Cedar Grove South Res Dam
Cedar Grove South Res Dam is an earth dam located in Essex County, New Jersey, built in 1903. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Cedar Grove South Res Dam
The primary purpose of Cedar Grove South Res 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 Newark, Department Of Water And Sewer Utilities (local government). It impounds the Offstream near Little Falls.
The dam stands 51 feet tall and stretches 587 feet across, creates a reservoir covering 98 acres, has a maximum storage capacity of 2,584 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1903, the structure is over a century old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 10/15/2024.
At 51 feet, this dam is taller than 93% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New Jersey dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New Jersey |
| County | Essex |
| Nearest City | Little Falls |
| River/Stream | Offstream |
| Coordinates | 40.85307, -74.21652 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 51 ft |
| Dam Height | 51 ft |
| Dam Length | 587 ft |
| Year Completed | 1903 (123 years old) |
Storage & Hydraulics
| NID Storage | 2,584 acre-ft |
| Max Storage | 2,584 acre-ft |
| Normal Storage | 2,080 acre-ft |
| Surface Area | 98 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | City of Newark, Department of Water and Sewer Utilities |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/15/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00549 |
| Federal ID | NJ00549 |
| More Info | State Dam Safety Program |