Matanzas Creek

Matanzas Creek· Sonoma, California· Built 1963· Earth· 95 ft tall
High Hazard Flood Risk Reduction Local Government

Key Takeaway

Matanzas Creek is classified as high hazard in California. It was completed in 1963 and is 63 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 Height 95 ft (taller than 80.6% in CA)
Dam Length685 ft
Dam TypeEarth
Max Storage1.5K acre-ft
Surface Area62 acres
Drainage Area11 sq mi
Year Completed1963 (63 years old)
NID IDCA00794

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 23, 2021
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Sonoma County Water Agency

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Matanzas Creek?

Matanzas Creek 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 Matanzas Creek?

Matanzas Creek is owned by Sonoma County Water Agency (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Matanzas Creek built?

Matanzas Creek was completed in 1963, making it 63 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 Matanzas Creek?

Matanzas Creek 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.

How tall is Matanzas Creek?

Matanzas Creek has a dam height of 95 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Matanzas Creek last inspected?

Matanzas Creek was last inspected on September 23, 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.