Cascade Dam

Cascade Dam is a rockfill dam located in Valley County, Idaho, built in 1948. It carries a High hazard potential classification.

About Cascade Dam

The primary purpose of Cascade Dam 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 Bureau Of Reclamation (federal). It impounds the North Fork Payette River Payette River near Cascade.

The dam stands 110 feet tall and stretches 785 feet across, creates a reservoir covering 27,700 acres, has a maximum storage capacity of 693,200 acre-feet, and collects water from a drainage area of 614 square miles. Completed in 1948, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 10/28/2020.

At 110 feet, this dam is taller than 98% 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 HazardNot Available ConditionEmergency Action Plan: Yes

Location

StateIdaho
CountyValley
Nearest CityCascade
River/StreamNorth Fork Payette River Payette River
Coordinates44.52530, -116.05080

Physical Characteristics

Dam TypeRockfill
NID Height110 ft
Dam Height110 ft
Dam Length785 ft
Year Completed1948 (78 years old)

Storage & Hydraulics

NID Storage693,200 acre-ft
Max Storage693,200 acre-ft
Surface Area27,700 acres
Drainage Area614 sq mi
Max Discharge12,500 cfs
Spillway TypeControlled

Ownership & Safety

PurposeHydroelectric
OwnerBUREAU OF RECLAMATION
Owner TypeFederal
Hazard ClassificationHigh
Condition AssessmentNot Available
Last Inspection10/28/2020
Emergency Action PlanYes

Identifiers

NID IDID00283
Federal IDID00283
More InfoState Dam Safety Program

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