Lake Sylvan Dam
Lake Sylvan Dam is an earth dam located in Clark County, Ohio, built in 1947. It carries a Significant hazard potential classification and has a poor condition assessment.
About Lake Sylvan Dam
The primary purpose of Lake Sylvan Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Andrew T. Warnock (private). It impounds the Tributary To Beaver Creek near Harmony.
The dam stands 21 feet tall and stretches 580 feet across, creates a reservoir covering 42 acres, has a maximum storage capacity of 423 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1947, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 10/29/2024.
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Location
| State | Ohio |
| County | Clark |
| Nearest City | Harmony |
| River/Stream | Tributary To Beaver Creek |
| Coordinates | 39.93528, -83.59306 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 21 ft |
| Dam Height | 21 ft |
| Dam Length | 580 ft |
| Year Completed | 1947 (79 years old) |
Storage & Hydraulics
| NID Storage | 423 acre-ft |
| Max Storage | 423 acre-ft |
| Normal Storage | 238 acre-ft |
| Surface Area | 42 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 1,152 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Andrew T. Warnock |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 10/29/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OH00041 |
| Federal ID | OH00041 |
| More Info | State Dam Safety Program |