Osborn Mills Dam is an earth dam located in Somerset County, New Jersey. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 15 ft15 ft tall and 250 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 Osborn Mills Dam
The primary purpose of Osborn Mills 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 New Jersey-american Water Company (private). It impounds the Passaic River near Madisonville.
The dam stands 15 feet tall and stretches 250 feet across, creates a reservoir covering 10 acres, has a maximum storage capacity of 100 acre-feet, and collects water from a drainage area of 10 square miles.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 02/29/2024.
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Location
| State | New Jersey |
| County | Somerset |
| Nearest City | Madisonville |
| River/Stream | Passaic River |
| Coordinates | 40.72118, -74.53207 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 250 ft |
Storage & Hydraulics
| NID Storage | 100 acre-ft |
| Max Storage | 100 acre-ft |
| Normal Storage | 30 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 10 sq mi |
| Max Discharge | 500 cfs |
Ownership & Safety
| Purpose | Water Supply |
| Owner | New Jersey-american Water Company |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 02/29/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00365 |
| Federal ID | NJ00365 |
| More Info | State Dam Safety Program |