area around

Carterton, between the Waingawa River in the north and the Waiohine River in the south. The

total net supplied area would be approximately 9,700ha.

The scheme distribution arrangements would consist of outlet works at the dam, 2.5km of

conveyance via the Mangatarere Stream to a diversion weir and 3km of synthetic-lined

conveyance headrace canal feeding a gravity-fed, pumped and piped distribution network. The

pipe network would comprise approximately 35km of pipe (T&T, June 2015).

6.2 Scope of Prefeasibility The aim of the Prefeasibility investigations was to determine which scheme options, if any,

showed sufficient feasibility to proceed to a more detailed feasibility study beginning in 2015.

The objective was narrowed to focus on only doing enough to decide which scheme/s should

progress to feasibility. In addition, early assessment of any possible ‘fatal flaws’ that could be

used to discount schemes and avoid unnecessary work was favoured.

Investigations covered financial, engineering, environmental, social and cultural aspects. While

Prefeasibility work was more detailed than preliminary investigations, it was still at a relatively

broad level.

The scope and direction of the Prefeasibility phase was developed progressively in an adaptive

and collaborative manner. At the completion of each stage, the scope of the remainder of

Prefeasibility was reviewed with the WWUP Working Group and either endorsed or revised as

appropriate. Other specialists, peer reviewers, and representatives of the IAF also provided

input at key points (T&T, June 2015).

In addition, the WWUP Governance, Leadership and Stakeholder Advisory Groups provided

input into what should be investigated during Prefeasibility.

The concept of investigating a ‘multi-storage scheme’ was not pursued during this phase as

recommended in the Options Refinement phase. Instead each option was investigated as

stand-alone scheme.

The three reserve schemes were not brought into the Prefeasibility investigation because none

of the preferred schemes were discounted during this phase.

The Prefeasibility programme was divided into six workstreams, undertaken by the WWUP

Working Group, Tonkin & Taylor and various other experts.

• Workstream 1: Revise command area and assess use of rivers for conveyance

• Workstream 2: Geotechnical assessment of reservoirs focussing on 5 shortlisted storage

sites including site visits, digger pits, and a ‘fatal flaws’ assessment

• Workstream 3: Supply-demand matching, design, geotechnical assessment, and cost

estimates for the distribution aspects of a multi-storage scheme in order to confirm

selected storage sites are appropriate for a cost-effective, long-term strategy

14

• Workstream 4: Non-engineering studies, including arranging access for site visits,

stakeholder and community engagement activities, and coordination of hydrometric data

collection for possible schemes

• Workstream 5: Additional scheme-specific studies that were identified and fully-scoped

following review points part way through the programme; and

• Workstream 6: Overall management, coordination and reporting on Prefeasibility

investigations (T&T, June 2015).

Workstreams were interspersed with review points to enable due consideration of issues by the

WWUP Working Group, Governance Group and stakeholders and the discounting of schemes not

deemed feasible at these review points. These are shown in Figure 3 below.

15

Figure 3: WWUP Prefeasibility work programme (WWUP, 2014)

16

Throughout the Prefeasibility phase, the scope of work and project criteria changed and adapted

as information came to light.

One of the major refinements was a Value Engineering exercise carried out in September 2014

which followed investigation and high-level design of water storage infrastructure and

distribution networks.

Value Engineering was undertaken to provide a critical assessment of scheme costs and therefore

economic feasibility, and involved project team members, consultants and Ministry for Primary

Industries (IAF) and industry experts. It confirmed scheme costings appropriate for this stage of

the project and economic feasibility to continue Prefeasibility investigations. It also identified a

range of potentially large cost saving opportunities to allow better relative comparison of the

scheme options.

The results of the Value Engineering exercise are described in Section 5.4 of the WWUP

Prefeasibility Phase - Engineering Report (T&T, June 2015).

6.3 Assumptions and limitations The work undertaken in the Prefeasibility phase was based on several assumptions and

performance criteria regarding water demand estimates, water availability, scheme service

parameters (reliability, water pressure etc.), and engineering design criteria. The engineering

design assumptions are outlined in Section 4.4 of the Tonkin & Taylor WWUP Prefeasibility

Phase - Engineering Report.

These may potentially change during future phases of work and more detailed investigations.

In addition, GWRC is currently reviewing policies around water allocation and minimum flows

as part of its Regional Plan review process. The work undertaken on the WWUP to date has

made assumptions on water allocation scenarios that may change particularly as the Regional

Plan review process evolves.

The assessment of likely costs of potential schemes is preliminary due to the number of

uncertainties at this early stage of investigation. The scheme layouts have been developed to

a Prefeasibility level, and modifications to arrangements can be expected during future

investigation, consultation and design stages (T&T, June 2015).

6.4 Factors not yet investigated It is important to note that at this Prefeasibility phase of the WWUP, many factors have not yet

been investigated and are still therefore unknown. The following is a list of these factors which

is not exclusive but provides an indication of investigations that will need to be added in future

phases of the project.

• Water quality within reservoir/s

• Effects on ground and surface water

• Future land use and the effects of land use change

• The effects of climate change on the demand for water and the availability of water

• Detailed dam geotechnical information

• Analysis of the risk of dam break for dam design purposes

• Possible environmental improvements that could result from a scheme

• Landscape and visual effects

• National, regional and district planning implications for consenting

• The shape and form of the legal entity or development structure for ownership and

construction of any scheme

• The price of water to users/farmers

17

7. Scheme comparison using Multi-Criteria Analysis (MCA) During the Prefeasibility phase, the six scheme options were compared against each other and

ranked using multi-criteria analysis (MCA). This follows the same process used in the Options

Refinement phase.

MCA is a structured and well-established framework that explicitly evaluates and weighs

multiple criteria to help compare options relative to each other for the purpose of decision-

making.

MCA processes are now a standardised tool for assessing and comparing options and have been

recognised as being appropriate through a number of significant consenting processes

considered through the Courts or Boards of Inquiry.

The criteria provided a structured approach to determining the respective advantages and

disadvantages of each of the options, based on a range of environmental and other attributes

which reflected, amongst other considerations, the statutory tests under the RMA.

Where possible, quantifiable data is obtained to provide a measureable assessment of potential

impacts (e.g. cost). Otherwise, MCA relies on a qualitative or subjective evaluation of the

options based on the experience and knowledge of the relevant experts involved, consultation

and subsequent testing, usually at multi-disciplinary workshops or the like.

The criteria used for the MCA were divided into four main themes - financial, environmental,

social and cultural. Under each of these were a series of sub-themes. Schemes were ranked

against each other on a 1-5 scale, using the same process for each theme and sub-theme.

In addition, risks and opportunities associated with each scheme option were identified and

considered. The findings from the MCA are an important part of the decision as to which

scheme/s, if any, should advance to the WWUP’s Feasibility phase.

This section of the Prefeasibility report presents a summary of the MCA analysis for the four

main themes. More detail and full reports on each of these themes are referenced in this report

and available on the ‘Reports’ page of the WWUP website at: www.wairarapawater.org.nz

7.1 The MCA process

For consistency, the same themes (from the Options Refinement phase) were continued in the

Prefeasibility phase; in many cases more information that has been gathered has enabled

categories to be broken down to another level or sub-theme (T&T, June 2015).

The process undertaken to arrive at the relative scheme rankings for each criteria involved four

steps.

1. Under each criterion, scores were applied to each scheme option

2. Criteria were weighted (as a percentage) according to their importance within each theme

3. Scores were then translated into a ranking from 1-5

4. Sensitivity analysis was undertaken to determine at what point the altered weightings

significantly affect the outcomes.

18

A scale of 1-5 was used to provide a comparative rather than absolute ranking for each criterion

in order to differentiate between schemes i.e. a score of 1 was least favourable compared with

the other schemes under consideration but was not necessarily unacceptable in a wider context.

Likewise, a score of 5 does not necessarily mean a scheme is favourable in an absolute sense. The

comparative scale is described as follows:

1. Least favourable

2. Less favourable

3. Moderately favourable

4. Favourable

5. Most favourable

For each criterion at least one scheme must score a 5 and another scheme as score of 1 to provide

the range. No other ‘rules’ apply to scoring e.g. four ‘5’s and one ’1’ is possible.

Criteria, weightings and scores were finally decided by the nominated professional experts. The

MCA rankings have been made by professional experts employed by the project e.g. geologists,

hydrologists, ecologists, engineers and economists. Each expert independently scored their own

area of expertise, providing written justification for each score. The experts also needed to

ensure the sub-themes were correct within their area of expertise and approve weightings for

each.

For the Social theme, the WWUP Working Group used local knowledge to score the four sub-

themes with expert guidance from Tonkin & Taylor, Opus International Consultants and Taylor

Baines.

Throughout the MCA process, the WWUP Stakeholder Advisory Group, Governance Group and

Leadership Group provided comment on the draft MCA scores. Elements, themes and rankings

were debated and group members provided input into reports by experts. In some cases expert

information was challenged and returned to the experts for further consideration. While experts

considered feedback, they ultimately decided whether their scores should be adjusted or

retained. The process and the assumptions should be able to be replicated.

