Originating from the northwest Richmond Ranges, the Wai-iti and Wairoa rivers combine near the settlement of Brightwater to form the Waimea River which flows into the Waimea Inlet on the southern edge of Tasman Bay. The Waimea Inlet is the largest enclosed estuary in the South Island and is highly valued as a breeding area for seabirds.
Irrigation is heavily utilised on the Waimea Plains which can compound water restrictions during periods of very dry weather. The rivers feed the aquifers used by the Wakefield, Brightwater and Richmond water supplies – servicing a population of over 16,000 people. To help meet the growing need for water, the Waimea Community Dam is under construction in the Lee Valley.