Hillside

Hillside is a rockfill dam located in Inyo County, California, built in 1910. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Hillside

The primary purpose of Hillside 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 Southern California Edison Company (private). It impounds the South Fork Bishop Creek near Bishop.

The dam stands 82 feet tall and stretches 645 feet across, creates a reservoir covering 173 acres, has a maximum storage capacity of 12,883 acre-feet, and collects water from a drainage area of 13 square miles. Completed in 1910, 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 08/19/2025.

At 82 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 California 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

StateCalifornia
CountyInyo
Nearest CityBishop
River/StreamSouth Fork Bishop Creek
Coordinates37.17300, -118.56650

Physical Characteristics

Dam TypeRockfill
NID Height82 ft
Dam Height82 ft
Dam Length645 ft
Year Completed1910 (116 years old)

Storage & Hydraulics

NID Storage12,883 acre-ft
Max Storage12,883 acre-ft
Normal Storage12,883 acre-ft
Surface Area173 acres
Drainage Area13 sq mi
Max Discharge1,700 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeHydroelectric
OwnerSouthern California Edison Company
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection08/19/2025
Emergency Action PlanYes

Identifiers

NID IDCA00446
Federal IDCA00446
More InfoState Dam Safety Program

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