Dams in Coos County, New Hampshire
60Total Dams
10High Hazard
16Significant
Dam Safety in Coos County, New Hampshire
Coos County has 60 dams tracked in the National Inventory of Dams. Of these, 10 are classified as high hazard — meaning failure would probably cause loss of human life. Another 16 carry a significant hazard classification. Currently, 11 dams have a condition assessment of poor or unsatisfactory.
The average dam in Coos County is 84 years old. The most common purpose is recreation. The tallest dam is Murphy Dam at 106 ft.
Explore more: Oldest dams in New Hampshire · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Murphy Dam | High | Not Rated | 106 | Recreation | 1938 |
| Cascade | High | Fair | 57 | Hydroelectric | 1903 |
| First Connecticut Lake Dam | High | Fair | 56 | Hydroelectric | 1930 |
| Dead River Dam 1 | High | Fair | 47 | Flood Risk Reduction | 1970 |
| Abeniki Lake Dam | High | Satisfactory | 40 | Recreation | 1900 |
| Lake Gloriette Dike | High | Poor | 34 | Recreation | 1913 |
| Lake Gloriette Dam | High | Poor | 33 | Recreation | 1913 |
| J. Brodie Smith | High | Satisfactory | 31 | Hydroelectric | 1948 |
| Cross Power | High | Satisfactory | 25 | Hydroelectric | 1903 |
| Stratford Bog Pond Dam | High | Poor | 16 | Recreation | 1934 |
| Balsams Mohawk River Dam | Significant | Not Rated | 55 | Recreation | |
| Whitefield Lagoon Dam | Significant | Satisfactory | 32 | Other | 1984 |
| Balsams Wastewater Lagoons Dam | Significant | Fair | 28 | Other | 1965 |
| Groveton Paper Mill Lagoons Dam | Significant | Fair | 25 | Other | 2010 |
| Groveton Municipal Lagoons Dam | Significant | Satisfactory | 20 | Other | 2012 |
| Faraway Pond Dam | Significant | Satisfactory | 20 | Recreation | 1975 |
| Mwh Sewage Lagoons Dam | Significant | Fair | 19 | Other | 2000 |
| Brooklyn | Significant | Unsatisfactory | 19 | Hydroelectric | 1919 |
| Godfrey Dam | Significant | Satisfactory | 18 | Water Supply | 1920 |
| Icy Gulch Reservoir Dam | Significant | Satisfactory | 18 | Water Supply | 1940 |
| Resort Waste Water Lagoon Dam | Significant | Satisfactory | 15 | Other | 1987 |
| Colebrook Sewage Lagoon Dam | Significant | Satisfactory | 15 | Other | 1975 |
| Cascade Wastewater Lagoon Dam | Significant | Satisfactory | 13 | Other | 1975 |
| Big Brook Bog Dam | Significant | Fair | 11 | Recreation | 1946 |
| Moose Falls Dam | Significant | Poor | 10 | Fish and Wildlife Pond | 1950 |
| Mt Carberry Leachate Pond Dam | Significant | Satisfactory | 5 | Other | |
| Gilman | Low | Satisfactory | 38 | Hydroelectric | 1898 |
| Second Connecticut Lake Dam | Low | Fair | 28 | Hydroelectric | 1849 |
| Shehan Pond Dam | Low | Poor | 25 | Fish and Wildlife Pond | 1960 |
| Errol | Low | Satisfactory | 25 | Hydroelectric | 1887 |
| Lake Twotowns Dam | Low | Satisfactory | 25 | Recreation | 1936 |
| Gorham | Low | Satisfactory | 24 | Hydroelectric | 1904 |
| Israel River Dam | Low | Unsatisfactory | 22 | Flood Risk Reduction | 1981 |
| Riverside | Low | Satisfactory | 21 | Hydroelectric | 1970 |
| Gorham | Low | Satisfactory | 20 | Hydroelectric | 1958 |
| Weston | Low | Satisfactory | 20 | Hydroelectric | 1987 |
| Canaan | Low | Satisfactory | 19 | Hydroelectric | 1927 |
| Little Bog Pond Dam | Low | Not Rated | 18 | Recreation | 1930 |
| Shelburne | Low | Satisfactory | 17 | Hydroelectric | 1906 |
| Phillips Pond Dam | Low | Not Rated | 15 | Recreation | 1926 |
| Sawmill | Low | Satisfactory | 15 | Hydroelectric | 1965 |
| Pontook | Low | Satisfactory | 15 | Hydroelectric | 1909 |
| Dead River Dike | Low | Fair | 14 | Flood Risk Reduction | 1970 |
| Pearley Terrill Dam | Low | Not Rated | 14 | Recreation | 1965 |
| First Conn Lake South Bay Dike | Low | Fair | 14 | Recreation | |
| East Inlet Dam | Low | Satisfactory | 13 | Recreation | 1900 |
| Burns Lake Dam | Low | Fair | 13 | Recreation | 1921 |
| Akers Pond Dam | Low | Satisfactory | 12 | Recreation | 1930 |
| York Pond Dam | Low | Not Rated | 12 | Recreation | 1930 |
| Airport Marsh Dam | Low | Poor | 11 | Recreation | 1956 |
| Lower Trio Pond Dam | Low | Not Rated | 11 | Recreation | 1936 |
| Mud Pond Dam | Low | Fair | 10 | Water Supply | 1920 |
| Coon Brook Bog Dam | Low | Poor | 10 | Recreation | 1947 |
| Lime Pond Dam | Low | Satisfactory | 10 | Recreation | 1934 |
| Boundary Pond Dam | Low | Satisfactory | 10 | Recreation | 1952 |
| Scott Bog Pond Dam | Low | Satisfactory | 9 | Fish and Wildlife Pond | 1942 |
| Back Lake Dam | Low | Poor | 7 | Recreation | 1930 |
| Godbout Pond West Dike | Undetermined | Not Rated | 35 | Recreation | |
| Washburn Mill Dam | Undetermined | Not Rated | 25 | Fish and Wildlife Pond | |
| Perry Pond Dam | Undetermined | Poor | 7 | Fish and Wildlife Pond | 1947 |