Millham Reservoir Dam
Millham Reservoir Dam is an earth dam located in Middlesex County, Massachusetts, built in 1893. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Millham Reservoir Dam
The primary purpose of Millham Reservoir Dam 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 City Of Marlborough (local government). It impounds the Milham Brook & North Branch Milham Brook near Marlborough.
The dam stands 26 feet tall and stretches 1,160 feet across, creates a reservoir covering 68 acres, has a maximum storage capacity of 960 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1893, 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 08/14/2020.
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Location
| State | Massachusetts |
| County | Middlesex |
| Nearest City | Marlborough |
| River/Stream | Milham Brook & North Branch Milham Brook |
| Coordinates | 42.34550, -71.61210 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Length | 1,160 ft |
| Year Completed | 1893 (133 years old) |
Storage & Hydraulics
| NID Storage | 960 acre-ft |
| Max Storage | 960 acre-ft |
| Normal Storage | 560 acre-ft |
| Surface Area | 68 acres |
| Drainage Area | 4 sq mi |
| Max Discharge | 800 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | City of Marlborough |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/14/2020 |
| Emergency Action Plan | No |
Identifiers
| NID ID | MA00450 |
| Federal ID | MA00450 |
| More Info | State Dam Safety Program |