US Army Corps of Engineers ®

Green Peter and Foster Dams and Reservoirs

Foster Reservoir Status

Green Peter Dam on the Middle Santiam River and Foster Dam on the South Santiam, just downstream from the mouth of the Middle Santiam, are two of the 13 Corps of Engineers multi-purpose dams in the Willamette Valley. Foster Dam regulates the flow from Green Peter dam. Both dams provide flood control, irrigation, hydropower generation, navigation, improved downstream water quality, and water-based recreation.  To learn about recreation at Foster and Green Peter Lakes, click here.

Construction of Green Peter and Foster Dams began in 1961 and was completed in 1968 at a cost of $82.3 million.  Green Peter dam is a concrete structure with a gated spillway, and Foster dam is a rockfill structure with a gated spillway. The powerhouse at each dam contains two generators.

To mitigate impacts to salmon and steelhead caused by the dams, the Corps of Engineers built the South Santiam Fish Hatchery and a fish collection facility at the base of Foster Dam.  Returning salmon and steelhead enter a fish ladder adjacent to the powerhouse and move upstream to a fish trap.  Fish collected at the facility are transported back to the hatchery or released above Foster Dam to access upstream spawning habitat. The fish facilities are operated by the Oregon Department of Fish and Wildlife, with funds provided by the Corps and the state of Oregon.

PROJECT DATA

*National Geodetic Vertical Datum (Mean Sea Level)