May to August 2026 Edition
Hydrologic Conditions Update An exceptionally low snowpack, early meltout, and continued drought conditions are driving water supply challenges across Washington, highlighting the need for adaptive management and collaborative drought response strategies. Lack of early summer snowpack is the driving story of summer 2026. We saw this coming months ago when the major precipitation events were large rainfall events in December and March. Temperatures were near record highs for the usual snow accumulation season. The meager snowpack melted off well ahead of average. Ecology declared a statewide drought emergency in April due to predictions of very low summer streamflows and short water supply which are now reality. This report provides a brief update of current conditions and an example of how watersheds in Washington are adapting to recurring drought. Numbers, trends, and forecasts The Water Supply Availability Committee, convened monthly by Ecology, met on July 9th. Presentations from several state and federal agencies detailed existing and forecast conditions. This update relies heavily on these presentations which are available on line at Department of Ecology - Committees, Boards, and Workgroups. First the forecasts. Hydrologic conditions don’t generally change much during the summer. The die is cast in winter by snowpack accumulation or lack thereof and by the timing and pace of spring snowmelt and accumulation of reservoir storage where it exists. So barring unexpected major upticks in precipitation and sustained cooling trends, what you see in July tells what to expect for the rest of the growing season. How did we get here? The below graphic from NOAA presentation at July WSAC encapsulates the water year to mid July. Average to above average precipitation for the water year owing to the large December and March events. Above average temperatures – 4th warmest water year on record (behind 2015, 1934, and 1992). Peak snowpack well below average except near the Canadian border. October to July runoff above average with a few exceptions. Warmer and drier than normal spring and early summer. A formula for summer water supply shortages for instream and out of stream uses.
By early July every SNOTEL site in Washington showed zero snow water equivalent, which occurred some weeks earlier than average (light green line). Plot shows the race to the bottom with 2015 and last year, which looks good by comparison. (NRCS)
NRCS reports soil moisture levels below to far below average in most of Washington with the notable exception of the upper Columbia in NE Washington. (from July WSAC meeting)
A strong El Nino is expected to persist into the fall, which leans toward warmer and drier conditions in Washington, but with high variability. Some El Nino winters such as 82-83 have been anonymously wet with persistent snowpack. Yakima Basin The Bureau of Reclamation held their monthly Yakima Project Water Status Update on July 2nd. Reclamation operates the Yakima Project reservoirs to supply irrigation water to about one half million acres of land and instream flow under the 1855 Treaty of the Yakama Nation and target flows laid out in 1994 federal legislation. After deducting instream flows from total water supply, irrigation water is divided between pre-1905 priority date water users and May 10, 1905 water rights created under the Reclamation Act and other laws. Pre-1905 rights receive full supply, and the 1905 rights receive a pro-rata share of remaining supply. Each month Reclamation calculates Total Water Supply Available based on projected runoff, reservoir storage, and projected return flows, then sets the prorationing level for 1905 users. The July estimate is that the 1905 rights will receive 56% of full supply. The June estimate was 52%, and the 4% increase is due to a brief rainy spell in June which added to reservoir storage. The 4% increase will provide additional late season supply for pro-ratables. Since its inception in the early 20th century, the Yakima Project has depended heavily on its 1.1 million acre feet of reservoir storage to provide late summer irrigation water. Back in the good old days of the mid-20th century, melting Cascades snowpack provided for early season irrigation and instream flow while reservoirs continued to fill. When snowmelt is less than irrigation demand, Reclamation begins drafting the reservoirs and the system goes on “storage control”. Ideally snowmelt limits the need for reservoir releases such that there is considerable “carryover” storage in the reservoirs at the end of the irrigation season. In recent years the reservoirs have been drawn down to minimum pool levels, meaning that an exceptional winter is needed to refill them. That happened in the winter of 25-26 to a remarkable level given particularly the December rain event, but even with full reservoirs the lack of snowmelt prevents full supply to 1905 irrigators and incremental increases in instream target flows. These two graphs from the Reclamation July 2nd update paint the picture.
This plot compares water year 2026 with historical max, min, and average reservoir storage. From record lows in October, December rains pushed storage well above average and May rains pushed it to record high.
