The Waimea Community Dam

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The Waimea Community Dam is an augmentation scheme, which means that it will add to the region’s water supply. It will do this by ...

  • capturing Lee River flows
  • storing the water in a reservoir in the Lee Valley, and then
  • allowing controlled release of stored water into the river system during periods of high water demand and/or low natural river flows.
Connectivity of the rivers and aquifers

There is a high level of interconnection between the surface waterways and groundwater aquifers under the Waimea Plains. Water from the Lee River flows into the Wairoa / Waimea River system, recharging the groundwater aquifers. At periods of low-flow in the Waimea River, the Dam can release water that will flow into the river systems to maintain groundwater aquifer levels. At the same time, a higher minimum flow means improved river health, which benefits instream fish and other aquatic life, recreational pursuits, and environmental amenity values.

Dam structure

The proposed dam is a concrete-face rock fill dam. It will be approximately 53m high, 220m long and 6m wide at the crest and will have a total reservoir storage volume of approximately 13.4 million cubic metres. The dam is designed to the highest safety standards applicable for dams in New Zealand. It is expected that it will take about 30 months to complete construction. The start date is yet to be confirmed, but is anticipated to be around the middle of 2018.

Regional water security

The Dam will maintain groundwater aquifer levels during periods of drought, resulting in improved water security for the next 100 years for water users in Richmond, Brightwater, Mapua and Wakefield (Wakefield currently has a sufficient supply of water for the next 30 years with the Wai-iti Dam at Kainui), as well as providing a third water source for Nelson residents.