Cape Horn

Cape Horn is an earth dam located in Mendocino County, California, built in 1907. It carries a High hazard potential classification and has a fair condition assessment.

About Cape Horn

The primary purpose of Cape Horn 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 Pacific Gas And Electric Company (private). It impounds the Eel River.

The dam stands 63 feet tall and stretches 520 feet across, creates a reservoir covering 65 acres, has a maximum storage capacity of 390 acre-feet, and collects water from a drainage area of 349 square miles. Completed in 1907, 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 06/28/2023.

At 63 feet, this dam is taller than 96% 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 HazardFair ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountyMendocino
Nearest CityNone
River/StreamEel River
Coordinates39.38605, -123.11626

Physical Characteristics

Dam TypeEarth
NID Height63 ft
Dam Height60 ft
Dam Length520 ft
Year Completed1907 (119 years old)

Storage & Hydraulics

NID Storage390 acre-ft
Max Storage390 acre-ft
Normal Storage102 acre-ft
Surface Area65 acres
Drainage Area349 sq mi
Max Discharge115,000 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeHydroelectric
OwnerPacific Gas and Electric Company
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection06/28/2023
Emergency Action PlanYes

Identifiers

NID IDCA00399
Federal IDCA00399
More InfoState Dam Safety Program

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