Le Val-Saint-François County, Québec · Water Quality Report Card
Lac Desmarais
Lac Desmarais in Le Val-Saint-François, Québec received a water quality grade of B (Good). Water clarity: 2.6 m visibility. Phosphorus: 12.7 µg/L. Chlorophyll-a (algae): 4.5 µg/L.
- Clarity
- 2.6 m
- Type
- Mesotrophic
Lac Desmarais is a mesotrophic lake in Le Val-Saint-François County, Québec. Water quality is graded B based on 3 sampling years through 2025. Compared to the 9 other monitored lakes in Le Val-Saint-François County, Lac Desmarais ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, MELCCFP, last sampled 2025-08-01. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 8.5 ft. Phosphorus level: 12.7 µg/L. Chlorophyll-a: 4.5 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.6 m | C |
| Phosphorus | 12.7 µg/L | A |
| Chlorophyll-a (Algae) | 4.5 µg/L | A |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Lac Desmarais
Location
County Ranking
Ranked #4 of 10 lakes in Le Val-Saint-François
Cleaner Lakes Within 30 Miles
Lac Desmarais holds Grade B. 5 nearby lakes hold higher grades.
- APetit Lac BromptonLe Val-Saint-François · 0.9 mi · Higher grade (B → A)
- ALac MontjoieLe Val-Saint-François · 3.2 mi · Higher grade (B → A)
- ALac SimoneauMemphrémagog · 4.6 mi · Higher grade (B → A)
- ALac BromptonMemphrémagog · 2.3 mi · Higher grade (B → A)
- ALac des MontsMemphrémagog · 4.6 mi · Higher grade (B → A)
Nearby Lakes in Le Val-Saint-François
Explore Lac Desmarais across LakeGrade
More Québec Lake Rankings
Other Grade B Lakes in Québec
Mesotrophic Lakes in Québec
More records, surveys & data sources
Where this data comes from
Measurements for Lac Desmarais come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2025-08-01
Monitoring stations: