Mud Mountain Dam

WHITE RIVER· King, Washington· Built 1948· Rockfill·
High Hazard Flood Risk Reduction Recreation Federal Government

Key Takeaway

Mud Mountain Dam is classified as high hazard in Washington. It was completed in 1948 and is 78 years old. Its primary use is flood risk reduction. 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 Length700 ft
Dam TypeRockfill
Max Storage106.0K acre-ft
Normal Storage0 acre-ft
Surface Area1 acres
Drainage Area400 sq mi
Max Discharge156,000 cfs
Year Completed1948 (78 years old)
NID IDWA00300

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: May 15, 2021
State Regulated: No

Ownership

USACE - Seattle District

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mud Mountain Dam?

Mud Mountain Dam 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 Mud Mountain Dam?

Mud Mountain Dam is owned by USACE - Seattle District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mud Mountain Dam built?

Mud Mountain Dam was completed in 1948, making it 78 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 Mud Mountain Dam?

Mud Mountain Dam serves the following purposes: Flood Risk Reduction, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Mud Mountain Dam last inspected?

Mud Mountain Dam was last inspected on May 15, 2021. 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.