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.
Dam profile
NID height · 174 ft174 ft tall and 480 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against the Statue of Liberty, 305 ft ground to torch; the profile is a generic arch section and the water level is illustrative.
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.
Location
| State | Alaska |
| County | Ketchikan Gateway Borough |
| Nearest City | N/a |
| River/Stream | Falls Creek, Carroll Inlet |
| Coordinates | 55.61538, -131.34179 |
Physical Characteristics
| Dam Type | Arch |
| NID Height | 174 ft |
| Dam Height | 174 ft |
| Dam Length | 480 ft |
| Year Completed | 1984 (42 years old) |
Storage & Hydraulics
| NID Storage | 144,763 acre-ft |
| Max Storage | 144,763 acre-ft |
| Normal Storage | 144,763 acre-ft |
| Surface Area | 1,567 acres |
| Drainage Area | 36 sq mi |
| Max Discharge | 27,900 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | South East Alaska Power Agency |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/30/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | AK83013 |
| Federal ID | AK83013 |
| More Info | State Dam Safety Program |