Lac Saint-Augustin (lake)

The City is fortunate to have a lake in its urban environment. With the health of this lake ever at heart, the City works in close cooperation with the Conseil de bassin versant du lac Saint-Augustin.

Nautical activities

Swimming : forbidden at all times

Boating allowed. Maximum speeds are 10 km per hour 20 metres or less from the lakeshore and 55 km per hour on the lake.


Two public accesses for boats: Camping Juneau for motor boats and the Parc Riverain[ML1]  for lightweight, non-motorized craft that can be carried from the parking lot located 130 metres from the lake.

Lac Saint-Augustin is where the dragon boat club holds its practices.



The Riparian Buffer Strip

The riparian buffer strip plays an important role in maintaining the health of a lake. It marks the transition between land and water and is characterized by river vegetation: trees, shrubs and herbaceous plants. Allowing the riparian buffer strip to remain in its natural state protects the shoreline – the part of the lake teaming with life that serves as the lake’s nursery. 

The impact of maintaining lake shores

  • Shores trap sediment and nutrients  before they run into the lake;
  • Shores prevent the erosion of banks through the protective action of the root systems of riparian plants that serve as shields against the erosive effects of waves and ice; 
  • Shores act like reflectors to prevent the sun’s rays from warming shoreline water and encouraging blue-green algae bloom;
  • Shores promote the maintenance of flora and fauna that inhabit the land and water ecosystem.

 What can I do?

  • Stop cutting the grass and let nature follow its course;
  • Complete any existing regeneration by planting vegetation and recreating blends of indigenous vegetation already present along the shoreline;
  • Landscape using primarily indigenous, adapted varieties of plants.


Prevention of blue-green algae

The City has launched a program jointly with the Ministère des Affaires municipales et de l’Occupation du territoire and the Conseil de bassin versant du lac Saint-Augustin. The purpose of the two-phase program is to heighten the awareness of shoreline property owners regarding the phenomenon of the proliferation of blue-green algae.

Other action taken includes replanting along the shoreline and extensions to the water and sewer system networks on the north side of the lake.

The phenomenon of cyanobacteria is not new in itself. It has been present since the 1960s and has progressed since. Direct, natural action to mitigate its effects is possible through the development of strata of herbaceous plants and shrubs along the lake’s shores.

Therefore, we must limit the input of nitrogen, phosphorus and pesticides, eliminate septic systems and prohibit the use of pesticides, fertilizers and compost within the first 30 metres of the lake. The prohibition on the use of pesticides may only be lifted in the event of a major infestation in the band located 30 to 300 metres around the lak

Guide algues bleu-vert : Consultez le Guide du riverain

Research on the Lake

Several studies have been conducted on the lake. The most recent study was by Université Laval students who carried out a series of tests leading to possible sediment capping in Lac Saint-Augustin. This technique consists of isolating polluted sediment in a body of water by covering it with stable layers of natural material that will curb, even prevent, the contamination of the water and aquatic flora and fauna.  

Application of Salt in Winter

The City of Saint-Augustin-de-Desmaures continues to take concrete action to preserve Lac Saint-Augustin and has adopted a new approach to managing the application of salt on the streets of some neighbourhoods near the lake.  

The sector covered by the restriction includes the area bordered by Chemin du Lac, Rue de la Desserte, Chemin de la Butte, Rue de l’Hêtrière and Rue de l’Artimon towards the lake.

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For safety reasons, some sections of streets and main roads are maintained with an application of a salt and gravel mixture with a 5% salt content. The same applies to all street intersections, and roads with stop signs and traffic lights. This practice is already implemented for streets located on the north side of the lake.  

Drivers must adapt their driving to this context. If weather conditions become hazardous or dangerous, safety is always prioritized.