Foster Lake will be filled this recreation season but Green Peter will be used to provide instream flows for the Willamette River, and may only see a brief period of being at maximum pool level.
That was the information provided to about two dozen persons Wednesday evening by the Corps of Engineers at their annual public meeting on summer water curves.
Along with Foster, Detroit and Fern Ridge Reservoirs are expected to be full most of the summer season, according to Wade Stampe, Willamette Valley project manager. There are 13 dams in the Willamette Valley region, 11 of which are multiple use and two are re regulation dams.
The three largest in terms of amount of water stored are Detroit, 18%; Green Peter, 16% and Hills Creek, 12%.
The dams are intended for flood control, hydropower, irrigation and recreation.
Hydrologist Karl Kanbergs, said that through March, the region had experienced 83% of normal precipitation and 50% of snowpack.
“We use 65 years of records to shape our inflow projections,” Kanbergs said. “The dams regulate about 30% of water inflow in the Willamette Basin.”
Foster Lake will remain full until mid April when it will be drafted to 614 feet to allow smolt passage. About May 19 the water level will be brought up to full pool by Memorial Day.
Green Peter will be used to control the water flow based on numbers at the Salem checking site. Green Peter could be as low as 23 feet above its minimum pool by mid-June.
In the past, Green Peter has been lower on the water demand scale in terms of use for river flow augmentation. After the Detroit reservoir area was severely impacted by drought two years ago, Green Peter was moved into the second highest priority from third.
Ozzie Shaw, a member of the Linn County Parks Board, said he is concerned with the fish passage project that has been in place at Foster reservoir for several years.
He said the project costs local businesses and the parks because it cuts short the number of days the lake can be most effectively used for recreation.
“We’d like to get Green Peter back up there,” Shaw said. “We need more parks and recreation. We’re just getting jerked around by this.”
Stampe responded by saying “There are just so many places we can draw water.”
He added that the Oregon Department of Fish and Wildlife, which is conducting the fish passage experiment, is expected to issue a biological opinion.
That opinion may determine how much longer the project will continue.
Fish biologist Greg Taylor said the project has helped increase the wild winter steelhead population in the South Santiam. The returns had dwindled to about 200 in the early 1990s to more than 750 last year.