Decker Lake Dam is an earth dam located in Miami County, Ohio, built in 1940. It carries a Significant hazard potential classification and has a poor condition assessment.
Dam profile
NID height · 16 ft16 ft tall and 305 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Decker Lake Dam
The primary purpose of Decker 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 Wildlife (state). It impounds the Patterson Run near Piqua.
The dam stands 16 feet tall and stretches 305 feet across, creates a reservoir covering 17 acres, has a maximum storage capacity of 163 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1940, 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 10/30/2024.
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Location
| State | Ohio |
| County | Miami |
| Nearest City | Piqua |
| River/Stream | Patterson Run |
| Coordinates | 40.18806, -84.28333 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 16 ft |
| Dam Height | 16 ft |
| Dam Length | 305 ft |
| Year Completed | 1940 (86 years old) |
Storage & Hydraulics
| NID Storage | 163 acre-ft |
| Max Storage | 163 acre-ft |
| Normal Storage | 68 acre-ft |
| Surface Area | 17 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 1,132 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Odnr, Division of Wildlife |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 10/30/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OH00516 |
| Federal ID | OH00516 |
| More Info | State Dam Safety Program |