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Pacific Northwest Region
Boise, Idaho
Media Contact:
John Redding
(208) 378-5021
David Murrillo
(509) 575-5848 ext. 213

Released On: May 19, 2005

Yakima Basin Water Supply Mid-May Release
The Bureau of Reclamation has released a Mid-May 2005 forecast for irrigation water supply in the Yakima Basin, according to David Murillo, Yakima, Washington project manager. The Mid-May 2005 forecast shows an increase in the total water supply available. The wet and mild conditions this spring in the Yakima Basin have helped improve the water supply. Even though the outlook is improved, it continues to indicate severe prorationing for junior users.

The Yakima Field Office declared official prorationing on April 6. Rationing is in effect at this time.

Senior water rights holders will receive their full water supply. The adopted prorationing level for junior users updated Mid-May is listed below:

Adopted prorationing level: 38 percent of full supply.

Precipitation for the period March 1 to May 17 is 114 percent of average. Runoff during May has been greater than anticipated. Irrigation demands have been moderated by the cool, rainy weather and the Yakima Basin reservoir system continues to fill.

Future precipitation is only one factor affecting the water supply. The weather conditions that determine the timing of the run-off and demand for water are critical in determining the extent to which the reservoirs fill, the amount of water available for irrigation, and rationing levels. Because of these unknown future factors and uncertainty in the basin conditions, the Yakima Field Office provides a likely range for the total water supply available estimate and the associated rationing level. In Mid-May, a reasonable range for the rationing level is between 32 percent and 49 percent of full supply with the adopted rationing level at 38 percent of full supply. The total water supply available will be adjusted bi-weekly or as needed to reflect changing conditions. The next update will be released June 6.

The water supply can be improved through prudent use of water. Please conserve water!

Untitled Document

Reservoir storage on May 18

Reservoir

Content (acre-ft)

Total Capacity

Percent of Capacity

Keechelus

104000

157,800

66 percent

Kachess

164175

239,000

69 percent

Cle Elum

359550

436,900

82 percent

Bumping

33892

33,900

100 percent

Rimrock

196662

198,000

99 percent

Totals

858278

1,065,600

81 percent

 

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