Upper Unionville Reservoir Dam
Upper Unionville Reservoir Dam is an earth dam located in Hartford County, Connecticut, built in 1909. It carries a Significant hazard potential classification and has a fair condition assessment.
About Upper Unionville Reservoir Dam
The primary purpose of Upper Unionville Reservoir Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Town Of Avon (local government). It impounds the Hawley Brook near Unionville.
The dam stands 23 feet tall and stretches 220 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 18 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1909, 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 12/03/2024.
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Location
| State | Connecticut |
| County | Hartford |
| Nearest City | Unionville |
| River/Stream | Hawley Brook |
| Coordinates | 41.78607, -72.90919 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 220 ft |
| Year Completed | 1909 (117 years old) |
Storage & Hydraulics
| NID Storage | 18 acre-ft |
| Max Storage | 18 acre-ft |
| Normal Storage | 17 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 100 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Avon |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 12/03/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00267 |
| Federal ID | CT00267 |
| More Info | State Dam Safety Program |