Stemilt Hill irrigation water iffy at times
WENATCHEE, Wash. — Several hundred acres of cherry orchards south of Wenatchee lost water one night recently because of lower flows in the Columbia River, but irrigation districts likely will have to wait until mid-August for a fix.
Water to about 3,000 acres of orchards, mostly cherry and some apple, was jeopardized this spring by the drawdown of Columbia River reservoirs due to a crack in the Wanapum Dam.
The orchards, which stretch from the river up to the 3,000-foot level of Stemilt Hill and Wenatchee Heights, are served by three irrigation districts pumping water from a pond just off the Columbia River at Stemilt Creek. River water seeps through a rock berm into the pond and is pumped uphill.
During a drawdown of the Rock Island Dam reservoir, the pond wasn’t getting enough water. It took time for the irrigation districts to gain state and federal permission to install two large pipes between the river and the pond to provide a more reliable flow of water. Rising river levels and flows from spring runoff prevented the project from being done in April and May and the pond had enough water.
On June 15, water was held back at Grand Coulee Dam to fill Lake Roosevelt and riverflow at Wenatchee dropped to 100,000 cubic feet per second. That caused the pond to run low again, and pumping for the Lower Stemilt Irrigation District was suspended overnight, said Jon Johnston, district water auditor.
“Anytime our pumps suck air it can burn them up. I was down at the pond checking the water level eight times that weekend,” Johnston said.
Lack of water for the cherries wasn’t a big problem for one night but made irrigators and growers nervous, said Kevin Juchmes, water manager of Stemilt Irrigation District.
A longer water outage during warm weather would affect cherry size, he said.
Cherries are being picked up to the 800-foot level and will continue into mid- or late August at the highest elevations.
Riverflow was back up to 128,000 cfs the morning of June 16 and since then has risen to 177,000, said Suzanne Hartman, Chelan County Public Utility District spokeswoman. It likely will drop back closer to 100,000 cfs in mid-August as mountain snow runoff lessens, she said.
The irrigation districts will try to do the project then, said Steve Shiflett, a grower and project overseer.
Two, 36-inch-diameter, 80-foot-long steel pipes will be placed in trenches 11 feet deep to keep water flowing into the pond during times of lower riverflow. The project will cost about $80,000, Juchmes has said. The value of the fruit on Stemilt Hill and Wenatchee Heights has been estimated at $25 million.
Meanwhile, a $61 million repair of Wanapum Dam continues. Grant County PUD hopes to increase the level of the Wanapum reservoir in the fourth quarter of the year. It is 25 feet lower than normal but is the next reservoir downriver from the one feeding the Stemilt irrigation pond.