Aquifers still going strong despite drought
Water table drops in places but not at alarming rates; water district monitors conditions
Despite desperate drought conditions for reservoirs and irrigators, the aquifer holding Jefferson County’s pristine Opal Springs water still gushes forth.
“We’ve been monitoring our water source at Opal Springs, and we have not had any noticeable impact from current drought conditions,” says Joel Gehrett, manager of the Deschutes Valley Water District. “We continue to monitor source water conditions daily.”
When the normal or better snowpack this winter didn’t result in better stream flows, some wondered if the moisture shortage was depleting aquifers in the Deschutes Basin.
Hydrologists like Kyle Gorman have a different theory.
“The working theory is that it was so dry in the spring when we’d usually get additional water to boost that snowpack, and then on top of being dry, it was very windy,” says Gorman, “and wind can reduce snowpack substantially.”
Gorman works for the Oregon Water Resources Department. He monitors more than 20 wells to keep track of the water underground in the Deschutes Basin.
Gorman says the aquifers on the east flank of the Cascades especially respond to changes in climate. “They’ll go up in wet years and down in dry years,” says Gorman.
The headwaters to the Metolius River showed an especially dramatic change. “During the wet cycles, we measure over 100 cubic feet per second of discharge,” says Gorman. “Our recent measurement was 55 cubic feet per second.”
He says the water in unpopulated areas near the Cascades mimic the fluctuation in the Metolius.
“They’re virtually unaffected by pumping, so they’re the natural variations in water table,” says Gorman.
In the more populated areas, Gorman has seen the water table drop 20 feet or more over the past 30 years. Water once reached at 350 feet below the surface in 1990 might be 370 feet below the surface today.
“The water table is dropping, but it’s not dropping at a dramatic rate,” says Gorman. “There are some places in the state that have seen levels drop over 400 feet. That’s the time we’ve got to change what we’re doing.”
Gorman says those drops are occurring in Northeast Oregon. Water conditions underground look good for Central Oregon. “The saturated thickness in the aquifer here in the Deschutes Basin in some places is probably greater than 1,000 feet,” says Gorman. “So, we have a very robust aquifer that’s being recharged continually.”
While there’s no indication we’re running out of our underground water supply, Gorman emphasizes water is a precious commodity.
“Whether we’re in a drought or not, folks should always have that mindset of conserving water and using it as efficiently as they can,” says Gorman, “no matter what their source is.”
Pat Kruis
