Syphon Canyon
Syphon Canyon is an earth dam located in Orange County, California, built in 1949. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Syphon Canyon
Syphon Canyon is a dam in Orange, California. The dam is owned by Irvine Ranch Water District (public utility). It impounds the Tr Newport Bay near Irvine.
The dam stands 59 feet tall and stretches 843 feet across, creates a reservoir covering 28 acres, and has a maximum storage capacity of 578 acre-feet. Completed in 1949, the structure is well-established, with more than 75 years of service.
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 05/06/2025.
At 59 feet, this dam is taller than 95% 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 | Orange |
| Nearest City | Irvine |
| River/Stream | Tr Newport Bay |
| Coordinates | 33.70970, -117.73260 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 59 ft |
| Dam Height | 59 ft |
| Dam Length | 843 ft |
| Year Completed | 1949 (77 years old) |
Storage & Hydraulics
| NID Storage | 578 acre-ft |
| Max Storage | 578 acre-ft |
| Surface Area | 28 acres |
Ownership & Safety
| Purpose | Other |
| Owner | Irvine Ranch Water District |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/06/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00749 |
| Federal ID | CA00749 |
| More Info | State Dam Safety Program |