Grand Lake is a mesotrophic lake in Grand County, Colorado. Water quality is graded B based on 3 sampling years through 2024. Compared to the 5 other monitored lakes in Grand County, Grand Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Colorado DNR, last sampled 2024-01-30. 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 8.9 ft. Phosphorus level: 14 µg/L. Chlorophyll-a: 2.7 µg/L. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.9 ft | C |
| Phosphorus | 14 µg/L | A |
| Chlorophyll-a (Algae) | 2.7 µg/L | A |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Grand Lake
Location
County Ranking
Ranked #3 of 6 lakes in Grand County
Cleaner Lakes Within 30 Miles
Grand Lake holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Grand County
Explore Grand Lake across LakeGrade
More Colorado Lake Rankings
Other Grade B Lakes in Colorado
Mesotrophic Lakes in Colorado
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-01-30
Monitoring stations: 2