News Release
| Release Number: | 02-095 |
| Dated: | 5/24/2002 |
| Contact: | Matt Rabe, 503-808-4510 |
Portland, Ore.-Cool, relatively dry, weather combined with special operations at U.S. Army Corps of Engineers reservoirs has added complexity to the delicate balancing act of maintaining critical flows in the Willamette River.
Maintaining flows, filling reservoirs, and supporting the needs of fish and anglers in the Willamette Basin are all part of the equation.
“We really have very little flexibility right now as to which reservoirs we can draw from to meet downstream needs,” said Willamette Basin Coordinator Matt Rea.
Weekly, and sometimes daily, discussions have taken place between the Corps, the state of Oregon and other federal agencies to determine the best course of action for this years’ water needs.
Now through May 31 the Corps will maintain Willamette River flows above a minimum of 15,000 cubic feet per second (cfs), as measured at Salem. Minimum flows will be reduced to 13,000 cfs beginning June 1, with a further reduction to 8,700 cfs around June 16.
The Corps maintains these minimum flows to support the migration of steelhead and salmon in the Willamette Basin. To maintain this critical flow, the Corps combines additional releases of water held in 13 reservoirs in the Willamette Basin with natural flows in the river.
Because of construction of a new water control tower at Cougar Dam on the South Fork McKenzie River, the Corps is unable to store any water in that reservoir this year.
The Corps used water stored at Lookout Point Reservoir on the Middle Fork Willamette River earlier this month to help meet the downstream flow need. At present the Corps is trying to hold Lookout Point at a stable elevation to protect habitat for Oregon chub, a fish species listed as endangered under the Federal Endangered Species Act.
After a severe drought last year, the Corps has placed a very high priority on keeping Detroit, Foster, and Fern Ridge lakes, the most popular recreation lakes in the basin, as full as possible during the summer. They are currently full.
Because of these constraints, the Corps is left with only two large reservoirs in the basin from which to release water to meet downstream requirements, Hills Creek and Green Peter.
Last week, the Corps was releasing water from Hills Creek at a rate up to a maximum of 3,000 cfs with an average rate of about 2,200 cfs. At that rate of flow, access to the Middle Fork Willamette River for fishing was difficult and the lake elevation quickly dropped about five feet. Presently, outflows from Hills Creek are about 1,800 cfs. Fishing access and use of the river should be improved. The Corps expects outflows from the dam to remain at about that level for the next week or so. Current inflow forecasts for Hills Creek are between 1,100 cfs and 1,700 cfs with an average of 1,300 cfs.
Depending on weather conditions the level of Hills creek may be between elevation 1,530 feet to 1,532 feet by June 1. This level would allow use of boat ramps at Bingham Landing, CT Beach Park and Packard Creek. Hills Creek maximum conservation full elevation is 1,541 feet.
Last week, the Corps used water stored in Green Peter Reservoir to help refill Foster Reservoir, located immediately downstream. Foster Lake is now full and will be kept full through the summer. Debris has been cleared from the reservoir in time for the holiday weekend.
At the present time, Green Peter outflow is about 2,400 cfs. This flow is passed through Foster Dam and released into the South Santiam River downstream. Foster is currently releasing about 1,700 cfs and may release up to 2,200 cfs over the Memorial Day weekend depending on the amount of natural inflow to Foster. The Corps is maintaining the elevation at Foster between 636 feet and 637 feet for recreation.
Depending on weather conditions the level of Green Peter may be between elevations 998 feet to 1,010 feet by June 1. This level would allow use of boat ramps at Whitcomb Creek and Thistle Creek. The maximum conservation full elevation at Green Peter Reservoir is 1,010 feet.
The Corps does not expect Hills Creek or Green Peter lakes to refill this summer, but depending on rainfall and snow pack runoff they may.
The other smaller reservoirs in the Willamette Basin, including Fall Creek, Cottage Grove, and Dorena are at or near full and are expected to remain that way through much of the summer.
“We didn’t expect to have to pull water so hard this early from Green Peter and Hills Creek,” said Rea. “It is a balancing act, and using the best management techniques, this is the best alternative we have to meeting the needs of everyone.”
The Corps will evaluate the water situation weekly and will adjust water releases as weather conditions change. This evaluation process will include coordination with the Oregon Water Resources Department, U.S. Fish and Wildlife Service, National Marine Fisheries Service and National Oceanic and Atmospheric Administration.