Bitter Lake Reservoir

Tr-Puget Sound-Offstream· King, Washington· Built 1958· Earth·
High Hazard Water Supply Local Government

Key Takeaway

Bitter Lake Reservoir is classified as high hazard in Washington. It was completed in 1958 and is 68 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 Length1,100 ft
Dam TypeEarth
Max Storage71 acre-ft
Normal Storage65 acre-ft
Surface Area3 acres
Drainage Area0 sq mi
Max Discharge4 cfs
Year Completed1958 (68 years old)
NID IDWA00213

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 Bitter Lake Reservoir?

Bitter Lake 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 Bitter Lake Reservoir?

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

When was Bitter Lake Reservoir built?

Bitter Lake Reservoir was completed in 1958, making it 68 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 Bitter Lake Reservoir?

Bitter Lake 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 Bitter Lake Reservoir last inspected?

Bitter Lake 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.