YAKIMA, Wash. – The Bureau of Reclamation’s March 2023 total water supply available forecast for the Yakima basin indicates the water supply will be adequate to meet irrigation demands this season. The early estimate of the total water supply available for the April-September period indicates senior water rights will receive 100% of entitlements and junior water rights will receive 86% of entitlements.
Storage in the Yakima basin reservoirs on March 1 was 49% of capacity, or 521 thousand acre-feet, which is 82% of average. Precipitation was 72% of average for February and was 74% of average for October-February. On March 1, the amount of water in the snowpack, known as snow water equivalent, was 91% of average.
Reclamation manages the water in the five Yakima Project storage reservoirs, which is used along with other unregulated flows in the basin to fulfill water rights, water contracts and instream flow obligations. Water shortages in the basin are shared equally by the junior water rights, which represent over half of the water rights in the basin.
Reclamation will provide an updated water supply forecast monthly—at least through July—using the latest data each month to reflect any changing conditions.
The March forecast is based on flows, precipitation, snowpack, and reservoir storage as of March 1, along with estimates of future precipitation and river flows. Other future weather conditions that determine the timing of the runoff and the demand for water also are critical in determining stream flows, the extent to which the reservoirs fill, and the water supply for irrigation.
For more information, visit https://www.usbr.gov/pn/hydromet/yakima/.