Ayer Reservoir Dam

Tr-East Sound· San Juan, Washington· Built 1964· Earth·
Low Hazard Recreation Private

Key Takeaway

Ayer Reservoir Dam is classified as low hazard in Washington. It was completed in 1964 and is 62 years old. Its primary use is recreation.

Physical Details

Dam TypeEarth
Max Storage135 acre-ft
Normal Storage125 acre-ft
Surface Area10 acres
Drainage Area1 sq mi
Max Discharge21 cfs
Year Completed1964 (62 years old)
NID IDWA00165

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: February 7, 2020
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

Orcas Sound LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Ayer Reservoir Dam?

Ayer Reservoir Dam 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 Ayer Reservoir Dam?

Ayer Reservoir Dam is owned by Orcas Sound LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Ayer Reservoir Dam built?

Ayer Reservoir Dam was completed in 1964, making it 62 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 Ayer Reservoir Dam?

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

When was Ayer Reservoir Dam last inspected?

Ayer Reservoir Dam was last inspected on February 7, 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.