Upper Letts

LETTS CREEK· Colusa, California· Built 1958· Earth· 21 ft tall
High Hazard Recreation Federal Government

Key Takeaway

Upper Letts is classified as high hazard in California. It was completed in 1958 and is 68 years old. Its primary use is recreation. 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 21 ft (taller than 17.3% in CA)
Dam Length212 ft
Dam TypeEarth
Max Storage319 acre-ft
Normal Storage319 acre-ft
Drainage Area0 sq mi
Year Completed1958 (68 years old)
NID IDCA10302

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: No
Last Inspection: June 23, 2014
State Regulated: No

Ownership

USDA FS

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper Letts?

Upper Letts 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 Upper Letts?

Upper Letts is owned by USDA FS (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Upper Letts built?

Upper Letts was completed in 1958, making it 68 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 Upper Letts?

Upper Letts serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Upper Letts?

Upper Letts has a dam height of 21 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 Upper Letts last inspected?

Upper Letts was last inspected on June 23, 2014. 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.