Lake Granby is a mesotrophic lake in Grand County, Colorado. Water quality is graded A based on 3 sampling years through 2024. Compared to the 5 other monitored lakes in Grand County, Lake Granby ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Colorado DNR, last sampled 2024-01-31. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 12.7 ft. Phosphorus level: 17 µg/L. Chlorophyll-a: 1.7 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.7 ft | B |
| Phosphorus | 17 µg/L | A |
| Chlorophyll-a (Algae) | 1.7 µg/L | A |
| Trophic State Index (TSI) | 40 | Mesotrophic |
Moderate nutrients, good water quality
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Fishing Lake Granby
Location
County Ranking
Ranked #1 of 6 lakes in Grand County
Nearby Lakes in Grand County
Explore Lake Granby across LakeGrade
More Colorado Lake Rankings
Other Grade A 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: 2024-01-31
Monitoring stations: 4