Central Plains Water

The Central Plains Water Enhancement Scheme is a community irrigation scheme which will provide water to an irrigable area of 60,000Ha within a command area of over 100,000Ha of the Canterbury Plains between the Southern Alps to the west, State Highway I and the Waimakariri and Rakaia Rivers.

The scheme, which will be built in stages, will utilise run-of-river water from both the Rakaia and Waimakariri rivers supported by stored water from Lake Coleridge.

With a current estimated construction cost of $500 million (excluding on-farm costs), the Central Plains Water Scheme is a significant construction project for the South Island.

The Waimakariri and Rakaia Rivers will be linked via a 56km headrace canal running around the foothills and water from the canal will be distributed by gravity feed throughout the 60,000Ha by over 500kms of underground piping. Water within the canal will be about 4m deep and approximately 25m wide at the surface.

The first Stage will comprise 20,000Ha between the Rakaia and Selwyn Rivers. The footprint of future stages will depend on farmer demand and are likely to be within the Hororata Greendale areas and the Darfield Sheffield areas.

About Central Plains Water Limited:Italic text Central Plains Water Ltd is a shareholder-owned company that was established in 2003 to progress the resource consent application, and more recently the detailed design for the scheme which will be developed in stages. CPWL will be responsible for the implementation and operation of the scheme.

CPWL employs a core team of 12 professional staff and is governed by a Board of 9 Directors from a variety of backgrounds including farming, legal, finance and farm advisory. A number of the Board members are also shareholders of the Company.

CPWL Scheme Overview The original CPWL philosophy of developing the whole scheme with all shareholders having equal rights, is still the intention. However, given the issues that arose during the consent process such as loss of Waianiwaniwa storage and only moderate shareholder demand for irrigation in some areas, a staged approach is considered to be the best way to ensure that the scheme proceeds initially and can then be extended to cover the full area. The original intent of providing all shareholders with water at the same cost per share is also confirmed, but this will require a fully cooperative approach from shareholders. It is possible some extreme situations may not be able to be serviced in that way – such as areas requiring pumping above the scheme design parameters.

Whole of Scheme DesignA review of the scheme concept has been completed to take into account the changes that have occurred since the original design was undertaken for consents. Key issues that have changed are:

•Loss of Waianiwaniwa storage •Availability of Lake Coleridge storage •Reduced availability of Waimakariri water due to consent condition •Scheme total delivery demand refined and reduced •Requirement to transfer water both ways through canal reduced.

The revised design has confirmed the best route for the headrace canal is still on the consented alignment but has resulted in significant reduction in the size of the canal through the central and northern stages. The indicative size of the canal shows a reduction from 35 cumecs to 16 cumecs. This will be further refined when detailed design is undertaken.

Pipework has been designed for Stage 1 of the scheme and this will be applicable for the pipework for most of the remainder as well.

STAGE 1 OVERVIEW OverviewStage 1 of the Central Plains Water Scheme will irrigate approximately 20,000 hectares of farmland in the Canterbury Plains in an area bordered by the Rakaia and Hororata Rivers. An intake at the Rakaia River will direct water into a 17km long gravity fed headrace, or canal. A network of underground pipes will distribute water to shareholders downstream of the headrace.

The key components of stage 1 are:

•An intake and headworks at the Rakaia River to bring water into the headrace. •A headrace alongside and traversing ‘up’ the northern bank of the Rakaia river to the top of the main Rakaia terrace. •A level headrace along the plains to convey water north and into the reticulation system. •A piped reticulation system providing pressurised water to all shareholder properties in the scheme area.

Stage 1 infrastructureItalic text Intake structures The river intake is located approximately 8km downstream of the Rakaia Gorge Bridge. It will intercept the stable river braid in this location and be conveyed into the flow control structures, sediment retention ponds and fish barrier before entering the main headrace.

The intake structures and fish screens will be scaled appropriately for stage 1, but will be designed so that they can be increased in size for future scheme stages.

Headrace Once past the intake structures water will be conveyed into a level headrace, which commences an 8km traverse ‘up’ the northern bank of the river terrace. The headrace crests the terrace at the 235m contour line around Earlies Pond, near Steeles Road.

The terrace headrace will be constructed within an engineered fill embankment ‘bench’ rising to around 15m high and then into a bench cutting into the terrace face for the remainder of its length to eventually rise onto the upper terrace. Around two million cubic metres of earth will be moved to form the bench and headrace. Once up onto the upper terrace the headrace travels north for approximately 10km through to Leaches Road following the most practical route through farmland. The water level in this section will be approximately at ground level.

Throughout the length of the headrace a liner will be used to control seepage from the canal. Ground tests along the headrace have been completed and are currently being analysed for suitability of local materials to form a lining base. Crossings The headrace crosses several public roads, farm access tracks and catchment streams. Crossings will be by bridge, culverts or siphons. The headrace will include three major off-take structures for the pipeline distribution network.

