Collins Lake
Collins Lake in Portage County, Wisconsin has a water quality grade of B (Good). 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 →
- Clarity
- 6.5 ft
- Typical in August
- 72°F
- Max depth
- 56 ft
- Area
- 43 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
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Collins Lake is a 43-acre mesotrophic lake in Portage County, Wisconsin with a maximum depth of 56 feet. Water quality is graded B based on 1 sampling years through 2026. 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. Grade methodology: LakeQuality 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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Murky, only visible to about 6.5 ft. Phosphorus level: 20.6 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.5 ft | Not graded |
| Phosphorus | 20.6 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay 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
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Collins Lake typically sits around 72°F at the surface in August. 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.
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 a water-quality grade. LakeQuality grades Collins Lake B from EPA Water Quality Portal chemistry, 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
| Characteristic | Value |
|---|---|
| Maximum Depth | 56 ft |
| Surface Area | 43 acres |
| Public Access | Yes |
Lake Size & Watershed
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
Fish Species
Click a species to see every graded 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: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.17 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.34 µg/L/yr | 6 |
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit WI10000447 · Official waterbody report
County Ranking
Ranked #6 of 14 lakes in Portage County
Nearby Lakes in Portage County
Frequently asked questions about Collins Lake
Where is Collins Lake?
- Collins Lake is a lake in Portage County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Collins Lake?
- Collins Lake in Portage County, Wisconsin has a water quality grade of B (Good). 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?
- Good for swimming, clear water with low algae levels. Collins Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Collins Lake?
- Collins Lake typically sits around 72°F at the surface in August, 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 a water-quality grade. LakeQuality grades Collins Lake B from EPA Water Quality Portal chemistry, 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.
Explore Collins Lake across LakeQuality
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Moderate nutrients, good water quality
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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)
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)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory