Upper Millpond Dam
Upper Millpond Dam is an earth dam located in New London County, Connecticut, built in 1820. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Upper Millpond Dam
The primary purpose of Upper Millpond Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Richard O'connor Trustee (private). It impounds the Mill Brook near Old Lyme.
The dam stands 11 feet tall and stretches 120 feet across, creates a reservoir covering 11 acres, has a maximum storage capacity of 50 acre-feet, and collects water from a drainage area of 8 square miles. Completed in 1820, the structure is one of the older dams in the region, with over a century and a half 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 10/27/2021.
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Location
| State | Connecticut |
| County | New London |
| Nearest City | Old Lyme |
| River/Stream | Mill Brook |
| Coordinates | 41.34327, -72.31068 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 11 ft |
| Dam Height | 11 ft |
| Dam Length | 120 ft |
| Year Completed | 1820 (206 years old) |
Storage & Hydraulics
| NID Storage | 50 acre-ft |
| Max Storage | 50 acre-ft |
| Normal Storage | 50 acre-ft |
| Surface Area | 11 acres |
| Drainage Area | 8 sq mi |
| Max Discharge | 413 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Richard O'Connor Trustee |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/27/2021 |
| Emergency Action Plan | No |
Identifiers
| NID ID | CT00417 |
| Federal ID | CT00417 |
| More Info | State Dam Safety Program |