Altoona Lake
Eau Claire County, Wisconsin720 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Altoona Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 2 aquatic invasives
- 25 ft max depth
- Public access
Altoona Lake in Eau Claire County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 99.6 µg/L. Maximum depth: 25 ft. Surface area: 720 acres.
Wisconsin DNR lists Smallmouth Bass as common on Altoona Lake. DNR survey details →
Altoona Lake is a 720-acre productive, nutrient-rich eutrophic lake in Eau Claire County, Wisconsin with a maximum depth of 25 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Smallmouth Bass. Public access is available with 2 public boat landings. Compared to the 1 other monitored lakes in Eau Claire County, Altoona Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-21. Methodology: how these readings are compared.
Altoona Lake covers about 720 acres in Eau Claire County. It has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. Vrbo is where to look for cabins and lake homes around Altoona Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Altoona Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
- Fishing4 species recorded
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. Altoona Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Altoona 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 Altoona Lake
These are the measurements Wisconsin DNR publishes for Altoona Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3 ft of visibility. Phosphorus 99.6 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 99.6µg/L | Poor 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. | 66 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Altoona Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Altoona Lake typically sits around 62°F at the surface in October. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in Mar (about 42°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (42°F) to its warmest (77°F).
Typical surface water temperature by month, from 64 field readings (2024–2025) via the EPA Water Quality Portal. See the full Altoona Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Altoona Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (496,592 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR lists Smallmouth Bass as common on Altoona Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Altoona 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 2011. 4 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Altoona 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).
- 2025Lake Altoona spring netting/shocking survey, 2025Netting Survey · WI DNR · 2025 (PDF)
Lake Details
Max depth
25 ft
Surface area
720 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
811 sq mi
HydroLAKES / HydroSHEDS
Shoreline
9.4 mi
HydroLAKES / HydroSHEDS
Elevation
794 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lake Altoona County ParkPublic
- Indian Hills DrivePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Altoona Lake
Compare lakeside cabins, hotels, and vacation rentals near Altoona Lake in Eau Claire 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Altoona Lake are listed below.
Top-rated places to stay near Altoona Lake
Prices for Oct 9–11, 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 Altoona Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Altoona 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+5.1 µg/L/yr5 years
Reservoir Info (USACE NID)
Altoona Lake is a man-made reservoir impounded by the Altoona (completed 1938), built primarily for recreation on the Eau Claire River; buttress-type dam, 44 ft tall and 240 ft long.
- Surface area
- 720 ac
- Normal storage
- 8,200 ac-ft
- Max storage
- 14,000 ac-ft
- Drainage area
- 883 sq mi
- Hazard class
- High
- Owner
- Eau Claire County
Source: USACE National Inventory of Dams, NID ID WI00011 · Operator website
EPA Impairment Status
Altoona Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit WI10004661 · Official waterbody report
Regulated Pollution Sources Nearby
4 EPA-permitted facilities operate within about 5 miles of Altoona Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Cascades Tissue Group Wisc IncEau Claire · 4.3 mi away · NPDES WI0003077MajorRecent violation
- Lake Altoona Protection & Rehab DistrictAltoona · 0.7 mi away · NPDES WI0049352
- Fairfax Park Municipal SwimminEau Claire · 3.7 mi away · NPDES WI0048721
- Wrr Environmental Services Co IncBrunswick · 4.3 mi away · NPDES WI0058718
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.
Nearby Lakes in Eau Claire County
Frequently asked questions about Altoona Lake
Where is Altoona Lake?
- Altoona Lake is a lake in Eau Claire County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Altoona Lake?
- Altoona Lake in Eau Claire County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 99.6 µg/L. Maximum depth: 25 ft. Surface area: 720 acres.
Is Altoona Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Altoona Lake is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Altoona Lake?
- Altoona Lake typically sits around 62°F at the surface in October, from 64 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Altoona Lake?
- Altoona Lake has a maximum depth of 25 feet. The lake covers 720 acres.
What fish are in Altoona Lake?
- Fish species found in Altoona Lake include Musky, Panfish, Smallmouth Bass, Walleye. Altoona Lake is located in Eau Claire County, Wisconsin.
What did the DNR fisheries survey find at Altoona Lake?
- Wisconsin DNR lists Smallmouth Bass as common on Altoona Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Altoona 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 Altoona Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Altoona Lake (clouds, ice, or an off-season gap). The most recent reading was high (496,592 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Altoona Lake?
- Altoona Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Lake Altoona County Park, Indian Hills Drive. Public access is listed as yes.
Can I fish at Altoona Lake?
- Altoona Lake has 2 documented boat landings 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 Altoona Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Eau Claire County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Lakes in the Chippewa River Watershed, ranked by water quality
Wisconsin's cleanest lakes, ranked on agency measurements
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Compare Altoona Lake With Nearby Lakes
Where this data comes from
214 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_WQX214 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
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
Impairment status from EPA ATTAINS 303(d) database
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