The Waimea Community Dam along the Lee River works like this: when it rains in wet months, the Lee River will run higher and the dam system captures those higher flows and stores the water in the reservoir, named Te Kurawai o Pūhanga by Ngāti Koata, that sits in the Lee Valley. During drier months when the Lee and downstream Waimea and Wairoa systems are running below desired flow levels, the dam releases some of the stored water (slowly!) down the river, increasing their flows and naturally adding water to the aquifers.
Everyone living in Richmond, Brightwater, Mapua, and other urban areas along the Waimea Plains relies on these aquifers for their water supply, including for drinking. Where other dams function with lots of piping to extend the water supply to urban areas, we are using nature as the piping system. Topping up the river flows naturally refreshes and resupplies groundwater aquifer levels.
Importantly, a higher minimum flow throughout the Lee, Waimea, and Wairoa River system means improved river health, which benefits fish and other aquatic life, recreational pursuits, and environmental amenity values.
Regional water security
Access to water affects every person in Nelson Tasman. The dam provides access to water for 100 years for residential, industrial and commercial needs across the region. 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) will have water security for ongoing residential and commercial needs. The dam can also be a third water source for Nelson.
