Swan Lake

Swan Lake is an arch dam located in Ketchikan Gateway Borough, Alaska, built in 1984. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Swan Lake

The primary purpose of Swan 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 South East Alaska Power Agency (public utility). It impounds the Falls Creek, Carroll Inlet near N/a.

The dam stands 174 feet tall and stretches 480 feet across, creates a reservoir covering 1,567 acres, has a maximum storage capacity of 144,763 acre-feet, and collects water from a drainage area of 36 square miles. Completed in 1984, the structure is 42 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 09/30/2020.

At 174 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
CountyKetchikan Gateway Borough
Nearest CityN/a
River/StreamFalls Creek, Carroll Inlet
Coordinates55.61538, -131.34179

Physical Characteristics

Dam TypeArch
NID Height174 ft
Dam Height174 ft
Dam Length480 ft
Year Completed1984 (42 years old)

Storage & Hydraulics

NID Storage144,763 acre-ft
Max Storage144,763 acre-ft
Normal Storage144,763 acre-ft
Surface Area1,567 acres
Drainage Area36 sq mi
Max Discharge27,900 cfs
Spillway TypeControlled

Ownership & Safety

PurposeHydroelectric
OwnerSouth East Alaska Power Agency
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection09/30/2020
Emergency Action PlanYes

Identifiers

NID IDAK83013
Federal IDAK83013
More InfoState Dam Safety Program

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