SEQUIM — It looked good in March. Now, not so much.
Snowpack that was reported at 169 percent of normal in the Olympic Mountains as of early March has melted away, siphoned off by an unprecedented late June heat and a dry summer.
That has led to low flows in the Dungeness River and the implementation of the Dungeness Water Users Association drought response program, said Ben Smith, president of the association, which is made up of seven irrigation districts and companies that divert water from the Dungeness River to supply irrigation water throughout the area between Sequim Bay and Siebert Creek..
“We had a great snowpack going into the season and thought we were going to be fine this year,” Smith said Friday. ”What looked like a very promising snowpack and water year back in the spring has quickly turned dismal.”
On average, the combined diversions of the association’s membership run about 40 cubic feet per second (cfs) during the irrigation season, which is April 15 to Sept. 15, Smith said in a press release. One cubic foot of water is equal to just under 7.5 gallons. A cubic foot per second is about 7.5 gallons passing by each second.
Flows hit 115 cfs at the mouth of the Dungeness River earlier this month. Irrigators are required to reduce their diversions in order to maintain at least 62 cfs in the river. Since then, flow has increased, with 143 cfs reported by USGS on Saturday morning on the river near Sequim, an amount that still is below the long-term median flow of 205 cfs.
It also won’t last.
“We’ll get a short-term blip when we get a rain, like we did last night, but this rain will come down and be out of the system within 36 hours and then we’ll be back to that base snowpack,” Smith said.
“We want everyone to be cautious … If it ends up raining for the next three weeks we’ll be in good shape, but that probably won’t happen.”
Although the river hasn’t reached the low flows that require reduced diversions, flows overall have been declining rapidly, Smith said.
Over the first three weeks of August, the flow at the Dungeness River mouth dropped by nearly half.
Just one month ago, the flow was over 300 cfs, Smith said. The flow upstream of all diversions on Friday was 127 cfs. The mean for that day, based on a 92-year record, is 230 cfs. The lowest flow ever recorded on that date was 92.9 cfs in 2015.
To protect the water supply, the association is asking all its water users to cease any unnecessary uses of irrigation water and where possible use well water for livestock and essential residential needs.
“Please consider the needs of our area farmers whose livelihoods depend on irrigation,” Smith said in the release.
Details on water user association rules, as well as a guide to responsible irrigation, can be found at on the Clallam Conservation District website at clallamcd.org.
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Executive Editor Leah Leach can be reached at 360-417-3530 or at lleach@peninsuladailynews.com.
