YAKIMA, Wash. — The latest forecasts for summer streamflows in Washington state contain record low numbers, underscoring the concerns of irrigators on the east slopes of the Cascades.
The upper Yakima River at Cle Elum Lake inflows is forecast at 33 percent of normal flow for May through September, said Scott Pattee, water supply specialist of the Washington Snow Survey Office of the USDA Natural Resources Conservation Service in Mount Vernon.
The forecast, released May 6, projects the Yakima River at Cle Elum at 25 percent, the Teanaway River at 18, the Naches River at 17, Ahtanum Creek near Union Gap at 8 and the Yakima River at Parker at 27.
“A lot of these numbers are the lowest in history. We’re in record-setting territory,” Pattee said.
The forecast is down from earlier this season. Pattee will do one more on June 1.
The Yakima Basin is hardest hit. Crop losses and costs of coping with drought are estimated in the tens of millions of dollars in the Roza Irrigation District in the Yakima Valley. The district is suspending water deliveries to 1,700 customers on 72,000 acres from Selah to Benton City for 14 to 21 days to save water for later in the season. Farmers are deciding which crops they’ll let go.
Farther upstream in the Yakima Basin, the Kittitas Reclamation District is rationing water and Timothy growers are preparing for one cutting instead of two.
The Yakima Tieton Irrigation District began water deliveries April 1 at its normal rate of 4.9 gallons per minute and should be able to sustain that because it has a highly efficient, mostly pressurized pipe system, said Rick Dieker, manager.
The district’s 28,000 acres is 75 percent tree fruit and wine grapes and 25 percent rural residential areas west of Yakima. It’s 75 percent senior water rights and 25 percent junior.
“At worst we may not run into October but shut off in September,” Dieker said. “Our greatest concern is if we have the same kind of season next year with minimal (reservoir) carryover.”
The district’s diversion on the Tieton River is seven miles downriver from Tieton Dam on Rimrock Lake, one of the Yakima Basin’s five main reservoirs.
The district is considering leasing water to Roza but probably won’t because it wants to make sure it has enough, he said.
The Naches Selah Irrigation District also is considering leasing water to Roza but any amount would be small, said Justin Harter, district manager.
The district diverts from the Naches River and has some storage in Bumping Lake and serves 11,000 acres from Naches to Selah, 80 percent of which is tree fruit. It is mostly senior rights and isn’t anticipating rationing, Harter said.
To the north, the forecast for the Wenatchee River is 47 percent of normal.
The Wenatchee Reclamation District, serving a mix of mostly pear orchards and residential users on 12,500 acres, could run low in late summer. It has no reservoirs and is delivering water at normal rates. Upriver, the Peshastin and Icicle irrigation district have some storage capacity.
Other streamflow forecasts: Entiat, 60; Chelan, 65; Methow, 41; Okanogan, 68; Kettle, 52; Pend Oreille, 80; Spokane, 42; Walla Walla, 69; Grande Ronde, 48; Klickitat, 46; Cowlitz, 64; Green, 50; Cedar, 45; South Fork Tolt, 51; Skagit, 76; Baker, 69; Dungeness, 47; Elwha, 53.
The east side of the state was about 50 percent of normal rainfall for April and the west side was 70 percent, Pattee said.