Iola Lake
Iola Lake in Waupaca County, Wisconsin has a water quality grade of B (Good). Water clarity: 10 ft visibility. Phosphorus: 16.4 µg/L. Surface area: 220 acres.
Wisconsin DNR rates Panfish as abundant on Iola Lake. DNR survey details →
- Clarity
- 10 ft
- Area
- 220 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
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Iola Lake is a 220-acre mesotrophic lake in Waupaca County, Wisconsin. Water quality is graded B based on 1 sampling years through 2023. Overall water quality is declining over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 20 other monitored lakes in Waupaca County, Iola Lake ranks #17 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-22. 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)
Good clarity, visible to about 10 ft. Phosphorus level: 16.4 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10 ft | Not graded |
| Phosphorus | 16.4 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Iola Lake
Compare lakeside cabins, hotels, and vacation rentals near Iola Lake in Waupaca 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 Iola Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR rates Panfish as abundant on Iola Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Iola Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 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. 4 stations on file (most recent sample 2023).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 220 acres |
| Public Access | Yes |
The available depth estimate for Iola Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Iola 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 Iola 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 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.357 m/yr | 6 |
| Phosphorus | → Stable | -0.25 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Iola Lake is a man-made reservoir impounded by the Iola (completed 1865), built primarily for recreation on the SOUTH BRANCH LITTLE WOLF; gravity-type dam, 12 ft tall and 694 ft long.
- Surface area
- 206 ac
- Normal storage
- 638 ac-ft
- Max storage
- 1,000 ac-ft
- Drainage area
- 100 sq mi
- Hazard class
- Significant
- Owner
- Village Of Iola
Source: USACE National Inventory of Dams, NID ID WI00337 · Operator website
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Iola Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Iola Wastewater Treatment FacilityIola · 1.2 mi away · NPDES WI0021717Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #17 of 21 lakes in Waupaca County
Nearby Lakes in Waupaca County
Frequently asked questions about Iola Lake
Where is Iola Lake?
- Iola Lake is a lake in Waupaca County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Iola Lake?
- Iola Lake in Waupaca County, Wisconsin has a water quality grade of B (Good). Water clarity: 10 ft visibility. Phosphorus: 16.4 µg/L. Surface area: 220 acres.
Is Iola Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Iola Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Iola Lake?
- The available depth estimate for Iola Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown. The lake covers 220 acres.
What fish are in Iola Lake?
- Fish species found in Iola Lake include Panfish, Largemouth Bass, Northern Pike. Iola Lake is located in Waupaca County, Wisconsin.
What did the DNR fisheries survey find at Iola Lake?
- Wisconsin DNR rates Panfish as abundant on Iola Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Iola Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Iola Lake?
- Iola Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Iola Lake. Public access is listed as yes.
Explore Iola Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Waupaca County
Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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State Parks Near Iola Lake
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
28 measurements from 1 monitoring station, 2021–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX28 samples · 2021–2023
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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