Catherine Lake
Lake County, WisconsinEutrophic
Catherine Lake is a productive, nutrient-rich eutrophic lake in Lake County, IL. Water quality is graded B based on 2 sampling years through 2022. Compared to the 15 other monitored lakes in Lake County, Catherine Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-10-17. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 7.4 ft. Phosphorus level: 27.5 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.4 ft | C |
| Phosphorus | 27.5 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 50 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #6 of 16 lakes in Lake County
Nearby Lakes in Lake County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
EPA Impairment Status
Catherine Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_RTD · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-10-17
Monitoring stations: 2