Powderhorn Lake
Cook County, WisconsinMesotrophic
Powderhorn Lake is a mesotrophic lake in Cook County, IL. Water quality is graded A based on 2 sampling years through 2021. Compared to the 67 other monitored lakes in Cook County, Powderhorn Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2021-10-06. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 10.1 ft. Phosphorus level: 13 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.1 ft | B |
| Phosphorus | 13 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Location
County Ranking
Ranked #4 of 68 lakes in Cook County
Nearby Lakes in Cook County
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
EPA Impairment Status
Powderhorn 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 IL_RHG · 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: 2021-10-06
Monitoring stations: 3