Bass Lake
Bass Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.4 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.5 µg/L.
- Clarity
- 17.4 ft
- Typical in August
- 74°F
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in Otter Tail County
Bass Lake is a cold, clear oligotrophic lake in Otter Tail County, Minnesota. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 65 other monitored lakes in Otter Tail County, Bass Lake ranks #14 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-25. Grade methodology: LakeGrade methodology.
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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)
Crystal clear, you can see 17.4 ft down. Phosphorus level: 14 µg/L. Chlorophyll-a: 2.5 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17.4 ft | Not graded |
| Phosphorus | 14 µg/L | Good |
| Chlorophyll-a (Algae) | 2.5 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Bass Lake
Compare lakeside cabins, hotels, and vacation rentals near Bass Lake in Otter Tail 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 Bass Lake
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Water Temperature
Bass Lake typically sits around 74°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 77°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 24 field readings (2010–2021) via the EPA Water Quality Portal. See the full Bass Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Bass Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (26,546 cells/mL) on April 12, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Fishing Bass Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.051 m/yr | 6 |
| Phosphorus | → Stable | -0.14 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.13 µg/L/yr | 6 |
EPA Impairment Status
Bass Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN56-0786-00 · Official waterbody report · Matched by proximity (1.67 km)
County Ranking
Ranked #14 of 66 lakes in Otter Tail County
Nearby Lakes in Otter Tail County
Frequently asked questions about Bass Lake
What is the water quality grade for Bass Lake?
- Bass Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.4 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 2.5 µg/L.
Is Bass Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Bass Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Bass Lake?
- Bass Lake typically sits around 74°F at the surface in August, from 24 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
Does Bass Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Bass Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (26,546 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Bass Lake across LakeGrade
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Where this data comes from
90 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA90 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)