Sonoma Hills

Tr Tolay Creek· Sonoma, California· Built 1991· Earth· 38 ft tall
Low Hazard Water Supply Irrigation Recreation Private

Key Takeaway

Sonoma Hills is classified as low hazard in California. It was completed in 1991 and is 35 years old. Its primary use is water supply.

Physical Details

Dam Height 38 ft (taller than 43.2% in CA)
Dam Length323 ft
Dam TypeEarth
Max Storage240 acre-ft
Surface Area29 acres
Drainage Area1 sq mi
Year Completed1991 (35 years old)
NID IDCA01321

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: August 11, 2022
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Private Entity

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Sonoma Hills?

Sonoma Hills is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Sonoma Hills?

Sonoma Hills is owned by Private Entity (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Sonoma Hills built?

Sonoma Hills was completed in 1991, making it 35 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 Sonoma Hills?

Sonoma Hills serves the following purposes: Water Supply, Irrigation, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Sonoma Hills?

Sonoma Hills has a dam height of 38 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 Sonoma Hills last inspected?

Sonoma Hills was last inspected on August 11, 2022. 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.