Blanche Lake
Blanche Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12.5 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 4.5 µg/L. Maximum depth: 64 ft. Surface area: 1295.92 acres.
- Clarity
- 12.5 ft
- Typical in August
- 74°F
- Max depth
- 64 ft
- Area
- 1,296 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 20
- Open water
- 225 days
Next lake in Otter Tail County
Free interactive depth-contour map of Blanche Lake, reaching a maximum surveyed depth of 60 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Blanche Lake is a 1,296-acre mesotrophic lake in Otter Tail County, Minnesota with a maximum depth of 64 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including black crappie, bluegill, and hybrid sunfish. Public access is available with 1 public boat landing. Compared to the 65 other monitored lakes in Otter Tail County, Blanche Lake ranks #24 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-27. 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)
Good clarity, visible to about 12.5 ft. Phosphorus level: 11 µg/L. Chlorophyll-a: 4.5 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | 11 µg/L | Good |
| Chlorophyll-a (Algae) | 4.5 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Blanche Lake
Compare lakeside cabins, hotels, and vacation rentals near Blanche 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.
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Water Temperature
Blanche Lake typically sits around 74°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 108 field readings (2011–2025) via the EPA Water Quality Portal. See the full Blanche Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Blanche Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (11,912 cells/mL) on November 15, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 64 ft |
| Surface Area | 1,296 acres |
| Shoreline Length | 5.6 mi |
| Littoral Zone | 77% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Blanche LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Blanche 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.
DNR Fisheries Survey Summary
7 surveys on file from MN DNR Fisheries. Most recent: 2025-06-12 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 29.05 | 0.16 lb |
| Largemouth Bass | 8.98 | 0.63 lb |
| Pumpkinseed | 6.20 | 0.25 lb |
| Northern Pike | 3.63 | 0.82 lb |
| Yellow Bass | 2.89 | 0.76 lb |
| Walleye | 2.23 | 1.31 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Largemouth Bass
Pumpkinseed
Northern Pike
From the 2025-06-12 survey
Blanche Lake is a 1,228-acre mesotrophic (moderately fertile) lake located in central Otter Tail County approximately four miles northeast of Battle Lake, MN. An inlet from Annie Battle Lake is located on the southwest shoreline and an outlet to Otter Tail Lake is located on the north shoreline. The immediate…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Blanche Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BlancheFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Blanche (1176)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — BlancheFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — BlanchePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.03 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.41 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.23 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (26 observations).
Estimated open water season: 225 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2016-03-15 (2016) | 2013-05-09 (2013) |
| Ice-In | 2006-11-20 (2006) | 2017-12-07 (2017) |
Most recent ice-out: 2023-04-28
Reservoir Info (USACE NID)
Blanche Lake is a man-made reservoir impounded by the Blanche Lake (completed 1938), built primarily for recreation on the Blanche Creek; gravity-type dam, 7 ft tall and 83 ft long.
- Surface area
- 1,352 ac
- Normal storage
- 20,400 ac-ft
- Max storage
- 24,500 ac-ft
- Drainage area
- 160 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00214 · Operator website
EPA Impairment Status
Blanche 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 MN56-0240-00 · Official waterbody report
County Ranking
Ranked #24 of 66 lakes in Otter Tail County
Nearby Lakes in Otter Tail County
Frequently asked questions about Blanche Lake
What is the water quality grade for Blanche Lake?
- Blanche Lake in Otter Tail County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12.5 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 4.5 µg/L. Maximum depth: 64 ft. Surface area: 1295.92 acres.
Is Blanche Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Blanche Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Blanche Lake?
- Blanche Lake typically sits around 74°F at the surface in August, from 108 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Blanche Lake?
- Blanche Lake has a maximum depth of 64 feet. The lake covers 1295.92 acres.
What fish are in Blanche Lake?
- Fish species found in Blanche Lake include black crappie, bluegill, hybrid sunfish, pumpkinseed. Blanche Lake is located in Otter Tail County, Minnesota.
When does Blanche Lake thaw?
- Blanche Lake typically has ice-out around Apr 20. Ice typically forms around Dec 1. The open water season is approximately 225 days.
Does Blanche Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Blanche Lake (clouds, ice, or an off-season gap). The most recent reading was low (11,912 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Blanche Lake?
- Blanche Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Blanche Lake. Public access is listed as yes.
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Where this data comes from
188 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA188 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 (4)
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)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate