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School Section Lake

Waukesha County, WisconsinMesotrophic

On the LakeGrade rubric, School Section Lake pulls an A: clarity at 16.7 ft and 26 µg/L of phosphorus put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Mesotrophic conditions dominate at School Section Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. At 122 acres, School Section Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within Waukesha County's 48 graded lakes, School Section Lake ranks 34 — below the local median, though not at the bottom.

School Section Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-11-23. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 16.7 ft down. Phosphorus level: 26.2 µg/L. Trophic State Index: 44.

MetricValueGrade
Water Clarity (Secchi Depth)16.7 ftA
Phosphorus26.2 µg/LB
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)44Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Surface Area122 acres
Public AccessYes

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for School Section Lake (14-day solunar calendar)

→ Is it safe to eat fish from School Section Lake? (mercury & PFAS guide)

School Section Lake fishing regulations (limits, seasons, special rules)

Invasive Species

Curly-Leaf PondweedEurasian Water-MilfoilPurple Loosestrife

Water Quality Trend: Improving

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.575 m/yr7
Phosphorus Improving-1.79 µg/L/yr6

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #34 of 48 lakes in Waukesha County

Nearby Lakes in Waukesha County

State Parks Near School Section Lake

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 2 stations on file (most recent sample 2026).

DNR Assessment
Good · Shallow Lowland lake
Trophic State Index 54 (eutrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Present)Northern Pike(Present)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-11-23

Monitoring stations: 1