2020-21: The year of water surprises


When water managers talk about the year of water 2020-21, they describe it starting in October and ending in September. The irrigation is done, and the harvest is finished.

By October, we expect rain or even snow – and fires will go out – and planting of winter wheat and new trees, anticipating regrowth in the spring.

During the winter, snow accumulates in the mountains, creating a slowly melting cushion to irrigate and nourish crops, provide passage for migrating salmon in streams and streams, and recreational opportunities for them. people on lakes and rivers. Rain and snowmelt recharge our aquifers and support our rainforests and communities in both the east and the west.

Overall, the snowpack generates electricity for the entire region at the dams on the Columbia River. It creates a corridor for container ships calling in Portland below major dams and barges carrying goods and crops to and from Clarkston via the Snake River.

Yet here we are in September, despite recent rains, in some of the driest conditions in history.

In April, a huge supply of water, stored as snow in the High Cascades, reached a whopping 132% of normal statewide. It seemed like we were set.

Now wildfires are still smoldering, and 11 counties in eastern Washington are drier than they’ve ever been, since the data was first tracked in 1895.

According to the National Weather Service, overall from March to August, the state recorded 6.90 inches of precipitation. Normal during this time is 13.03 inches – a deficit of over 6 inches, making the statewide water year the second driest year in history.

In addition, from March to August, nearly three-quarters of the state experienced record drought and the other quarter was “well below normal” at the bottom 10%. Not a pretty picture, even for the rainiest parts of Washington.

For example, to end the current drought in the Lower Columbia River region, ecological drought coordinator Jeff Marti noted that we would need 11 inches of rain by next April. The chances of this type of rebound are low and have only happened less than five times in the past 120 years.

“The question is, will we have a full recovery before next spring?” said Marti. “The chances of a significant improvement in conditions are pretty good for western Washington. But I’m less optimistic about the east side. Based on historical climatology, the odds of significantly improving current conditions are about 1 in 5 in eastern Washington. For a full recovery in eastern Washington, the odds are about 1 in 20. “

Data from the National Oceanic and Atmospheric Administration (NOAA) shows that in August, Grays Harbor County experienced the fourth driest “hydrologic year” – hydrologic years begin with the typical storm season, the October 1 – since records began to be kept in 1895..

From March to August of this year, the NOAA (surface water supply) water value for the county is almost 11 inches lower than the average value for the past 125+ years, normally over 27 inches. .

Examining the data and analyzing the probabilities helps us anticipate conditions and provide assistance where we can. This year, the snowmelt captured in the storage protected the irrigated farmer, but there was not enough precipitation retained in the loamy soil for the dryland farmer. So there is a lot to look at in the coming months.

La Nina effect

While a forecast from La Nina increases the chances of a wetter winter, it doesn’t guarantee it, Marti said.

“And even a good La Nina could leave areas of persistent deficits, so people need to be vigilant,” he added. “Remember that last winter was also a La Nina winter.

“It may be sobering, but we want to expose what we know to try to help farmers, lawmakers, water managers and others make the best decisions for what they need. We can’t tell people what’s going to happen, but we can at least share what we know about the odds.

Focusing on the unexpected, Marti noted that on August 26, the Nooksack River in Whatcom County experienced record low flows – this in a basin where the snowpack was 120% of normal.

“In April, looking at our impressive snowpack, I certainly didn’t expect the Nooksack to set record one-day-of-the-year lows this year,” said Marti. “You can never turn your back and relax because things can go downhill.”

Near-zero precipitation in the spring and a heat wave that dominated the state in early summer resulted in rapid runoff from the snowmelt. Watersheds with storage, particularly the Yakima River Basin and the mainstream Columbia River, are largely unscathed. However, the soil is parched and the water stored in the reservoirs is low.

For areas with zero rainfall and lack of irrigation, this has been particularly difficult.

Washington wheat, lentils, chickpeas and potatoes are a huge commodity – in the billions of dollars. Emergency federal drought aid is on its way for many, but that is not reassuring for next year.

“We’re still on time,” said Marti, as we look at the end of one water year and anticipate another.

Daily World writer Dan Hammock contributed to this report.

Low waters of the Salmon River, a tributary of the Queets River, in 2019, which was just as dry a year as in 2021. (Courtesy of the Department of Ecology)


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