Forecasts predict that average Methow River flows will be less than three-fourths of normal from April through August.
Alert intended to help farmers, fish managers prepare for summer
A few days of rain — while welcome — aren’t enough to reverse the drought emergency declared last week for the Methow, Okanogan and Upper Yakima watersheds by Gov. Jay Inslee.
A combination of the low snowpack and a forecast for less rain and hotter weather in coming months prompted Inslee to follow the drought-emergency recommendation from the Executive Water Emergency Committee.
Although there are genuine concerns about dry conditions, the main purpose of the drought emergency is to help farmers and fish managers plan for potential water shortfalls this summer and fall, according to Joye Redfield-Wilder, communications manager for the state Department of Ecology’s central regional office.
Knowing about a drought early in the season can help farmers make arrangements to obtain water or decide what crops to plant, she said. The emergency lets Ecology prioritize emergency requests from irrigators.
“What farmers and fish people tell us is they need to know now so they can shift resources,” said Redfield-Wilder. “Otherwise, it would be too late for a farmer to decide not to plant. He might lease water to someone else and make more money.”
The drought declaration is based on predictions of average streamflows from April to September. Those forecasts expect the Methow River will be 72% of normal; the Okanogan, 58%; and the Upper Yakima, 74%. State law defines a drought as water flow below 75% of normal.
As of last week, the forecast for April-to-August Methow River flows at Winthrop was the 62nd-lowest in 71 years of record-keeping. It was 59th-lowest for the river at Pateros, said Jeff Marti, drought coordinator for Ecology. “That’s lower than 2015, and that was a pretty major drought year,” he said.
A little rain
The Methow received about 1/2 inch of rain Friday through Sunday (April 5 – 7), measured at Winthrop, according to the National Weather Service.
“People will say, ‘It’s raining — why the hell are you declaring a drought?’” said Redfield-Wilder. The recent rains will help with soil moisture and could allow farmers to wait to start irrigation, helping preserve scarce resources, she said. And while there’s a chance the region could recover in coming months, forecasts don’t make that likely, she said.
“It’s definitely a forward-looking declaration,” said Marti. “It means we do expect water conditions will be extremely low.”
The primary benefit of the rain and cloud cover is that they keep temperatures cooler, slowing melt-off of the mountain snowpack, said Scott Pattee, a water supply specialist with Natural Resources Conservation Service (NRCS).
Although the next few weeks are expected to be cooler than normal — and to have some rain — May and June are expected to be drier than usual, said Marti.
Losing snowpack
The state lost a lot of its snowpack in late March and early April, when it’s typically at its peak. “March was extra-dry. Every day without snow, we lose ground,” said Pattee.
Although cold weather helped snow linger until the end of March in the lowlands, snowpack was already low in the mountains.
At the beginning of April, snow depth at Rainy Pass was 55 inches, or 60% of normal. At Harts Pass, it was 71 inches, or 69% of normal, said Pattee, who released the most recent Washington Water Supply Outlook Report on April 1. The measurements are based on normal snowpack over the past 16 years.
The overall snowpack that feeds the Methow watershed — now 77% of normal — is markedly less than last year, when it was 129%. The Okanogan snowpack is 70% today, versus 141% last year, according to Pattee.
Pattee focuses on snow-water content (also called snow-water equivalent), which measures the percentage of snow depth that will become water when it melts. “That’s really what we keep an eye on,” he said. “Once the density reaches 50%, it turns into liquid.”
The snow-water equivalent is also lagging this year. At the beginning of April, snow-water equivalent at Rainy Pass was 64% of normal. Harts Pass was 88% of normal, said Marti.
The rate at which the snowpack melts is also more important than snowpack depth in assessing the coming wildfire season, according to the National Interagency Fire Center. The faster the snow melts at higher elevations, the drier those fuels become — and the more susceptible to burning. Forecasts for a cool spring could help delay fire season.
The fire center expects an above-normal potential for large fires west of the Cascade crest, where forecasts are for a warm and dry spring and summer.
Complex dynamics
While a drought was declared early this year, it’s not unprecedented. In 2015, state water managers declared a drought on March 13 for watersheds including Chelan and Wenatchee. That was expanded to include the Okanogan watershed on April 17, and the entire state — including the Methow — on May 15.
The 2015 drought was called a “snowpack drought.” This year, snow in the valley didn’t melt till the end of March because of colder-than-usual weather, but there was less snow than usual in the mountains, said Redfield-Wilder.
The drought makes it likely that the 62 junior water-right holders in the Methow will face restrictions earlier than usual, meaning they have to call a hotline before they can water, said Redfield-Wilder. Their rights are junior because they were issued after minimums were set for streamflow in rivers.
“The prediction is that there won’t be enough precipitation to make up the difference, and things won’t get any better than 75% of normal,” she said.
Complex dynamics influence the amount of water we can expect. If soil freezes before it snows — as it did in much of the valley last fall — when the snow starts to melt, it runs off and rapidly enters streams and rivers. “It’s to the ocean right now,” said Pattee.
In the mountains, snow generally falls before the soil has a chance to freeze. But because the fall was so dry, the melting snow may just replenish the soil and not make it into the rivers, said Pattee.
That’s why a wet fall and less snow could produce a normal runoff, while a dry fall with lots of snow could actually mean a low runoff, said Pattee.
Ecology has requested $2 million from the Legislature for drought response, including water leasing and ways to move water to help salmon, according to the governor’s drought declaration.
While the drought covers only three watersheds now, several areas across the state are already on the cusp of drought, said Marti.
