Blanchester Reservoir No. 4 Dam
Blanchester Reservoir No. 4 Dam is an earth dam located in Clinton County, Ohio, built in 1950. It carries a High hazard potential classification and has a unsatisfactory condition assessment.
About Blanchester Reservoir No. 4 Dam
The primary purpose of Blanchester Reservoir No. 4 Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Village Of Blanchester (local government). It impounds the Offstream near Blanchester.
The dam stands 16 feet tall and stretches 2,900 feet across, creates a reservoir covering 11 acres, has a maximum storage capacity of 164 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1950, 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 unsatisfactory, indicating serious safety deficiencies exist that require immediate attention or remedial action. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 06/25/2024.
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.
Location
| State | Ohio |
| County | Clinton |
| Nearest City | Blanchester |
| River/Stream | Offstream |
| Coordinates | 39.28611, -83.97111 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 16 ft |
| Dam Height | 16 ft |
| Dam Length | 2,900 ft |
| Year Completed | 1950 (76 years old) |
Storage & Hydraulics
| NID Storage | 164 acre-ft |
| Max Storage | 164 acre-ft |
| Normal Storage | 129 acre-ft |
| Surface Area | 11 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Village of Blanchester |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 06/25/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | OH00781 |
| Federal ID | OH00781 |
| More Info | State Dam Safety Program |