Lower Phantom Lake
Waukesha County, Wisconsin373 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Lower Phantom Lake. Here is what has been measured.
- Mesotrophic
- 3 aquatic invasives
- 12 ft max depth
- Public access
Lower Phantom Lake in Waukesha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 6.7 ft visibility. Phosphorus: 15.7 µg/L. Maximum depth: 12 ft. Surface area: 373 acres.
Wisconsin DNR lists Largemouth Bass as common on Lower Phantom Lake. DNR survey details →
Lower Phantom Lake is a 373-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 12 feet. Overall water quality is improving 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 34 other monitored lakes in Waukesha County, Lower Phantom Lake ranks #30 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-03-30. Methodology: how these readings are compared.
Lower Phantom Lake covers about 370 acres in Waukesha County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Lower Phantom Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Lower Phantom Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing3 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 Lower Phantom 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 Lower Phantom Lake
These are the measurements Wisconsin DNR publishes for Lower Phantom 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 6.7 ft. Phosphorus 15.7 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 15.7µg/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. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lower Phantom Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Largemouth Bass as common on Lower Phantom Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Phantom 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. 1 station on file (most recent sample 2026).
Fish Species (DNR-rated)
Lake Details
Max depth
12 ft
Surface area
373 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
77 sq mi
HydroLAKES / HydroSHEDS
Shoreline
5 mi
HydroLAKES / HydroSHEDS
Elevation
784 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lower Phantom 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 Lower Phantom Lake
Compare lakeside cabins, hotels, and vacation rentals near Lower Phantom 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 Lower Phantom 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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lower Phantom Lake
- → Lower Phantom Lake fishing: DNR survey catch rates, species & stocking
- → Lower Phantom Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Lower Phantom Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Lower Phantom Lake? (mercury & PFAS guide)
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-0.22 µg/L/yr6 years
Reservoir Info (USACE NID)
Lower Phantom Lake is a man-made reservoir impounded by the Mukwonago (completed 1848), built primarily for recreation on the MUKWONAGO; gravity-type dam, 10 ft tall and 250 ft long.
- Surface area
- 540 ac
- Normal storage
- 2,200 ac-ft
- Max storage
- 2,740 ac-ft
- Drainage area
- 60 sq mi
- Hazard class
- Low
- Owner
- Village Of Mukwonago
Source: USACE National Inventory of Dams, NID ID WI00334 · Operator website · Matched by proximity (0.79 km)
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lower Phantom 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.
- Mukwonago Wastewater Treatment PlantMukwonago · 1.3 mi away · NPDES WI0020265MajorRecent 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 Waukesha County
Frequently asked questions about Lower Phantom Lake
Where is Lower Phantom Lake?
- Lower Phantom 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 Lower Phantom Lake?
- Lower Phantom Lake in Waukesha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 6.7 ft visibility. Phosphorus: 15.7 µg/L. Maximum depth: 12 ft. Surface area: 373 acres.
Is Lower Phantom Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Lower Phantom Lake?
- Lower Phantom Lake has a maximum depth of 12 feet. The lake covers 373 acres.
What fish are in Lower Phantom Lake?
- Fish species found in Lower Phantom Lake include Panfish, Largemouth Bass, Northern Pike. Lower Phantom Lake is located in Waukesha County, Wisconsin.
What did the DNR fisheries survey find at Lower Phantom Lake?
- Wisconsin DNR lists Largemouth Bass as common on Lower Phantom Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Phantom 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 Lower Phantom Lake?
- Lower Phantom Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lower Phantom Lake. Public access is listed as yes.
Can I fish at Lower Phantom Lake?
- Lower Phantom 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 Lower Phantom 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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State Parks Near Lower Phantom Lake
Other Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
47 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_WQX47 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