Rainy River District County, Ontario · Water Quality Report Card
Rainy Lake
Rainy Lake in Rainy River District, Ontario received a water quality grade of B (Good). Water clarity: 2.8 m visibility. Phosphorus: 13.9 µg/L.
- Clarity
- 2.8 m
- Type
- Mesotrophic
Rainy Lake is a mesotrophic lake in Rainy River District County, Ontario. Water quality is graded B based on 2 sampling years through 2025. Compared to the 79 other monitored lakes in Rainy River District County, Rainy Lake ranks #42 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2025-09-28. 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 9.2 ft. Phosphorus level: 13.9 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.8 m | C |
| Phosphorus | 13.9 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Rainy Lake
Location
County Ranking
Ranked #42 of 80 lakes in Rainy River District
Cleaner Lakes Within 30 Miles
Rainy Lake holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Rainy River District
Explore Rainy Lake across LakeGrade
More Ontario Lake Rankings
Other Grade B Lakes in Ontario
Mesotrophic Lakes in Ontario
More records, surveys & data sources
Where this data comes from
Measurements for Rainy Lake 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: 2025-09-28
Monitoring stations: