Dams in Alameda County, California
22Total Dams
18High Hazard
3Significant
Dam Safety in Alameda County, California
Alameda County has 22 dams tracked in the National Inventory of Dams. Of these, 18 are classified as high hazard — meaning failure would probably cause loss of human life. Another 3 carry a significant hazard classification.
The average dam in Alameda County is 66 years old. The most common purpose is water supply. The tallest dam is Del Valle at 222 ft.
Explore more: Oldest dams in California · 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 |
|---|---|---|---|---|---|
| Del Valle | High | Fair | 222 | Flood Risk Reduction | 1968 |
| New Calaveras | High | Satisfactory | 210 | Water Supply | 2018 |
| James H. Turner | High | Satisfactory | 193 | Water Supply | 1964 |
| New Upper San Leandro | High | Satisfactory | 182 | Other | 1977 |
| Middlefield Reservoir | High | Satisfactory | 147 | Water Supply | 1958 |
| Chabot | High | Satisfactory | 142 | Water Supply | 1892 |
| Lake Temescal | High | Satisfactory | 116 | Water Supply | 1869 |
| Bethany Forebay | High | Satisfactory | 95 | Water Supply | 1961 |
| Ward Creek | High | Satisfactory | 71 | Flood Risk Reduction | 1963 |
| San Lorenzo Creek | High | Satisfactory | 65 | Flood Risk Reduction | 1964 |
| Central | High | Satisfactory | 55 | Water Supply | 1910 |
| Cull Creek | High | Satisfactory | 55 | Flood Risk Reduction | 1963 |
| Dunsmuir Reservoir | High | Satisfactory | 43 | Water Supply | 1968 |
| Patterson | High | Fair | 39 | Water Supply | 1962 |
| Decoto Reservoir | High | Satisfactory | 33 | Water Supply | 1966 |
| Dyer | High | Fair | 30 | Water Supply | 2011 |
| Almond | High | Satisfactory | 30 | Water Supply | 1954 |
| Quarry Pits | High | Satisfactory | 26 | Tailings | 1997 |
| Patterson | Significant | Fair | 100 | Water Supply | 1962 |
| Shinn | Significant | Satisfactory | 45 | Tailings | 1987 |
| Rubber Dam 3 | Significant | Satisfactory | 17 | Other | 1990 |
| Piedmont | Low | Satisfactory | 64 | Water Supply | 1905 |