Lake Cohasset Dam is a masonry dam located in Mahoning County, Ohio, built in 1897. It carries a Significant hazard potential classification and has a poor condition assessment.
Dam profile
NID height · 25 ft25 ft tall and 190 ft long, taller than 50% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Lake Cohasset Dam
The primary purpose of Lake Cohasset Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Mill Creek Metropolitan Park Dist. (local government). It impounds the Mill Creek near Youngstown.
The dam stands 25 feet tall and stretches 190 feet across, creates a reservoir covering 28 acres, has a maximum storage capacity of 373 acre-feet, and collects water from a drainage area of 74 square miles. Completed in 1897, the structure is over a century old.
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 10/13/2021.
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Location
| State | Ohio |
| County | Mahoning |
| Nearest City | Youngstown |
| River/Stream | Mill Creek |
| Coordinates | 41.08194, -80.68083 |
Physical Characteristics
| Dam Type | Masonry |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 190 ft |
| Year Completed | 1897 (129 years old) |
Storage & Hydraulics
| NID Storage | 373 acre-ft |
| Max Storage | 373 acre-ft |
| Normal Storage | 175 acre-ft |
| Surface Area | 28 acres |
| Drainage Area | 74 sq mi |
| Max Discharge | 6,987 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Mill Creek Metropolitan Park Dist. |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 10/13/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OH00417 |
| Federal ID | OH00417 |
| More Info | State Dam Safety Program |