Dams in Orange County, California
43Total Dams
35High Hazard
1Significant
Dam Safety in Orange County, California
Orange County has 43 dams tracked in the National Inventory of Dams. Of these, 35 are classified as high hazard — meaning failure would probably cause loss of human life. Another 1 carry a significant hazard classification. Currently, 3 dams have a condition assessment of poor or unsatisfactory.
The average dam in Orange County is 55 years old. The most common purpose is water supply. The tallest dam is Trampas Canyon at 229 ft.
Explore more: Oldest dams in California · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Trampas Canyon | High | Satisfactory | 229 | Other | 1975 |
| San Joaquin Reservoir | High | Satisfactory | 224 | Water Supply | 1966 |
| Walnut Canyon | High | Satisfactory | 187 | Water Supply | 1968 |
| Upper Chiquita | High | Satisfactory | 177 | Water Supply | 2012 |
| Palisades Reservoir | High | Satisfactory | 146 | Water Supply | 1963 |
| Upper Oso | High | Satisfactory | 142 | Water Supply | 1979 |
| Santiago Creek | High | Poor | 136 | Water Supply | 1933 |
| Lake Mission Viejo | High | Poor | 123 | Water Supply | 1976 |
| Villa Park | High | Satisfactory | 118 | Flood Risk Reduction | 1963 |
| El Toro Reservoir | High | Satisfactory | 113 | Water Supply | 1967 |
| Trabuco | High | Satisfactory | 108 | Water Supply | 1984 |
| Carbon Canyon Dam | High | Not Available | 99 | Flood Risk Reduction | 1961 |
| Dove Canyon | High | Poor | 88 | Flood Risk Reduction | 1989 |
| Brea Dam - Saddle Dike 1 | High | Not Available | 87 | Flood Risk Reduction | 1942 |
| Rattlesnake Canyon | High | Fair | 79 | Water Supply | 1959 |
| Harbor View | High | Satisfactory | 65 | Flood Risk Reduction | 1964 |
| Big Canyon | High | Satisfactory | 65 | Water Supply | 1959 |
| Syphon Canyon | High | Satisfactory | 59 | Other | 1949 |
| Sand Canyon | High | Satisfactory | 58 | Water Supply | 1912 |
| Peters Canyon | High | Satisfactory | 54 | Other | 1932 |
| Portola | High | Satisfactory | 53 | Water Supply | 1980 |
| Ler Peters Canyon Retarding Basin | High | Satisfactory | 52 | Flood Risk Reduction | 1990 |
| Fullerton Dam | High | Not Available | 46 | Flood Risk Reduction | 1941 |
| Yorba | High | Satisfactory | 45 | Flood Risk Reduction | 1907 |
| Sulphur Creek | High | Satisfactory | 42 | Water Supply | 1966 |
| Agua Chinon | High | Satisfactory | 41 | Debris Control | 1998 |
| Eastfoot Retarding Basin | High | Satisfactory | 39 | Flood Risk Reduction | 2007 |
| Veeh | High | Satisfactory | 37 | Water Supply | 1936 |
| Rossmoor No. 1 | High | Satisfactory | 36 | Other | 1964 |
| Diemer Ozone Contact Basin | High | Satisfactory | 32 | Water Supply | 2011 |
| 30 Mg Central Reservoir | High | Satisfactory | 30 | Water Supply | 1924 |
| Marshburn Retarding Basin | High | Satisfactory | 27 | Debris Control | 1998 |
| Diemer Reservoir | High | Satisfactory | 22 | Water Supply | 1963 |
| Orchard Estates Retarding Basin | High | Satisfactory | 21 | Flood Risk Reduction | 1999 |
| Trabuco Retarding Basin | High | Satisfactory | 18 | Flood Risk Reduction | 1996 |
| Diemer No. 8 | Significant | Satisfactory | 172 | Water Supply | 1968 |
| Orange County Reservoir | Low | Satisfactory | 103 | Water Supply | 1941 |
| Round Canyon Retarding Basin | Low | Satisfactory | 98 | Flood Risk Reduction | 1994 |
| Bee Canyon Retention Basin | Low | Satisfactory | 62 | Flood Risk Reduction | 1994 |
| Hicks Canyon Retention Basin | Low | Satisfactory | 60 | Debris Control | 1997 |
| East Hicks Canyon Retarding Basin | Low | Satisfactory | 49 | Debris Control | 1997 |
| Galivan Retarding Basin | Low | Satisfactory | 14 | Water Supply | 2000 |
| Rossmoor Retarding Basin | Low | Satisfactory | 14 | Flood Risk Reduction | 2002 |