Salmon The update on the Salmon Run at the July 2nd Yakima Project meeting was not encouraging. Spring chinook passing the lower Columbia River dams numbered 107k fish, 75% of average and well below forecast numbers. 2047 passed Prosser Dam in the lower Yakima, which is not enough brood stock for full production at the Cle Elum supplementation hatchery. Likewise Sockeye salmon, which were reintroduced by the Yakama Nation in 2009 after a 99 year absence due to lack of reservoir fish passage, are coming up the Columbia in significantly lower numbers than forecasted. Why so poor? Pat Monk, fish biologist at Reclamation offered that we have had four years of drought, which is an entire life cycle for these fish.
Drought response: The Dungeness example. Thanks to Jason Hatch of the Washington Water Trust for providing material for this update on a dry-year leasing project in the Dungeness River basin. The Dungeness watershed lies in the rainshadow of the Olympics. In contrast with other watersheds in Western Washington the Dungeness receives only 16 inches of precipitation each year (compared with about 155 inches across the Olympics in Forks). The Dungeness climate is more like Spokane than Mount Vernon, and the 6,000 acres of agriculture receives irrigation water from 5 river diversions. The Dungeness River is home to nine different salmonid species. The primarily snow-pack driven system, with a warmer winter and more rainfall than snow, is now in the middle of the fourth consecutive drought where 2026 may rival the record-breaking 2015 year for low flows. This year, on July 17 flows at the upstream of all diversions USGS gage read 125 cfs. July 17, 2015….127 cfs. As with most of Washington, snowpack lagged below average through the winter and full melt out occurred a month earlier than normal.
Beginning in 2009, and in 2015 as well as every drought year following (excepting 2021), Washington Water Trust (WWT) has worked with the Dungeness Water Users Association (the umbrella group for the 7 Dungeness River districts/companies with senior water rights) on the Dry Year Leasing Program, paying irrigators to forgo irrigation on lands typically irrigated the last month of the irrigation season. The irrigators districts/companies turn down their headgates to leave water that would usually serve those acres. This has resulted in 8-9 cfs of additional flow. Starting in 2023, WWT and the irrigators, coordinating with the Jamestown S’Klallam Tribe, initiated a Pulse Flow Program in which the 5 headgate diversions that serve irrigators would be simultaneously turned down, resulting in an additional 20-25 cfs of flow over a 13-24 hour period to support upstream Chinook passage. These programs have been consistently supported by Ecology with WWT securing private funding support. Dry Year Leasing and Pulse Flows, in conjunction with the Tribes’ significant floodplain restoration work and drought season in channel modification to support passage, have contributed to nearly double the chinook escapement targets. Yet, the recurrence of these drought years and the impact on instream conditions continues to pose a significant challenge. This year, in 2026, WWT has secured five-year agreements with irrigators that run through 2030, in which acres may be “called” when drought conditions are emerging, and will enable these programs to be activated in shorter timelines and activate drought response. This year, Dry Year Leasing will begin August 8 and run through the end of the irrigation season on September 15th, 39 days. And in anticipation of these extreme low flows, the first 24 hour pulse flows was scheduled for July 18th. Overall, irrigators have contracted for potential 84 cfs of Pulse Flow over 3-4 Pulse Flow Events. A four-year streak of droughts is not the record you want, yet as we face these recurring low flow years, partners in the Dungeness are organizing actions which can be mobilized quicker and provide timely drought response. We will touch on actions other basins are taking to mitigate drought in future updates. |
This graph shows the last 4 years, all drought years. Starting with full reservoirs, lack of snowmelt and reservoir releases due to warm dry conditions early in the irrigation season brought levels below average, but still above the previous 3 years. Carryover storage is expected to be at minimal levels like the last 3 years. The system went off storage control on May 21st coinciding with the observed drop in storage (the green line). Storage control dates for 2023, 2024, and 2025 were June 1st, June 14th, and June 5th respectively. The earlier storage control date this year was driven by the poor snowpack and lack of late winter snowmelt. In 2015 (not pictured), the archetypal snowpack drought year, storage control began on April 15th, the earliest in the modern record, a reflection of full reservoirs, but virtually no snowpack to melt off. The climate forecast is hot dry, so no significant changes in water availability are expected in the Yakima basin this summer.
