Boundary

Pend Oreille River· Pend Oreille, Washington· Built 1967· Concrete· 340 ft tall
High Hazard Hydroelectric Recreation Local Government

Physical Details

Dam Height 340 ft (taller than 93.5% in WA)
Dam Length740 ft
Dam TypeConcrete
Max Storage95.0K acre-ft
Normal Storage95.0K acre-ft
Surface Area1,668 acres
Drainage Area25,200 sq mi
Max Discharge360,000 cfs
Year Completed1967 (59 years old)
NID IDWA00009

Safety Information

High Hazard

Loss of human life is likely if the dam fails

Emergency Action Plan: Yes
Last Inspection: May 24, 2022
State Regulated: No

Ownership

City of Seattle

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Boundary?

Boundary is classified as High Hazard. Loss of human life is likely if the dam fails.

Who owns Boundary?

Boundary is owned by City of Seattle (Local Government).

When was Boundary last inspected?

Boundary was last inspected on May 24, 2022.

When was Boundary built?

Boundary was completed in 1967, making it 59 years old.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.