Wells Dam turbine and sign

The sign next to the turbine at the Wells Dam viewpoint area reads,

Running with the Columbia's Water

Each generating unit at Wells Dam is housed in its own silo. When turbines or generators require major repairs or replacement, the rotating assemblies are lifted out of their silos with the gantry cranes on the powerhouse deck. This is a major task: first the 450-ton generator rotor must be removed, and then the turbine components are lifted 120 feet above their normal position. All of the dam's turbine runners were replaced with new models in the late 1980s - a process requiring nearly three years. The turbine runner in front of you was one of the originals installed when the dam was built in the 1960s.

Turbine runners use the river to spin the turbine generator shaft. The pressure difference between the forebay (reservoir upriver) and tailwater (downriver) forces the water to flow over and under the turbine runner's adjustable blades. This differential pressure on the blades, like lift on an airplane's wing, drives the shaft. The generator coverts shaft power to electric power.