Nimbus

AMERICAN RIVER· Sacramento, California· Built 1955· Concrete· 87 ft tall

Key Takeaway

Nimbus is classified as high hazard in California. It was completed in 1955 and is 71 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 Height 87 ft (taller than 78.3% in CA)
Dam Length1,093 ft
Dam TypeConcrete
Max Storage8.8K acre-ft
Normal Storage8.8K acre-ft
Surface Area540 acres
Drainage Area1,898 sq mi
Max Discharge300,000 cfs
Year Completed1955 (71 years old)
NID IDCA10174

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 17, 2020
State Regulated: No

Ownership

RECLAMATION

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Nimbus?

Nimbus 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 Nimbus?

Nimbus is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Nimbus built?

Nimbus was completed in 1955, making it 71 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 Nimbus?

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

How tall is Nimbus?

Nimbus has a dam height of 87 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 Nimbus last inspected?

Nimbus was last inspected on September 17, 2020. 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.