Cowan Lake Dam

Cowan Lake Dam is an earth dam located in Clinton County, Ohio, built in 1947. It carries a High hazard potential classification and has a poor condition assessment.

About Cowan Lake Dam

The primary purpose of Cowan Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Odnr, Division Of Parks & Watercraft (state). It impounds the Cowan Creek near Clarksville.

The dam stands 63 feet tall and stretches 860 feet across, creates a reservoir covering 670 acres, has a maximum storage capacity of 24,974 acre-feet, and collects water from a drainage area of 49 square miles. Completed in 1947, 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 06/11/2024.

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 Ohio 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 HazardPoor ConditionEmergency Action Plan: Yes

Location

StateOhio
CountyClinton
Nearest CityClarksville
River/StreamCowan Creek
Coordinates39.38806, -83.92444

Physical Characteristics

Dam TypeEarth
NID Height63 ft
Dam Height63 ft
Dam Length860 ft
Year Completed1947 (79 years old)

Storage & Hydraulics

NID Storage24,974 acre-ft
Max Storage24,974 acre-ft
Normal Storage10,273 acre-ft
Surface Area670 acres
Drainage Area49 sq mi
Max Discharge35,900 cfs

Ownership & Safety

PurposeRecreation
OwnerODNR, Division of Parks & Watercraft
Owner TypeState
Hazard ClassificationHigh
Condition AssessmentPoor
Last Inspection06/11/2024
Emergency Action PlanYes

Identifiers

NID IDOH00500
Federal IDOH00500
More InfoState Dam Safety Program

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