Riparian zone

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Definitions drawn from the  Protection Policy for Lakeshores, Riverbanks, Littoral Zones and Floodplains of Quebec's environmental administration, the Ministère du Développement durable, de l’Environnement et de la Lutte aux changements climatiques (MDDELCC) (http://www.mddelcc.gouv.qc.ca/EAU/rives/richesse/index.htm):

Littoral zone: that part of lakes and rivers running from the high-water mark toward the centre of the body of water (up to the point where sunlight no longer penetrates to the bottom).

Riparian zone (shore): a strip of land, sometimes called riverbank, lakeshore or seashore, covered with a variety of native herbaceous plants, shrubs and trees, which constitutes the transition zone between terrestrial and aquatic environments. Depending on its slope, the riparian zone extends at minimum 10 to 15 m inland from the high-water mark.

High-water mark: a line delimiting the riparian and littoral zones of bodies of water, located at the place where one passes from a predominance of aquatic plants to a predominance of terrestrial plants.


The Ecological Functions of Riparian (Shore) Zones

  • Riparian vegetation acts as a filter to prevent fertilizer, pesticide and sediment content in runoff waters: The roots of riparian vegetation filter the water by retaining certain polluting substances, organic matter and pathogenic organisms carried in runoff water. This natural barrier also promotes the capture of sediments before they reach the body of water. 
 
  • Improves water quality by reducing the proliferation of algae and aquatic weeds: The presence of vegetation prevents rain water runoff entering the body of water and carrying with it a large quantity of nutrient contaminants such as nitrogen and phosphorus. Accumulation of these nutrients in the body of water leads to the proliferation of algae and aquatic plants, which is detrimental to the water quality and species that live therein.
 
  • Stabilizes the soil to reduce erosion and landslides and decreases the silting up of spawning grounds: The root systems of riparian vegetation strengthen the capacity of waterfront areas to counter mechanical erosion resulting from water currents, wind, certain microorganisms and human activity. These root systems retain soil particles, which prevents them being drawn into the water by currents, thus stabilizing the shores.
 
  • Acts as a natural windbreak in order to reduce wind erosion and thus protects nearby dwellings and their installations: Riparian vegetation acts as a windbreak by limiting wind erosion of the shoreline and wind damage to infrastructures and cultivated areas. This vegetation creates a microclimate favourable to the survival of riparian flora and fauna.
 
  • Provides habitats, food and shelter for wildlife: Shore areas are also an ideal habitat for a wide variety of plant and animal species, some of which are threatened with extinction. For wildlife, riparian zones are a source of food, a refuge during breeding seasons and a travel corridor.
 
  • Ensures the regulation of the hydrological (water) cycle: Vegetation on the shores regulates the flow of water by slowing it down. This helps halt erosion and sedimentation that can ultimately lead to silting of bodies of water. By absorbing and storing the surplus water from rivers and precipitation, riparian zones act as buffers to reduce the risk of flooding and drought.
 
  • Creates a solar screen to limit the warming of the water and the formation of heat islands: Riparian vegetation creates zones of shade above water bodies, helping prevent excessive warming. This creates a microclimate. Any variation could threaten the survival of plant and animal species that are adapted to it. 
 
  • Preserves the aesthetic quality of the landscape: In addition to constituting a physical and visual transition zone between aquatic and terrestrial environments, riparian biodiversity is an essential structural element of the landscape. The natural beauty of these landscapes, among other things, contributes to increasing the value of nearby properties.
 

Protect the Shores

Protection and Preservation of the Shores (Riparian Zones)

Important: Any work carried out along shores (in the riparian zone) within the city limits of Brossard is strictly controlled by municipal and provincial regulations.
 
Under the zoning regulations in force, any work likely to destroy or modify the plant cover of the riparian zone, devegetate the ground or affect its stability are prohibited unless authorized by the Ministère du Développement durable de l’Environnement et de la Lutte contre les changements climatiques under the Environment Quality Act.
  • Leave the zone nearest the body of water in its natural state, by ceasing to mow it.
  • Avoid the nearby use of chemical or other fertilizers.
  • Revegetate it (replant approved species):
    • Consult the Directory of Recommended Plants for Revegetation of Quebec Riparian Zones to identify recommended species.
    • Opt for native Quebec vegetation of diverse ages and species, including herbaceous plants, shrubs and trees.
    • Ask an arborist or horticulturalist for information on planting and maintenance procedures specific to your vegetation 
    • Avoid planting invasive alien species because they can disperse and adversely affect the natural environment.
  • Permeable surfaces (vegetation, gravel, etc.) are to be preferred. Divert runoff waters toward vegetated areas located at a good distance from the body of water.
  • Limit the width of access areas to the body water to minimize the devegetated area.
For more information, or if you want to plan a revegetation of your shore, please contact Services Brossard at 450 923-6311 or e-mail services@brossard.ca


Additional Resources

  • RIVES flyer ( French only) : Useful document in Right Sector on Website
  • Protection Policy for Lakeshores, Riverbanks, Littoral Zones and Floodplains. Ministère du Développement durable et de l’Environnement et de la Lutte contre les changements climatiques (MDDELCC)  http://www.mddelcc.gouv.qc.ca/eau/rives/