Protecting our lakes against eutrophication (or aging), requires protecting our shorelines first and foremost.

What is a riparian zone?

A riparian zone is a strip of land of 10 to 15 metres, depending on the steepness of the bank, that borders a lake or watercourse.

Why is it important to our lakes?

Riparian areas play a filtration role for the water that flows into the lakes, largely because of their complex networks of roots. The effectiveness of this filtration also depends on the composition of the soil. Plants that are indigenous to the area are better adapted to local conditions, and can grow in abundance on the shoreline.

The riparian zone can limit the infiltration of products like phosphorus and nitrogen into the lake. The richer a shoreline is in plant life, the more it serves to slow the eutrophication of the lake.

Situation in the Cedar lakes

The Cedar lakes are oligotrophic, which means they are not advanced in their aging. Our objective is to slow the aging process—eutrophication—as much as possible. To do this, it’s important to pay attention to the evolution of our shorelines, through study of our riparian zones.

We also do water quality tests to gather information on the amounts of phosphorus, chlorophyll and organic carbon in the water, and we annually test the transparency of the water (see our page on water quality testing).

Over a number of years, we can see how our management of our shorelines affects the results of our water tests.

See the reports:
Grand lac des Cèdres
Petit lac des Cèdres

What measures can we take?

• Reduce our phosphorous and nitrogen usage and waste. These are the main causes of excessive plant growth involved in the eutrophication of lakes. They are found in certain detergents, soaps, garden fertilizers and waste water generally. Limiting the use of these products, inspecting septic systems regularly and letting plants grow naturally (at least in the 15 metres closest to the shoreline) are all actions we can take to help our lakes.
• Manage the riparian zones on our properties so that they return to natural and native vegetation. A degraded riparian zone can be improved by planting species that require very little care. The Government of Quebec proposes a variety of plants, well adapted to our climate: https://drive.google.com/file/d/1RHDVSIhiSpHERsPX6I0VRUPWQ2iyViXk/view?usp=sharing.

What is the APLC doing?

• We are studying the riparian zone as part of evaluating the health of our lakes. This includes describing and identifying the location of different types of soils and characterizing the different environments around the lake, to see what role these play in lake quality. The idea is that, the less the land is developed, the more it is able to filter water and the healthier the lake will be.
• We are raising awareness amongst residents. Our studies and observations of the shoreline are not only for information. We can all use this information to voluntarily make changes on our own properties that will have benefits for our lake now and for generations to come.
• We regularly try to organize the distribution of trees that can be planted near our shorelines (see this page).

History of APLC actions

2022

• Compilation of data and production of reports for each lake.
• Finalize the characterization of the riparian zone of the Lakes des Cèdres carried out by two students, following the protocols of the RSVL (Voluntary Lake Monitoring Network). https://www.environnement.gouv.qc.ca/eau/rsvl/bande_riveraine.pdf 

2021

• Characterization of the riparian zone of the two lakes by two students following the protocols of the RSVL (Réseau de surveillance volontaire des lacs). https://www.environnement.gouv.qc.ca/eau/rsvl/bande_riveraine.pdf
• This work resulted in a categorization of each zone studied. There are three management categories:
  • Natural vegetation: The shoreline is in its most natural state.
  • Ornamental vegetation: There has been some development with the removal of trees (grass, flowers, etc.).
  • Inert materials: All permanent infrastructure and material that is not of a natural origin and that could block the passage of water (cottage, porch, walls, embankments).

1986

• The Shorleine Restoration Program was undertaken by the Clean Lake Association, founded by Ron Ensom.

In 1986, the predecessor to the APLC undertook a study of the destruction of the shoreline of Petit lac des Cèdres. Compared to the results in 2021, despite different methodologies, we see an improvement in the past 35 years. For example, the surface area of natural vegetation on the shorelines has increased by 11%.

Since the 1980s, we’ve seen the impact of efforts to raise awareness about the importance of protecting our 15-metre riparian zones, and of reforestation campaigns.