Forebay – Water diverted from the American River into the forebay was used to power the turbines.

Headgates – Hydraulically operated gates which controlled the flow of water into the turbines, and also diverted water to dump canals to maintain proper water levels in the forebay.

Hydraulic Headgate Lifts – Raised and lowered the headgates to control the flow of water in and around the powerhouse.

Dump Canal Flume – Diverted excess water from the forebay back into the American river, bypassing the powerhouse entirely.

Generators – Each of the four 800 volt generators weigh 57,877 pounds and pin at 300rpm.

Control Panel

Turbine Shaft


Fire extinguisher


Flow Control Apparatus

Forebay Level Indicators -‘These mechanical gauges were near the ceiling of the powerhouse, monitored the water levels in the forebay.

Governor controlled the flow of water through the turbine to maintain proper generator output. The governor measured the speed of the turbine shafts and adjusted the flow of water accordingly.

Exciter Generator – Produced D.C. (direct current) to energize the windings of the main generators.


Generators 2, 3 & 4

Control Panel – All power generation functions were monitored and controlled from this panel made from 2” thick marble.


Phone Booth – This phone booth, located inside the powerhouse, is constructed of double oak walls and double paned glass to minimize the roar of the power generation equipment.

Disconnect Switches – Disconnected the powerhouse from the transmission grid. The transformers and disconnect switches seen today are not the original units installed when the powerhouse was built, but were retrofitted as modernization and upkeep.

Want to learn more information about the Folsom Powerhouse? Click here for its history.

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