Swan Falls

Swan Falls is a concrete dam located in Ada County, Idaho, built in 1901. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Swan Falls

The primary purpose of Swan Falls 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 Idaho Power Company (private). It impounds the Snake River.

The dam stands 88 feet tall and stretches 1,150 feet across, creates a reservoir covering 1,525 acres, has a storage capacity of 7,425 acre-feet, and collects water from a drainage area of 41,900 square miles. Completed in 1901, the structure is over a century 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 04/05/2023.

At 88 feet, this dam is taller than 97% 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 Idaho 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

StateIdaho
CountyAda
Nearest CityNone
River/StreamSnake River
Coordinates43.24329, -116.37940

Physical Characteristics

Dam TypeConcrete
NID Height88 ft
Dam Height88 ft
Dam Length1,150 ft
Year Completed1901 (125 years old)

Storage & Hydraulics

NID Storage7,425 acre-ft
Normal Storage7,425 acre-ft
Surface Area1,525 acres
Drainage Area41,900 sq mi
Max Discharge105,112 cfs
Spillway TypeControlled

Ownership & Safety

PurposeHydroelectric
OwnerIdaho Power Company
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection04/05/2023
Emergency Action PlanYes

Identifiers

NID IDID00049
Federal IDID00049
More InfoState Dam Safety Program

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