Lake Saint-Louis is a lake in southwestern

Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirte ...

, Canada, at the confluence of the

Saint Lawrence Saint Lawrence or Laurence ( la, Laurentius, lit. " laurelled"; 31 December AD 225 – 10 August 258) was one of the seven deacons of the city of Rome under Pope Sixtus II who were martyred in the persecution of the Christians that the Roman ...

and

Ottawa River The Ottawa River (french: Rivière des Outaouais, Algonquin: ''Kichi-Sìbì/Kitchissippi'') is a river in the Canadian provinces of Ontario and Quebec. It is named after the Algonquin word 'to trade', as it was the major trade route of Eastern ...

s. The

Saint Lawrence Seaway The St. Lawrence Seaway (french: la Voie Maritime du Saint-Laurent) is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North Ameri ...

passes through the lake. Lake St. Louis is a widening of the St. Lawrence River in the

Hochelaga Archipelago The Hochelaga Archipelago (), also known as the Montreal Islands, is a group of islands at the confluence of the Saint Lawrence and Ottawa rivers in the southwestern part of the province of Quebec, Canada. Population On 1 July 2021, the Ho ...

. It is also fed by the

via the Lake of Two Mountains at Sainte-Anne-de-Bellevue, the

Beauharnois Canal The Beauharnois Canal is located in southwestern Quebec, Canada. The canal is part of the Saint Lawrence Seaway. Located in Beauharnois-Salaberry Regional County Municipality within the cities of Salaberry-de-Valleyfield, Beauharnois, Saint-L ...

, the

Soulanges Canal The Soulanges Canal is an abandoned shipping canal in Quebec, Canada. It follows the north shore of the Saint Lawrence River between Pointe-des-Cascades, Quebec, Pointe-des-Cascades and Les Coteaux, Quebec, Coteaux-Landing, bypassing the rapids be ...

, the Saint-Louis River, and the

Châteauguay River The Chateauguay River (or Chateaugay River in the United States, moh, Oshahrhè:’onKaronhí:io Delaronde and Jordan Engel, The Decolonial Atlas, Haudenosaunee Country in Mohawk, February 4, 201Link/ref>) is a tributary of the South Shore of th ...

. The lake is bounded to the north and the east by the

Island of Montreal The Island of Montreal (french: Île de Montréal) is a large island in southwestern Quebec, Canada, that is the site of a number of municipalities including most of the city of Montreal and is the most populous island in Canada. It is the main ...

, by Beauharnois-Salaberry,

Roussillon Roussillon ( , , ; ca, Rosselló ; oc, Rosselhon ) is a historical province of France that largely corresponded to the County of Roussillon and part of the County of Cerdagne of the former Principality of Catalonia. It is part of the ...

, and Vaudreuil-Soulanges. The town of Beauharnois with its power-dam and canal lie to the south. The

West Island The West Island () is the unofficial name given to the cities, towns and boroughs at the western end of the Island of Montreal, in Quebec, Canada. It is generally considered to consist of the Lakeshore municipalities of Dorval, Pointe-Cla ...

shore is mostly built up with private houses, but it includes some parks and clubs such as the Pointe-Claire Canoe Club, and the Pointe-Claire Yacht Club. Islands in the lake include

Dorval Dorval () is an on-island suburban city on the island of Montreal in southwestern Quebec, Canada. In 2016, the Canadian Census indicated that the population increased by 4.2% to 18,980. Although the city has the largest surface area in Montr ...

and Dowker Islands. Lake St. Louis is the second of three

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

lakes on the St. Lawrence River; upstream of it is Lake Saint Francis, and downstream is Lake Saint Pierre. Lake St. Louis has an average flow of . The lake has many species of fish, including

yellow perch The yellow perch (''Perca flavescens''), commonly referred to as perch, striped perch, American perch, American river perch or preacher is a freshwater perciform fish native to much of North America. The yellow perch was described in 1814 by Sam ...

. A small map by Samuel Champlain of 1611 names the lake. The same year, Champlain reported that a young man named Louys was drowned in what is now known as the Lachine Rapids, and in 1870 Charles-Honoré Laverdière stated that the rapids, and later the lake, were named in honour of the drowned man. A 1656 Jesuit account describes a crossing «Lac Saint Louys». In 2014 there was a report of fecal coliform flowing into the lake from a

Beaconsfield Beaconsfield ( ) is a market town and civil parish within the unitary authority of Buckinghamshire, England, west-northwest of central London and south-southeast of Aylesbury. Three other towns are within : Gerrards Cross, Amersham and High W ...

creek, and of PCBs flowing into it from a

Pointe-Claire Pointe-Claire (, ) is a Quebec local municipality within the Urban agglomeration of Montreal on the Island of Montreal in Canada. It is entirely developed, and land use includes residential, light manufacturing, and retail. As of the 2021 cen ...

industrial site.

References

{{reflist Landforms of Montreal Saint Louis Saint Lawrence River