Opuha Water Ltd

Opuha Water Ltd (OWL) is a New Zealand water infrastructure and irrigation company based in South Canterbury. It owns and operates the Opuha Dam scheme, a community-driven project at the confluence of the North and South Opuha Rivers, about 17 kilometres north-east of Fairlie. The scheme centres on a 50-metre-high earth dam, a lake covering up to 710 hectares and storing more than 74 million cubic metres of water, and a single-turbine 7 MW hydro power station at the base of the dam. Water released from the dam sustains environmental flows in the Opuha and Opihi Rivers, supplies irrigation to the Levels Plain, Kakahu, Totara Valley and Sutherlands sub-schemes, and provides commercial and domestic water to the Timaru District Council. The company traces its origins to discussions between the Electricity Corporation of New Zealand (ECNZ) and the Opihi Augmentation Society, which led to the formation of the Opuha Dam Partnership in 1992 to commercialise the project. Construction of the dam began in 1995, but on Waitangi Day 1997 the partially completed structure was overwhelmed and breached by high inflows after three days of heavy rain in the upper catchment. The project was subsequently completed and has become a notable example of community-owned water storage and irrigation infrastructure in New Zealand. Opuha Water is governed by a seven-member board: four directors elected by farmer shareholders and three appointed independent directors. The board is responsible for governance and leadership, with a stated long-term objective of being recognised as a leader in the irrigation and water sector. Day-to-day operation of the scheme is managed by company personnel, while maintenance of the power station and river control gate is contracted to Manawa Energy. Electricity sales contribute approximately half of Opuha Water's income, alongside irrigation and water supply activities. The company publishes quarterly water quality monitoring reports for Lake Opuha and the wider scheme catchment, maintains environmental management strategies and policies, and engages with shareholders through newsletters, events and a shareholder portal. Its operations are closely tied to the South Canterbury rural economy, supporting farming through reliable irrigation while managing environmental flows and dam safety. Recent public communications have highlighted safety upgrades that significantly boost the dam's flood protection function.

The Opuha scheme originated in discussions between the Electricity Corporation of New Zealand (ECNZ) and the Opihi Augmentation Society. These talks led to the formation of the Opuha Dam Partnership in 1992 to commercialise the project. The partnership enjoyed the support of the local lines company Alpine Energy Ltd, the Timaru and MacKenzie District Councils, the Opihi River Development Company, and two irrigation companies: Levels Plain Irrigation Company Ltd, which existed before the dam, and the South Canterbury Farmers Irrigation Society (SCFIS), established to represent farmers who would gain access to water from the dam. Construction of the dam began in 1995 and progressed well until Waitangi Day 1997, when three days of solid rain in the upper catchment caused the partially completed dam to be overwhelmed and breached by high inflows. Despite this setback, the project was completed. The Opuha Dam is a 50-metre-high earth dam at the confluence of the North and South Opuha Rivers, 17 kilometres north-east of Fairlie. Its lake covers up to 710 hectares and stores over 74 million cubic metres of water. The scheme includes a single-turbine 7 MW hydro station at the base of the dam, generating electricity from all water released from storage. The scheme operates by releasing stored water from Lake Opuha via the dam into the Opuha River, which flows into the Opihi River. This ensures minimum environmental flows, especially during droughts or low natural flows, and allows irrigation takes for the Levels Plain, Kakahu, Totara Valley and Sutherlands sub-schemes through distribution races and channels. Landowners pump from these races or directly from rivers via galleries or adjacent bores. Water is also supplied to the Timaru District Council for commercial and domestic use. During the irrigation season, irrigators order water daily; orders are aggregated and sufficient water is released to meet demand while maintaining minimum river flows. Opuha Water Ltd has its own management and administration structure. It contracts maintenance of the power station and river control gate to Manawa Energy, which operates from Tauranga and provides support from its Lake Coleridge base. Electricity sales account for approximately half of Opuha Water's income, making the hydro station a key commercial pillar alongside irrigation. The company is governed by a seven-member board comprising four shareholder-elected directors and three independent directors. It publishes quarterly water quality monitoring reports, maintains environmental management strategies and policies, and communicates with shareholders through newsletters, events and a portal. In September 2026, the company announced that a safety upgrade had significantly boosted the dam's flood protection function.

• 2026

  Opuha Water announces a safety upgrade that significantly boosts the dam's flood protection function.

• 1997

  On Waitangi Day, the partially completed dam is overwhelmed and breached by high inflows after three days of heavy rain.

• 1995

  Construction of the Opuha Dam begins.

• 1992

  Opuha Dam Partnership formed to commercialise the project, following discussions between ECNZ and the Opihi Augmentation Society.

Community-owned, multi-purpose water infrastructure provider combining irrigation, environmental flows, urban supply and renewable hydroelectricity in South Canterbury.

• Opuha Dam and Lake Opuha

  50-metre-high earth dam with a lake covering up to 710 hectares and storing over 74 million cubic metres of water.

• Opuha hydro power station

  Single-turbine 7 MW station at the base of the dam, generating electricity from all released water.

• Irrigation sub-schemes

  Levels Plain, Kakahu, Totara Valley and Sutherlands sub-schemes supplied via distribution races and channels.

• Urban and industrial water supply

  Water supplied to Timaru District Council for commercial and domestic purposes.

1. 1Home Page - Opuha Water Limitedopuhawater.co.nz
2. 2History of the Dam Project - Opuha Water Limitedopuhawater.co.nz
3. 3Board of Directors - Opuha Water Limitedopuhawater.co.nz
4. 4Scheme Operation - Opuha Water Limitedopuhawater.co.nz
5. 5Opuha Water Ltd - Wikidatawikidata.org