Collins Lake
Portage County, Wisconsin43 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Collins Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 56 ft max depth
- Public access
Collins Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 6.5 ft visibility. Phosphorus: 20.6 µg/L. Maximum depth: 56 ft. Surface area: 43 acres.
Wisconsin DNR lists Largemouth Bass as common on Collins Lake. DNR survey details →
Collins Lake is a 43-acre mesotrophic lake in Portage County, Wisconsin with a maximum depth of 56 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 13 other monitored lakes in Portage County, Collins Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-20. Methodology: how these readings are compared.
Collins Lake covers about 43 acres in Portage County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Collins Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Collins Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing4 species recorded
- Deep water56 ft surveyed max depth
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. Collins Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Collins 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 Collins Lake
These are the measurements Wisconsin DNR publishes for Collins Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 6.5 ft. Phosphorus 20.6 µg/L. TSI 49.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20.6µg/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. | 49 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Collins Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Collins Lake typically sits around 67°F at the surface in September. Summer average is about 73°F. Usually warmest in Jul (about 78°F) and coldest in Feb (about 35°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (35°F) to its warmest (78°F).
Typical surface water temperature by month, from 40 field readings (2024–2026) via the EPA Water Quality Portal. See the full Collins Lake water temperature breakdown →
Wisconsin DNR lists Largemouth Bass as common on Collins Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Collins Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. 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 2001. 2 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Collins Lake covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2022Collins Lake spring shocking, 2022Spring Shocking Survey · WI DNR · 2022 (PDF)
Lake Details
Max depth
56 ft
Surface area
43 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,152 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Collins ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Collins Lake
Compare lakeside cabins, hotels, and vacation rentals near Collins Lake in Portage 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 Collins 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 →
Follow Collins Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Collins 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: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+1.34 µg/L/yr6 years
EPA Impairment Status
Collins Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit WI10000447 · Official waterbody report
Nearby Lakes in Portage County
Frequently asked questions about Collins Lake
Where is Collins Lake?
- Collins Lake is a lake in Portage County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Collins Lake?
- Collins Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 6.5 ft visibility. Phosphorus: 20.6 µg/L. Maximum depth: 56 ft. Surface area: 43 acres.
Is Collins Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Collins Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Collins Lake?
- Collins Lake typically sits around 67°F at the surface in September, from 40 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Collins Lake?
- Collins Lake has a maximum depth of 56 feet. The lake covers 43 acres.
What fish are in Collins Lake?
- Fish species found in Collins Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Collins Lake is located in Portage County, Wisconsin.
What did the DNR fisheries survey find at Collins Lake?
- Wisconsin DNR lists Largemouth Bass as common on Collins Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Collins Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Collins Lake?
- Collins Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Collins Park. Public access is listed as yes.
Can I fish at Collins Lake?
- Collins 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 Collins Lake across LakeQuality
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Fish species and best lakes in Portage County
Species activity outlook by water temperature and season
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Where this data comes from
58 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX58 samples · 2020–2026
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