Chain Lake
Chain Lake in Chisago County, Minnesota has a water quality grade of A (Excellent). Water clarity: 5.9 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 2.7 µg/L.
- Clarity
- 5.9 ft
- Typical in August
- 76°F
- Mean depth
- ~12 ft est.
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- No
Next lake in Chisago County
Chain Lake is a mesotrophic lake in Chisago County, Minnesota with an estimated average depth of about 12 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 29 other monitored lakes in Chisago County, Chain Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Grade methodology: LakeGrade methodology.
Watch Chain Lake water quality
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Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Murky, only visible to about 5.9 ft. Phosphorus level: 16 µg/L. Chlorophyll-a: 2.7 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.9 ft | Not graded |
| Phosphorus | 16 µg/L | Good |
| Chlorophyll-a (Algae) | 2.7 µg/L | Good |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Chain Lake
Compare lakeside cabins, hotels, and vacation rentals near Chain Lake in Chisago County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Water Temperature
Chain Lake typically sits around 76°F at the surface in August. Summer average is about 79°F. Usually warmest in Jul (about 83°F) and coldest in Sep (about 71°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 15 field readings (2023–2025) via the EPA Water Quality Portal. See the full Chain Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~12 ft est. |
| Public Access | No |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Chain Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Chain Lake
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.2 m/yr | 3 |
| Phosphorus | ↓ Declining | +7.25 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -1.85 µg/L/yr | 3 |
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Chain Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- North Branch WwtpNorth Branch · 2.4 mi away · NPDES MN0024350Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #10 of 30 lakes in Chisago County
Nearby Lakes in Chisago County
Frequently asked questions about Chain Lake
What is the water quality grade for Chain Lake?
- Chain Lake in Chisago County, Minnesota has a water quality grade of A (Excellent). Water clarity: 5.9 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 2.7 µg/L.
Is Chain Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Chain Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.7 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Chain Lake?
- Chain Lake typically sits around 76°F at the surface in August, from 15 EPA Water Quality Portal field readings (2023–2025). That is a typical value for the month, not a live reading.
How deep is Chain Lake?
- No published bathymetric survey covers Chain Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 12 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Chain Lake across LakeGrade
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Fish species and best lakes in Chisago County
Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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State Parks Near Chain Lake
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
45 measurements from 2 monitoring stations, 2023–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA45 samples · 2023–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (2)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder