Nagawicka Lake
Waukesha County, Wisconsin981 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Nagawicka Lake. Here is what has been measured.
- Mesotrophic
- 3 aquatic invasives
- 90 ft max depth
- Public access
Nagawicka Lake in Waukesha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9.5 ft visibility. Phosphorus: 13.5 µg/L. Maximum depth: 90 ft. Surface area: 981 acres.
Wisconsin DNR lists Largemouth Bass as common on Nagawicka Lake. DNR survey details →
Nagawicka Lake is a 981-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 90 feet. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 1 public boat landing. Compared to the 34 other monitored lakes in Waukesha County, Nagawicka Lake ranks #29 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-04-29. Methodology: how these readings are compared.
Nagawicka Lake covers about 980 acres in Waukesha County. It has one public boat landing. Vrbo is where to look for cabins and lake homes around Nagawicka Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Nagawicka Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing5 species recorded
- Deep water90 ft surveyed max depth
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 Nagawicka 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 Nagawicka Lake
These are the measurements Wisconsin DNR publishes for Nagawicka Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.5 ft. Phosphorus 13.5 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 13.5µg/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. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Nagawicka Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Largemouth Bass as common on Nagawicka Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Nagawicka Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. 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. 7 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
90 ft
Surface area
981 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
115 sq mi
HydroLAKES / HydroSHEDS
Shoreline
7.8 mi
HydroLAKES / HydroSHEDS
Elevation
886 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Nagawicka LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Nagawicka Lake
Compare lakeside cabins, hotels, and vacation rentals near Nagawicka Lake in Waukesha 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 Nagawicka Lake
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Follow Nagawicka Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Nagawicka 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: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Stable-0.07 µg/L/yr5 years
Reservoir Info (USACE NID)
Nagawicka Lake is a man-made reservoir impounded by the Delafield Fish Hatchery (completed 1936), built primarily for other on the BARK; gravity-type dam, 10 ft tall and 140 ft long.
- Surface area
- 917 ac
- Normal storage
- 6,000 ac-ft
- Max storage
- 917 ac-ft
- Drainage area
- 46 sq mi
- Hazard class
- Low
- Owner
- CITY OF DELAFIELD
All listed purposes: Other;Recreation.
Source: USACE National Inventory of Dams, NID ID WI00683 · Operator website
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Nagawicka Lake under Clean Water Act (NPDES) discharge permits.
- Medline Industries, Inc.Hartland, Village Of · 1.5 mi away · NPDES WI0065943
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 Waukesha County
Frequently asked questions about Nagawicka Lake
Where is Nagawicka Lake?
- Nagawicka Lake is a lake in Waukesha County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Nagawicka Lake?
- Nagawicka Lake in Waukesha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9.5 ft visibility. Phosphorus: 13.5 µg/L. Maximum depth: 90 ft. Surface area: 981 acres.
Is Nagawicka Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Nagawicka Lake?
- Nagawicka Lake has a maximum depth of 90 feet. The lake covers 981 acres.
What fish are in Nagawicka Lake?
- Fish species found in Nagawicka Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Nagawicka Lake is located in Waukesha County, Wisconsin.
What did the DNR fisheries survey find at Nagawicka Lake?
- Wisconsin DNR lists Largemouth Bass as common on Nagawicka Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Nagawicka Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Nagawicka Lake?
- Nagawicka Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Nagawicka Lake. Public access is listed as yes.
Can I fish at Nagawicka Lake?
- Nagawicka Lake has 1 documented boat landing 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 Nagawicka 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 Waukesha County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Wisconsin's cleanest lakes, ranked on agency measurements
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Compare Nagawicka Lake With Nearby Lakes
Where this data comes from
46 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX46 samples · 2020–2026
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