The final part of the MCA process, sensitivity testing, is a recognised means of checking the

strength of the initial analysis. This process is conducted once the sub-themes have been ranked

(1-5) the weightings applied and the totals added. The aim of sensitivity testing is to establish

how different theme weightings affect the overall ranking of the schemes. The starting point was

the same as in the Options Refinement phase of work.

Care has been taken to ensure that criteria have not been ‘double counted’. Where expenditure

of capital can be applied to avoid, remedy, or mitigate an ‘effect’, it has been included in the

‘Financial’ category. This also helps avoid double counting e.g. a fish passage that would help

mitigate environmental issues is counted as cost to the project.

In addition, opportunities and risks have been identified with each scheme option. Some of these

are quantifiable and others are not. Opportunities and risks (outlined in Section 7.6 below) are

considered alongside the MCA themes.

19

The following themes and sub-themes were considered. The MCA rankings of each of these are

summarised in this report. Full reports for each theme and sub-theme are referenced in this

report and available on the ‘Reports’ page of the WWUP website at www.wairarapawater.org.nz.

Financial theme

• Scheme capital and operating costs

• Regional economic return

• On-farm economics

− Land use capability

− Increase in productivity

• Scheme economics

− Demand

− Rate of uptake

Social theme

• Community dislocation

• Loss of employment in inundated areas

• Construction activity effects

• Recreation implications and opportunities

Environmental theme

• Terrestrial ecology

• Aquatic ecology

Māori cultural theme

• Recorded cultural archaeological/historic sites

Risks and opportunities (scheme-specific)

• Financial

• National Policy Statement for Freshwater Management 2014 (NPS)

Risks and opportunities (general)

20

7.2 Financial theme The financial assessment of the Prefeasibility study was made up of four parts:

1. Scheme construction and operating costs

2. Regional economic return

3. On-farm economics

4. Scheme economics

7.2.1 Scheme capital and operating costs

The most significant financial sub-theme is scheme capital and operating costs because this

underpins the ultimate cost of water and therefore the economic viability of a scheme.

For this reason, scheme costs have received a weighting of 70% of the overall financial theme.

Costs include the capital cost of constructing the scheme headworks and distribution network,

and the annual operating and maintenance components spanning a 50-year period.

Consulting engineers Tonkin & Taylor were tasked with providing MCA scores in relation to

engineering aspects. A financial score, a risk score and an opportunity score was prepared for

each scheme in relation to engineering aspects. The financial score is based on the most likely

scheme layouts given the current level of investigation, while the risk and opportunity scores

reflect areas of uncertainty. Risk and opportunity scores are presented in Section 7.6 of this

summary report and in Tonkin & Taylor’s Prefeasibility Phase Engineering Report (2015).

Scheme characteristics such as topography, geology and geotechnical conditions, water

demand and water availability (which contribute to reservoir size) have all contributed to the

storage, water harvesting and distribution arrangements described in Section 13 of Tonkin &

Taylor’s Prefeasibility Phase Engineering Report (2015). Cost estimates have been prepared for

these arrangements, and used to compare the schemes on a financial basis as part of the multi-

criteria analysis.

Development of cost estimates involved the following steps:

1. Estimate of initial construction cost and selected costs during the operational period that

may differentiate schemes based on current understanding of engineering aspects (T&T,

June 2015) and

2. PricewaterhouseCoopers (PWC) combined these costs into a Net Present Cost (NPC) for

each scheme that accounts for the time-value-of-money (PwC, April 2015).

Tonkin & Taylor developed prefeasibility level estimates of initial construction costs and some

of the operational costs, considered at this stage because of their potential to differentiate

between schemes:

• Average annual cost of electricity for pumping

• Average annual cost of maintenance and servicing of valves and pumps, and

• Refurbishment/replacement cost for electrical mechanical components of pump stations

applicable in year 25 of the nominal 50-year operational period.

21

Other operational costs, such as ongoing administration of schemes, are excluded on the basis

that they will be broadly similar for all schemes based on limited understanding of these costs at

the current Prefeasibility level of investigation. A list of costs not included in the estimates can

be found in Section 14 of Tonkin & Taylor’s Prefeasibility Phase Engineering Report (2015).

WWUP has worked to integrate known costs of the scheme options through a robust

process using independent expert consultants. These are presented in Table 1 below (PwC, April

2015).

At this stage of investigation, the estimated cost ranges for the scheme options does NOT relate

to the cost of water to users or the cost of a scheme to investors. This will be depend on factors

such as scheme funding structure and water uptake rates which have not yet been investigated.

A range of opportunities and risks also needs further investigation during subsequent phases of

the project. These will be pursued with the aim of optimising scheme costs, and reducing

contingency and the range of uncertainty.

Table 1 below presents the net present cost (NPC) for each of the six scheme options. The NPC

is presented for each of the low (-15%), mid (+0%) and high (+30%) construction cost estimates.

Table 1: Net present cost (NPC) by scheme option (PwC, April 2015)

$million Black Creek*

Mangatarere

Te Mara Tividale Wakamoekau

White Rock Rd

Low NPC (-15%)

$138m $69m $73m $71m $55m $64m

Mid (+0%) $161m $81m $85m $82m $64m $74m

High NPC (+30%)

$205m $105m $108m $105m $81m $94m

*Black Creek figures include Wakamoekau

The cost estimates are considered appropriate for comparison of schemes in the multi-criteria

analysis, but a wide cost range is considered realistic for the current level of design development.

In terms of accuracy, it is expected that a ‘typical’ range for initial construction cost estimates

could be in the order of -15%/+30%. If atypical changes are made to performance scope or there

are significant changes from findings and assumptions to date, costs would be expected to be

beyond the ‘typical’ range shown in figures.

Prefeasibility is an early stage of investigation, and this necessarily limits the degree of cost

certainty that can be achieved. Cost estimates are based on the information currently available,

level of assessment completed to date, and assumptions and design criteria that may change

with future phases of the WWUP.

The scheme cost estimates exclude the following, which represents a relatively typical list for a

Prefeasibility level of assessment:

• General upgrades to the wider electricity grid

• On-farm costs

• Land purchase beyond reservoir extents

• Landowner compensation for easements

• Replacement of private access and amenities such as air strips

• Relocation of public utilities, power lines and services

22

• Subsidies, compensation, or purchase of commercial operations such as quarries.

• Foundation grouting at dam sites

• Government taxes

• Design and investigation costs up to and including the Specimen Design of the chosen

option/s

• Legal costs

• Financing and developer administration associated with initial construction

• Consenting and approvals

• Insurance

• Construction cost volatility

• All operational and maintenance costs other than electricity for pumping, pump/valve

maintenance and pump/valve replacement. (T&T, June 2015)

Figures 4 and 5 on page 23 present the typical range of net present cost estimates for each

scheme in terms of net present cost per hectare supplied ($/ha) and net present cost per cubic

metre of water supplied in a drought year ($/m3) respectively.

23

Figure 4: Net Present Cost ranges in terms of $/h (net area supplied) (T&T, June 2015)

Figure 5: Net present cost ranges in terms of $/m³ supplied in a drought year (T&T, June 2015)

Note: The estimated cost ranges in Tables 4 and 5 above do NOT relate to the cost of water to

users or the cost of a scheme to investors. There is a great deal more work to be done before

the cost of water can be determined.

24

The results of Tonkin & Taylor’s MCA ranking for combined scheme construction and operating

costs are shown in Table 2 below. Financial scores are presented for both $/ha and $/m³ supplied

in a drought year. The details that contributed to the MCA scores are presented in Appendices

C and D of Tonkin & Taylor’s Wairarapa Water Use Project Prefeasibility Phase – Engineering

Report (T&T, June 2015).

Table 2 - Combined construction and some operating costs – MCA rankings3 (T&T, June 2015)

Scheme

Financial Score

$/ha $/m³ supplied in a drought year

Scheme 10 Tividale 4.1 1.0 (least favourable)

Scheme 135 White Rock Road

1.0 (least favourable) 1.1 (close to least favourable)

Scheme 197 Te Mara 3.3 2.7

Scheme 206 Wakamoekau 5.0 (most favourable) 5.0 (most favourable)

Scheme 210 Black Creek 4.5 3.5

Scheme 215 Mangatarere 4.1 3.4

Note: when scored on the basis of $/m³ supplied in a drought year, Tividale compares much less favourably

than when scored on a $/ha basis. This is because the annual water demand ($/ha) in a drought year is

expected to be notably lower for the Tividale scheme than the other five schemes.


25

Table 3 - Sensitivity testing of $/ha and $/m³ for capital and operating costs4 (WWUP, April 2015)

Opex and Capex score

Weightings

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

210

- Bla

ck C

reek

215

Man

gata

rere

0% weighting on $/ha & 100% on $/m3

1.0 1.1 2.7 5.0 3.5 3.4


1.5 1.1 2.8 5.0 3.7 3.5


2.1 1.1 2.9 5.0 3.9 3.6


2.6 1.1 3.0 5.0 4.0 3.8


3.0 1.0 3.1 5.0 4.2 3.9


3.6 1.0 3.2 5.0 4.4 4.0


4.1 1.0 3.3 5.0 4.5 4.1

MCA Ranking on 50/50 split 2 1 3 5 4 4

The key conclusions from the Prefeasibility cost estimates (T&T, June 2015) are:

• There is substantial overlap of the cost estimates for the six schemes when the expected range of -

15%/+30% is considered.

• When financial favourability is considered in terms of $/ha (net area supplied) or $/m³ supplied in a

dry year, Wakamoekau appears the most promising. Black Creek and Mangatarere are the next most

promising and are similarly favourable. Te Mara is moderately favourable. White Rock Road appears

to be the least promising of the six schemes. Tividale appears similarly favourable as Black Creek

and Mangatarere if considered on the basis of $/ha (net supplied), but appears the least favourable

if considered on the basis of $/m³ supplied to farm gate in a dry year.

• The lowest ranked scheme is 24% more expensive than the highest ranked scheme in terms of $/ha

and 22% more expensive in terms of $/m³ supplied in a dry year. This is a relatively small difference

when considered against the uncertainty range in the cost estimates. This indicates that all six

schemes are in a similar range in terms of overall affordability (T&T, June 2015).


26

It is important to note that this process does not determine a price for water; that includes

other factors such as the commercial model adopted, water uptake rates, funding sources etc.

As such, price will not be known until much later in the project.

7.2.2 Peer review - scheme capital and operating costs

The assessment of financial favourability has been based on comparing single-storage schemes

as independent alternative options that would not be developed in conjunction without

modifications to arrangements.

For the engineering and cost aspects of the Prefeasibility phase three independent peer

reviewers were commissioned to review Tonkin & Taylor’s work:

• Alan Pickens of Pickens Consulting Ltd (PCL), covering engineering components comprising

design of reservoirs, harvesting systems and distribution systems;

• Morgan Pheloung of Bond Construction Management Ltd, covering cost estimates; and

• Ian McIndoe of Aqualinc Research Ltd, covering water demand, water availability and

hydrology.

Details of their findings are outlined in Section 16 of Tonkin & Taylor’s report. This includes

further work suggested by the peer reviewers during future phases of the WWUP. With respect

to reservoirs, PCL provided the following comments in his peer review letter dated 11 May

2015:

‘In my experience, the approach has been extremely thorough, more so than is

usual in identifying and comparing potential solutions, but warranted, given that

the WWUP project involves a high level of complexity.

With the proviso that at the Prefeasibility level stage, cost constraints mean that it

is not possible to precisely evaluate all relevant aspects, particularly subsurface

conditions at dam sites and best material sources for construction, assessments to

date do not indicate any fatal flaws. I am satisfied that a thoroughgoing approach

has been adopted in quantifying engineering components and then costing them.’

(Pickens Consulting Ltd, 11 May 2015).’

7.2.3 Regional economic return

Regional economic return is the potential impact of the scheme options on the economy of

the greater Wellington region.

Benefits to the Wairarapa and greater Wellington regions potentially resulting from increased

irrigation were described by Butcher Partners in their report Regional Economic Impact Analysis

of the Proposed Wairarapa Water Use Project, 19 October 2014.

This report did not analyse economic impact by individual scheme option but provided an

analysis of economic impact by irrigated hectares (10,000ha and 30,000ha scenarios). This

impact was quantified based on a prescribed set of land use mix and land use profitability

assumptions. The land use profitability data came from the 2014 Baker & Associates report

Wairarapa Water Use: Land Use Affordability under Irrigation, April 2015.

Economic impact was measured in terms of GDP. Taking into account soil types in Wairarapa

and assumed land uses, this work estimated the GDP impact per cubic metre of water delivered

to primary producers. This parameter was applied to the number of hectares in the command

27

area of each scheme and the maximum cubic metres of water supplied by each scheme. The

resulting scheme rankings under the Regional Economic sub-theme were as follows:

Table 4: Regional economic return - MCA rankings5 (WWUP, May 2015)

The most favourable scheme in terms of GDP impact per cubic metre of water supplied was

Tividale, followed by Black Creek. Te Mara and Mangatarere were the next most favourable and

White Rock and Wakamoekau were equally the least favourable.

7.2.4 On-farm economics

On-farm economics scores the potential increased productivity of irrigated land over dry land.

The two factors measured were:

− Land use capability (LUC) and

− Increase in productivity per hectare under irrigation

Land use capability is the measurement of the land’s general versatility to sustain continuous

production. Increase in productivity per hectare measures the potential increase in disposable

surplus under irrigation over dry-land farming (WWUP, April 2015).

Land use capability (LUC)

Land Use Capability (LUC) is a standard that classifies New Zealand land into categories based on

its versatility. Land is rated on a scale of 1-8 with 1 being the most versatile and 8 being the least.

These classifications were applied to the command areas for each scheme option to gain a view

of which land had the most versatile land use.

Using mapping software, the percentage of each LUC class in the command area of each scheme

option was determined. LUC rankings were weighted as to favour the soils with greater

versatility. The scheme options were then ranked as follows, according to the versatility of land

in their command areas (WWUP, 2015).


Regional Economics

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Mar

a

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

nga

tare

re


28

Table 5: On-farm and scheme economics - MCA rankings6 (WWUP, April 2015)

Wei

ghtin

g %

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

210

- Bla

ck C

reek

215

Man

gata

rere

On-Farm Economics

Land Use Capability 50% 5 1 3 3 4 2

Increase in Productivity 50% 3 2 4 5 3 1

TOTAL 4 1.5 3.5 4 3.5 1.5

MCA score 5 1 3 5 3 1

Scheme Economics

Potential Demand 70% 4 1 3 3 2 5

Rate of Uptake 30% 4 1 3 3 2 5

TOTAL 4 1 3 3 2 5

MCA score 4 1 3 3 2 5

As shown in Table 5, the most favourable option for Land Use Capability is Tividale, followed by

Black Creek, then equally Te Mara and Wakamoekau. Mangatarere was the second least

favourable and White Rock the least favourable.

Increase in productivity

An indication of which schemes show the greatest potential to the farmer/land owner in the form

of increased disposable surplus after changing from dry land farming to irrigated farming.

Wairarapa farm consultants Baker and Associates Ltd measured potential increase in primary

production for each scheme option across a range of land uses, and three soil types. The increase

was the increase in production of irrigated land over dry land production.

The report compared financial returns under current land use with returns under irrigation for

different soil types and four different land uses - dairy, sheep & beef, mixed arable, viticulture.

An indication of the financial viability of irrigation, before the cost of water and existing debt

servicing were taken into account. Dairy, sheep & beef and mixed arable were then used for this

analysis.

Based on interviews with farmers and local rural professionals, and land use mixes of other actual

and proposed schemes elsewhere in New Zealand, the possible land use mix in the command

zone of each scheme option (not the whole Wairarapa valley) after irrigation is introduced was

predicted. Table 5 above ranks the scheme options according to their favourability to

increase disposable surplus income per irrigated hectare. Most favourable was Wakamoekau,

followed by Te Mara, then equally Black Creek and Tividale. White Rock was the second least

favourable and Mangatarere the least (WWUP, April 2015).

6 Rankings are comparative; 5 most favourable-1 least favourable. Raw scores are the weighted sum of sub-

themes.

29

7.2.5 Scheme economics Scheme economics measures the potential demand and rate of uptake of water by farmers and

growers. The measure used was cubic metres of water. In the MCA process, Scheme Economics

was given the least weight (5%) of the four financial sub-themes due to the preliminary nature

of the farmer surveys and the early estimations of demand and rate of uptake (WWUP, April

2015).

Demand for water

Throughout the Options Identification, Options Refinement and Prefeasibility phases of the

project the WWUP Working Group has engaged with farmers/landowners to broadly estimate

the potential demand for water. To date, farmers responsible for approximately 67 percent of

land area in the command areas have been interviewed (WWUP, April 2015).

During interviews with landowners, farmers and growers, they were asked about their interest

in accessing water to irrigate all or some of their land. Scheme options were then ranked

according to the level of interest expressed. It is important to note that the price of water, which

will be a key factor in uptake or water, was not available to be included in these discussions

(WWUP, April 2015).

As shown in Table 5 above, in the demand category the most favourable scheme was

Mangatarere, followed by Tividale, Te Mara and Wakamoekau, Black Creek with White Rock

Road being the least favourable.

In terms of command area locations, it is noted that:

• The White Rock Road and Tividale schemes would supply water to essentially independent

command areas, except for some minor overlap of Tividale and Black Creek.