Reticulation A piped reticulation system will distribute water to the stage 1 area, providing water to the farm gate at a pressure equivalent to a head of 40 metres. A number of pump stations will be installed where necessary to boost line pressures to achieve this.

The reticulation system will comprise a network of approximately 100km of pipeline, ranging in diameter from 1600mm to 100mm. The pipeline will be trenched on farms and along road easements in order to deliver up to 5m3/s of water through the pipe. The base plan is to reticulate water through three main lines with laterals to each farm from the main lines.

Various control and measuring devices will be installed along the pipe route as well as a telemetry system and central control building for the purposes of monitoring and controlling water flows to each of the farms within the stage 1 scheme area.

Timing Stage 1 will be constructed between December 2013 and September 2015.

In preparation for the 2014/15 irrigation season the goal is to have the intake structures, headrace to Rakaia Terrace road and the reticulation network sufficient to irrigate the first 5,000 hectares completed and commissioned.

The remaining headrace and pipelines will be completed in time for the 2015/16 irrigation season.

Future Development PlanIf uptake for the first stage is sufficient, this stage can be completed by September 2015. Similar demand in the Sheffield area could see a sub scheme developed there by the same date or earlier. Construction of the remainder of the scheme will depend on demand, but it will be possible to move from Stage one to Stage two design and construction progressively so that the second stage of the scheme could be delivering water by 2016 and the full scheme could be completed by 2018. There are a number of conditions to this timetable, the most important being shareholder commitment and development of sufficient storage to secure the required reliability. Further applications will be prepared for the Ministry for Primary Industry support to design the next stages of the scheme on the same basis as the subsidy for Stage one. These designs will have to start in early 2014 to meet the timeline.

Stage 1 – 23,000Ha – Te Pirita, Sheffield. Construction: January 2014 – September 2015.

Stage 2 – 10,000Ha – Hororata – Greendale – Burnham. Construction: September 2015 – September 2016.

Stage 3 – 27,000Ha – Colgate – Kirwee – Waimakariri. Construction: September 2016 – September 2018.

Environmental Management Italic text

Environmental benefitsThe Government and Selwyn-Waihora Zone Committee both agree a fully operational Central Plains Water Scheme will deliver environmental benefits for the area. Once the scheme is established, which will include the switch from ground water use to surface water irrigation supplied by new alpine water, the water levels in lowland streams will be restored and water quality improved for Te Waihora/Lake Ellesmere. Environment Canterbury cannot achieve these without CPWL bringing new alpine water into the Zone to irrigate the 60,000ha of farm land.

ConsentsCentral Plains Water Ltd has obtained all necessary Resource Consents from Environment Canterbury and Selwyn District Council to construct and operate a 60,000Ha surface water irrigation scheme in July 2012. The consents cover taking water (including taking winter water for on-farm storage), using water, access to the riverbeds and all the relevant consents relating to the construction stage, i.e. Environmental Construction Management Plans such as noise, dust, erosion control etc.

BackgroundThe ‘Take’ consents were lodged for both the Rakaia and Waimakariri Rivers in December 2001. The ‘Use’ consent was lodged with Environment Canterbury (ECan) in November 2005. Both the Take and Use consents were notified by ECan in June 2006. Land use and Land Designation consents were lodged with the Selwyn District Council (SDC) in May 2006, and were notified in November 2006. Both consent processes were brought to a single hearing, held between February 2008 and October 2008 The scheme has consents for run of river takes totalling 65 cumecs of water. 25 cumecs from the Waimakariri River, 40 cumecs from the Rakaia River which includes 6 Synlait band 2 and 3 cumecs of subservient water. There is an agreement with Ashburton Community Water Trust (ACWT) to share the 36 cumecs of Rakaia water. If both parties are accessing water, CPWL has the right to take 56% of what is available.

a.Waimakariri Consent Details i.The take from the Waimakariri River was reduced by agreement from 40 cumecs to 24 cumecs; ii.CPW also has the consent for 1 cumec of Band A water from Waimakariri; iii.The 24 cumecs is shared 1:1 with the river, so to take 24 cumecs there needs to be 48 cumecs available above 65 cumecs, i.e. 113 cumecs of unmodified flow. iv.A further rule restricts the ability to take during part of summer when the unmodified flow lies between 80 and 95 cumecs. During that period CPW can only take for 12 hours each day and then at a restricted rate.

b.Rakaia Consent Details i.Additional to the 6 cumecs of Subservient Band 2/3 water the consent for 40 cumecs was granted but the availability depends on other users. Providing the total allocable flow of 70 cumecs is available, and assuming all existing consent holders are taking, the water available to Ashburton Community Water Trust (ACWT) and CPW is 36 cumecs at 1:1. This will be shared between CPW and ACWT as per an existing agreement.

