Dams in Nassau County, New York
6Total Dams
2High Hazard
0Significant
Dam Safety in Nassau County, New York
Nassau County has 6 dams tracked in the National Inventory of Dams. Of these, 2 are classified as high hazard — meaning failure would probably cause loss of human life. Currently, 1 dams have a condition assessment of poor or unsatisfactory.
The average dam in Nassau County is 116 years old. The most common purpose is recreation. The tallest dam is Hempstead Lake Dam at 24 ft.
Explore more: Oldest dams in New York · Tallest dams · High risk dams · Largest reservoirs
Data note: Hazard potential describes the consequences if a dam failed; it does not predict the likelihood of failure. Inspection, condition, and emergency-plan fields can be incomplete or delayed. Check state dam-safety officials and local emergency managers for official guidance.
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Hempstead Lake Dam | High | Satisfactory | 24 | Recreation | 1873 |
| Upper Massapequa Lake Dam | High | Poor | 11 | Recreation | 1900 |
| Mill Pond Dam | Low | Not Rated | 18 | Other | 1983 |
| South Pond Dam | Low | Not Rated | 13 | Water Supply | 1903 |
| Massapequa Lake Dam | Low | Not Rated | 11 | Recreation | 1890 |
| Leeds Pond Dam | Low | Not Rated | 10 | Recreation | 1908 |