Hidden Dam
Hidden Dam is an earth dam located in Madera County, California, built in 1975. It carries a High hazard potential classification.
About Hidden Dam
The primary purpose of Hidden Dam 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 Usace - Sacramento District (federal). It impounds the Fresno River near Madera.
The dam stands 184 feet tall and stretches 5,730 feet across, creates a reservoir covering 1,570 acres, has a maximum storage capacity of 116,727 acre-feet, and collects water from a drainage area of 234 square miles. Completed in 1975, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 12/06/2024.
At 184 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 | Madera |
| Nearest City | Madera |
| River/Stream | Fresno River |
| Coordinates | 37.11066, -119.88458 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 184 ft |
| Dam Height | 140 ft |
| Dam Length | 5,730 ft |
| Year Completed | 1975 (51 years old) |
Storage & Hydraulics
| NID Storage | 116,727 acre-ft |
| Max Storage | 116,727 acre-ft |
| Normal Storage | 64,298 acre-ft |
| Surface Area | 1,570 acres |
| Drainage Area | 234 sq mi |
| Max Discharge | 106,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Sacramento District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 12/06/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA10244 |
| Federal ID | CA10244 |
| More Info | State Dam Safety Program |