• Te Mara, Wakamoekau, Black Creek and Mangatarere would supply water to command

areas that overlap substantially (T&T, June 2015).

Rate of uptake

During the demand interviews farmers were also asked when they thought they would buy

water after a scheme became operational. This factor is important because a minimum uptake

is likely to be required when a scheme becomes operational, providing revenue from the start.

During the interviews, farmers/landowners were asked “If irrigation scheme ‘user pays’ water

was made available to your farm, how many years later would you expect to make any

agricultural land use changes?” The responses to this fell into five categories:

1. <1 Demand indicated by existing land owners immediately

2. 1-2 years Demand indicated by existing land owners in the first 2 years



5. 10-20 years Unaccounted for demand

By calculating the potential volume of water demand in each category, compared with available

water, then dividing this by the average volume of water supplied each command area was

ranked (WWUP, April 2015).

30

As shown in Table 5, above the most favourable scheme for rate of uptake was Mangatarere,

followed by Tividale and then equally, Te Mara and Wakamoekau. Black Creek was next and

White Rock was the least favourable.

7.2.6 Overall financial theme – summary MCA rankings for each of the four financial sub-themes described above are shown in Table 6

below, along with their associated weightings. When combined, the four sub-themes provide

an overall financial ranking for each scheme option.

Table 6: Overall financial theme - MCA rankings 7(WWUP, April 2015)

Financial Theme Sub-Theme Weightings

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

210

- Bla

ck C

reek

215

- M

anga

tare

re

Capex & Opex Mid Point Costs 70% 2.0 1.0 3.0 5.0 4.0 4.0

Regional Economics 15% 5.0 1.0 2.0 1.0 3.0 2.0

On-Farm Economics 10% 5.0 1.0 3.0 5.0 3.0 1.0

Scheme Economics 5% 4.0 1.0 3.0 3.0 2.0 5.0

Raw score

2.9 1.0 2.9 4.3 3.7 3.5

MCA Ranking

3 1 3 5 4 4

From an overall financial perspective, Wakamoekau is the most favourable, followed equally by

Black Creek and Mangatarere. Tividale and Te Mara are moderately favourable and White Rock

Road is the least favourable.

7 Rankings are comparative; 5 most favourable - 1 least favourable. Raw scores are the weighted sum of sub-

themes

31

Testing to analyse how sensitive the overall scheme rankings were to the relative weightings of

the four sub-themes is shown in Table 7 below. When the weightings were adjusted, scheme

rankings showed very little sensitivity and were largely unchanged. Tividale becomes more

favourable when Regional, On-farm and Scheme Economics are given more weight.

Table 7: Sensitivity testing on overall financial ranking8 (WWUP, April 2015

Financial Sensitivity Testing

C&O: Capex & Opex mid-point costs

Reg: Regional economics

OFS: Off-farm scheme economics

SE: Scheme economics

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

kam

oe

kau

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

50% C&O,

16.66%Reg,16.66%OFS,16.66%SE 4 1 3 5 4 4

60% C&O,

20%Reg,12.5%OFS,7.5%SE 3 1 2 5 4 4

60% C&O,

13.33%Reg,13.33%OFS,13.33%SE 3 1 2 5 4 4

70% C&O, 15%Reg,10%OFS,5%SE 3 1 3 5 4 4

70% C&O, 10%Reg,10%OFS,10%SE 3 1 3 5 4 4

80% C&O, 10%Reg,7.5%OFS,2.5%SE 2 1 3 5 4 4

80% C&O,

6.66%Reg,6.66%OFS,6.66%SE 2 1 3 5 4 4

7.3 Social theme The social theme of the MCA considered four sub-themes – community dislocation in inundated

areas, loss of employment, temporary construction effects and recreation impacts and

opportunities.

It did not include regional social benefits and impacts because information gathered on these

was not scheme-specific and therefore did not contribute to a comparison of schemes for

selection purposes.

This will be an area of further investigation in the Feasibility phase of work. These were

described in the Taylor Baines & Associates report Preliminary Social Impact Assessment,

October 2014.


32

7.3.1 Community dislocation in inundated areas The estimated number of permanent residents in the area within each water storage reservoir

option was considered and taken into account when comparing the five scheme options.

Community dislocation is a measure of the approximate number of people who would need to

leave their place of residence to allow for the construction of the reservoir.

A weighting of 50% was applied to this sub-theme as part of the overall social theme. This

relatively high weighting reflects the effect of the storage reservoirs displacing people from

their homes. Table 8 below ranks the scheme options with respect to the estimated numbers

of people involved.

Table 8 - Community dislocation in inundated areas - MCA rankings9 (WWUP, April 2015)

Note: Resident numbers are estimates. Compensation for loss of assets and/or land is accounted for in

the Financial Theme.

With respect to community dislocation, Te Mara is the most favourable option, with

Wakamoekau and Tividale equally next most favourable. White Rock is moderately favourable.

Due to the number of people living in the areas, Mangatarere and Black Creek are the least

favourable.

7.3.2 Loss of employment in inundated areas Loss of employment in inundated areas is a measure of the approximate number of full time

equivalent (FTE) jobs that would be lost within the reservoir areas. Some of these would be

temporary as people working in these areas could use their expertise in other areas in

Wairarapa or elsewhere as they chose. A weighting of 10% has been applied to this measure

as part of the overall social theme.

Table 9 below estimates the number of employees that could be expected to be displaced for

each of the scheme options. It excludes any new opportunities created.

Table 9 - Loss of employment in inundated areas - MCA rankings10 (WWUP, April 2015)

9 Rankings are comparative; 5 most favourable - 1 least favourable. 10 Rankings are comparative; 5 most favourable - 1 least favourable.

Community dislocation

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck

19

7 -

Te

Ma

ra

20

6 -

Wa

kem

oe

ka

u

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

nga

tare

re

Estimated permanent residents 2 8 1 4 39 18


33

With respect to loss of employment in inundated areas, Tividale and White Rock were the most

favourable scheme options. Te Mara and Wakamoekau were equally moderately favourable.

Mangatarere was the second least favourable and Black Creek the least favourable.

7.3.3 Temporary construction effects A preliminary assessment of the social effects of scheme construction that may be temporarily

experienced by groups such as residents, farmers, infrastructure companies and/or users and

recreationalists has been made for each scheme option for comparative purposes.

The temporary effects of scheme construction include digging, dam construction,

transportation of materials, extra traffic, more trucks on the road and the digging of pipe

networks. A weighting of 10% has been applied to this measure as part of the overall Social

theme (see Table 12 below).

MCA rankings for temporary social impacts associated with construction are shown in Table 10

below.

Table 10: Temporary construction effects - MCA rankings11 (WWUP, T&T, 2015)

Note: The rationale behind these scores is based on one possible approach to construction given

the current level of investigation. Details are likely to change with further investigation.

11 Rankings are comparative; 5 most favourable - 1 least favourable. Raw scores are the weighted sum of the

sub-themes.

Loss of employment

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck

19

7 -

Te

Mar

a

20

6 -

Wak

amo

ekau

21

0 -

Bla

ck C

reek

21

5 -

Man

gata

rere

Estimated FTEs displaced 0 0 1 1 4 2


Temporary

construction effects

Sub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

Borrow from off-site 20% 2 3 3 4 5 1

Spoil 10% 4 2 5 4 3 1

Impacts immediately at site 30% 2 1 4 5 4 1

Impacts of distribution

network construction40% 5 3 3 3 1 2

Raw score 3.4 2.3 3.5 3.9 2.9 1.4


34

With respect to temporary construction effects, Wakamoekau is the most favourable option,

followed equally by Tividale and Te Mara. Black Creek is moderately favourable. White Rock

Road and Mangatarere are the least favourable options.

7.3.4 Recreation implications and opportunities As part of the Prefeasibility phase, a high-level preliminary view of the implications and

opportunities for recreation presented by each of the scheme options was undertaken by Opus

International Consultants. This was included in the Prefeasibility study at the request of the

Stakeholder Advisory Group.

The purpose of the Opus Preliminary Recreation Implications and Opportunities Report, October

2014 was to provide a desk-top study of the current recreation activities undertaken at the five

water storage sites being considered, and understand the potential implications on these

activities as a result of the project. Consideration was also been given to the opportunities

associated with the potential water storage sites including potentially improved up/down

stream flows, through seasonal environmental and flushing flows.

Background research in the form of a brief site visit to each site, literature research and

consultation was undertaken to inform the Preliminary Report. Early in the assessment, a key

contacts comprising the WWUP Stakeholder Advisory Group (SAG) and key current and

potential stakeholders were sent a questionnaire and to inform the recreation assessment.

These included potential users of the water storage sites such as kayaking groups.

Table 11 below presents the MCA rankings for the recreation sub-theme which was comprised

of three sub-themes; location, implications for existing recreation activities and new

opportunities.

Table 11: Recreation theme MCA - rankings12 (Opus, 2014)

Note: At the time the Preliminary Report was done by Opus International Consultants,

Wakamoekau was part of the Black Creek site. It is now being considered as a standalone scheme.

