Lake Saint Clair (North America)

Lake St. Clair
Landsat satellite photo, showing Lake Saint Clair (center), as well as St. Clair River connecting it with Lake Huron and the Detroit River connecting it to Lake Erie
Location	(Great Lakes)
Coordinates	42°28′N 82°40′W / 42.467°N 82.667°W / 42.467; -82.667Coordinates: 42°28′N 82°40′W / 42.467°N 82.667°W / 42.467; -82.667
Type	Fresh water lake
Primary inflows	St. Clair River, Thames River, Sydenham River, Clinton River, Pine River
Primary outflows	Detroit River
Basin countries	Canada, United States
Max. length	26 mi (42 km)
Max. width	24 mi (39 km)
Surface area	430 sq mi (1,114 km2)
Average depth	11 ft (3.4 m)
Max. depth	27 ft (8.2 m)
Water volume	0.82 cu mi (3.4 km3)
Residence time	7 days (2–30 days)
Shore length1	130 mi (210 km) plus 127 mi (204 km) for islands
Surface elevation	574 ft (175 m)
Islands	Gull Island, Harsens Island
Settlements	Detroit
1 Shore length is not a well-defined measure.

Lake St. Clair (French: Lac Sainte-Claire) is a freshwater lake that lies between the Canadian province of Ontario and the U.S. state of Michigan. It was named after Clare of Assisi, on whose feast day it was navigated and christened by French Catholic explorers in 1679. It is part of the Great Lakes system, and along with the St. Clair River and Detroit River, Lake St. Clair connects Lake Huron (to its north) with Lake Erie (to its south). It has a total surface area of about 430 square miles (1,100 km²) and average depth of just 11 ft (3.4 m); to ensure an uninterrupted waterway, government agencies on both sides of the lake have maintained a deep shipping channel through the shallow lake for more than a century.

This lake is situated about 6 miles (10 km) northeast of the downtown areas of Detroit, Michigan, and Windsor, Ontario. Along with the St. Clair River and Detroit River, Lake St. Clair connects Lake Huron (to its north) with Lake Erie (to its south); the area is notable for the fact that the Canadian territory around the lake (Windsor metropolitan area) lies south of the adjacent United States territory.

Lake Saint Clair measures about 22.5 nautical miles (42 km; 26 mi) from north to south and about 21 nautical miles (39 km; 24 mi) from east to west. Its total surface area is about 430 square miles (1,100 km²). This is a rather shallow lake for its size, with an average depth of about 11 feet (3.4 m), and a maximum natural depth of 21.3 feet (6.5 m). However, it is 27 feet (8.2 m) deep in the navigation channel which has been dredged for lake freighter passage. The lake is fed by the St. Clair River, which flows southwards from Lake Huron and has an extensive river delta where it enters Lake Saint Clair. This is the largest delta of the Great Lakes System. Also, the Thames River and Sydenham River flow into Lake Saint Clair from Southwestern Ontario, and the Clinton River and Pine River (Michigan) flows into it from Michigan. The outflow from Lake Saint Clair flows from its southwestern end into the Detroit River, and thence into Lake Erie.