A ground water mapping study that tracks how water trickles under Eastern Washington shows deep wells in four counties are in deep trouble.
The two-year study done by the Columbia Basin ground water Management Area, based in Othello, found that aquifer levels are dropping fast, that most deep wells in the study area are drawing water left from the Ice Age floods at least 10,000 years ago, and that there is virtually no chance Lake Roosevelt is recharging deep wells in Eastern Washington’s driest counties.
“This is a major issue for cities and big irrigators,” said Paul Stoker, executive director of the ground water agency.
Franklin, Adams, Grant and Lincoln counties are most affected in a study area covering about 8,000 square miles.
“Water level records show ground water mining is occurring with many wells declining faster than they can naturally recharge,” Stoker said in a release last week.
Stoker explained some wells have a combination of new and old water. The oldest flows come from sources connected with the Ice Age floods, and the newer water is from various sources that recharge the wells such as reservoirs, lakes, rivers and irrigation.
As well water levels drop, irrigators drill deeper, pushing as far as a quarter-mile deep in pursuit of the aquifer. While that makes more water available, water levels continue dropping and eventually will be beyond the capability of pumps to lift it to the surface, Stoker said.
“Going deeper isn’t going to solve this,” he said.
The study also found old water from the deepest strata isn’t being recharged because it is beneath layers of impermeable basalt. That means at some point the Ice Age waters will be depleted if pumping continues, he said.
Stoker said the study identified 23 interflow zones, which have been grouped into three strata: The upper, middle and lower levels, also known as the Wanapum, Upper Grand Ronde and the Lower Grand Ronde.
Monitoring wells show the Wanapum strata is relatively stable because it is recharged from surface water. But wells show the Upper Grand Ronde is steadily dropping and the Lower Grand Ronde is also dropping, Stoker said.
But the big surprise came where deep wells tapped the Lower Grand Ronde.
“When they hit the lower level, the static level in the wells took a nosedive,” Stoker said. “Irrigators have been spending a lot of money – up to $1 million per well – for not much.”
Stoker said farmers know their wells are in trouble and plant water-thirsty crops like potatoes at the beginning of the growing season, then switch to dry peas, wheat and grass seed later because they can produce those with less water when the well water levels are lowest.
The study was supported by a $2 million state grant, and Stoker said his agency asked for another $2.5 million from Gov. Chris Gregoire’s 2009-11 budget to develop a hydrogeologic model to find potential solutions. But the request was cut.
“We need to know what we can do about this. The study is very sobering and documents the serious threat the declining aquifers pose to our future and the sustainability of our communities,” Stoker said in his statement.
A community meeting in Othello drew about 60 people, including commissioners from the four affected counties, and representatives from the state Department of Ecology, the Department of Natural Resources and the offices of Sen. Maria Cantwell, D-Wash., and Rep. Doc Hastings, R-Wash.
Stoker said he will spend this week in Olympia championing the cause.