RELAIS - Online Service (For existing RSVL lake monitoring participants)
Contact us (French)
Location of participating lakes (French, PDF, 1.1 Mb)
Water quality results (French)
Folder (French, PDF, 293 kb)
Application to join
the RSVL network
(To add a new lake to the network only)
Together with its partners, the Réseau de surveillance volontaire des lacs pursues the following objectives:
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.
In order to support the monitoring and protection of lakes, the Ministère will assume 75% of the fees associated with the RSVL (French, PDF, 417 Kb) for the next three years. 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 accompanying documentation, 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 are subject to change without prior notice.
No charges are incurred for years when participants only monitor water clarity.
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 (PDF, 170 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.