67Total Dams
8High Hazard
7Significant
Dam Safety in Penobscot County, Maine
Penobscot County has 67 dams tracked in the National Inventory of Dams. Of these, 8 are classified as high hazard — meaning failure would probably cause loss of human life. Another 7 carry a significant hazard classification. Currently, 13 dams have a condition assessment of poor or unsatisfactory.
The average dam in Penobscot County is 112 years old. The most common purpose is hydroelectric. The tallest dam is Dolby at 66 ft.
Explore more: Oldest dams in Maine · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Dolby | High | Satisfactory | 66 | Hydroelectric | 1906 |
| Mattaceunk | High | Satisfactory | 45 | Hydroelectric | 1939 |
| North Twin | High | Satisfactory | 35 | Hydroelectric | 1934 |
| Stone Dam | High | Satisfactory | 27 | Hydroelectric | 1900 |
| Grand Lake (matagamon) | High | Poor | 25 | Hydroelectric | 1941 |
| Millinocket Lake | High | Satisfactory | 20 | Hydroelectric | 1910 |
| Wassookeag Lake | High | Satisfactory | 14 | Flood Risk Reduction | 1914 |
| Stone Dam - Dike 8 | High | Satisfactory | 9 | Hydroelectric | 1900 |
| Malletts Mill | Significant | Poor | 16 | Fire Protection, Stock, Or Small Fish Pond | 1836 |
| North Twin - Dike 3 | Significant | Satisfactory | 15 | Hydroelectric | 1934 |
| North Twin - Dike 4 | Significant | Satisfactory | 11 | Hydroelectric | 1934 |
| North Twin - Dike 2 | Significant | Satisfactory | 11 | Hydroelectric | 1934 |
| North Twin - Dike 5 | Significant | Satisfactory | 11 | Hydroelectric | 1934 |
| North Twin - Dike 1 | Significant | Satisfactory | 11 | Hydroelectric | 1934 |
| Swetts Pond | Significant | Poor | 6 | Flood Risk Reduction | 1946 |
| Pond Farm | Low | Fair | 40 | Recreation | 1920 |
| West Enfield | Low | Satisfactory | 39 | Hydroelectric | 1988 |
| Medway | Low | Satisfactory | 35 | Hydroelectric | 1922 |
| Milford | Low | Satisfactory | 34 | Hydroelectric | 1906 |
| Lowell Tannery | Low | Satisfactory | 27 | Hydroelectric | 1987 |
| East Millinocket | Low | Satisfactory | 26 | Hydroelectric | 1907 |
| Stillwater | Low | Satisfactory | 25 | Hydroelectric | 1902 |
| Rocky Bottom | Low | Not assessed | 20 | Hydroelectric | 1965 |
| Mattanawcook Pond | Low | Poor | 19 | Flood Risk Reduction | 1918 |
| Folsom Pond | Low | Poor | 18 | Flood Risk Reduction | 1918 |
| Mill Pond Lpp | Low | Not assessed | 18 | Flood Risk Reduction | 1917 |
| Howland | Low | Not assessed | 17 | Hydroelectric | 1916 |
| Village | Low | Not assessed | 16 | Hydroelectric | 1826 |
| Whitney Irrigation Pond | Low | Poor | 16 | Irrigation | 1950 |
| Sebasticook | Low | Satisfactory | 15 | Hydroelectric | 1988 |
| Garland Pond | Low | Fair | 15 | Fire Protection, Stock, Or Small Fish Pond | 1905 |
| Gristmill Pond | Low | Unsatisfactory | 15 | Hydroelectric | 1978 |
| Run Around | Low | Satisfactory | 15 | Hydroelectric | 1894 |
| Gilman Mill | Low | Not assessed | 15 | Hydroelectric | 1963 |
| Orono | Low | Satisfactory | 15 | Hydroelectric | 1917 |
| Brewer Lake | Low | Not assessed | 14 | Water Supply | 1900 |
| Long Pond | Low | Not assessed | 14 | Hydroelectric | 1949 |
| Spragues Mill | Low | Poor | 14 | Recreation | 1955 |
| Cold Stream Pond | Low | Fair | 13 | Fish and Wildlife Pond | 1890 |
| Sam Ayers Deadwater Outlet Dam | Low | Not assessed | 13 | Fish and Wildlife Pond | 2002 |
| Stanhope Mill #2 Lower | Low | Not assessed | 13 | Hydroelectric | 1827 |
| Lowell Lake | Low | Poor | 12 | Other | 1900 |
| French Stream | Low | Not assessed | 12 | Recreation | 1850 |
| Cambolasse Pond | Low | Not assessed | 12 | Recreation | 1950 |
| Lovley's Dam | Low | Not assessed | 12 | Recreation | 1974 |
| Long Pond | Low | Not assessed | 12 | 1915 | |
| Stump Pond | Low | Poor | 12 | Hydroelectric | 1936 |
| Plymouth | Low | Not assessed | 11 | Other | 1920 |
| Puffers Pond | Low | Satisfactory | 10 | Recreation | 1810 |
| Upper | Low | Poor | 10 | Hydroelectric | 1900 |
| Eskutassis Pond | Low | Poor | 10 | Other | 1860 |
| Dwinal Pond | Low | Not assessed | 10 | Recreation | 1947 |
| Stone Dam - Dike 3 | Low | Satisfactory | 10 | Hydroelectric | 1900 |
| Stone Dam - Dike 1 | Low | Satisfactory | 10 | Hydroelectric | 1900 |
| Stone Dam - Dike 2 | Low | Satisfactory | 10 | Hydroelectric | 1900 |
| Upper Stetson Stream | Low | Not assessed | 10 | Recreation | 1853 |
| Stone Dam - Dike 7 | Low | Satisfactory | 9 | Hydroelectric | 1900 |
| Stone Dam - Dike 4 | Low | Satisfactory | 9 | Hydroelectric | 1900 |
| Stone Dam - Dike 6 | Low | Satisfactory | 9 | Hydroelectric | 1900 |
| Stone Dam - Dike 5 | Low | Satisfactory | 9 | Hydroelectric | 1900 |
| Eddington-holbrook | Low | Not assessed | 8 | Recreation | 1802 |
| Garland Pond Dike | Low | Poor | 8 | Recreation | 1905 |
| Sawtelle Deadwater | Low | Not assessed | 8 | Hydroelectric | 1880 |
| Great Works Stream | Low | Not assessed | 8 | Other | 1963 |
| Gilman Falls | Low | Satisfactory | 8 | Hydroelectric | 1906 |
| Pushaw Lake | Low | Not assessed | 8 | Other | 1920 |
| Leonards Mill | Low | Not assessed | 7 | Hydroelectric | 1796 |