Contact us (French)
RSVL (Overview) (PDF, 571 kb)
RELAIS - Online Service (For existing RSVL lake monitoring participants)
Location of participating lakes (French, PDF, 1.1 Mb)
Methods used to assess lake trophic status
Water quality results (French)
Folder (French, PDF, 293 kb)
Application to join
the RSVL network
(Check if your lake meets the eligibility criteria listed on the left before registering)
Water Atlas - Lakes (French) .
Blue-green algae = cyanobacteria! (French)
Together with its partners, the Réseau de surveillance volontaire des lacs pursues the following objectives:
Certain eligibility criteria have been established to ensure that the water bodies listed in the RSVL meet the definition of a lake. The objective is to immediately exclude ponds and other wetlands for which the proposed monitoring would be less relevant.
To be eligible for the RSVL, a lake should, in the vast majority of cases, have the following characteristics:
You have until February 15 of each year to register a lake for the RSVL and be assured that the application can be assessed for the current year’s sampling season. Applications filed after February 15 will be considered for the following year.
Note that, in exceptional cases, some water bodies might not meet all the criteria but may still be eligible for the RSVL. Write to email@example.com if you have questions about the eligibility of a body of water.
In order to support the monitoring and protection of lakes, the Ministère will assume 75% of the fees provided for under the RSVL (French, PDF, 417 Kb) for three consecutive years, i.e. from 2021 to 2023. Consequently, in 2021, the cost for performing laboratory analyses is $120 per station. In addition to the cost of analyzing three samples per station, the total includes delivery and taxes. In addition, $69 is added to the cost for the acquisition of a Secchi Disk for each new station added to the network. Prices may change without prior notice.
No charges are incurred for years when participants only monitor water clarity.
For optimal results, participants who register a lake should commit to a long-term monitoring effort.
collecting water samples for laboratory measurements of phosphorus, dissolved organic carbon and chlorophyll a. All water analyses are performed by the Ministère’s laboratory, the Centre d’expertise en analyse environnementale du Québec (CEAEQ).
Transparency measurements and water samples are taken at a station generally located in the deepest part of the lake. For a very large lake, more than one station may be needed.
Using a Secchi disk, water transparency should be measured every two
weeks, from the beginning of June to the beginning of October, on an
Water transparency is an easy and inexpensive measure that can reveal long-term changes in water quality and the general state of the lake.
The basic water monitoring program was modified in 2010. The program
now involves sampling for two or three consecutive years, in
June, July and August. A pause of four years is taken before
For example, if the last sampling took place in 2010, sampling would resume in 2015 after a four-year break.
This monitoring plan is designed to achieve greater precision in estimating average concentrations of the water quality variables used to evaluate the lake’s trophic level.
The approach taken by the RSVL is to evaluate the precision obtained for each lake after a two-year monitoring period. Depending on the results, an optional third year of sampling may be suggested to the participants to improve precision. However, a participant may choose right from the start to sample for two or three consecutive years. After each additional year of sampling, precision of the mean concentration estimates will be recalculated. For lakes displaying a high variability, RSVL specialists could recommend that the number of samples taken annually be increased to improve precision.
The RSVL program is getting better with time
Analyses of the data collected since 2004 have revealed that in order to account for normal variations in water quality over the course of a summer and from year to year, the best monitoring strategy for the RSVL is to sample over several consecutive years. This allows obtaining enough data for average concentrations to be calculated with acceptable precision, while holding down the expense of laboratory analyses.
How many years of monitoring are required to obtain sufficient precision? This varies from lake to lake and from one water quality variable to another. Without being a stringent constraint, the total phosphorus parameter objective is to achieve a margin of error of within 20% of average value.
Field card (French, PDF, 204 KB)
Field card(PDF, 299 KB)
English versions available upon request.
Planning inventories (riparian strips and littoral zones) (French, PDF, 539 KB)
Field card (French, PDF, 1.5 MB)
Support document for the riparian strip characterization protocol (French, PDF, 3,9 MB)
RELAIS is an online service that allows RSVL participants to access their files, enter and/or change information and dialogue with RSVL managers at the Ministère.
As part of its 2019—2023 Strategic Plan, the Ministère wishes to improve access to information that is available on its website. Can we count on your co-operation by responding to a survey at the bottom of each page? This will enable us to evaluate how easy it was to find the information you were looking for.