Prairie Lake
Otter Tail County, Minnesota1,004 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Prairie Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- zebra mussel
- 22 ft max depth
- Public access
Prairie Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8.9 ft visibility. Phosphorus: 18 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Maximum depth: 22 ft. Surface area: 1004.41 acres.
Minnesota DNR's Targeted Survey on June 4, 2024 caught 30.59 largemouth bass per hour of electrofishing at Prairie Lake. Length samples in the latest survey that recorded them ran 4–20 inches. DNR survey details →
Free interactive depth-contour map of Prairie Lake, reaching a maximum surveyed depth of 20 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Prairie Lake is a 1,004-acre mesotrophic lake in Otter Tail County, Minnesota with a maximum depth of 22 feet (10-foot average). Overall water quality is improving over recent sampling years. The lake supports 15 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing. Compared to the 65 other monitored lakes in Otter Tail County, Prairie Lake ranks #50 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Methodology: how these readings are compared.
What Prairie Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing15 species recorded
- Ice seasonIce-out around Apr 7
- Big water1,004 acres
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Prairie Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Prairie Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Prairie Lake
These are the measurements Minnesota PCA publishes for Prairie Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 8.9 ft. Phosphorus 18 µg/L. Chlorophyll-a 7.3 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 18µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 7.3µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Prairie Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Prairie Lake typically sits around 66°F at the surface in September. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (58°F) to its warmest (80°F).
Typical surface water temperature by month, from 27 field readings (2010–2021) via the EPA Water Quality Portal. See the full Prairie Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Prairie Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (77,983 cells/mL) on November 22, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Targeted Survey on June 4, 2024 caught 30.59 largemouth bass per hour of electrofishing at Prairie Lake. Length samples in the latest survey that recorded them ran 4–20 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Prairie Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2024-06-04 (Targeted Survey).
10 surveys on file · most recent 2024-06-04 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 27.00 | 2–8 in 2024-06-03 | 0.17 lb |
| Largemouth Bass | 8.80 | 4–20 in 2024-06-04 | 1.28 lb |
| Yellow Bullhead | 7.64 | 7–12 in 2019-07-29 | 0.54 lb |
| Pumpkinseed | 6.05 | 4–8 in 2024-06-03 | 0.24 lb |
| Northern Pike | 5.22 | 4–30 in 2019-07-29 | 1.37 lb |
| Hybrid Sunfish | 3.78 | 3–8 in 2024-06-03 | 0.28 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Yellow Bullhead
Pumpkinseed
From the 2024-06-04 survey
Prairie Lake is a 1,016-acre eutrophic (fertile) lake located in northwestern Otter Tail County. The city of Pelican Rapids, MN abuts the south shoreline of the lake. Prairie Lake is part of the Otter Tail River Watershed. The Pelican River inlet is located along the northeast shoreline while the outlet is located…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Prairie Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — PrairieFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Prairie (1040)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — PrairieFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — PrairiePublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
22 ft
Average depth
10 ft
Surface area
1,004 acres
Shoreline
7.3 mi
Littoral zone
80%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
342 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,302 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Prairie LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Prairie Lake
Compare lakeside cabins, hotels, and vacation rentals near Prairie 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 Prairie Lake
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Follow Prairie Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Prairie 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: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-1.06 µg/L/yr6 years
Chlorophyll-a
Improving-0.46 µg/L/yr6 years
Ice season
Typical ice-out
Apr 7
Earliest Mar 30, 2021 · Latest May 5, 2022
Most recent ice-out
Apr 10
2025
4 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Prairie Lake is a man-made reservoir impounded by the Prairie Lake (completed 1936), built primarily for recreation on the Pelican River; gravity-type dam, 12 ft tall and 49 ft long.
- Surface area
- 1,025 ac
- Normal storage
- 10,250 ac-ft
- Max storage
- 16,400 ac-ft
- Drainage area
- 340 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00192 · Operator website
EPA Impairment Status
Prairie Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN56-0915-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Prairie Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Pelican Rapids WwtpPelican Rapids · 2.2 mi away · NPDES MN0022225Recent 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.
Nearby Lakes in Otter Tail County
Frequently asked questions about Prairie Lake
Where is Prairie Lake?
- Prairie Lake is a lake in Otter Tail County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Prairie Lake?
- Prairie Lake in Otter Tail County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 8.9 ft visibility. Phosphorus: 18 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Maximum depth: 22 ft. Surface area: 1004.41 acres.
Is Prairie Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Prairie Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Prairie Lake?
- Prairie Lake typically sits around 66°F at the surface in September, from 27 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Prairie Lake?
- Prairie Lake has a maximum depth of 22 feet and an average depth of 10 feet. The lake covers 1004.41 acres.
What fish are in Prairie Lake?
- Fish species found in Prairie Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Prairie Lake is located in Otter Tail County, Minnesota.
What did the DNR fisheries survey find at Prairie Lake?
- Minnesota DNR's Targeted Survey on June 4, 2024 caught 30.59 largemouth bass per hour of electrofishing at Prairie Lake. Length samples in the latest survey that recorded them ran 4–20 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Prairie Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Prairie Lake thaw?
- Prairie Lake typically has ice-out around Apr 7.
Does Prairie Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Prairie Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (77,983 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Prairie Lake?
- Prairie Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Prairie Lake. Public access is listed as yes.
Can I fish at Prairie Lake?
- Prairie Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Prairie Lake across LakeQuality
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Where this data comes from
88 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
MNPCA88 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)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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