The Salt River begins high in the White Mountains as runoff from melting snow, flowing into streams and creeks that eventually form the White and Black rivers, whose confluence marks the beginning of the Salt. Early Phoenix farmers struggled with the river's erratic flow, as it dwindled to nothing in summer but flooded at other times of the year, bursting rock and brush dams and washing out fields. Roosevelt Dam was intended to manage the river and provide a dependable water supply, and when it was completed in 1911 it controlled the flow of the Salt's water to irrigation districts, cities, farms, and residential irrigators through smaller canals, laterals and ditches.