Mill Creek Dam Cosmopolis

Mill Creek· Grays Harbor, Washington· Built 2019· Gravity·
High Hazard Fish And Wildlife Pond Recreation Local Government

Key Takeaway

Mill Creek Dam Cosmopolis is classified as high hazard in Washington. It was completed in 2019 and is 7 years old. Its primary use is fish and wildlife pond. 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 Length200 ft
Dam TypeGravity
Max Storage20 acre-ft
Normal Storage10 acre-ft
Surface Area10 acres
Drainage Area2 sq mi
Max Discharge0 cfs
Year Completed2019 (7 years old)
NID IDWA01730

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: December 21, 2023
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

Cosmopolis City Public Works

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mill Creek Dam Cosmopolis?

Mill Creek Dam Cosmopolis 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 Mill Creek Dam Cosmopolis?

Mill Creek Dam Cosmopolis is owned by Cosmopolis City Public Works (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mill Creek Dam Cosmopolis built?

Mill Creek Dam Cosmopolis was completed in 2019, making it 7 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 Mill Creek Dam Cosmopolis?

Mill Creek Dam Cosmopolis serves the following purposes: Fish And Wildlife Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Mill Creek Dam Cosmopolis last inspected?

Mill Creek Dam Cosmopolis was last inspected on December 21, 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.