Henderson
Henderson is an earth dam located in Amador County, California, built in 1923. It carries a High hazard potential classification and has a fair condition assessment.
About Henderson
The primary purpose of Henderson is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Amador Regional Sanitation Authority (public utility). It impounds the Jackass Creek near Ione.
The dam stands 56 feet tall and stretches 630 feet across, creates a reservoir covering 31 acres, has a maximum storage capacity of 500 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1923, the structure is over a century 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 09/18/2024.
At 56 feet, this dam is taller than 94% of dams nationwide.
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 | Amador |
| Nearest City | Ione |
| River/Stream | Jackass Creek |
| Coordinates | 38.38560, -120.87710 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 56 ft |
| Dam Height | 56 ft |
| Dam Length | 630 ft |
| Year Completed | 1923 (103 years old) |
Storage & Hydraulics
| NID Storage | 500 acre-ft |
| Max Storage | 500 acre-ft |
| Surface Area | 31 acres |
| Drainage Area | 1 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Amador Regional Sanitation Authority |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 09/18/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00005 |
| Federal ID | CA00005 |
| More Info | State Dam Safety Program |