Information on the US Army Corps of Engineers – USACE Willamette Valley Project – was presented by Wendy Jones, a natural resource manager. Her office does sensitive plant and animal monitoring, as well as cultural resource protection, general land management, and a bit of recreation. She shared information about the Willamette Valley Project and the 13 dams and how the whole system works.
The Willamette Valley Project has 13 multi-purpose dams. The Detroit Lake Dam is the largest. The 13 dams are operated as a single system.
Without the dams, there would be a lot of flooding in the Willamette Valley. Congress passed the Flood Control Act in 1936 so that engineers could study and solve the problem of flooding and they began building the dams in 1940. Dams have prevented $25 billion in flood damages to the Willamette Valley to date (about $900 million annually). The Willamtee Valley Project controls 27% of the runoff areas in the Willamette River Basin at Portland.
Additional purposes for the dams include hydro-power, water quality, irrigation, recreation, fish & wildlife, among others. The Army Corps of Engineers must balance between competing authorized purposes. Water management decisions include collaboration with agency partners.
Hydro-power is generated at 8 of the dams plus one private plant at Dorena. Hydroelectricity is generated from the power of water passing through the dams. These dams can provide enough power to service about 300,000 homes.
Water once stored for navigation is now being used for water quality benefits. Clean cool water from reservoirs also improve conditions for fish. Some water is stored and contracted for irrigation.
The Willamette Valley Project is a nationally recognized stewardship program for critical habitat and ESA-listed species including steelhead, spring Chinook salmon, and many others. Together with other agencies, they work on the best solutions to help these species and ensure their survival.
Over 3.5 million visitors recreate in Oregon waters annually and this brings $100 million in economic benefits annually.
Generally, none of the lakes are drained. There needs to be enough water to operate hydropower. During winter, the lakes are really low. During summer, the focus is conservation of water.
2010 inspections found spillway tainter gates at nine dams needed repairs so repairs are underway and will be complete soon. Earthquakes are a concern and dams may get damaged, but total failure is unlikely. Dams were built to seismic standards of the day. Dams are being re-evaluated for seismic hazard. Downriver residents should be prepared for any dam safety emergency, and coordinate with their county emergency management office.