YAKIMA, Wash. – The Bureau of Reclamation’s October 2026 water supply available forecast for the Yakima basin indicates that irrigation demands will be fully met this October. This release provides the final water supply forecast for the 2026 irrigation season.
Storage in the Yakima basin reservoirs on Oct. 1 was 20% full with 210,396 acre-feet, which is 66% of average. Precipitation for September was 145% of average and for water year 2026 precipitation was 113% of average.
Water year 2027 began on Oct. 1 for the Yakima Basin Project, and current projections for the Oct. 1–20, 2026 period show that senior and junior water rights holders will receive 100% of their entitlements.
“With October underway, we’re reviewing this year’s hydrologic conditions to guide winter planning and reservoir management. We appreciate the continued collaboration from our irrigation districts, communities, and partners as we work to balance water needs across the basin and prepare for months ahead,” said Candace Carmack, Reclamation acting Columbia Cascade Area Office manager.
Reclamation manages the water in the five Yakima Project storage reservoirs, along with the basin’s unregulated inflows, 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.
The October forecast is based on flows, precipitation, snowpack, and reservoir storage as of Oct.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 Reclamation’s website at https://www.usbr.gov/pn/hydromet/yakima/.