L'Assomption River

Rivière L' Assomption in the Parc des Chutes Monte -à- Peine in the regional county municipality Matawinie

Flow loop of the Rivière L' Assomption in the town of L' Assomption

Rivière L' Assomption (English Assomption River, named after the Virgin Mary into heaven ) is the most important waterway in the Lanaudière region in the Canadian province of Québec.

The river has a length of 172 km and a catchment area of ​​4222 km ². The source is located in the massif of Mont Tremblant. The seven main tributaries of the river are: Rivière de la Boule Rivière Versailles, Rivière Noire, Riviere Ouareau, Rivière Saint -Esprit and Rivière de l' Achigan. Finally, the Rivière L' Assomption opens near Repentigny in the Rivière des Prairies, just before it meets the St. Lawrence River.

In the catchment area of the river live about 150,000 people.

Geography

The catchment area of ​​the Rivière L' Assomption lies in two natural areas, the Laurentinische mountains and the St. Lawrence lowlands. The latter covers a third of the catchment area. Meanwhile, relief corresponds to a level with few hills ( with heights up to 100 m). Here dominates the agricultural land use. The fine-grained soil is here on a low permeability shale - clay layer.

The Laurentian Mountains form part of the Canadian Shield. These are clearly separated by a 150 m high escarpment. Along the Escarpment are a series of waterfalls. The Laurentian Mountains have an average height of 230 m in the south and 460 m in the north. However, there are higher mountains in Mont Tremblant massif with heights of over 600 m. There arises the Rivière L' Assomption.

Hydrographic

From north to south, reduces the average gradient of the water. The steep river sections in the higher elevations forms strong currents, while in the lowlands prevail shallow flow paths and low flow rates. Furthermore the flow to form a plurality of meanders. Most obviously this is at the town of L' Assomption, which lies almost completely within a loop of the river.

In the catchment area of the Rivière L' Assomption are 490 lakes, 24 of which have a water area larger than 1 km ². Most of the lakes are located in the Laurentian Highlands.

Water quality

Urban and industrial pollution

The water quality of the river is heavily dependent on the socio-economic conditions of the area. Since 1950 the situation has been complicated - by urbanization of the river bank, through diversified agriculture and industrialization along the southern section of the river. Although the sources of pollution have changed since 1950, because of strict environmental regulations and the use of sewage treatment plants, the environmental problem is still existent.

About 150,000 people live in the catchment area. They are spread over 43 municipalities. The most important of these are Repentigny, Joliette, Le Gardeur and L' Assomption. In addition, the northern part of the catchment area is a popular holiday destination, so that their population during the holidays, to over 45,000 people.

The majority of municipalities draw their drinking water to the river and thus supply 100,000 people.

Agricultural pollution

In addition to urban and industrial pollution, agriculture has a significant share of the environmental impact.

Agriculture is an important factor along the river: In 1995 there were 1305 farmers with 60 221 ha of cultivated land area and 73 563 animals.

Places along the river course

• Saint -Côme
• Saint -Alphonse- Rodriguez
• Sainte- Beatrix
• Saint -Jean -de- Matha
• Sainte- Mélanie
• Saint- Félix- de -Valois
• Notre- Dame-des- Prairies
• Saint-Charles- Borromeé
• Joliette
• Saint -Paul
• Saint -Gérard - Majella ( incorporated by L' Assomption )
• L' Assomption
• Repentigny
• Le Gardeur ( Repentigny incorporated by )
• Charlemagne