Round Valley Dike
Round Valley Dike is an earth dam located in Hunterdon County, New Jersey, built in 1961. It carries a High hazard potential classification and has a poor condition assessment.
About Round Valley Dike
The primary purpose of Round Valley Dike 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 Water Supply Authority (state). It impounds the Prescott Brook near Lebanon.
The dam stands 80 feet tall and stretches 2,350 feet across, creates a reservoir covering 2,300 acres, has a maximum storage capacity of 196,600 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1961, 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 09/23/2019.
At 80 feet, this dam is taller than 97% of all dams in the United States.
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 | Hunterdon |
| Nearest City | Lebanon |
| River/Stream | Prescott Brook |
| Coordinates | 40.63133, -74.84155 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 80 ft |
| Dam Height | 80 ft |
| Dam Length | 2,350 ft |
| Year Completed | 1961 (65 years old) |
Storage & Hydraulics
| NID Storage | 196,600 acre-ft |
| Max Storage | 196,600 acre-ft |
| Normal Storage | 168,000 acre-ft |
| Surface Area | 2,300 acres |
| Drainage Area | 5 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | New Jersey Water Supply Authority |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 09/23/2019 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00022 |
| Federal ID | NJ00013S002 |
| More Info | State Dam Safety Program |