Shadow Lake Dam
Shadow Lake Dam is an earth dam located in Bergen County, New Jersey, built in 1928. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Shadow Lake Dam
The primary purpose of Shadow Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Shadow Lake, Inc. (private). It impounds the Hohokus Creek near Mahwah.
The dam stands 16 feet tall and stretches 565 feet across, creates a reservoir covering 18 acres, has a maximum storage capacity of 72 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1928, the structure is well-established, with more than 75 years 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 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 10/25/2023.
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Location
| State | New Jersey |
| County | Bergen |
| Nearest City | Mahwah |
| River/Stream | Hohokus Creek |
| Coordinates | 41.03170, -74.19122 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 16 ft |
| Dam Height | 16 ft |
| Dam Length | 565 ft |
| Year Completed | 1928 (98 years old) |
Storage & Hydraulics
| NID Storage | 72 acre-ft |
| Max Storage | 72 acre-ft |
| Normal Storage | 55 acre-ft |
| Surface Area | 18 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 1,600 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Shadow Lake, Inc. |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/25/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NJ00232 |
| Federal ID | NJ00232 |
| More Info | State Dam Safety Program |