Roosevelt Reservoir

Tr-Puget Sound-Offstream· King, Washington· Built 1910· Earth·
High Hazard Water Supply Local Government

Key Takeaway

Roosevelt Reservoir is classified as high hazard in Washington. It was completed in 1910 and is 116 years old. Its primary use is water supply. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Length1,920 ft
Dam TypeEarth
Max Storage181 acre-ft
Normal Storage153 acre-ft
Surface Area8 acres
Drainage Area0 sq mi
Max Discharge45 cfs
Year Completed1910 (116 years old)
NID IDWA00212

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: September 5, 2023
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

Seattle Public Utilities

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Roosevelt Reservoir?

Roosevelt Reservoir is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Roosevelt Reservoir?

Roosevelt Reservoir is owned by Seattle Public Utilities (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Roosevelt Reservoir built?

Roosevelt Reservoir was completed in 1910, making it 116 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Roosevelt Reservoir?

Roosevelt Reservoir serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Roosevelt Reservoir last inspected?

Roosevelt Reservoir was last inspected on September 5, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.

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.