Neshonoc Lake
Neshonoc Lake in La Crosse County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 0.4 ft visibility. Surface area: 687 acres.
- Clarity
- 0.4 ft
- Mean depth
- ~18 ft est.
- Area
- 687 acres
- Public access
- Yes
Next lake in La Crosse County
Why Neshonoc Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: 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 Neshonoc Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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.
Neshonoc Lake is a 687-acre lake in La Crosse County, Wisconsin with an estimated average depth of about 18 feet. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-06-16. Grade methodology: LakeGrade methodology.
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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 Neshonoc Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Very murky, less than 0.4 ft of visibility. Trophic State Index: 91.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.4 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 91 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Neshonoc Lake
Compare lakeside cabins, hotels, and vacation rentals near Neshonoc Lake in La Crosse 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Average Depth | ~18 ft est. |
| Surface Area | 687 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Wisconsin has not published bathymetry for Neshonoc Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Neshonoc Lake - SouthPublic
- Neshonoc Swarthout ParkPublic
Fishing Neshonoc Lake
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Neshonoc 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).
- 2024Lake Neshonoc netting survey, 2024Netting Survey · WI DNR · 2024 (PDF)
Reservoir Info (USACE NID)
Neshonoc Lake is a man-made reservoir impounded by the Neshonoc (completed 1914), built primarily for hydroelectric on the La Crosse River; concrete-type dam, 18 ft tall and 218 ft long.
- Surface area
- 687 ac
- Normal storage
- 3,100 ac-ft
- Max storage
- 3,100 ac-ft
- Drainage area
- 390 sq mi
- Hazard class
- Low
- Owner
- North American Hydro Inc
All listed purposes: Hydroelectric;Recreation.
Source: USACE National Inventory of Dams, NID ID WI00148 · Operator website
EPA Impairment Status
Neshonoc Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10008309 · Official waterbody report
Regulated Pollution Sources Nearby
4 EPA-permitted facilities operate within about 5 miles of Neshonoc Lake under Clean Water Act (NPDES) discharge permits. 4 facilities have a reported Clean Water Act violation in the past three years.
- Bostwick Valley Mhp WwtfWest Salem · 1 mi away · NPDES WI0028908Recent violation
- West Salem Wastewater Treatment FacilityWest Salem · 1.1 mi away · NPDES WI0020389Recent violation
- Maple Grove Estates Sanitary DistrictHamilton · 1.4 mi away · NPDES WI0036552Recent violation
- Bangor Wastewater Treatment FacilityBangor · 4.6 mi away · NPDES WI0031224Recent 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.
Graded lakes near Neshonoc Lake
Neshonoc Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in La Crosse County
Frequently asked questions about Neshonoc Lake
What is the water quality grade for Neshonoc Lake?
- Neshonoc Lake in La Crosse County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 0.4 ft visibility. Surface area: 687 acres.
Is Neshonoc Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Neshonoc Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Neshonoc Lake?
- No published bathymetric survey covers Neshonoc Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 18 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 687 acres.
Are there boat ramps on Neshonoc Lake?
- Neshonoc Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Neshonoc Lake - South, Neshonoc Swarthout Park. Public access is listed as yes.
Explore Neshonoc Lake across LakeGrade
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Where this data comes from
1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX1 sample · 2022
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory