Nepco Lake
Wood County, Wisconsin496 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Nepco Lake. Here is what has been measured.
- Mesotrophic
- 4 aquatic invasives
- 29 ft max depth
- Public access
Nepco Lake in Wood County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 10.9 µg/L. Maximum depth: 29 ft. Surface area: 496 acres.
Wisconsin DNR lists Panfish as common on Nepco Lake. DNR survey details →
Nepco Lake is a 496-acre mesotrophic lake in Wood County, Wisconsin with a maximum depth of 29 feet. Water clarity is declining over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 2 public boat landings. Compared to the 2 other monitored lakes in Wood County, Nepco Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-28. Methodology: how these readings are compared.
Nepco Lake covers about 500 acres in Wood 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 Nepco Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Nepco Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.5 ft of visibility
- Boat launch2 documented ramps
- Fishing6 species recorded
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 Nepco 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 Nepco Lake
These are the measurements Wisconsin DNR publishes for Nepco 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 10.5 ft. Phosphorus 10.9 µg/L. TSI 41.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.9µg/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. | 41 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Nepco Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Nepco Lake typically sits around 69°F at the surface in September. Summer average is about 74°F. Usually warmest in Jul (about 78°F) and coldest in Sep (about 69°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (69°F) to its warmest (78°F).
Typical surface water temperature by month, from 16 field readings (2024–2025) via the EPA Water Quality Portal. See the full Nepco Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Nepco Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Nepco Lake’s water-quality measurements separately, and the water-quality trend over 5 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 2013. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
29 ft
Surface area
496 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
91 sq mi
HydroLAKES / HydroSHEDS
Shoreline
8.3 mi
HydroLAKES / HydroSHEDS
Elevation
978 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Nepco Lake County ParkPublic
- Wisconsin River 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 Nepco Lake
Compare lakeside cabins, hotels, and vacation rentals near Nepco Lake in Wood 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 Nepco 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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Nepco 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 5 years of monitoring (2022–2026).
Water clarity
Worsening5 years
Phosphorus
Improving-1.75 µg/L/yr3 years
Reservoir Info (USACE NID)
Nepco Lake is a man-made reservoir impounded by the Four Mile Creek (completed 1926), built primarily for water supply on the FOURMILE CREEK & BLOODY RUN; gravity-type dam, 33 ft tall and 2,084 ft long.
- Surface area
- 494 ac
- Normal storage
- 4,748 ac-ft
- Max storage
- 6,000 ac-ft
- Drainage area
- 29 sq mi
- Hazard class
- Low
- Owner
- Domtar Wisconsin Dam Corp.
All listed purposes: Water Supply;Recreation;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WI00032 · Operator website
Regulated Pollution Sources Nearby
6 EPA-permitted facilities operate within about 5 miles of Nepco Lake under Clean Water Act (NPDES) discharge permits, including 3 classified by the EPA as major dischargers. 6 facilities have a reported Clean Water Act violation in the past three years.
- Wisconsin Rapids City WwtfWisconsin Rapids · 2.2 mi away · NPDES WI0025844MajorRecent violation
- Erco Worldwide (Usa) Inc - Port EdwardsPort Edwards · 2.4 mi away · NPDES WI0003565MajorRecent violation
- Domtar - NekoosaNekoosa · 3.4 mi away · NPDES WI0003620MajorRecent violation
- Port Edwards Wastewater Treatment FacilityPort Edwards · 0.8 mi away · NPDES WI0020451Recent violation
- Vesper Wastewater Treatment FacilityVesper · 1.8 mi away · NPDES WI0030309Recent violation
- Nekoosa Wastewater Treatment FacilityNekoosa · 4.6 mi away · NPDES WI0020613Recent 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.
Nearby Lakes in Wood County
Frequently asked questions about Nepco Lake
Where is Nepco Lake?
- Nepco Lake is a lake in Wood County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Nepco Lake?
- Nepco Lake in Wood County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.5 ft visibility. Phosphorus: 10.9 µg/L. Maximum depth: 29 ft. Surface area: 496 acres.
Is Nepco 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 Nepco Lake?
- Nepco Lake typically sits around 69°F at the surface in September, from 16 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Nepco Lake?
- Nepco Lake has a maximum depth of 29 feet. The lake covers 496 acres.
What fish are in Nepco Lake?
- Fish species found in Nepco Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Nepco Lake is located in Wood County, Wisconsin.
What did the DNR fisheries survey find at Nepco Lake?
- Wisconsin DNR lists Panfish as common on Nepco Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Nepco Lake’s water-quality measurements separately, and the water-quality trend over 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Nepco Lake?
- Nepco Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Nepco Lake County Park, Wisconsin River Drive. Public access is listed as yes.
Can I fish at Nepco Lake?
- Nepco 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 Nepco 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 Wood County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Lakes in the Wisconsin River Watershed, ranked by water quality
Wisconsin's cleanest lakes, ranked on agency measurements
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State Parks Near Nepco Lake
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Where this data comes from
37 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_WQX37 samples · 2022–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
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
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