Lower Blue Lake

Blue Creek· Alpine, California· Built 1885· Earth· 40 ft tall
Low Hazard Hydroelectric Private

Key Takeaway

Lower Blue Lake is classified as low hazard in California. It was completed in 1885 and is 141 years old. Its primary use is hydroelectric.

Physical Details

Dam Height 40 ft (taller than 46.3% in CA)
Dam Length1,063 ft
Dam TypeEarth
Max Storage5.1K acre-ft
Normal Storage5.1K acre-ft
Surface Area198 acres
Drainage Area5 sq mi
Max Discharge1,150 cfs
Year Completed1885 (141 years old)
NID IDCA00380

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: September 7, 2022
State Regulated: Yes
Regulatory Agency: DWR, Safety of Dams

Ownership

Pacific Gas and Electric Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lower Blue Lake?

Lower Blue Lake 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 Lower Blue Lake?

Lower Blue Lake is owned by Pacific Gas and Electric Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lower Blue Lake built?

Lower Blue Lake was completed in 1885, making it 141 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 Lower Blue Lake?

Lower Blue Lake serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Lower Blue Lake?

Lower Blue Lake 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 Lower Blue Lake last inspected?

Lower Blue Lake was last inspected on September 7, 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.