Courtesy Roza Irrigation District
SUNNYSIDE, Wash. — The first water has flowed into a new, $31 million reservoir off the Roza Canal that soon will capture irrigation water once lost to wasteways and the Yakima River.
The first of five pumps was tested Aug. 2. It pumps water from the canal into the 1,600-acre-foot reservoir in Washout Canyon, five miles north of Sunnyside.
“This project had its origins in the 1970s and really gathered steam in the early 1980s when the Roza Irrigation District adopted a water conservation plan,” said Scott Revell, district manager.
Early on, the district considered building a larger reservoir for greater storage but decided it would cost too much money, Revell said.
Geologic and technical studies on where to locate the reservoir took 10 to 15 years. Property acquisition, design and funding all took time.
The U.S. Bureau of Reclamation is paying 65 percent of the project and the state Department of Ecology and Roza district are each paying 17.5 percent.
The Roza Irrigation District operates 95 miles of main canal and more than 350 miles of laterals serving 1,700 growers on 72,000 acres from the northwestern edge of the Yakima Valley at Selah to the southeastern end at Benton City. Water is diverted from the Yakima River at Roza Dam into the canal 10 miles north of Selah in Yakima Canyon.
The district is the largest one most severely impacted in drought years because it operates solely on junior water rights which are the first restricted in droughts.
The district uses about 300,000 acre feet of water annually.
Right now, when a grower in the lower part of the district orders water it takes two days for the water to arrive from the dam and by then the weather may have changed and the grower may not need as much. Water that isn’t used goes into one of several wasteways that takes it back to the Yakima River, Revell said.
The new reservoir, called a reregulation reservoir, allows the district to pump such excess water from the canal into the reservoir and hold it for later use in the lower half of the district instead of dumping it into the wasteways. It will enable the water master at the dam to fine tune diversions, saving water and providing more equal shares to everyone in the district.
The reservoir covers 35 acres, is 70 feet deep and will hold 1,600 acre-feet of water. It will be operating at the end of August but won’t be full until next spring’s mountain runoff.