Sycamore
Sycamore is an earth dam located in Riverside County, California, built in 1956. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Sycamore
The primary purpose of Sycamore is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Riverside County Flood Control And Water Conservation District (local government). It impounds the Sycamore Canyon near City Of Riverside.
The dam stands 63 feet tall and stretches 620 feet across, creates a reservoir covering 57 acres, has a maximum storage capacity of 1,150 acre-feet, and collects water from a drainage area of 10 square miles. Completed in 1956, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 12/01/2025.
At 63 feet, this dam is taller than 96% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | California |
| County | Riverside |
| Nearest City | City Of Riverside |
| River/Stream | Sycamore Canyon |
| Coordinates | 33.95470, -117.34340 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 63 ft |
| Dam Height | 63 ft |
| Dam Length | 620 ft |
| Year Completed | 1956 (70 years old) |
Storage & Hydraulics
| NID Storage | 1,150 acre-ft |
| Max Storage | 1,150 acre-ft |
| Surface Area | 57 acres |
| Drainage Area | 10 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Riverside County Flood Control and Water Conservation District |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/01/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00800 |
| Federal ID | CA00800 |
| More Info | State Dam Safety Program |