FAQs.

Central Plains Water Limited (CPWL) is the largest irrigation scheme in the South Island. We supply irrigation to just over 45,000 hectares and hold consent to deliver water to 63,000 hectares of land between the Rakaia and Waimakariri rivers. Around 265 farmer shareholders own CPWL, and we operate based on cooperative principles. Every one of our farmers knows that water is a precious taonga, critical to sustaining life, and that value shapes every part of our business.

The Take and Use Water Permit sets out how much water farmers can use each year while leaving enough for the environment. These consents sit at the heart of the scheme and drive our compliance and reporting. In 2026, CPWL shareholders used 2.3% of the water that flowed in the Rakaia River, and 0.14% of the total water available in the Waimakariri River, to grow food and fibre. We monitor water takes in 15-minute increments, 365 days a year, and provide this data to the regulator annually as part of the scheme’s compliance reporting.

The operations of CPWL have a profound impact on the wider Canterbury economy, with flow-on impacts supporting the region’s industries, businesses, and employees. In FY2026, CPWL shareholders generated $406 million in direct expenditure, contributed $417 million to Canterbury GDP and supported 2,439 full-time equivalent jobs across the region (Source: CPWL Business and Economic (BERL) Report 2026).

CPWL operations are aligned with the vision of the Canterbury Water Management Strategy (CWMS), and we are committed to doing our bit to deliver on CWMS outcomes. By taking low-nutrient alpine water from the river in a controlled way, shareholders reduce water abstraction from groundwater wells. As a result, more water is left in aquifers, contributing to water quantity goals within the CWMS. Annually ~50 million cubic metres of groundwater is retained in the aquifers because of CPWL farmers switching off their bores and utilising run-of river scheme water. This is resulting in beneficial increased flows in lowland streams.

Approximately 40,000ha of the scheme is supplied from the Rakaia River (Stages 1 and 2), and ~4,300ha is supplied from the Waimakariri River (Sheffield scheme).

Run-of-river water is ~65% reliable, which is not sustainable for agriculture alone. Therefore, to ensure reliable water delivery to shareholders on Stages 1 and 2, an agreement was reached between CPWL and Manawa Energy Ltd (formally Trustpower Ltd) for CPWL’s consented water to be captured and stored in Lake Coleridge. When the Rakaia River flow drops and CPWL is unable to take water due to flow restriction, CPWL takes the released stored water which effectively ‘sits on top of minimum flow levels’ and is compliant with the Rakaia River Water Conservation Order (RWCO). CPWL shareholders pay for stored Rakaia River water they use.

Environment Canterbury publishes irrigation restrictions for each day depending on the river flow. Water restrictions determine how much water CPWL can take from the river. CPWL then allocate the daily water available to shareholders; if there is a water shortfall, shareholders can purchase CPWL stored water from Lake Coleridge. Note that as the river drops, CPWL consents are some of the first consents to have their water takes restricted on the river.

The Environmental Management Strategy (EMS) is the foundation of how CPWL manages and improves environmental performance across our irrigation scheme command area. Rather than relying solely on regulatory oversight or requiring every shareholder to manage environmental compliance independently, the EMS provides a coordinated framework that brings together compliance, monitoring, auditing, reporting and continuous improvement. It allows CPWL to take a proactive role in helping shareholders meet environmental expectations while demonstrating accountability to regulators and the wider community.

The EMS was developed to fulfil the requirements of Condition 17 of resource consent CRC165686 and reflects the scheme’s commitment to self-management of its environmental obligations. It sets out the policies, procedures, protocols and standards that CPWL applies to
ensure that both the scheme and its shareholders achieve high environmental standards and sustainable outcomes.

Through the EMS, CPWL works alongside shareholders to:
• meet resource consent requirements and evolving regulatory obligations
• manage risks associated with water quality, nutrient losses, irrigation practices and climate variability
• support continuous improvement in water-use efficiency and nutrient management
• verify environmental performance through independent auditing
• provide aggregated annual reporting to Environment Canterbury.

This coordinated approach creates efficiencies for both shareholders and regulators, and provides a pathway to achieve
meaningful environmental improvements at a catchment scale rather than on an individual farm-by-farm basis.

Every farm on the CPWL scheme has a Farm Environment Plan (FEP) which is independently audited.

A key component of the EMS is the Farm Environment Plan (FEP) audit programme. The audit programme does not simply measure compliance. It is designed to identify opportunities for improvement and support better environmental outcomes over time.

Every CPWL shareholder farm operates under a certified FEP, covering 73,000ha of land across the scheme. FEPs identify the environmental risks on a property and the actions required to manage those risks. Independent audits assess whether farmers are implementing those actions and whether management practices meet Good Management Practice (GMP) standards.

The frequency of audits for FEPs depends on the grade received at the previous audit. For example, audits carried out
in 2025–26 are likely to be farms that received an A grade FEP Audit in the 2021–22 year (due every four years) or a B grade in 2023–24 (due every two years) unless audited earlier due to land-use change or farm manager changes. C grades are audited every year, and D grades every six months.

As a result of the adoption and continual improvement of management practices, our shareholders recorded a 33% reduction in nitrogen lost below the root zone in 2026, compared with pre-scheme levels.

CPWL works with landowners to protect and enhance indigenous biodiversity and establish new habitats. This includes restoration and enhancement of native biodiversity values on the Canterbury Plains, which is essential for securing our future. CPWL manages 73,000 ha of land through shareholders Farm Environmental Plans (FEP). This provides a unique opportunity to enhance ecological health at a meaningful scale through various actions, such as targeted planting of appropriate species on wetlands and riparian margins. For example, areas along the Rakaia, Selwyn and Hororata rivers have been identified as being of local and regional significance, especially regarding mahinga kai.

The Central Plains Water Environmental Management Fund (EMF) was established as part of the CPWL consents, with annual contributions being made to the fund. The EMF is administered by a committee allowing representatives from the community, iwi, environmental and recreational interests, and local councils. Projects selected for funding by the committee include wetland enhancement, projects that minimise nutrient losses to lowland streams and riparian planting.

In addition, our consents require contributions to two other environmental funds and initiatives: The Lake Ellesmere Te Waihora fund for improvements to the lake, and a 12.5% contribution towards the costs of opening the lake to the sea.

Since 2016, CPWL has contributed at total $2.14 million across all three funds to enhance biodiversity and freshwater initiatives in the district.