Trois-Lacs Restoration Project in the MRCs of Arthabaska and des Sources
Type of initiative
FCM Green Municipal Fund - Plans, Studies, Pilots
Sector
Water
Project value$1,905,370
Project Type
Pilot Project
Sub Sector
Watershed Management
Grant amount$350,000
Program type
GMF
Municipality
MRC des Sources, QC
Status
Fully Disbursed
Population
14,623
Project timeline
2011 - 2015
Project number
10408
Description
The Régie intermunicipale de restauration et de préservation des Trois Lacs (RIRPTL) will test a restoration project on the Trois-Lacs basins, located approximately 60 kilometres from Sherbrooke, in order to prevent the acceleration of the lake’s eutrophication that is attributable to the massive amounts of anthropogenic nutrients and sediment that have accumulated over the last few decades.
Several measures have been taken to reduce the amount of sediment that has seeped into the lake and many others will be taken in the coming years, but a large-scale intervention has become necessary to prevent further damage to the lake. The chosen solution involves testing the soil suction of the silty sediment layer in which the aquatic plants are rooted in eleven targeted zones. Previous studies have shown that this method creates the least amount of disturbance to the ecosystem. The sediment will be pumped with a hydraulic dredge into two settling basins created from old sand pits. Once dried, the sediment will be used for restoration work at mining dumps. The restoration activities will take place over a period of approximately one month for three consecutive years and will improve, among others, the water quality by reducing the area and density of aquatic grass and favouring a decrease in the turbidity of the water.
The RIRPTL, along with the provincial environment department, developed a vast environmental follow-up program that aims at verifying the scope of certain repercussions identified during the impact study and measuring the effectiveness of the mitigation measures. The follow-up program will measure, among other things, the water quality, the plant regrowth rate in the excavated areas, as well as the state of fish and herpetofauna communities. This project, which was authorized by decree of the Government of Quebec, is part of a vast restoration plan for the lake’s watershed and is closely related to the actions of the water master plan for the Trois-Lacs watershed. The results obtained during this field test will allow the RIRPTL to plan the second phase of the intervention.
(Project description from original funding application)
Applicant
Régie intermunicipale de restauration et de préservation des Trois Lacs (RIPTL), QC