Diversion Dam
Diversion Dam is an earth dam located in Sussex County, New Jersey, built in 1959. It carries a High hazard potential classification and has a poor condition assessment.
About Diversion Dam
The primary purpose of Diversion 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 Pequannock River near Hardyston.
The dam stands 8 feet tall and stretches 225 feet across, creates a reservoir covering 47 acres, has a maximum storage capacity of 300 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1959, the structure is well into its service life at over 50 years 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 11/07/2024.
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 | Sussex |
| Nearest City | Hardyston |
| River/Stream | Pequannock River |
| Coordinates | 41.13252, -74.49253 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 8 ft |
| Dam Height | 8 ft |
| Dam Length | 225 ft |
| Year Completed | 1959 (67 years old) |
Storage & Hydraulics
| NID Storage | 300 acre-ft |
| Max Storage | 300 acre-ft |
| Normal Storage | 200 acre-ft |
| Surface Area | 47 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 845 cfs |
Ownership & Safety
| Purpose | Water Supply |
| Owner | City of Newark, Department of Water and Sewer Utilities |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 11/07/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00880 |
| Federal ID | NJ00880 |
| More Info | State Dam Safety Program |