As upper reach waterways approach flood stages, the Grand Coulee Dam is doing all it can to maintain the flooding due to recent weather in the region. Here we are seeing above average rainfall/snow pack for the region and how Grand Coulee Dam can help mitigate damage caused traditionally through flooding. Grand Coulee is sending 76,000 CFS over the spillway alone and allowing 300,000 CFS to pass through the dam today. This would be 10% of the bypass maximum. If the dam were to reach half its potential Portland dykes could not withstand the flooding; neither could the lower dams along the Columbia. The good thing is that Grand Coulee makes provisions before the spring runoff starts by lowering the reservoir. People always seem to think we are in a drought when they see the Bureau of Reclamation drop the reservoir as low as it was this past April (el. 1222 from a full pool el. of 1290). We are not like Lake Mead, we are water rich as of late. The Bureau lowers the reservoir in anticipation of high runoff and thus mitigates flooding potential down the lower Columbia.