The MCA ranking of 4 has been agreed by Opus as appropriate.

With respect to recreation, Black Creek is the most favourable scheme, followed by

Wakamoekau. Te Mara is moderately favourable. Tividale and White Rock Road are equally

ranked next. Mangatarere is the least favourable for recreation.

12 Rankings are comparative;5 most favourable-1 least favourable. Raw scores are the weighted sum of sub-

themes.

RecreationSub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

Location 20% 1 3 3 5 2

Implications for existing

recreation activities 30% 5 3 1 4 1

New opportunities 50% 1 2 4 5 2

Raw Score 2.2 2.5 2.9 4.7 1.7


35

7.3.5 Overall social theme - summary When combined, the four social sub-themes described above provide an overall social ranking

for each scheme option.

The combined MCA rankings for the four social sub-themes are shown in Table 12 below, along

with their associated weightings:

Table 12: Social theme summary - MCA rankings13 (Opus, 2014; T&T, 2015; WWUP, 2015)

The weighting of the social factors, the most important sub-theme being identified as the effect of the

storage reservoirs displacing people from their homes/place of work; hence the relatively high weighting

applied. Principally for this reason, Black Creek and Mangatarere are ranked lowest overall.

Mangatarere consistently received low rankings for all social sub-themes, whereas Black Creek received

mid-range scores for two of four sub-themes, namely construction effects and recreation, but because

of Black Creek’s scale it is ranks lowest on two sub-themes.

The 30% weighting for recreation reflects the more permanent/ongoing outcomes and impacts to the

region compared with the more transitional effects of the loss of employment and temporary

construction effects sub-themes.

Even though Wakamoekau and Black Creek have overlapping storage areas, the difference between them

lies in the number of residents affected by each scheme.

Sensitivity testing of the four social sub-themes which make up the overall social theme rankings tested

the effect that different weightings had on the scheme rankings. This is shown in Table 13 below. The

most notable outcomes from the sensitivity testing were that irrespective of the weightings:

• Wakamoekau remained the most favourable scheme

• Mangatarere remained the least favourable scheme

• All sites were insensitive or almost insensitive to a change of weightings.

13 Rankings are comparative; 5 most favourable-1 least favourable.

Prefeasibility MCA

Social Theme

Sub-Theme

Weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oad

19

7 -

Te

Ma

ra

20

6 -

Wak

amo

ekau

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

nga

tare

re

Community Dislocation 50% 4 3 5 4 1 2

Loss of Employment 10% 5 5 3 3 1 2

Temp Construction Effects 10% 4 2 4 5 3 1

Recreation 30% 2 2 3 4 5 1

Raw score 3.5 2.8 4.1 4.0 2.4 1.6


36

Table 13: Social sub-themes - MCA sensitivity testing14 (WWUP, April 2015)

SOCIAL Sub-Themes Sensitivity Testing

Sub -Theme Abbreviations:

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

210

- Bla

ck C

reek

215

- M

anga

tare

re

CD - Community Dislocation

LE - Loss of Employment

CE - Temporary Construction effects

Rec - Recreation

CD 50%, LE 10%, CE 10%, Rec 30 % 4 3 5 5 2 1

CD 40%, LE 15%, CE 15%, Rec 30 % 4 3 5 5 2 1

CD 30%, LE 20%, CE 20%, Rec 30 % 4 3 5 5 2 1

CD 20%, LE 25%, CE 25%, Rec 30 % 4 3 4 5 2 1

CD 10%, LE 30%, CE 30%, Rec 30 % 4 3 4 5 2 1

CD 40%, LE 10%, CE 10%, Rec 40 % 3 2 5 5 2 1

CD 30%, LE 10%, CE 10%, Rec 50 % 3 2 4 5 3 1

CD 25%, LE 25%, CE 25%, Rec 25 % 4 3 4 5 3 1

CD 10%, LE 40%, CE 40%, Rec 10 % 4 3 4 5 3 1

7.4 Environmental theme The Prefeasibility environmental assessment was a desk-top study of the ecological values

within the reservoir footprints and the stream/river(s) affected. More detailed environmental

assessments, including of the effects of land use change will be carried out in the feasibility

phase. At this stage, issues relating to the National Policy Statement for Freshwater

Management (NPS) are presented as environmental risks and opportunities in Appendix B.

As outlined in Section 2.2, separately from the WWUP, the Ruamāhanga Whaitua committee is

working to determine community values and needs and set the vision for the catchment as part

of the Regional Plan review. It will then create policies and rules for how land and water

resources are managed. Any water scheme developed would need to operate within the

Regional Plan’s water quality and quantity limits.


37

Two components were considered as part of the Environmental theme of the MCA - terrestrial

ecology and aquatic ecology. GWRC’s Biodiversity department initially undertook the

assessment of both of these aspects as reported in MCA scores for Environmental Theme (Jamie

Steer, GWRC).

MCA scores were calculated for the terrestrial and aquatic sub-themes for each of the water

storage options. Combined (terrestrial and aquatic) MCA scores were also calculated for each.

A peer review was then conducted by Dr Vaughan Keesing of Boffa Miskell which resulted in

some changes to several elements of the assessments. The rationale for and nature of the

changes made are outlined in the peer review report Wairarapa Water Use Project Ecological

Review (Boffa Miskell, 2015). It was agreed by the original author and the peer reviewer that

the peer reviewer’s adjustments would be used as the final MCA scores.

The principal outcomes of the peer review were:

• Decrease in the Mangatarere reservoir footprint from the most favoured to the least

favoured with respect to The LENZ (Land Environments of NZ) Threatened Environments

Classification (combined with presence of indigenous systems).

• switch in scores for Black Creek and Wakamoekau with Tividale and White Rock with

respect to the NIWA freshwater database.

With respect to point a. above, the primary difference between the initial assessment and the

peer review was the use of the LENZ threatened environment layer. The authors of the initial

assessment used the LENZ vegetation cover data to establish where value for potential

vegetation lay (irrespective of current land cover vegetation). They also used the LENZ data to

assess where under-represented categories of the “environment” were and which might be

returned to an indigenous system sometime in the future. It was considered that a more

relevant approach was to only value LENZ categories where indigenous vegetation is currently

present, which effectively meant the LENZ category had no influence where no indigenous

system is present. This approach was used to rework the LENZ classification analysis in the

terrestrial sub-theme previously undertaken.

With respect to point b. above, the peer reviewer conducted a re-analysis of the NIWA

freshwater database, and as a result made some changes to two categories namely ‘habitat for

indigenous fish species of conservation interest’ and ‘habitat for six or more migratory

indigenous fish species’.

7.4.1 Terrestrial Ecology Factors considered in the terrestrial ecology Prefeasibility assessment were as follows:

• Total number of hectares covered by the water storage footprint, including a 20-metre

buffer

• Land Environments of NZ (LENZ) classifications

• Existing ecosystem types identified using LCDB2

• Department of Conservation-administered estate, reserves and covenants

• Land covenanted by the Queen Elizabeth II National Trust

• The NZ Geopreservation Inventory which highlights the best examples of the wide diversity

of natural physical features and processes that together characterise each part of NZ.

38

Table 14 below presents the agreed MCA rankings for the terrestrial ecology aspects of the scheme

options, incorporating the peer review adjustments.

Table 14: Terrestrial ecology - MCA rankings15 (Boffa Miskell, 2015; GWRC, 2015)

With respect to terrestrial ecology, the most favourable site is clearly Wakamoekau. Te Mara is

moderately favourable (3). White Rock Road and Black Creek are next with an equal ranking of 2. The

least favourable sites are Tividale and Mangatarere with an equal ranking of 1.

7.4.2 Aquatic Ecology Factors considered in the aquatic ecology Prefeasibility assessment were as follows:

• Main watercourses (e.g. rivers, streams) and total length of watercourse affected.

• Presence of wetlands

• Draft Natural Resources Plan (Wellington region) rivers and lakes with significant

indigenous ecosystems

− High micro invertebrate community health

− Habitat for indigenous fish species of conservation interest

− Habitat for six or more migratory indigenous fish species

• Regional Policy Statement (RPS) rivers and lakes with significant indigenous ecosystems

− High micro invertebrate community health

− Habitat for threatened indigenous fish species

− Habitat for six or more migratory indigenous fish species

• Cawthron Highest Value Reaches for Fish

• Cawthron Sports Fish Spawning & Recruitment

• Draft Natural Resources Plan (Wellington Region) Trout Habitat


themes

Pre-feasibility MCA

Environmental

(Terrestrial theme)

Sub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 M

an

ga

tare

re

Hectares 30% 2.0 4.5 4.5 5.0 1.0 5.0

LENZ Threatened

Environments Classification25% 3.0 2.0 4.0 4.5 5.0 1.0

Ecosystem types 15% 3.0 4.0 4.0 5.0 4.0 1.0

DoC land 10% 5.0 5.0 5.0 5.0 5.0 1.0

QEII 10% 2.0 3.0 1.0 5.0 1.0 5.0

NZ Geo-preservation 10% 5.0 1.0 5.0 5.0 5.0 5.0

Raw Score 3.0 3.4 4.1 4.9 3.3 3.0

MCA Ranking 1.0 2.0 3.0 5.0 2.0 1.0

39

Table 15 below presents the agreed MCA rankings for the aquatic ecology aspects of the scheme options,

incorporating the peer review adjustments:

Table 15: Aquatic ecology - MCA rankings16 (Boffa Miskell, 2015; GWRC, 2015)

The most favourable site is White Rock Road. Black Creek, Te Mara and Mangatarere (all 1) are the least

favourable sites.

