Enloe Dam

Restoring vital Tribal fishery

About the Project

Enloe Dam, built between 1919 and 1923, is a 54-foot-high concrete wall spanning the Similkameen River, four miles from Oroville, Washington. The dam was built to provide power to a downstream powerplant, but hydropower operations ceased in 1958.

For more than 60 years, the dam’s two-mile-long reservoir has been filling with silt, its depth reduced to nine feet. The dam also blocks 348 miles of high-quality, cold-water fish habitat in the Similkameen Basin, which impedes fishing access as guaranteed by treaty rights for the Confederated Tribes of the Colville Reservation and Upper and Lower Similkameen Band of Indians. Though they have reintroduced salmon in other parts of the river system, removing Enloe Dam unlocks massive potential for ESA-threatened salmon, steelhead, and lamprey, supporting up to 98,000 spawning steelhead and 55,000 Chinook salmon according to river surveys. Dam removal also offers a valuable cold-water refugia under extreme climate change conditions.

The Confederated Tribes of the Colville Reservation are pursuing a removal strategy for the defunct dam. Their hope is to reintroduce fish populations that once sustained their people. The Tribe and USGS are collaborating on sediment assessments, which will inform a conceptual design and removal cost estimate in 2021.

FACTS AT A GLANCE
Owner: Okanogan Public Utilities District
Size: 290 feet long, 54 feet high
Project Cost: $3-51 million, depending on sediment quantity
ORF Investment: Project management and feasibility studies
Miles Opened: 348 miles
Fish: Spring and summer/fall Chinook; sockeye, steelhead
Status: Early planning and assessment


RESOURCES
OUTCOMES
  • Open 348 miles of habitat for ESA-threatened upper Columbia steelhead, spring and summer/fall upper Columbia Chinook, and Okanogan River sockeye
  • Reestablish sediment transport to nourish downstream spawning beds
  • Support Tribal treaty rights for Confederated Tribes of the Colville Reservation and Upper and Lower Similkameen Band of Indians
  • Invigorate a recreation-based economy for fishing, cycling, and whitewater and flatwater boating in an economically depressed region
  • Resolve public health and safety issues arising from an aging dam retaining contaminated sediments

Project Partners

Okanogan Public Utilities District

Confederated Tribes of the Colville Reservation

Lower Similkameen Band of Indians

Upper Similkameen Band of Indians

Trout Unlimited

Methow Valley Citizens Council

American Rivers

American Whitewater

Columbiana

National Oceanic and Atmospheric Administration