The Lower Folsom Powerhouse was put into service in 1897, two years after the opening of the original plant due to increasing demand for electricity in Sacramento. The lower powerhouse contains a single 750 watt AC generator.
Since the building was located on the river bank, it has been flooded a number of times during the spring when snowmelt swells the American River’s flow. A few of the high water marks are recorded on the building’s inside wall. Note that the highest levels — in 1907 (27 feet) and in 1928 — occurred prior to construction of the upstream Folsom Dam in 1955.