Morris
Morris is a gravity dam located in Los Angeles County, California, built in 1935. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Morris
Morris is a dam in Los Angeles, California. The dam is owned by Los Angeles County Department Of Public Works (local government). It impounds the San Gabriel River near Azusa.
The dam stands 245 feet tall and stretches 750 feet across, creates a reservoir covering 420 acres, has a maximum storage capacity of 27,500 acre-feet, and collects water from a drainage area of 210 square miles. Completed in 1935, 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 11/18/2025.
At 245 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 | Los Angeles |
| Nearest City | Azusa |
| River/Stream | San Gabriel River |
| Coordinates | 34.17500, -117.88130 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 245 ft |
| Dam Height | 245 ft |
| Dam Length | 750 ft |
| Year Completed | 1935 (91 years old) |
Storage & Hydraulics
| NID Storage | 27,500 acre-ft |
| Max Storage | 27,500 acre-ft |
| Surface Area | 420 acres |
| Drainage Area | 210 sq mi |
Ownership & Safety
| Purpose | Other |
| Owner | Los Angeles County Department Of Public Works |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/18/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00216 |
| Federal ID | CA00216 |
| More Info | State Dam Safety Program |