Table 16 below summaries the agreed MCA rankings for the combined environmental values (terrestrial

and aquatic), incorporating the peer review adjustments.

Table 16: Overall environmental theme - MCA rankings17 (Boffa Miskell, 2015; GWRC, 2015)

For the combined terrestrial and aquatic sub-themes, Wakamoekau is the most favourable site, followed

by Black Creek. White Rock Road and Te Mara are ranked relatively favourably. Mangatarere and Tividale

are the least favourable options.


themes 17 Rankings are comparative; 5 most favourable-1 least favourable. Raw scores are the weighted sum of sub-

themes

Prefeasibility MCA

Environmental

(Aquatic theme)

Sub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 M

an

ga

tare

re

Watercourses 30% 1 3.5 5 5 2.5 2.5

Wetlands 10% 5 5 1 5 5 5

Draft NRP rivers & lakes with

significant indigenous

ecosystems

30% 2 1 4 5 5 3

Cawthron highest value

reaches for fish10% 5 5 1 5 5 1

Cawthron sports fish spawning

& recruitment10% 5 5 1 5 5 1

Draft NRP trout habitat 10% 1 5 1 1 1 1

Raw score 2.5 3.4 3.1 4.6 3.9 2.5


Prefeasibility MCA

Environmental ThemeSub-Theme

Weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 M

an

ga

tare

re

Terrestrial sub-theme scores 50% 1 2 3 5 2 1

Aquatic sub-theme scores 50% 1 3 2 5 4 1

Raw Scores 1 2.5 2.5 5 3 1

MCA Rankings 1 3 3 5 4 1

40

7.5 Māori cultural theme Joint discussions held with Wairarapa iwi members from Rangitāne o Wairarapa and Ngāti

Kahungunu ki Wairarapa identified opportunities for further development of the project’s

relationship with iwi. In addition, feedback was sought on cultural value of the areas covered

by the five scheme options. This included benefits, concerns, risks and opportunities.

These discussions and a review of previous work completed in the Options Refinement phase

formed the basis of the MCA rankings for the Māori Cultural sub-theme.

Subsequently, advice was provided by archaeologist Christine Barnett on known Māori

archaeological and historic sites of significance in her report Archaeological and Historic Sites -

Sites of Significance, April 2015.

This report was a desk-top study using existing historic and archaeological information; no field

work was conducted. It focused on the storage site options and gave secondary consideration

to the scheme command areas. This was because there is flexibility around the impact of the

distribution infrastructure which can be considered during the Feasibility phase (Barnett, 2015).

Christine Barnett’s report broadly covered the following:

a. Archaeological site recording: recorded and unrecorded sites.

b. Historic sites

c. Traditional trails and artefacts

d. The significance of all the historic and archaeological sites

e. Archaeological site information within the five preferred scheme areas

f. Legislation in New Zealand with regard to archaeological sites. (Barnett, 2015)

A subsequent meeting with members of both iwi was held on 18 May 2015 to review the draft

cultural report and scheme rankings. The scheme rankings as shown in Table below were

agreed:

Table 17: Māori cultural theme - MCA rankings18 (Barnett, 2015)

Prefeasibility MCA Cultural Theme

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

210

- Bla

ck C

reek

215

Man

gata

rere

Archaeological & Historic Sites Ranking

3.5 4.0 1.0 5.0 5.0 4.0


41

With respect to Maori archaeological and historic sites, Wakamoekau and Black Creek are equally

the most favourable options. Mangatarere and White Rock Road are also equally favourable.

Tividale is moderately favourable and Te Mara is clearly the least favourable.

In addition to the rankings above, the peer review process by iwi identified a number of

opportunities and risks from a cultural perspective which will be further developed during the

Feasibility phase.

7.6 Risks & Opportunities (scheme-specific)

7.6.1 Financial The risk scores for each scheme option developed for the MCA by Tonkin & Taylor focus on

potential cost increases or technical risks relating primarily to engineering components. The

focus of opportunity scores has been on potential cost savings, though the potential to

incorporate a hydropower add-on at dams was also considered (T&T, June 2015).

In order to put factors into a quantitative context and ensure the weightings reflect the likely

impact on overall scheme costs, consideration has been given to the component of net present

cost represented by each factor. Indicative weightings based on judgement have been assigned

for the hydro-power add-on opportunity and geotechnical risks for aspects not represented in

cost schedules (T&T, June 2015).

Overall risk and opportunity scores for each scheme were then developed based on a weighted

average across these factors. Finally, an adjustment was applied so that scores ranged from 1

‘least favourable’ to 5 ‘most favourable’ (T&T, June 2015).

Detailed thinking behind scores for each factor is provided in Appendix D of the Tonkin & Taylor

WWUP Prefeasibility report, noting that much of this thinking is relatively speculative and

subjective which is considered appropriate at this Prefeasibility phase (T&T, June 2015).

Table 18 and Table 19 below rank the relative technical and financial risks and opportunities

respectively for each of the scheme options:

42

Table 18: Engineering opportunities for cost savings - MCA rankings19 (T&T, June 2015)

In terms of opportunities for cost savings, Te Mara is clearly the most favourable, followed by Black Creek,

and then Mangatarere. Tividale and Wakamoekau are similarly moderately favourable. White Rock Road

is clearly the least favourable of the six schemes in terms of opportunities (T&T, June 2015).

The opportunities listed above can relate to matters which are yet to be investigated and which may

result in benefits and/or potential cost savings.


sub-themes or opportunity factors.

Engineering OpportunitiesSub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

kam

oe

kau

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

atar

ere

Hydropotential 3% 3 4 1 1 2 5

Potential for cost savings / optimisation of

public road realignment6% 5 5 1 1 1 2

Potential for cost savings / optimisation of extra

infrastructure for flow management i.e. buffer

pond and connecting channel

3% 5 1 2 1 4 1

Potential for cost savings / optimisation of dam

construction diversion6% 4 3 2 1 1 5

Potential cost savings / optimisation of dam

earthworks15% 2 1 5 4 4 3


spillways 5% 5 4 1 1 1 3


operational outlet works4% 1 4 4 4 3 5

Potential cost savings / optimisation of water

harvesting infrastructure (including electricity

for pumping)11% 1 1 5 5 4 1

Potential cost savings / optimisation of

distribution (including electricity for pumping) 40% 2 1 5 3 4 3

Potential cost savings / optimisation of land

purchase, easements, offset mitigation and fish

passage

8% 5 1 1 1 1 4

Raw opportunity score 2.7 1.7 3.8 2.8 3.2 3.0

Adjusted opportunity score

(1=Least favourable, 5=Most favourable) 2.8 1.0 5.0 3.1 3.8 3.4

43

Table 19: Engineering risks for additional costs/technical issues - MCA rankings20 (T&T, June 2015)

In terms of risks of cost increases and technical constraints, Te Mara is clearly the most favourable, very

closely followed by Wakamoekau and Mangatarere. Black Creek is less favourable to moderately

favourable in terms of risk. Tividale is the least favourable of the six schemes, though White Rock Road

only slightly more favourable than Tividale (T&T, June 2015).

There is unavoidable uncertainty across many areas given the Prefeasibility stage of investigation. In

combination, the many factors tend to balance each other out. Nevertheless, there is still the potential

for a ‘fatal flaw’ to arise with respect to one of these factors (T&T, June 2015).


sub-themes or risk factors.

Engineering RisksSub-theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

ka

mo

ek

au

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

Potential for additional costs / technical

issues due to geotechnical complexity &

uncertainty at dam sites

10% 3 1 5 4 2 4

Potential for additional cost / technical

issues for public road realignment5% 2 1 5 5 5 3


issues for extra infrastructure for

operational flow management i.e.

buffer pond and connecting channel

3% 1 3 5 5 3 5


issues for dam construction diversion5% 2 1 5 3 3 2


issues for dam earthworks (including

dead storage allowances, such as

sedimentation)

14% 1 2 5 4 3 4


issues for dam spillways5% 2 1 4 5 4 3


issues for dam operational outlet works3% 5 5 5 5 5 1


issues of water harvesting infrastructure

(including electricity for pumping)

10% 5 5 2 3 1 5


issues for distribution (including

electricity for pumping)

37% 1 2 4 4 3 5


issues for land purchase, easements,

offset mitigation and fish passage

7% 2 3 4 5 1 2

Raw Scores 2.0 2.3 4.2 4.1 2.8 4.1

Adjusted Risk scores

(1=Least favourable, 5=Most favourable)1.0 1.5 5.0 4.8 2.4 4.7

44

7.6.2 National Policy Statement for Freshwater Management (NPS) Environmental risks and opportunities for each of the scheme options have been developed as

the result of a workshop that focused on issues relating to the National Policy Statement for

Freshwater Management (NPS) and regarding water and nutrient allocation and efficiency. The

focus was on the relativity between the scheme options so that the differences could be

considered as part of the WWUP Prefeasibility decision-making process.

