Trout Lake Storage Dam

Trout Lake Storage Dam is a concrete dam located in San Juan County, Washington, built in 1929. It carries a High hazard potential classification and has a fair condition assessment.

About Trout Lake Storage Dam

The primary purpose of Trout Lake Storage Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Friday Harbor Town (local government). It impounds the Tr-false Bay.

The dam stands 37 feet tall and stretches 141 feet across, creates a reservoir covering 63 acres, has a maximum storage capacity of 1,540 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1929, the structure is well-established, with more than 75 years of service.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 06/07/2023.

At 37 feet, this dam is taller than 84% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateWashington
CountySan Juan
River/StreamTr-false Bay
Coordinates48.52643, -123.12259

Physical Characteristics

Dam TypeConcrete
NID Height37 ft
Dam Length141 ft
Year Completed1929 (97 years old)

Storage & Hydraulics

NID Storage1,540 acre-ft
Max Storage1,540 acre-ft
Normal Storage1,440 acre-ft
Surface Area63 acres
Drainage Area1 sq mi
Max Discharge960 cfs

Ownership & Safety

PurposeRecreation
OwnerFriday Harbor Town
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection06/07/2023
Emergency Action PlanYes

Identifiers

NID IDWA00202
Federal IDWA00202
More InfoState Dam Safety Program

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