WENATCHEE, Wash. — Washington State University will spend $74,000 and others may spend more to extend irrigation systems to reach the Columbia River lowered because of a crack in Wanapum Dam.
The WSU Tree Fruit Research and Extension Center in Wenatchee will add a pump and extend a 12-inch-diameter irrigation pipe 280 to 300 feet to reach water for its Sunrise Research Orchard 15 miles southeast of Wenatchee and 6 miles southeast of Rock Island.
A crack was discovered in the base of a portion of Wanapum Dam on Feb. 27. The Wanapum reservoir was lowered 26 feet to relieve pressure on the dam. The Rock Island Dam reservoir was lowered three to four feet.
Beside a reduction of hydropower generation and recreational access, the drawdowns have affected orchard irrigation along 20 miles of the river from Spanish Castle Orchard northwest to Wenatchee.
The 50-acre WSU Sunrise Research Orchard may miss an early pest-control spray for lack of water, said Jay Brunner, director of the WSU Tree Fruit Research and Extension Center. Water won’t be trucked in, as was earlier considered, but should be available with the extension to the river by mid-April, he said.
It will be a permanent fix allowing the orchard deep enough access to avoid weeds and future drawdowns of Wanapum reservoir, Brunner said. The additional pump, part way down the pipe, won’t be needed and will be removed when the reservoir returns to normal levels, he said.
The system serves the research orchard and 60 acres of orchard WSU leases to Pieple Premium Fruit. WSU has about 190 additional acres at the site for buffers and future expansion.
Several other orchards in the vicinity are extending pipes and drilling a well to get water.
One of them is the 900-acre CRO Orchard, owned by Zirkle Fruit Co., Selah. Mark Zirkle, company president, declined comment other than to say the company is working to get water.
Across the river from CRO, Lacey Ledbetter, owner of an 18-acre cherry orchard, said he’s concerned about getting water soon but is impressed with the speed of agencies in issuing permits. He said he needs to move his main submersible pump and irrigation line 80 to 100 feet downriver because it may be swept away in the river current if he extends it where it is.
“I can’t imagine it will be cheap,” he said, adding he hopes to get a smaller line operational sooner for water for early pesticides.
His neighbor to the north, Alyse Barnes, said she has her hydraulic project approval from the state Department of Fish and Wildlife and hopes to extend her irrigation pipe into the river soon.
Upriver in the Rock Island reservoir, Stemilt Irrigation District is now planning to install gravity-flow pipes instead of pumps to get river water into a pond south of Wenatchee from which water is pumped some 2,000 feet uphill to serve orchards of Wenatchee Heights and Stemilt Hill.
The pond has been fed by seepage of water through rocks but that’s no longer working because of the river drawdown, low flow and sediment that’s filled in the cracks between the rocks, said Kevin Juchmes, water manager of Stemilt Irrigation District.
Creek water, up on the hills, should be sufficient for early sprays but the pond is needed by May 1, Juchmes said. It serves three irrigation districts.
Six investigative holes have been drilled in a portion of Wanapum Dam but windy weather has created delays and a larger platform will be constructed for workers and their equipment before drilling resumes, Grant County Public Utility District, operator of the dam, said in an April 1 news release. Platform construction and drilling is expected to take another three to four weeks without significant wind delays. Work is stopped in winds of more than 35 mph. The work area is only accessible by boat and crane.
The drilling will help determine the geometry of the fracture and how far it reaches into the dam.
Grant County PUD and Chelan County PUD, operator of Rock Island Dam, are working to modify fish passage systems in time for the April 15 return of spring Chinook salmon and downriver passage of juvenile salmon.