water stored in lake oroville is released through the 819 mw edward hyatt pumped-storage powerplant and two other hydroelectric plants downstream of oroville dam, which together make up the oroville-thermalito complex. the thermalito forebay and afterbay support the 120 mw thermalito pumping-generating plant, and the thermalito diversion dam supports a smaller 3.3 mw powerplant. the entire system generates approximately 2.2 billion kilowatt hours per year, making up about a third of the total power generated by swp facilities.