Balch Afterbay is a concrete dam located in Fresno County, California, built in 1928. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 165 ft165 ft tall and 237 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against the Statue of Liberty, 305 ft ground to torch; the profile is a generic concrete gravity section and the water level is illustrative.
About Balch Afterbay
The primary purpose of Balch Afterbay is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Pacific Gas and Electric Company (private). It impounds the North Fork Kings River near Balch Camp.
The dam stands 165 feet tall and stretches 237 feet across, creates a reservoir covering 7 acres, has a maximum storage capacity of 325 acre-feet, and collects water from a drainage area of 13 square miles. Completed in 1928, 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 08/16/2023.
At 165 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 | Fresno |
| Nearest City | Balch Camp |
| River/Stream | North Fork Kings River |
| Coordinates | 36.90906, -119.09247 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 165 ft |
| Dam Height | 165 ft |
| Dam Length | 237.5 ft |
| Year Completed | 1928 (98 years old) |
Storage & Hydraulics
| NID Storage | 325 acre-ft |
| Max Storage | 325 acre-ft |
| Normal Storage | 317 acre-ft |
| Surface Area | 7 acres |
| Drainage Area | 13 sq mi |
| Max Discharge | 43,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Pacific Gas and Electric Company |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/16/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00336 |
| Federal ID | CA00336 |
| More Info | State Dam Safety Program |