Dams in Cowlitz County, Washington
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 dams have 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
Data note: Hazard potential describes the consequences if a dam failed; it does not predict the likelihood of failure. Inspection, condition, and emergency-plan fields can be incomplete or delayed. Check state dam-safety officials and local emergency managers for official guidance.
| 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 Available | 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 | 15 | Flood Risk Reduction | 1971 | |
| Coweeman Gravel Pit No. 2 Dam | Low | 12 | Recreation | 1962 | |
| Longview Sewage Lagoon No 4 | Low | 12 | Other | 1987 | |
| Longview Sewage Lagoon No 2 | Low | 11 | Other | 1986 | |
| Longview Sewage Lagoon No 3 | Low | 10 | Other | 1987 | |
| Longview Sewage Lagoon No 1 | Low | 9 | Other | 1986 | |
| Coldwater Debris Dam | Undetermined | Not Rated | 200 | Other | 1981 |
| Castle Lake Debris Dam | Undetermined | Not Rated | 190 | Other | 1980 |