The following two extracts from the NPS provide further context for the workshop.

“This national policy statement sets out objectives and policies that direct local

government to manage water in an integrated and sustainable way, while

providing for economic growth within set water quantity and quality limits.

The national policy statement is a first step to improve freshwater

management at a national level.”

“Overall freshwater quality within a region must be maintained or improved.

This national policy statement allows some variability in terms of freshwater

quality, including between freshwater management units, as long as the

overall freshwater quality is maintained within a region.”

(Ministry for the Environment, 2014 Preamble p3, p4)

The outcomes of this workshop are presented in Appendix B, “Notes of workshop on

opportunities and risks related to the National Policy Statement on Freshwater Management”.

The NPS will have an impact on the future feasibility of the WWUP scheme options. This impact

will be better understood as the Ruamāhanga Whaitua process, the proposed Natural Resources

Plan and science modelling work described in Section 2.0 of this report evolves.

7.7 Other risks and opportunities (general) Risks and opportunities are not an integral part of the MCA summary rankings and sensitivity

analysis but rather an indicator of ‘known unknowns’. They are, however, taken into account

during the overall decision making process.

A record of all risks and opportunities that have been noted as a result of discussions with the

Stakeholder Advisory Group and within the WWUP Working Group is provided in Appendix C.

Where a risk or opportunity has been accounted for in the MCA process or referred to in

another report it has been removed.

8. Summary of results – comparisons of schemes

8.1 Summary table – MCA The MCA rankings for each of the four main themes; financial, social, environmental and

cultural, considered during the WWUP Prefeasibility phase are presented in Table 20 below,

together with their associated weightings. The weightings are consistent with those applied to

the four themes in the previous phase of the WWUP, Options Refinement. When combined

and weighted, the four main themes provide an overall ranking for each scheme option.

From an overall perspective, Wakamoekau appears to be the most favourable scheme (5),

followed by Black Creek with a ranking of 4. Mangatarere is moderately favourable with an

overall ranking of 3. Tividale and Te Mara are next with an equal ranking of 2. White Rock Road

is the least favourable scheme option with a ranking of 1.

45

Table 20: Combined themes – MCA rankings21

(Barnett, 2015; Boffa Miskell 2015; GWRC, 2014; Opus, 2014; T&T, 2015; WWUP, 2015)

8.2 Sensitivity analysis – overall

As Table 21 below indicates, four of the scheme options are relatively insensitive to varying the

financial and combined social/environmental/cultural weightings.

No matter what weighting is applied, Wakamoekau is consistently the most favourable scheme

from an overall perspective, followed by Black Creek which is also insensitive to weightings. Te

Mara and Tividale are also relatively insensitive. When more weight is given to

social/environmental/cultural factors, Mangatarere is highly sensitive and becomes the least

favourable. When more weight is given to financial factors, White Rock is highly sensitive and

becomes the least favourable of the scheme options.


Combined Themes MCA

Rankings

Weightings are based on Options Refinement

MCA pre-sensitivity testing weighting

Theme

weightings

10

- T

ivid

ale

13

5 -

Wh

ite

Ro

ck R

oa

d

19

7 -

Te

Ma

ra

20

6 -

Wa

kam

oek

au

21

0 -

Bla

ck C

ree

k

21

5 -

Ma

ng

ata

rere

Financial 70% 3.0 1.0 3.0 5.0 4.0 4.0

Social 10% 4.0 3.0 5.0 5.0 2.0 1.0

Environmental 10% 1.0 3.0 3.0 5.0 4.0 1.0

Cultural 10% 3.5 4.0 1.0 5.0 5.0 4.0

Raw Combined Score 3.0 1.7 3.0 5.0 3.9 3.4


46

Table 21: Sensitivity testing on combined themes - MCA rankings22 (WWUP, April 2015)

Sensitivity Testing on Combined Themes MCA Rankings

10 - T

ivid

ale

135

- W

hite

Roc

k R

oad

197

- Te

Mar

a

206

- W

akam

oeka

u

0% Env/Cult/Soc, 100% Financial 3 1 3 5










9. Other storage opportunities

9.1 On-plains storage

The option of storing and distributing water from reservoirs located on plains, as opposed to in

valleys was first considered by WWUP during the Prefeasibility phase. Opus International

Consultants Ltd was commissioned to investigate at a conceptual level how on-plain storage

might be compatible and compare with the current in-valley oriented scheme options already

under investigation.

Their work is covered in two reports Wairarapa Water Use Project, Preliminary assessment of

‘on-plains’ storage (Opus, 2014) and On-plains Storage Refinement (Opus, 2014). The

Preliminary assessment (Opus, 2014) outlined the advantages and disadvantages of on-plains

storage.

The Storage Refinement (Opus, 2014) report broadly considered how on-plains storage could

be part of wider scheme arrangements and recommended further work to find an optimal

overall solution.

Further investigation of on-plains storage options will be considered in the future, especially

with regard to their inter-relationship with in-valley water storage scenarios.


47

9.2 Reserve scheme options

Three schemes were set aside as ‘reserve’ options at the beginning of the Prefeasibility phase

as alternatives to some of the six scheme options investigated during this phase. They were

Kiriwhakapapa (Scheme 200), Te Ore Ore (Scheme 63) and Martinborough South (Scheme 175).

These reserve scheme options were not investigated during Prefeasibility because none of the

six preferred scheme options were discounted during this phase.

48

Acknowledgements

The Wairarapa Water Use Project acknowledges the many organisations and individuals who contributed

to the Prefeasibility investigations outlined in this summary report.

We particularly acknowledge and thank the owners of property who gave permission for members of the

Working Group and consulting engineers to enter their property for site walk-overs and initial

geotechnical investigations. We also acknowledge the owners and occupiers of properties within the six

possible reservoir sites and the three reserve sites and recognise the uncertainty that the investigations

have caused them.

We acknowledge and thank the members of the WWUP Governance Group and Leadership Group, and

the member organisations of the Stakeholder Advisory Group (see Appendix A), and staff of the Ministry

for Primary Industries’ Irrigation Acceleration Fund.

We appreciate the work carried out by a range of consultants who have provided expert input into this

phase of work, particularly Tonkin & Taylor, Baker and Associates, Butcher Partners, Taylor Baines and

Associates, Opus International Consultants, staff of Ngāti Kahungunu ki Wairarapa and Rangitāne o

Wairarapa, Christine Barnett and staff of GWRC (Wellington and Wairarapa).

49

References

Tonkin & Taylor, Wairarapa Water Use Project Prefeasibility Phase - Engineering Report (June 2015)

PricewaterhouseCoopers, Memo, WWUP Cost Analysis (April 2015)

Butcher Partners, Regional Economic Impact Analysis (October 2014)

Baker & Associates, Land use affordability under irrigation (April 2014)

WWUP Working Group, Preliminary Regional, On-farm and Scheme Economics (May 2015)

Taylor Baines & Associates Preliminary Social Impact Assessment (October 2014)

Opus International Consultants Ltd, Opportunities and implications for Recreation (October 2014)

Jamie Steer, GWRC Biodiversity Department, MCA scores for Environmental Theme (March 2015)

Dr Vaughan Keesing, Boffa Miskell, Wairarapa Water Use Project Ecological Review (May 2015)

Christine Barnett, Māori Archaeological and Historic Sites - Sites of Significance (April 2015)

Opus International Consultants Ltd, Preliminary Assessment of On-Plain Storage (April 2014)

Opus International Consultants Ltd, On-Plains Storage Refinement (September 2014)

Ministry for the Environment, National Policy Statement for Freshwater Management (2014)

50

Appendices

Appendix A: WWUP Governance, Stakeholder Advisory and Leadership Group Membership

Appendix B: Notes of workshop on opportunities & risks related to the National Policy Statement for Freshwater

Appendix C: Risks & opportunities (general)

51

Appendix A: Wairarapa Water Use Project Governance, Stakeholder and Leadership group membership

WWUP Governance Group (GG) - membership

Bob Francis Chairman

Mandy Armstrong Environmental interest groups representative

John Booth Carterton Mayor (representing Wairarapa’s district councils)

