The Braden River is a 21-mile (34 km) waterway that drains an 83-square-mile (210 km2) area watershed in west-central Florida and is the largest tributary of the Manatee River. The hydrology of the Braden River was altered in 1936 when the city of Bradenton created Ward Lake, a reservoir with an 838-foot (255 m) broad-crested weir 6 miles (9.7 km) upstream from the mouth. In 1985 the reservoir, which is the sole source of drinking water for the city of Bradenton, was expanded and supplies an annual average of 5.7 million gallons of water per day.