Yakima Basin Water Supply - July Forecast

Media Contact: Annette Ross, (208) 378-5322, aross@usbr.gov

For Release: July 09, 2018

YAKIMA, Wash. – The Bureau of Reclamation’s July 2018 Total Water Supply Available (TWSA) forecast for the Yakima basin indicates a full water supply for senior and junior water rights this irrigation season. This is an improvement for the junior users whose entitlements were limited to 96% of their full supply since June 11, based on the June TWSA. Prorationing is now 100%.

“The basin started using reservoir storage on June 11 to help meet basin irrigation and instream flow demands. This is about 10 days earlier than normal,” said Chuck Garner, Yakima Project River Operations supervisor. “Although the overall supply is adequate, the reservoir carry-over at the end of the season is likely to be below normal.”

Reclamation will provide water supply forecasts monthly through July. Specific water delivery levels will not be determined until later in the year after reservoir storage begins to decline.

This forecast is based on flows, precipitation, snowpack, and reservoir storage as of July 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 streamflows, prorations, and the extent to which the reservoirs fill.

If summer temperatures, precipitation, and runoff are unfavorable, Reclamation still expects an adequate supply. Because longer term weather conditions can be unpredictable, Garner recommends water conservation always be considered by users in the Yakima basin.

For more information, visit Reclamation’s website at https://www.usbr.gov/pn/hydromet/yakima.

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Reclamation is the largest wholesale water supplier in the United States, and the nation's second largest producer of hydroelectric power. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits. Visit our website at https://www.usbr.gov and follow us on Twitter @USBR.

Relevant Link:

https://www.usbr.gov/pn/hydromet/yakima