Environmental ComplianceThe key consents that will ensure the scheme operation does not adversely impact on the environment are the Take and Use consents CRC061973, which encompass the take and use of water from the Waimakariri River and the Rakaia River. As part of the consent requirements, CPWL must put in place mechanisms to monitor the effects of the scheme on the environment and to carry out mitigation measures where necessary. These include:

•Establishing a 6-person Community Liaison Group •Establishing an Environmental Management Fund of approximately $160,000 per year (based on 60,000 operational scheme, pro rata for staged development) •Establishing a Ground and Surface Water Expert Review Panel (GSWERP) •Developing a Ground and Surface Water Monitoring plan outlining the measures undertaken to monitor and mitigate potential adverse effects. The monitoring regime includes sampling from a number of sites, including ◦20 monitoring sites across the scheme area ◦ 8 sites within the lowland streams ◦ 4 sites within Lake Ellesmere/Te Waihora – sites at lowland springheads ■The monitoring regime will monitor water levels and water quality ■Preparation of individual farm management plans that will incorporate nutrient discharge limits, water management and soil management requirements ■Independent audits for all farm management plans; and ■A Scheme Environmental Management Plan (Sustainability protocol)

The full details of the Resource Consents, as well as the Hearing evidence and the Decision Document are available on the Environment Canterbury website.

Farm Environmental PlanItalic text Farm management plans are required for all farms in the Central Plains Water Limited (CPWL) scheme and CPWL advisers will help farmers with the formulation of these plans. Included in these plans will be establishing a nutrient management regime for each farm that complies with the nutrient criteria for the Selwyn Waihora Zone. These plans are subject to an annual audit, which will be carried out by an independent assessor. Any non-compliance must be rectified within a specified period of time. If not rectified, the supply of water to the offending user will be turned off.

The key aims of the farm management plans are:

•To minimise the loss of nitrate-nitrogen to soil drainage water and to minimise any loss of sediment, phosphorus or nitrogen to surface waters •To establish an annual nutrient budget

In addition, the farm management plan will ensure:

•Stock is excluded from waterways and wetlands including drains and races •All native plants and native animals and their habitats are protected •Water application effectiveness is maximised •All irrigation systems meet industry and scheme standards

CPWL has been working with consultants to review the farm management plan template that was included in the consent. The template has been updated to include lessons learned from other Schemes. There has been no material change to the information that the farmer is required to provide as set out in the CPWL consent. The next step is to review this template with a focus group – farmer board members, key shareholder farmers, irrigation industry representatives and farm advisors to establish if further adjustments are required. CPWL are about to commence the public process to establish the Community Liaison Group. One of the first jobs for this group will be to review and comment on the Farm management template.

The farm management plan will be rolled out to Stage 1 farmer shareholders early 2014, training workshops to assist farmers with the preparation of their farm management plans and on-site checking/auditing will be conducted. The success of the farm management plan is dependent on the accuracy of the preparation and implementation/record keeping and reporting.

CPWL are committed to ensuring that all farmers have the support they require to achieve successful implementation of their farm management plan.

Ground Surface Water MonitoringItalic textCentral Plains Water Limited are required to have a two-year ground water monitoring record in place before taking water for surface irrigation. CPWL began the monitoring of groundwater in selected bores in December 2012, following detailed discussions with Environment Canterbury.

The selected bores must be approved by the Ground and Surface Water Expert Review Panel (GSWERP). CPWL are in the final stages of confirming the GSWERP panel.

Benefits to our RegionWith a current estimated construction cost of $375 million, the proposed CPW scheme will be one of the largest construction projects ever undertaken in the South Island.

Agriculture is already the biggest driver of the Canterbury economy with the rural sector accounting for up to 70% of Christchurch’s economic activity. In addition, Canterbury farmers spend around $750 million every year on goods and services provided by Christchurch businesses.

Irrigated farmland, on average, generates three times the production of an equivalent area farmed under dry land systems. Studies on the economic effect of irrigated agriculture show that one third of the wealth and employment created from irrigation occurs on farm, with the other two thirds spread through the rural and city communities.

Once the Central Plains Water Limited scheme (60,000Ha) is fully operational, annual direct and indirect regional agricultural output is expected to increase by $264m per annum. A proportion of this agricultural output will be processed, generating an additional $328m per annum, a combined increase of $592m per annum. The impact on the wider economic activity is assessed at approximately $1b to $1.4b per annum.

Direct plus indirect employment from the scheme is estimated to increase by about 1130 jobs, 416 of them from the expansion in farm output. A further 714 jobs will come from processing, transport and related off-farm activity.

The construction phase alone is expected to generate 700 jobs and 1777 indirect jobs and generate $325m in direct benefits and $368m in indirect benefits.

Central Plains Water Limited Website: www.cpwl.co.nz