Dams in Lewis County, Washington
34Total Dams
9High Hazard
6Significant
Dam Safety in Lewis County, Washington
Lewis County has 34 dams tracked in the National Inventory of Dams. Of these, 9 are classified as high hazard — meaning failure would probably cause loss of human life. Another 6 carry a significant hazard classification. Currently, 3 dams have a condition assessment of poor or unsatisfactory.
The average dam in Lewis County is 49 years old. The most common purpose is tailings. The tallest dam is Mossyrock at 606 ft.
Explore more: Oldest dams in Washington · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Mossyrock | High | Unsatisfactory | 606 | Hydroelectric | 1968 |
| Mayfield | High | Unsatisfactory | 250 | Hydroelectric | 1963 |
| Centralia Coal Mine Pond 46 Dam | High | Fair | 30 | Flood Risk Reduction | 2004 |
| Carlisle Lake Dam | High | Poor | 19 | Fish and Wildlife Pond | 1920 |
| Centralia Coal Mine Dam No 8a | High | Satisfactory | 18 | Tailings | 1972 |
| Centralia Coal Mine Pond 46a Dam | High | Satisfactory | 16 | Flood Risk Reduction | 2004 |
| Packwood Lake | High | Satisfactory | 14 | Hydroelectric | 1964 |
| Centralia Coal Mine Dam No 8 | High | Satisfactory | 12 | Tailings | 1972 |
| Koppert Pond | High | Fair | 11 | Recreation | 1984 |
| Cowlitz Falls | Significant | Satisfactory | 145 | Hydroelectric | 1994 |
| Centralia Coal Mine Dam No 3b | Significant | Fair | 140 | Tailings | 1980 |
| Centralia Coal Mine Dam No 3c North | Significant | Satisfactory | 134 | Tailings | 1987 |
| Centralia Coal Mine Dam No 3c South | Significant | Satisfactory | 69 | Tailings | 1987 |
| Centralia Coal Mine Dam No 3c East | Significant | Satisfactory | 21 | Tailings | 1987 |
| Chehalis Regional Water Reclamation Pond | Significant | Satisfactory | 17 | Other | 2005 |
| Centralia Coal Mine Dam No 3d | Low | 285 | Tailings | 1988 | |
| South Bank Dairy Lagoon Dam | Low | 40 | Other | 1980 | |
| Swofford Pond | Low | Satisfactory | 26 | Hydroelectric | |
| Centralia Coal Mine Dam No 5c | Low | 20 | Tailings | 1970 | |
| Centralia Coal Mine Dam No 44 | Low | 19 | Tailings | 1975 | |
| Koa Dam No 1 | Low | 18 | Recreation | 1965 | |
| Long Bell Mill Pond Dam | Low | 18 | Other | 1943 | |
| Centralia Coal Mine Dam No 3a | Low | 18 | Tailings | 1970 | |
| Barrier Dam | Low | Satisfactory | 16 | Hydroelectric | 1968 |
| Mayfield Plunge Pool Barrier | Low | Satisfactory | 14 | Hydroelectric | 1963 |
| Centralia Coal Mine Dam No 36a | Low | 14 | Tailings | 1989 | |
| Centralia Coal Mine Dam No 5 | Low | 14 | Tailings | 1971 | |
| Centralia Power Plant Surge Pond Dam | Low | 13 | Water Supply | 1971 | |
| Centralia Coal Mine Dam No 36 | Low | 13 | Tailings | 1989 | |
| Centralia Coal Mine Dam No 19a | Low | 13 | Tailings | 1977 | |
| Centralia Coal Mine Dam No 19 | Low | 13 | Tailings | 1977 | |
| Centralia Coal Mine Dam No 6b | Low | 13 | Tailings | 1970 | |
| Powell Dam | Low | 11 | Irrigation | 1963 | |
| Winlock Waterski Pond Dam | Low | 11 | Recreation | 1990 |