Matilija
Matilija is an arch dam located in Ventura County, California, built in 1949. It carries a High hazard potential classification and has a poor condition assessment.
About Matilija
Matilija is a dam in Ventura, California. The dam is owned by Ventura County Watershed Protection District (local government). It impounds the Matilija Creek near Ojala.
The dam stands 163 feet tall and stretches 620 feet across, creates a reservoir covering 86 acres, has a maximum storage capacity of 1,800 acre-feet, and collects water from a drainage area of 55 square miles. 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 11/26/2024.
At 163 feet, this dam is taller than 99% 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 | Ventura |
| Nearest City | Ojala |
| River/Stream | Matilija Creek |
| Coordinates | 34.48380, -119.30840 |
Physical Characteristics
| Dam Type | Arch |
| NID Height | 163 ft |
| Dam Height | 163 ft |
| Dam Length | 620 ft |
| Year Completed | 1949 (77 years old) |
Storage & Hydraulics
| NID Storage | 1,800 acre-ft |
| Max Storage | 1,800 acre-ft |
| Surface Area | 86 acres |
| Drainage Area | 55 sq mi |
Ownership & Safety
| Purpose | Other |
| Owner | Ventura County Watershed Protection District |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 11/26/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00312 |
| Federal ID | CA00312 |
| More Info | State Dam Safety Program |