New Jersey Dams
830 dams tracked by the National Inventory of Dams
Total Dams
830
High Hazard
232
28%
Poor / Unsatisfactory
233
Average Age
95 yrs
Hazard Classification
High232 (28.0%)
Significant332 (40.0%)
Low266 (32.0%)
Condition Assessment
Satisfactory373 (44.9%)
Fair112 (13.5%)
Poor / Unsatisfactory233 (28.1%)
Not Rated112 (13.5%)
Federal
21
State
126
Local
287
Private
393
Tallest Dams
- Merrill Creek Main Dam280 ft
- Round Valley South Dam178 ft
- Monksville Dam150 ft
- Round Valley North Dam135 ft
- Boonton Dam120 ft
High Hazard Dams
Poor Condition Dams
All Dams in New Jersey
Showing 251–275 of 830
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Packanack Lake Dam Passaic County | 15 | 1921 | High | Fair |
| Pachoango Dam Burlington County | 12 | — | Low | Satisfactory |
| Oxycocus East Dike #1 Ocean County | 12 | 1880 | Low | Not Rated |
| Overpeck Tidal Dam Bergen County | 18 | 1950 | Low | Not Rated |
| Overflow Weir Dam Passaic County | 30 | 1928 | High | Satisfactory |
| Oswego Dam Burlington County | 13 | 1936 | Significant | Poor |
| Osborns Mills Dam Monmouth County | 12 | — | Significant | Poor |
| Osborn Mills Dam Somerset County | 15 | — | Significant | Satisfactory |
| Orange Reservoir Dam Essex County | 34 | 1958 | High | Fair |
| Oradell Reservoir Dam Bergen County | 25 | 1922 | High | Fair |
| Openaka Lake Dam Morris County | 20 | 1750 | Significant | Poor |
| Oliphants Mill Lake Dam Burlington County | 11 | — | Low | Satisfactory |
| Old Morris Canal Dam Morris County | 18 | 1932 | Significant | Satisfactory |
| Old Mill Pond Dam Monmouth County | 15 | 1948 | Significant | Satisfactory |
| Oldham Pond Dam Passaic County | 18 | 1849 | High | Satisfactory |
| Old Forge Lake Dam Burlington County | 12 | — | Low | Satisfactory |
| Off'S Pond Dam Atlantic County | 8 | — | Significant | Poor |
| Oak Ridge Reservoir Dam Passaic County | 60 | 1892 | High | Poor |
| Oakford Lake Dam Ocean County | 8 | 1929 | Low | Fair |
| Nummytown Mill Pond Dam Cape May County | 9 | — | Significant | Poor |
| Nosenzo Pond Dam Passaic County | 9 | 1927 | Significant | Satisfactory |
| Northridge Pond Dam Somerset County | 13 | — | Significant | Satisfactory |
| Nj No Name No. 118 Dam Salem County | 8 | — | Low | Not Rated |
| Nishisakawick Creek Dam Hunterdon County | 23 | 1930 | Low | Fair |
| Newton Lake Dam Camden County | 10 | 1929 | Significant | Satisfactory |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.