15Total Dams
5High Hazard
1Significant
Dam Safety in Cowlitz County, Washington
Cowlitz County has 15 dams tracked in the National Inventory of Dams. Of these, 5 are classified as high hazard — meaning failure would probably cause loss of human life. Another 1 carry a significant hazard classification. Currently, 1 dam has a condition assessment of poor or unsatisfactory.
The average dam in Cowlitz County is 52 years old. The most common purpose is other. The tallest dam is Yale at 323 ft.
Explore more: Oldest dams in Washington · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Yale | High | Fair | 323 | Hydroelectric | 1953 |
| Merwin | High | Fair | 313 | Hydroelectric | 1931 |
| Mount St. Helens Sediment Retention Structure | High | Not assessed | 239 | Flood Risk Reduction | 1988 |
| Yale Saddle Dam | High | Unsatisfactory | 40 | Hydroelectric | 1953 |
| South Fork Mccorkle Creek Detention Dam | High | Fair | 22 | Flood Risk Reduction | 1989 |
| Headquarters Landfill Leachate Pond | Significant | Satisfactory | 19 | Other | 1993 |
| Swift No 2 Hydroelectric Project | Low | Satisfactory | 121 | Hydroelectric | 1959 |
| Silver Lake Dam | Low | Not assessed | 15 | Flood Risk Reduction | 1971 |
| Coweeman Gravel Pit No. 2 Dam | Low | Not assessed | 12 | Recreation | 1962 |
| Longview Sewage Lagoon No 4 | Low | Not assessed | 12 | Other | 1987 |
| Longview Sewage Lagoon No 2 | Low | Not assessed | 11 | Other | 1986 |
| Longview Sewage Lagoon No 3 | Low | Not assessed | 10 | Other | 1987 |
| Longview Sewage Lagoon No 1 | Low | Not assessed | 9 | Other | 1986 |
| Coldwater Debris Dam | Undetermined | Not assessed | 200 | Other | 1981 |
| Castle Lake Debris Dam | Undetermined | Not assessed | 190 | Other | 1980 |