How Clean Is Colby Lake?
Colby Lake is among the cleanest lakes in Minnesota. Its nutrient and algae readings come from EPA monitoring data. Water clarity (Secchi depth): 3 ft. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Trophic State Index: 51.
Cleanliness Snapshot
| Metric | Colby Lake | Minnesota avg |
|---|---|---|
| Water Clarity (Secchi) | 3 ft | — |
| Phosphorus | 22 µg/L | <30 = clean |
| Chlorophyll-a (Algae) | 3.2 µg/L | <10 = clean |
| Trophic State Index | 51 | <50 = clean |
How does Colby Lake compare?
Colby Lake's readings match or beat the Minnesota state average. It ranks #3 of 68 lakes in St. Louis County on nutrient and algae readings. Multi-year monitoring data shows water quality is declining based on 6 years of records.
Stays via Stay22
Where to stay near Colby Lake
Compare cabins, hotels, and vacation rentals near Colby Lake in St. Louis County, Minnesota. Live availability and prices for your nights. Switch the map to Satellite to see how close each stay is to the water.
Top-rated places to stay near Colby Lake
Prices for Nov 6–8, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Colby Lake?
Get lake water-quality updates plus the best cabin & lodging deals near Colby Lake — straight to your inbox. No spam, unsubscribe anytime.
Watch Colby Lake water quality
Get an email when the clarity or algae readings change. Unsubscribe anytime.