But of more concern to Clear Springs than river conditions is the diminishing aquifer. The underground supply has dwindled by about one-fourth in the last 50 years because of consecutive drought years, withdrawals and less recharge from irrigation canals leaking water back into the ground. In addition to the valley's trout farms, a handful of cities and large irrigation districts also tap the underground lake. Clear Springs essentially borrows water from this ecosystem high in the canyon and dumps it back into the river lower down. The flow is important to the Snake because it recharges the warm trickle that remains in the river after irrigation diversions.
Gravity does most of the work.
Hundreds of thousands of gallons of water a second roar downhill through the stepped pools. The flow captures oxygen needed by the fish as it spills from one level to the next. Clear Springs Foods has rights to 949 cubic feet per second - roughly twice as much as flows down the Yakima River in late summer. In between inlets and outlets at Clear Springs' four facilities are hundreds of symmetrical gray pens covered in chicken wire to keep out herons. Processing starts within an hour of the fish being pulled from the ponds.