The Greater Winnipeg Water District aqueduct supplies the city of Winnipeg, Manitoba with water from Shoal Lake, Ontario. It was put in service in 1919 and cost nearly CDN $16 million. It has a capacity of 85 million Imperial gallons per day (4.4 cubic metres per second) and extends approximately 96 miles (153 km) from an intake structures on Shoal Lake to the Deacon reservoir on the east side of the city. Water flows by gravity from the lake, since the aqueduct drops about 300 feet (90 metres) over its length. The Greater Winnipeg Water District Railway was built for construction and maintenance of the aqueduct. The capacity was planned for a city of one million inhabitants; peak water usage by the city was in 1988 and the capacity of the aqueduct has never been entirely used. An additional 12-mile (19 km) branch was completed in 1960.
The entry structure is located at Indian Bay, Shoal Lake Ontario at 49°37′21″N 95°11′44″W / 49.62250°N 95.19556°WCoordinates: 49°37′21″N 95°11′44″W / 49.62250°N 95.19556°W. On its way to Winnipeg the aqueduct and railway pass through East Braintree, McMunn, Hadashville, Spruce, Larkhill, Monominto, Millbrook and Deacon stations.