Two miles upriver, the Folsom Water Power Company dam diverted water from the American River into a canal for delivery to this forebay. Intentionally constructed at an angle to the canal, the forebay served multiple functions. Wood slats under the bridge trapped floating debris such as uprooted trees. Its angle, center dividing wall, and parallel wood baffles along the bottom reduced water turbulence and helped settle river sediment. Because water flow through the canal varied, two bypass gates on each side regulated the water level in the forebay. A smooth and stable water supply was critical to the safe and efficient operation of the powerhouse turbines. Large hydraulic gates facing the powerhouse allowed water to flow into separate penstock pipes that fed each of the four main turbine generator sets. Two small center gates provided water for the turbines powering the Direct Current exciter generators used for starting the main Alternating Current generators.