Jason Kerehi Rangitāne o Wairarapa

Jim Lynch Independent Chair, WWUP Stakeholder Advisory Group

Nelson Rangi Ngati Kahungunu ki Wairarapa Chair

Bob Tosswill Wairarapa Regional Irrigation Trust Chair

Fran Wilde Greater Wellington Regional Council Chair

WWUP Stakeholder Advisory Group (SAG) - member organisations

Carterton District Council

Department of Conservation

Federated Farmers Wairarapa

Fish and Game

Forest and Bird

Greater Wellington Regional Council

Grow Wellington

Masterton District Council

Ngāti Kahungunu ki Wairarapa

Council of Outdoor Recreation Associations of New Zealand

Rangitāne o Wairarapa

Regional Public Health

South Wairarapa District Council

Sustainable Wairarapa

Wairarapa Chamber of Commerce

Wairarapa Development Group

Wairarapa Regional Irrigation Trust

Wairarapa Water Users Society

White Water NZ

Jim Lynch, Independent Chairman

WWUP Leadership Group (LG) - membership

Fran Wilde (Chair) Chair, Greater Wellington Regional Council

Lyn Patterson Masterton Mayor

John Booth Carterton Mayor

Adrienne Staples South Wairarapa District Mayor

Nelson Rangi Ngati Kahungunu ki Wairarapa Chair

Siobhan Garlick Rangitāne o Wairarapa

Mandy Armstrong Environment & Recreation interest groups representative

Gary McPhee Wairarapa Constituent Regional Councillor, GWRC

Gerard Quinn Chief Executive, Grow Wellington

Bob Tosswill Chair, Wairarapa Regional Irrigation Trust

Bob Francis Chair, Wairarapa Water Use Project Governance Group

Alastair Scott MP for Wairarapa

Jim Lynch Independent Chair, WWUP Stakeholder Advisory Group

Kevin Steel Ministry for Primary Industries Irrigation Acceleration Fund Manager

52

APPENDIX B: Notes of workshop on opportunities & risks related to the National Policy Statement on Freshwater Management

Note these are potential opportunities & risks – i.e. aspects or issues that could be considered in the future many of which have not been ‘tested’ or verified, or canvassed with interested &/or affected parties

OPPORTUNITIES 10 - Tividale 135 - White Rock Road 197 - Te Mara 206 - Wakamoekau 210 - Black Creek 215 - Mangatarere Other considerations

Efficiency Dividends

Release' of consent water from part

of the Moroa water race, existing &

future irrigation

Existing & future irrigation, Supply

of town water from cat A

groundwater, therefore not allocation

related

Release' of consented water from

MDC &/or CDC urban water

supplies, Taratahi water race,

existing & future irrigation

‘Release' of consented water from

MDC urban water supply, Taratahi

water race, existing & future

irrigation – but less than Black

Creek


MDC urban water supply, Taratahi

water race, existing & future

irrigation


MDC &/or CDC urban water

supplies, Carrington &/or part

Taratahi water race, existing &

future irrigation

White Rock - town water supply

from cat A groundwater, therefore

not allocation related efficiency

dividend

Increased security of supply

(quality & quantity – less than BC

Could feed MDC WTP

Driver for strategic renewal of

assets

Water races & town water supply ,

but limitedLimited to town supply

Water races & town water supply –

but less than BC

Water races & town water supply –

but less than BCWater races & town water supply Water races & town water supply

Quality of stock drinking water Water races & town water supply –

but less than BC

Improvement through piping c.f.

drainsImprovement through piping Improvement through piping

Reallocation of waterProvides more choice for multiple

uses

Provides more choice for multiple

uses – but less than BC


uses


uses

Henley Lake waterImproved water quality via

Ruamahanga River in summer

Flushing flows Includes flows in summer &

flushing, & supply existing users

Includes flows in summer &






Applicable to Black creek &

Wakamoekau stream



Efficiency potential ‘New’ take ‘New’ takeReallocation of existing users

leading to higher efficiency potential

Reallocation of existing users






RISKS Tividale White Rock Te Mara Wakamoekau Black Creek Mangatarere Other considerations

Environmental valuesLoss of water race values if

removed/changed

Loss of water race values if

removed/changed


removed/changed


removed/changed

Water Transfer mechanismRequires a policy or ‘deal’ & willing

parties

Requires a policy or ‘deal’ & willing

parties


parties


parties


parties

e.g. water races &/or urban water

supplies

Scale of water body affected by

the damSmall river Small river Small stream Very small stream 2 small streams Small river Note stream & river references

Scale of reservoir/water storedCan storage capacity supply

benefits

Can storage capacity supply

benefits


benefits


benefits-


benefits

Changed river flowsPartial reverse flow volumes – higher

summer, lower winter

. Partial reverse flow volumes –

higher summer, lower winter

Partial reverse flow volumes – higher





summer, lower winter on

Wakamoekau stream.



Proximity of irrigation areas to

natural water bodies

Proximity to lake/river – N&P losses

through increased production

Balances with opportunity re

nutrient headroom gain

Water losses‘Loss’ of conveyed water through

river seepage

Loss’ of conveyed water through

river seepage

Loss’ of conveyed water through

river seepage

Sediment Transfer

Flows will transport sediment to

Ruamahanga faster than natural

progression.

Sediment is not natural to Tauweru

River – stones are

2,800/9,700ha = 0.29

The greatest ‘headroom’ gains may

exist where most irrigation/LUI

currently exists . Also note,

headroom can be shifted

geographically.

Nutrient head room (based on

existing net irrigated area cf

command net irrigable area)

4,700/9,800ha = 0.48 Largest ratio

of existing irrigation - largest opp for

headroom gains

2,700/7,600 ha = 0.36 2,500/9,700 ha = 0.26

1,900/8,100ha = 0.23 Lowest ratio

of existing irrigation - least opp. for

headroom gains

7,400/19,700ha = 0.38

Flow Augmentation

70km stretch of enhanced flows &

possibility of Tauweru R returning to

stones An addition 17 km of

Ruamahanga River enhanced

by scheme water before

extraction point.

13 km enhanced by scheme water

before extraction plus additional 5

km enhanced by residual flows

before confluence with Ruamahanga

River.

- 3km enhanced by residual

flows to the confluence with

Kiriwhakapapa stream/Waipoua

River

- Wakamoekau stream

enhanced by residual flows for

10km before confluence with

Waipoua River.

- Wakamoekau stream

enhanced by residual flows for

10km before confluence with

Waipoua River.

2km enhanced by scheme water

with further 18km enhanced by

residual flows before confluence with

Waiohine River .

Urban Water Supply No urban supply possibilitiesExisting irrigation (grapes) could be

transferred to town supply

Increased security of supply – but

less than BC

Increased security of supply – but

less than BCIncreased security of supply

53

Appendix C: Risks & opportunities (general)

The following are general risks and opportunities that do not relate to specific scheme options and were

not included in engineering and cultural risks/opportunities in Prefeasibility. This list was largely

generated by the WWUP Stakeholder Advisory Group (SAG) with input from the WWUP Working Group.

Opportunities

• Regional self-determination and sufficiency

• Increased GDP within region and NZ

• Increased population leads to regional growth

• New industry to add value by processing primary produce

• Could allow for development for all alternative land uses – vineyards, horticulture, agriculture,

orchards, silviculture (not just dairy)

• Opportunity to increase the quality of life of Wairarapa people by costing in a sophisticated benefit

system that includes benefits that don’t just relate to financial gain

• Some native fish, birds and plants could have a suitable environment created

• Increase the amount of natural capital and ecosystem services by including an extensive programme

of habitat enhancement in project costs

• River management costs could be reduced by moderating extreme flood events

• Use of buffer ponds to improve water reliability especially where river conveyancing is used

• River/stream flushing flow used for other activities

• Opportunity to teach tamariki traditional water sports

• Waterfowl hunting opportunity

• Native fish as long as predatory fish are managed

• Create good road access for recreation

• On-farm cost savings (pressure at gate)

• Energy/power supply - hydro potential

• Staged development

Risks

• Lack of uptake of scheme water by farmers

• Inability to fund project

• Time and cost of consenting process

• Legal challenges and consenting

• Difficulty in creating distribution networks across private land

• Water quality threatened by increased nutrients from intensified farming

• Life supporting capacity not maintained

• Increased periphyton/slime for extended periods

• Ability to provide fish passage

• More flow abstracted from rivers than anticipated (river takes)

• Water loss from evaporation

• Catastrophic climate events

• Degraded environment in Tararua Forest Park

• Earth flows due to more saturated land

• Potential for reduced gravel transport affecting river bed

• Ability of region’s roading and infrastructure network to cope during construction

• Water level fluctuations restrict recreation for some of the year

• Less chance of recharge in dry summers

• Management of river conveyance

• Time for water to flow down river where river is used for conveyance

54

• Loss of traditional stories

• Influx of migrant workers to service farms – schooling pressures

• Amalgamation of farms makes recreational access more difficult

• ‘Corporate farms’ change culture

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