Stream temperatures affecting fish throughout Central WA, north and south
The water supply forecast continues to deteriorate across the state on both sides of the Cascade Range, and drought is being felt particularly on the Olympic Peninsula.
While drought impacts are more typical in the arid Yakima River Basin, water supply conditions here have dropped off significantly in the last month. Despite some rainfall this spring and a big snowstorm in February, the snow in the mountains is virtually gone.
Coupled with the lack of snow in the mountains and drier conditions, Ecology forecasts the total natural water supply available to the Yakima’s three watersheds comprising 6,150 square miles will be 75 percent of normal, May to September. Hence drought was declared in the Upper Yakima, Lower Yakima and Naches watersheds this spring.
That lack of snow means there’s less water to go around for Yakima Valley irrigators who rely on slowly melting snowpack as a “sixth reservoir” to water their crops over the summer. This also means some irrigators will receive a smaller ration of water, and others will be shut off.
Irrigation supports a $4.5 billion agricultural economy in the Yakima Basin, where the U.S. Bureau of Reclamation manages five reservoirs to deliver water to irrigate 464,000 acres of farmland and to release water in pulses to support salmon.
On Friday, June 7, 2019, Reclamation reported their reservoirs are about 80 percent full and because of the lack of snow, water deliveries are beginning to rely on this storage.
Formal curtailment notices
Junior irrigation districts, Kittitas, Roza and Kennewick, will receive at best 74 percent of their total allotment of water this year, according to Reclamation. And because of this rationing of water, some 217 water rights more junior than these irrigation districts are now shut off by court order.
These users, with priority dates after May 10, 1905, are part of an adjudicated water basin that controls when surface water may be diverted. Now that the Yakima adjudication final decree has been entered, Ecology is tasked with issuing these curtailment orders, which were sent out on Friday, June 7, 2019.
Camp and cabin owners who rely on surface water and who participated in our mitigation program, and domestic water users, will not be curtailed. Those irrigators being curtailed may be able to lease water from other irrigators or water right holders within the Yakima Basin.
Water users with questions may call our Central Regional office water rights customer service line at 509-575-2597.
Other Central Washington water tidbits
The U.S. Geological Survey Water Quality Watch indicates that water temperatures in the Lower Yakima are now exceeding 22 degrees Celsius (71.6 F). Salmon won’t move up into the river when it gets too hot. This is called a “thermal block.”
Water temperatures on the Okanogan below Oroville are also above 22 degrees C. The fisheries biologist for the Colville Tribe says that steelhead eggs die if the river experiences five consecutive days of water temps greater than 20C. He said it’s not unusual for the Okanogan to warm up, but this year it happened earlier than usual.
Ecology continues to work with the Oroville-Tonasket Irrigation District on a project to develop a water bank to address water supply limitations for irrigators in the Okanogan River basin.
Also this week, Ecology is raising the water level on Lake Osoyoos at Oroville to gain 3,000 acre-feet of water to help irrigation later in the season, due to drought conditions there.
State drought declarations
This spring, Gov. Jay Inslee officially declared drought emergencies for 27 watersheds.
By state statute, "drought conditions" are water supply conditions where a geographical area or a significant part of a geographical area is receiving, or is projected to receive, less than 75 percent of normal water supply as the result of natural conditions and the deficiency causes, or is expected to cause, undue hardship to water users within that area.
Drought emergency declarations allow Ecology to expedite response actions such as expediting water right transfers and providing funding to local governments to address hardships caused by drought. Some examples of drought-relief projects that funding might be used for include leasing water rights, implementing water conservation programs, and developing alternative sources of water supplies for communities, farmers, and fish hatcheries.