Pend Oreille River 1920s, there was a proposal to divert the Pend Oreille through a gravity canal to irrigate the Grand Coulee and surrounding lands in eastern Washington as part of the tentative Columbia Basin Project. These plans were later dropped with the construction of Grand Coulee Dam and a pumping plant on the Columbia River. Variant names, according to the USGS, include: Bitter Root River, Bitterroot River, Clark Fork, Clarke Fork, Clarkes Fork, Clarks Fork, Deer Lodge River, Hell Gate River, Missoula River, Pend d'Oreille River, Silver Bow River, Clark's Fork, and Pend-d'Oreille River. Pend Oreille River The Pend Oreille River (
Grand Coulee Dam of electricity. Each generator is supplied with water by an individual penstock. The largest of these feed the Third Powerplant and are in diameter and can supply up to . The dam's power facilities originally had an installed capacity of 1,974 MW but expansions and upgrades have increased generation to 6,809 MW installed, 7,079 MW maximum. Grand Coulee Dam generates 21 TWh of electricity annually. This means the dam generates about 2,397 MW of power on average, which results in a total plant factor efficiency of 35%. In 2014, 20.24 TWh of electricity was generated. Grand Coulee Dam's spillway is