Long Lake
Waushara County, Wisconsin254 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Oligotrophic
- 3 aquatic invasives
- 71 ft max depth
- Public access
Long Lake in Waushara County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 14.5 ft visibility. Phosphorus: 11.7 µg/L. Maximum depth: 71 ft. Surface area: 254 acres.
Wisconsin DNR rates Largemouth Bass as abundant on Long Lake. DNR survey details →
Long Lake is a 254-acre cold, clear oligotrophic lake in Waushara County, Wisconsin with a maximum depth of 71 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 15 other monitored lakes in Waushara County, Long Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-11. Methodology: how these readings are compared.
Long Lake covers about 250 acres in Waushara County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Long Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.5 ft of visibility
- Boat launch1 documented ramp
- Fishing4 species recorded
- Deep water71 ft surveyed max depth
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. Check local advisories before you swim.
Whether Long 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 Long Lake
These are the measurements Wisconsin DNR publishes for Long 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 14.5 ft. Phosphorus 11.7 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11.7µg/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. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Long Lake typically sits around 71°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 80°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (54°F) to its warmest (80°F).
Typical surface water temperature by month, from 8 field readings (2024–2025) via the EPA Water Quality Portal. See the full Long Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Long Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (751,623 cells/mL) on March 9, 2024.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR rates Largemouth Bass as abundant on Long Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long 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. 3 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
71 ft
Surface area
254 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Shoreline
4.1 mi
HydroLAKES / HydroSHEDS
Elevation
879 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Long 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 Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Lake in Waushara 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 Long 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 Long Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long 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+0.93 µg/L/yr5 years
Nearby Lakes in Waushara County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Waushara County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Waushara County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 14.5 ft visibility. Phosphorus: 11.7 µg/L. Maximum depth: 71 ft. Surface area: 254 acres.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Long Lake?
- Long Lake typically sits around 71°F at the surface in September, from 8 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 71 feet. The lake covers 254 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Long Lake is located in Waushara County, Wisconsin.
What did the DNR fisheries survey find at Long Lake?
- Wisconsin DNR rates Largemouth Bass as abundant on Long Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long 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.
Does Long Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Long Lake (clouds, ice, or an off-season gap). The most recent reading was high (751,623 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Long Lake?
- Long Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Long Lake. Public access is listed as yes.
Can I fish at Long Lake?
- Long 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 Long Lake across LakeQuality
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Waushara County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Wisconsin's cleanest lakes, ranked on agency measurements
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State Parks Near Long Lake
Other Lakes in Wisconsin
Oligotrophic Lakes in Wisconsin
Where this data comes from
69 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX69 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
- Total Phosphorus After Block Digestion
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (2)
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
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