Ocauchee Lake
Ocauchee Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 6.6 ft visibility. Phosphorus: 17.5 µg/L. Maximum depth: 90 ft. Surface area: 1210 acres.
Wisconsin DNR lists Musky as common on Ocauchee Lake. DNR survey details →
- Clarity
- 6.6 ft
- Max depth
- 90 ft
- Area
- 1,210 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Waukesha County
Swipe left or right on this bar to open the next or previous lake.
Ocauchee Lake is a 1,210-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 90 feet. Water quality is graded B based on 1 sampling years through 2024. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available. Compared to the 34 other monitored lakes in Waukesha County, Ocauchee Lake ranks #33 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-08-28. Grade methodology: LakeQuality methodology.
Watch Ocauchee Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLimited data
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)
Murky, only visible to about 6.6 ft. Phosphorus level: 17.5 µg/L. Trophic State Index: 48.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.6 ft | Not graded |
| Phosphorus | 17.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 48 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Ocauchee Lake
Compare lakeside cabins, hotels, and vacation rentals near Ocauchee 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 Ocauchee 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 →
Wisconsin DNR lists Musky as common on Ocauchee Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Ocauchee Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 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. Monitored by volunteers since 1995. 17 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 90 ft |
| Surface Area | 1,210 acres |
| Public Access | Yes |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Ocauchee 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: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.893 m/yr | 7 |
| Phosphorus | → Stable | +0.09 µg/L/yr | 7 |
| Chlorophyll-a | ↑ Improving | -0.61 µg/L/yr | 4 |
EPA Impairment Status
Ocauchee Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10009840 · Official waterbody report · Matched by proximity (1.39 km)
County Ranking
Ranked #33 of 35 lakes in Waukesha County
Nearby Lakes With Higher Grades
Ocauchee Lake holds Grade B. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Waukesha County
Frequently asked questions about Ocauchee Lake
Where is Ocauchee Lake?
- Ocauchee 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 Ocauchee Lake?
- Ocauchee Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 6.6 ft visibility. Phosphorus: 17.5 µg/L. Maximum depth: 90 ft. Surface area: 1210 acres.
Is Ocauchee Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Ocauchee Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Ocauchee Lake?
- Ocauchee Lake has a maximum depth of 90 feet. The lake covers 1210 acres.
What fish are in Ocauchee Lake?
- Fish species found in Ocauchee Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Ocauchee Lake is located in Waukesha County, Wisconsin.
What did the DNR fisheries survey find at Ocauchee Lake?
- Wisconsin DNR lists Musky as common on Ocauchee Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Ocauchee Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Ocauchee Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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 Ocauchee Lake
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Compare Ocauchee Lake With Nearby Lakes
Where this data comes from
6 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX6 samples · 2024
Analytical methods
- Phosphorus by Colorimetry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes