Blue Lake

Blue Lake is an arch dam located in City and Borough of Sitka, Alaska, built in 1961. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Blue Lake

The primary purpose of Blue Lake is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by City And Borough Of Sitka (local government). It impounds the Sawmill Creek.

The dam stands 294 feet tall and stretches 288 feet across, creates a reservoir covering 1,646 acres, has a maximum storage capacity of 266,000 acre-feet, and collects water from a drainage area of 37 square miles. Completed in 1961, the structure is well into its service life at over 50 years old.

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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/01/2022.

At 294 feet, this dam is taller than 99% of all dams in the United States.

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 Alaska 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 HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateAlaska
CountyCity and Borough of Sitka
Nearest CityNone
River/StreamSawmill Creek
Coordinates57.06286, -135.19850

Physical Characteristics

Dam TypeArch
NID Height294 ft
Dam Height294 ft
Dam Length288 ft
Year Completed1961 (65 years old)

Storage & Hydraulics

NID Storage266,000 acre-ft
Max Storage266,000 acre-ft
Normal Storage266,000 acre-ft
Surface Area1,646 acres
Drainage Area37 sq mi
Max Discharge14,000 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeHydroelectric
OwnerCity and Borough of Sitka
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection08/01/2022
Emergency Action PlanYes

Identifiers

NID IDAK00002
Federal IDAK00002
More InfoState Dam Safety Program

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