Magnolia Lake Dam
Magnolia Lake Dam is an earth dam located in Cape May County, New Jersey, built in 1684. It carries a Significant hazard potential classification and has a poor condition assessment.
About Magnolia Lake Dam
The primary purpose of Magnolia Lake 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 Njdot (state). It impounds the Mill Creek near Sea Isle City.
The dam stands 8 feet tall and stretches 750 feet across, creates a reservoir covering 8 acres, has a storage capacity of 83 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1684, the structure is one of the older dams in the region, with over a century and a half of service.
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 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 07/13/2023.
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Location
| State | New Jersey |
| County | Cape May |
| Nearest City | Sea Isle City |
| River/Stream | Mill Creek |
| Coordinates | 39.17322, -74.73660 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 8 ft |
| Dam Height | 8 ft |
| Dam Length | 750 ft |
| Year Completed | 1684 (342 years old) |
Storage & Hydraulics
| NID Storage | 83 acre-ft |
| Normal Storage | 83 acre-ft |
| Surface Area | 8 acres |
| Drainage Area | 2 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | NJDOT |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Poor |
| Last Inspection | 07/13/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00598 |
| Federal ID | NJ00598 |
| More Info | State Dam Safety Program |