Dams in St. Lawrence County, New York
65Total Dams
19High Hazard
11Significant
Dam Safety in St. Lawrence County, New York
St. Lawrence County has 65 dams tracked in the National Inventory of Dams. Of these, 19 are classified as high hazard — meaning failure would probably cause loss of human life. Another 11 carry a significant hazard classification. Currently, 1 dams have a condition assessment of poor or unsatisfactory.
The average dam in St. Lawrence County is 89 years old. The most common purpose is hydroelectric. The tallest dam is Long Sault at 132 ft.
Explore more: Oldest dams in New York · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Long Sault | High | Satisfactory | 132 | Hydroelectric | 1958 |
| Massena Intake | High | Satisfactory | 118 | Hydroelectric | 1958 |
| Rainbow | High | Satisfactory | 82 | Hydroelectric | 1956 |
| Blake | High | Satisfactory | 80 | Hydroelectric | 1957 |
| Flat Rock | High | Satisfactory | 72 | Hydroelectric | 1925 |
| Browns Falls | High | Satisfactory | 70 | Hydroelectric | 1922 |
| Five Falls | High | Satisfactory | 53 | Hydroelectric | 1954 |
| Newton Falls Upper | High | Satisfactory | 50 | Hydroelectric | 1927 |
| South Colton | High | Satisfactory | 42 | Hydroelectric | 1954 |
| Higley | High | Satisfactory | 37 | Hydroelectric | 1925 |
| Allens Falls | High | Satisfactory | 37 | Hydroelectric | 1991 |
| Norfolk Dam | High | Not Rated | 29 | Hydroelectric | 1965 |
| Colton | High | Satisfactory | 29 | Hydroelectric | 1919 |
| Long Sault North | High | Satisfactory | 25 | Hydroelectric | 1958 |
| Cranberry Lake Dam | High | Satisfactory | 24 | Recreation | 1917 |
| Norwood | High | Fair | 24 | Hydroelectric | 1928 |
| Piercefield | High | Satisfactory | 22 | Hydroelectric | 1914 |
| East Norfolk | High | Satisfactory | 16 | Hydroelectric | 1928 |
| Ogdensburg | High | Satisfactory | 12 | Hydroelectric | 1910 |
| Iroquois | Significant | Satisfactory | 72 | Hydroelectric | 1958 |
| South Edwards | Significant | Satisfactory | 53 | Hydroelectric | 1914 |
| Benson Mines Little River Dam | Significant | Poor | 44 | Irrigation | 1948 |
| Heuvelton | Significant | Satisfactory | 35 | Hydroelectric | 1923 |
| Stark Falls Dike A | Significant | Satisfactory | 22 | Hydroelectric | 1957 |
| Carry Falls Dike A | Significant | Satisfactory | 17 | Hydroelectric | 1953 |
| Hailsboro Mill #3 Dam | Significant | Not Rated | 16 | Hydroelectric | 1910 |
| Hailesboro Mill #6 Dam | Significant | Not Rated | 14 | Hydroelectric | |
| Hailesboro #4 Plant Dam | Significant | Not Rated | 12 | Hydroelectric | 1912 |
| Niagara Mohawk Power Dam | Significant | Not Rated | 11 | Hydroelectric | 1916 |
| Gouverneur | Significant | Satisfactory | 7 | Hydroelectric | 1925 |
| Chaumont Swamp Dam | Low | Not Rated | 100 | Irrigation | 1954 |
| Benson Mines Plant Dam | Low | Not Rated | 38 | Irrigation | |
| Massena Diversion Dam | Low | Not Rated | 35 | Other | 1912 |
| Newton Falls Stabilization Pond #4 Dam | Low | Not Rated | 35 | Other | 1965 |
| Sugar Island | Low | Satisfactory | 35 | Hydroelectric | 1925 |
| Hannawa | Low | Satisfactory | 34 | Hydroelectric | 1902 |
| Hollow Dam | Low | Satisfactory | 31 | Hydroelectric | 1987 |
| Bog River Dam | Low | Not Rated | 28 | Recreation | 1904 |
| Pyrites Intake | Low | Satisfactory | 27 | Hydroelectric | 1908 |
| Emeryville | Low | Satisfactory | 25 | Hydroelectric | 1959 |
| Fowler #7 - Dam No. 1 | Low | Satisfactory | 25 | Hydroelectric | 1928 |
| Newton Falls Lower | Low | Satisfactory | 25 | Hydroelectric | 1927 |
| Eel Weir | Low | Satisfactory | 23 | Hydroelectric | 1928 |
| Newton Falls Stabilization Pond #3 Dam | Low | Not Rated | 22 | Other | 1965 |
| Lows Lake Dam | Low | Not Rated | 21 | Recreation | 1903 |
| Unionville | Low | Satisfactory | 20 | Hydroelectric | 1907 |
| Parishville | Low | Satisfactory | 19 | Hydroelectric | 1925 |
| Hewittville | Low | Satisfactory | 18 | Hydroelectric | 1870 |
| Raymondville | Low | Satisfactory | 17 | Hydroelectric | 1928 |
| Chapman Dam | Low | Not Rated | 16 | Recreation | 1971 |
| Sissonville | Low | Satisfactory | 16 | Hydroelectric | 1990 |
| Weller Pond Dam | Low | Not Rated | 15 | Fire Protection, Stock, Or Small Fish Pond | |
| Grasse River Dam | Low | Not Rated | 13 | Flood Risk Reduction | 1881 |
| Talcville | Low | Satisfactory | 13 | Hydroelectric | 1987 |
| Mill Dam | Low | Not Rated | 12 | Other | 1916 |
| Upper & Lower Lakes Dam #1 | Low | Not Rated | 12 | Fish and Wildlife Pond | 1970 |
| Yaleville | Low | Satisfactory | 12 | Hydroelectric | 1914 |
| Smithline Wrp Dam | Low | Not Rated | 11 | Fish and Wildlife Pond | 1998 |
| Redwater Brook Dam | Low | Not Rated | 11 | Other | |
| Potsdam - West Dam | Low | Satisfactory | 11 | Hydroelectric | 1990 |
| Eli Sochia Dam | Low | Not Rated | 10 | Recreation | |
| L Hance Wetland Reserve Dam | Low | Not Rated | 10 | Fish and Wildlife Pond | 2000 |
| Massena Village Dam | Low | Not Rated | 8 | Recreation | 1860 |
| Twin Lakes Dam | Low | Not Rated | 7 | Other | |
| Potsdam - East Dam | Low | Satisfactory | 7 | Hydroelectric | 1903 |