204th Street Stormwater Detention Basin

Patterson Creek - Of· King, Washington· Built 2001· Earth·
Significant Hazard Flood Risk Reduction Private

Key Takeaway

204th Street Stormwater Detention Basin is classified as significant hazard in Washington. It was completed in 2001 and is 25 years old. Its primary use is flood risk reduction. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Length1,100 ft
Dam TypeEarth
Max Storage17 acre-ft
Normal Storage12 acre-ft
Surface Area3 acres
Drainage Area1 sq mi
Max Discharge450 cfs
Year Completed2001 (25 years old)
Year Modified2000
NID IDWA01819

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: December 14, 2023
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

SeaTac Public Works

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of 204th Street Stormwater Detention Basin?

204th Street Stormwater Detention Basin is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates 204th Street Stormwater Detention Basin?

204th Street Stormwater Detention Basin is owned by SeaTac Public Works (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was 204th Street Stormwater Detention Basin built?

204th Street Stormwater Detention Basin was completed in 2001, making it 25 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 204th Street Stormwater Detention Basin?

204th Street Stormwater Detention Basin serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was 204th Street Stormwater Detention Basin last inspected?

204th Street Stormwater Detention Basin was last inspected on December 14, 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.