Elmer J. Chesbro is an earth dam located in Santa Clara County, California, built in 1955. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 95 ft95 ft tall and 690 ft long, taller than 98% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Elmer J. Chesbro
The primary purpose of Elmer J. Chesbro 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 Santa Clara Valley Water District (public utility). It impounds the Llagas Creek near Morgan Hill.
The dam stands 95 feet tall and stretches 690 feet across, creates a reservoir covering 328 acres, has a maximum storage capacity of 8,086 acre-feet, and collects water from a drainage area of 19 square miles. Completed in 1955, 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 04/14/2025.
At 95 feet, this dam is taller than 98% 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 | Santa Clara |
| Nearest City | Morgan Hill |
| River/Stream | Llagas Creek |
| Coordinates | 37.11550, -121.69510 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 95 ft |
| Dam Height | 95 ft |
| Dam Length | 690 ft |
| Year Completed | 1955 (71 years old) |
Storage & Hydraulics
| NID Storage | 8,086 acre-ft |
| Max Storage | 8,086 acre-ft |
| Surface Area | 328 acres |
| Drainage Area | 19 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Santa Clara Valley Water District |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/14/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00806 |
| Federal ID | CA00806 |
| More Info | State Dam Safety Program |