Lake Combie

Lake Combie is a concrete dam located in Nevada County, California, built in 1928. It carries a High hazard potential classification and has a fair condition assessment.

About Lake Combie

The primary purpose of Lake Combie is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Nevada Irrigation District (public utility). It impounds the Bear River near Magnolia.

The dam stands 100 feet tall and stretches 762 feet across, creates a reservoir covering 360 acres, has a storage capacity of 5,555 acre-feet, and collects water from a drainage area of 135 square miles. Completed in 1928, 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. 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 08/21/2023.

At 100 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 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
CountyNevada
Nearest CityMagnolia
River/StreamBear River
Coordinates39.00980, -121.05810

Physical Characteristics

Dam TypeConcrete
NID Height100 ft
Dam Height95 ft
Dam Length762 ft
Year Completed1928 (98 years old)

Storage & Hydraulics

NID Storage5,555 acre-ft
Normal Storage5,555 acre-ft
Surface Area360 acres
Drainage Area135 sq mi
Max Discharge28,700 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeIrrigation
OwnerNevada Irrigation District
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection08/21/2023
Emergency Action PlanYes

Identifiers

NID IDCA00249
Federal IDCA00249
More InfoState Dam Safety Program

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