O'shaughnessy
O'shaughnessy is a gravity dam located in Delaware County, Ohio, built in 1924. It carries a High hazard potential classification and has a satisfactory condition assessment.
About O'shaughnessy
The primary purpose of O'shaughnessy 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 Columbus, City Of (local government). It impounds the Scioto River near Dublin.
The dam stands 79 feet tall and stretches 1,510 feet across, creates a reservoir covering 950 acres, has a maximum storage capacity of 33,000 acre-feet, and collects water from a drainage area of 980 square miles. Completed in 1924, the structure is over a century old.
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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 09/27/2022.
At 79 feet, this dam is taller than 97% 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.
Location
| State | Ohio |
| County | Delaware |
| Nearest City | Dublin |
| River/Stream | Scioto River |
| Coordinates | 40.15400, -83.12600 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 79 ft |
| Dam Height | 75 ft |
| Dam Length | 1,510 ft |
| Year Completed | 1924 (102 years old) |
Storage & Hydraulics
| NID Storage | 33,000 acre-ft |
| Max Storage | 33,000 acre-ft |
| Normal Storage | 14,800 acre-ft |
| Surface Area | 950 acres |
| Drainage Area | 980 sq mi |
| Max Discharge | 261,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Columbus, City of |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/27/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OH00751 |
| Federal ID | OH00751 |
| More Info | State Dam Safety Program |