Fountain Lake
Fountain Lake in Portage County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 21 ft visibility. Maximum depth: 23 ft. Surface area: 16 acres.
Wisconsin DNR rates Panfish as abundant on Fountain Lake. DNR survey details →
- Clarity
- 21 ft
- Typical in August
- 70°F
- Max depth
- 23 ft
- Area
- 16 acres
- Trend
- → Stable
- Public access
- Yes
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Why Fountain Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Fountain Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Fountain Lake is a 16-acre lake in Portage County, Wisconsin with a maximum depth of 23 feet. The lake supports 2 documented fish species including Panfish and Largemouth Bass. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-22. Grade methodology: LakeQuality methodology.
Watch Fountain Lake water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Fountain Lake
These readings exist but are not enough for an A–F grade — see why.
Crystal clear, you can see 21 ft down. Trophic State Index: 33.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 21 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 33 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Fountain Lake
Compare lakeside cabins, hotels, and vacation rentals near Fountain 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 Fountain Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Fountain Lake typically sits around 70°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 75°F) and coldest in Apr (about 47°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 48 field readings (2024–2026) via the EPA Water Quality Portal. See the full Fountain Lake water temperature breakdown →
Wisconsin DNR rates Panfish as abundant on Fountain Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Fountain Lake — official chemistry is on file, not a letter, and the water-quality trend over 4 years of monitoring is stable. 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 2011. 1 station on file (most recent sample 2026).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 23 ft |
| Surface Area | 16 acres |
| Public Access | Yes |
Recreation & Access
- Fountain LakePublic
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 Fountain 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: → Stable
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.086 m/yr | 4 |
Reservoir Info (USACE NID)
Fountain Lake is a man-made reservoir impounded by the Fountain Lake (completed 1938), built primarily for recreation on the EMMONS CREEK; gravity-type dam, 8 ft tall and 50 ft long.
- Surface area
- 16 ac
- Normal storage
- 75 ac-ft
- Max storage
- 120 ac-ft
- Drainage area
- 2 sq mi
- Hazard class
- Low
- Owner
- Wisconsin Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID WI01101 · Operator website
Graded lakes near Fountain Lake
Fountain Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Portage County
Frequently asked questions about Fountain Lake
Where is Fountain Lake?
- Fountain Lake is a lake in Portage County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Fountain Lake?
- Fountain Lake in Portage County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 21 ft visibility. Maximum depth: 23 ft. Surface area: 16 acres.
Is Fountain Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Fountain Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Fountain Lake?
- Fountain Lake typically sits around 70°F at the surface in August, from 48 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Fountain Lake?
- Fountain Lake has a maximum depth of 23 feet. The lake covers 16 acres.
What fish are in Fountain Lake?
- Fish species found in Fountain Lake include Panfish, Largemouth Bass. Fountain Lake is located in Portage County, Wisconsin.
What did the DNR fisheries survey find at Fountain Lake?
- Wisconsin DNR rates Panfish as abundant on Fountain Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Fountain Lake — official chemistry is on file, not a letter, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Fountain Lake?
- Fountain Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Fountain Lake. Public access is listed as yes.
Explore Fountain Lake across LakeQuality
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Where this data comes from
10 measurements from 1 monitoring station, 2022–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX10 samples · 2022–2026
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
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory