Fowler Lake
Fowler Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 14.5 ft visibility. Phosphorus: 15.5 µg/L. Maximum depth: 50 ft. Surface area: 97 acres.
Wisconsin DNR rates Panfish as abundant on Fowler Lake. DNR survey details →
- Clarity
- 14.5 ft
- Typical in August
- 76°F
- Max depth
- 50 ft
- Area
- 97 acres
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- Yes
Next lake in Waukesha County
Swipe left or right on this bar to open the next or previous lake.
Fowler Lake is a 97-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 50 feet. Water quality is graded B based on 1 sampling years through 2026. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 2 public boat landings. Compared to the 34 other monitored lakes in Waukesha County, Fowler Lake ranks #27 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-15. Grade methodology: LakeQuality methodology.
Watch Fowler Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 14.5 ft. Phosphorus level: 15.5 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | 15.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Fowler Lake
Compare lakeside cabins, hotels, and vacation rentals near Fowler 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 Fowler Lake
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 →
Water Temperature
Fowler Lake typically sits around 76°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in Jun (about 71°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 9 field readings (2024–2026) via the EPA Water Quality Portal. See the full Fowler Lake water temperature breakdown →
Wisconsin DNR rates Panfish as abundant on Fowler Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Fowler Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 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 2011. 7 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 50 ft |
| Surface Area | 97 acres |
| Public Access | Yes |
Recreation & Access
- Fowler LakePublic
- OconomowocPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Fowler 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.
Source: USGS Nonindigenous Aquatic Species (NAS) Database. Hover a chip to see scientific name, ecological context, status, and first-observed year.
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.196 m/yr | 7 |
| Phosphorus | → Stable | -0.21 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Fowler Lake is a man-made reservoir impounded by the Peacock (completed 1840), built primarily for recreation on the OCONOMOWOC; gravity-type dam, 11 ft tall and 150 ft long.
- Surface area
- 78 ac
- Normal storage
- 550 ac-ft
- Max storage
- 630 ac-ft
- Drainage area
- 88 sq mi
- Hazard class
- Significant
- Owner
- City of Oconomowoc
Source: USACE National Inventory of Dams, NID ID WI00704 · Operator website
EPA Impairment Status
Fowler 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 WI10001317 · Official waterbody report · Matched by proximity (2.62 km)
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Fowler 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.
- Oconomowoc Wastewater Treatment PlntOconomowoc · 0.9 mi away · NPDES WI0021181MajorRecent 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.
County Ranking
Ranked #27 of 35 lakes in Waukesha County
Nearby Lakes in Waukesha County
Frequently asked questions about Fowler Lake
Where is Fowler Lake?
- Fowler Lake is a lake in Waukesha County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Fowler Lake?
- Fowler Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 14.5 ft visibility. Phosphorus: 15.5 µg/L. Maximum depth: 50 ft. Surface area: 97 acres.
Is Fowler Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Fowler Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Fowler Lake?
- Fowler Lake typically sits around 76°F at the surface in August, from 9 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Fowler Lake?
- Fowler Lake has a maximum depth of 50 feet. The lake covers 97 acres.
What fish are in Fowler Lake?
- Fish species found in Fowler Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Fowler Lake is located in Waukesha County, Wisconsin.
What did the DNR fisheries survey find at Fowler Lake?
- Wisconsin DNR rates Panfish as abundant on Fowler Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Fowler Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Fowler Lake?
- Fowler Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Fowler Lake, Oconomowoc. Public access is listed as yes.
Explore Fowler Lake across LakeQuality
Fish species and top-graded 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 grade
Moderate nutrients, good water quality
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
State Parks Near Fowler Lake
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
105 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_WQX105 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory