Represa Billings is the largest reservoir in the state of São Paulo, Brazil, sprawling across an impressive 127 km² (49 square miles) at an elevation of 751 meters (2,464 feet) above sea level. Originally constructed beginning in 1925 and reaching its maximum operational quota in 1950, this massive impoundment was built primarily for hydroelectric power generation for the city of São Paulo. The reservoir is named after Asa White Kenney Billings, the American hydroelectric engineer who spearheaded its construction. Spanning portions of several municipalities — including Santo André, São Bernardo do Campo, Diadema, Ribeirão Pires, Rio Grande da Serra, and the city of São Paulo itself — Billings sits in the headwaters region of the Tietê River, a major left-bank tributary of the Paraná River. With a total water volume of approximately 1,228.7 million cubic meters, a mean depth of 10 meters, and a shoreline perimeter of roughly 900 km, this is a vast and complex fishery that rewards anglers who take the time to learn its waters.