Chain: South Lake
Chain: South Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 5.6 µg/L.
- Clarity
- 11 ft
- Typical in August
- 73°F
- Mean depth
- ~14 ft est.
- Type
- Mesotrophic
- Trend
- ↑ Improving
Next lake in Beltrami County
Chain: South Lake is a mesotrophic lake in Beltrami County, Minnesota with an estimated average depth of about 14 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 84 other monitored lakes in Beltrami County, Chain: South Lake ranks #51 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Grade methodology: LakeGrade methodology.
Watch Chain: South Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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)
Good clarity, visible to about 11 ft. Phosphorus level: 14 µg/L. Chlorophyll-a: 5.6 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11 ft | Not graded |
| Phosphorus | 14 µg/L | Good |
| Chlorophyll-a (Algae) | 5.6 µg/L | Good |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Chain: South Lake
Compare lakeside cabins, hotels, and vacation rentals near Chain: South Lake in Beltrami 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.
Top-rated places to stay near Chain: South Lake
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 whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Chain: South Lake typically sits around 73°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in Feb (about 33°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 65 field readings (2010–2025) via the EPA Water Quality Portal. See the full Chain: South Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~14 ft est. |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Chain: South 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: South Lake
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.547 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.1 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.35 µg/L/yr | 6 |
County Ranking
Ranked #51 of 85 lakes in Beltrami County
Nearby Lakes in Beltrami County
Frequently asked questions about Chain: South Lake
What is the water quality grade for Chain: South Lake?
- Chain: South Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 5.6 µg/L.
Is Chain: South Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Chain: South Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 5.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Chain: South Lake?
- Chain: South Lake typically sits around 73°F at the surface in August, from 65 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Chain: South Lake?
- No published bathymetric survey covers Chain: South Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 14 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: South Lake across LakeGrade
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Beltrami County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Mississippi Headwaters, ranked by water quality
Moderate nutrients, good water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Chain: South Lake
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
86 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Red Lake DNR
REDLAKE_WQX86 samples · 2020–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
Monitoring station identifiers (1)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder