Muskoka District County, Ontario · Water Quality Report Card
Riley Lake
Riley Lake in Muskoka District, Ontario received a water quality grade of B (Good). Water clarity: 2 m visibility. Phosphorus: 14.4 µg/L.
- Clarity
- 2 m
- Type
- Mesotrophic
Riley Lake is a mesotrophic lake in Muskoka District County, Ontario. Water quality is graded B based on 2 sampling years through 2025. Compared to the 169 other monitored lakes in Muskoka District County, Riley Lake ranks #150 for water quality.
Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2025-10-05. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Murky, only visible to about 6.6 ft. Phosphorus level: 14.4 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 m | D |
| Phosphorus | 14.4 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Riley Lake
Location
County Ranking
Ranked #150 of 170 lakes in Muskoka District
Cleaner Lakes Within 30 Miles
Riley Lake holds Grade B. 2 nearby lakes hold higher grades.
- AClearwater LakeMuskoka District · 3.8 mi · Higher grade (B → A)
- BKahshe LakeMuskoka District · 3.8 mi · Higher overall water quality score
Nearby Lakes in Muskoka District
Explore Riley 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 Riley 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: 2025-10-05
Monitoring stations: