Preston

Tr Mule Creek· Amador, California· Built 1949· Earth· 40 ft tall
High Hazard Water Supply Other Irrigation Public Utility

Key Takeaway

Preston is classified as high hazard in California. It was completed in 1949 and is 77 years old. Its primary use is water supply. 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 40 ft (taller than 46.3% in CA)
Dam Length647 ft
Dam TypeEarth
Max Storage268 acre-ft
Surface Area17 acres
Drainage Area0 sq mi
Year Completed1949 (77 years old)
NID IDCA00012

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 14, 2021
State Regulated: Yes
Regulatory Agency: DWR, Division of Safety of Dams

Ownership

Amador Regional Sanitation Authority

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Preston?

Preston 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 Preston?

Preston is owned by Amador Regional Sanitation Authority (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Preston built?

Preston was completed in 1949, making it 77 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 Preston?

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

How tall is Preston?

Preston has a dam height of 40 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 Preston last inspected?

Preston was last inspected on September 14, 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.