Deep Lake
Washburn County, Wisconsin43 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Deep Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 25 ft max depth
- Public access
Deep Lake in Washburn County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 7.5 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 25 ft. Surface area: 43 acres.
Wisconsin DNR rates Panfish and Largemouth Bass as abundant on Deep Lake. DNR survey details →
Deep Lake is a 43-acre mesotrophic lake in Washburn County, Wisconsin with a maximum depth of 25 feet. Overall water quality is improving over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 26 other monitored lakes in Washburn County, Deep Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-11-17. Methodology: how these readings are compared.
What Deep Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing4 species recorded
Swimming conditions
Readings onlyRecreation use not supported
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. Deep Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Deep Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Deep Lake
These are the measurements Wisconsin DNR publishes for Deep 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 7.5 ft. Phosphorus 16.5 µg/L. TSI 46.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 16.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Deep Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Deep Lake typically sits around 65°F at the surface in October. Summer average is about 75°F. Usually warmest in Jul (about 77°F) and coldest in Nov (about 45°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (45°F) to its warmest (77°F).
Typical surface water temperature by month, from 39 field readings (2024–2025) via the EPA Water Quality Portal. See the full Deep Lake water temperature breakdown →
Wisconsin DNR rates Panfish and Largemouth Bass as abundant on Deep Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Deep 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.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1968. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
25 ft
Surface area
43 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,253 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Deep 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 Deep Lake
Compare lakeside cabins, hotels, and vacation rentals near Deep Lake in Washburn County, Wisconsin — 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 Deep Lake
Prices for Oct 16–18, 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 Wisconsin’s top lakes →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Deep Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-3.82 µg/L/yr6 years
EPA Impairment Status
Deep Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit WI10004500 · Official waterbody report
Nearby Lakes in Washburn County
Frequently asked questions about Deep Lake
Where is Deep Lake?
- Deep Lake is a lake in Washburn County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Deep Lake?
- Deep Lake in Washburn County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 7.5 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 25 ft. Surface area: 43 acres.
Is Deep Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Deep Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Deep Lake?
- Deep Lake typically sits around 65°F at the surface in October, from 39 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Deep Lake?
- Deep Lake has a maximum depth of 25 feet. The lake covers 43 acres.
What fish are in Deep Lake?
- Fish species found in Deep Lake include Musky, Panfish, Largemouth Bass, Walleye. Deep Lake is located in Washburn County, Wisconsin.
What did the DNR fisheries survey find at Deep Lake?
- Wisconsin DNR rates Panfish and Largemouth Bass as abundant on Deep Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Deep 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.
Are there boat ramps on Deep Lake?
- Deep Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Deep Lake. Public access is listed as yes.
Can I fish at Deep Lake?
- Deep 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 Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Deep Lake across LakeQuality
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Where this data comes from
109 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX109 samples · 2020–2025
Analytical methods
- Phosphorus by Colorimetry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory