Washburn Lake
Cass County, Minnesota1,590 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Washburn Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- Eurasian watermilfoil
- 111 ft max depth
- Public access
Washburn Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14.1 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.7 µg/L. Maximum depth: 111 ft. Surface area: 1590.19 acres.
Minnesota DNR's Targeted Survey on August 5, 2024 caught 2.33 walleye per gill net at Washburn Lake. Length samples in the latest survey that recorded them ran 7–15 inches. DNR survey details →
Free interactive depth-contour map of Washburn Lake, reaching a maximum surveyed depth of 100 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Washburn Lake is a 1,590-acre mesotrophic lake in Cass County, Minnesota with a maximum depth of 111 feet. Overall water quality is improving over recent sampling years. The lake supports 21 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Washburn Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-25. Methodology: how these readings are compared.
Washburn Lake covers about 1,600 acres in Cass County. It has one public boat landing. The median ice-out date is April 19, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Washburn Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Washburn Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.1 ft of visibility
- Boat launch1 documented ramp
- Fishing21 species recorded
- Ice seasonIce-out around Apr 19
- Deep water111 ft surveyed max depth
- Big water1,590 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. Washburn Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Washburn 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 Washburn Lake
These are the measurements Minnesota PCA publishes for Washburn Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14.1 ft. Phosphorus 11 µg/L. Chlorophyll-a 3.7 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 3.7µg/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. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Washburn Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Washburn Lake typically sits around 64°F at the surface in September. Summer average is about 72°F. Usually warmest in Jul (about 76°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (59°F) to its warmest (76°F).
Typical surface water temperature by month, from 33 field readings (2011–2023) via the EPA Water Quality Portal. See the full Washburn Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Washburn Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (173,780 cells/mL) on May 9, 2026.
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 August 5, 2024 caught 2.33 walleye per gill net at Washburn Lake. Length samples in the latest survey that recorded them ran 7–15 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Washburn 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
27 surveys on file from MN DNR Fisheries. Most recent: 2025-09-24 (Targeted Survey).
27 surveys on file · most recent 2025-09-24 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Spottail Shiner | 18.36 | ||
| Golden Shiner | 14.13 | ||
| Bluntnose Minnow | 14.04 | ||
| Walleye | 9.32 | 7–15 in 2025-09-24 | 1.12 lb |
| Bluegill | 7.58 | 3–9 in 2024-08-05 | 0.21 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.
Walleye
Bluegill
From the 2025-09-24 survey
Walleye are currently stocked in Washburn as frylings (when available) or fingerlings in alternate (even-numbered) years. Night electrofishing was conducted on September 24th, 2025, to assess young-of-the-year (YOY) Walleye abundance. The total sample time was 2 hours, which resulted in no YOY Walleye being captured.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Washburn Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — WashburnFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Washburn (1491)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — WashburnFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — WashburnPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
111 ft
Surface area
1,590 acres
Shoreline
19.8 mi
Littoral zone
47%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
42 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,312 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Washburn 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 Washburn Lake
Compare lakeside cabins, hotels, and vacation rentals near Washburn Lake in Cass 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 Washburn Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Washburn 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
Stable6 years
Phosphorus
Stable+0.2 µg/L/yr6 years
Chlorophyll-a
Improving-0.09 µg/L/yr6 years
Ice season
Typical ice-out
Apr 19
Earliest Mar 16, 2024 · Latest May 6, 2008
Typical ice-in
Dec 1
Earliest Nov 24, 2006 · Latest Dec 20, 2001
Most recent ice-out
Mar 16
2024
54 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Washburn Lake is a man-made reservoir impounded by the Washburn Lake (completed 1936), built primarily for recreation on the Daggett Brook; gravity-type dam, 7 ft tall and 39 ft long.
- Surface area
- 1,554 ac
- Normal storage
- 68,165 ac-ft
- Max storage
- 72,776 ac-ft
- Drainage area
- 43.3 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00043 · Operator website
EPA Impairment Status
Washburn 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 MN11-0059-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Washburn Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Mdnr Spire Valley HatcheryRemer · 2.2 mi away · NPDES MN0069710Recent 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 Cass County
Frequently asked questions about Washburn Lake
Where is Washburn Lake?
- Washburn Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Washburn Lake?
- Washburn Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14.1 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.7 µg/L. Maximum depth: 111 ft. Surface area: 1590.19 acres.
Is Washburn Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Washburn 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 Washburn Lake?
- Washburn Lake typically sits around 64°F at the surface in September, from 33 EPA Water Quality Portal field readings (2011–2023). That is a typical value for the month, not a live reading.
How deep is Washburn Lake?
- Washburn Lake has a maximum depth of 111 feet. The lake covers 1590.19 acres.
What fish are in Washburn Lake?
- Fish species found in Washburn Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, greater redhorse, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, sunfish, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Washburn Lake is located in Cass County, Minnesota.
What did the DNR fisheries survey find at Washburn Lake?
- Minnesota DNR's Targeted Survey on August 5, 2024 caught 2.33 walleye per gill net at Washburn Lake. Length samples in the latest survey that recorded them ran 7–15 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Washburn 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 Washburn Lake thaw?
- Washburn Lake typically has ice-out around Apr 19. Ice typically forms around Dec 1. The open water season is approximately 226 days.
Does Washburn Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Washburn Lake (clouds, ice, or an off-season gap). The most recent reading was high (173,780 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Washburn Lake?
- Washburn Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Washburn Lake. Public access is listed as yes.
Can I fish at Washburn Lake?
- Washburn 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 Washburn Lake across LakeQuality
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Where this data comes from
433 measurements from 7 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
MNPCA433 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Phosphorus by Colorimetry
Monitoring station identifiers (7)
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