East Okoboji Lake
Dickinson County, WisconsinEutrophic
East Okoboji Lake is a productive, nutrient-rich eutrophic lake in Dickinson County, IA. Water quality is graded D based on 2 sampling years through 2024. Compared to the 7 other monitored lakes in Dickinson County, East Okoboji Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-10. Grade methodology: LakeGrade methodology.
Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 3.9 ft. Chlorophyll-a: 25.3 µg/L. Trophic State Index: 60.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.9 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 25.3 µg/L | D |
| Trophic State Index (TSI) | 60 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #5 of 8 lakes in Dickinson County
Cleaner Lakes Within 30 Miles
East Okoboji Lake holds Grade D. 3 nearby lakes hold higher grades.
- AWest Okoboji LakeDickinson County · 2.2 mi · Two grade letters higher (D → A)
- CUpper Gar LakeDickinson County · 1 mi · Higher grade (D → C)
- CBig Spirit LakeDickinson County · 6.9 mi · Higher grade (D → C)
Nearby Lakes in Dickinson County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
EPA Impairment Status
East Okoboji 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 IA 06-LSR-1652 · 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: 2024-09-10
Monitoring stations: 1