Carding Mill Pond Dam is an earth dam located in Middlesex County, Massachusetts, built in 1930. It carries a Significant hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 17 ft17 ft tall and 575 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 Carding Mill Pond Dam
The primary purpose of Carding Mill Pond 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 Sudbury (local government). It impounds the Hop Brook near Sudbury.
The dam stands 17 feet tall and stretches 575 feet across, creates a reservoir covering 42 acres, has a maximum storage capacity of 275 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1930, 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 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 03/10/2023.
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Location
| State | Massachusetts |
| County | Middlesex |
| Nearest City | Sudbury |
| River/Stream | Hop Brook |
| Coordinates | 42.36463, -71.46592 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 17 ft |
| Dam Length | 575 ft |
| Year Completed | 1930 (96 years old) |
Storage & Hydraulics
| NID Storage | 275 acre-ft |
| Max Storage | 275 acre-ft |
| Normal Storage | 150 acre-ft |
| Surface Area | 42 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 130 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Sudbury |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 03/10/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00742 |
| Federal ID | MA00742 |
| More Info | State Dam Safety Program |