Ice fishers beware: USBR began pumping into Banks Lake Feb. 17

The ice on Banks Lake could "could rapidly change without warning" as the Bureau of Reclamation began pumping water into the lake on Friday, Feb. 17.

A similar warning applies for those fishing at Potholes Reservoir.

The most popular spot for ice fishing in the local area may well be the area near North Dam where the feeder canal brings in water from deep in Lake Roosevelt.

"Recreationalists on Banks Lake and Potholes Reservoir should be aware that operational activities can lead to a rapid change in conditions without obvious warning signs," the Bureau said in a release Thursday.

Ice can appear uniformly smooth on the top surface, even as currents or subtle temperature differences caused by factors such as underwater springs may warm the ice from beneath.

On Friday the Bureau will add a significant current as it gets ready for the spring irrigation season that sustains some 670,000 acres of farmland in the Columbia Basin Project.

To prepare Banks Lake for the March 1, 2023, operation startup, Reclamation started pumping water from the John W. Keys III Pump-Generating Plant into the north end of Banks Lake Friday. "Water is pumped from Lake Roosevelt to maintain Banks Lake elevations for Columbia Basin Project irrigation activities," the Bureau said.

"Reclamation cautions ice anglers and other recreationists on Banks Lake and Potholes Reservoir that operational fill and spill activities may not be readily apparent to the casual observer and may cause ice conditions to deteriorate rapidly."

The Bureau "will begin to operate Potholes Reservoir/O'Sullivan Dam outlet works and Banks Lake/Dry Falls Dam outlet works on March 1, 2023," the Bureau said.

Water will begin flowing into Billy Clapp Reservoir on March 1and Reclamation will begin operating the Billy Clapp Reservoir/Pinto Dam outlet works on March 14, 2023.

Local anglers and boaters know that the big pumps that fill the lake can cause a significant circular current in the area of the lake next to North Dam, especially in the midst of heavy demand for water in the growing season. That's why a closed line of safety buoys sets off the body of the lake from the mouth of the feeder canal. Those pumps bring the water some 280 feet up from Lake Roosevelt's deeper and warmer reservoir.