Five Island Lake
Palo Alto County, WisconsinEutrophic
Five Island Lake is a productive, nutrient-rich eutrophic lake in Palo Alto County, IA. Water quality is graded F based on 2 sampling years through 2024. Compared to the 2 other monitored lakes in Palo Alto County, Five Island Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-11. Grade methodology: LakeGrade methodology.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1.6 ft of visibility. Chlorophyll-a: 53.3 µg/L. Trophic State Index: 70.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 53.3 µg/L | F |
| Trophic State Index (TSI) | 70 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #3 of 3 lakes in Palo Alto County
Cleaner Lakes Within 30 Miles
Five Island Lake holds Grade F. 4 nearby lakes hold higher grades.
- DLost Island LakePalo Alto County · 12.4 mi · Higher grade (F → D)
- DStolley Pit LakeClay County · 26.7 mi · Higher grade (F → D)
- DLake MinnewashtaDickinson County · 27.8 mi · Higher grade (F → D)
- DLower Gar LakeDickinson County · 27.5 mi · Higher grade (F → D)
Nearby Lakes in Palo Alto County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
EPA Impairment Status
Five Island Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 04-UDM-1300 · 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: 2024-09-11
Monitoring stations: 1