What is the water quality grade for East Lake Osceola?

East Lake Osceola in Clarke County, Wisconsin received a water quality grade of F (Very Poor). Water clarity: 1.2 ft visibility. Chlorophyll-a (algae): 81.6 µg/L. Surface area: 13 acres.

Is East Lake Osceola safe to swim in?

Avoid swimming, very poor water quality, potential algae toxins. East Lake Osceola has an overall water quality grade of F. Algae concentration (chlorophyll-a) is 81.6 µg/L. Always check local health department advisories before swimming.

East Lake Osceola

Clarke County, WisconsinHypereutrophic

East Lake Osceola is a 13-acre highly nutrient-loaded hypereutrophic lake in Clarke County, IA. Water quality is graded F based on 2 sampling years through 2024. Compared to the 1 other monitored lakes in Clarke County, East Lake Osceola ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-15. 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 1.2 ft of visibility. Chlorophyll-a: 81.6 µg/L. Trophic State Index: 74.

Metric	Value	Grade
Water Clarity (Secchi Depth)	1.2 ft	F
Phosphorus	No data
Chlorophyll-a (Algae)	81.6 µg/L	F
Trophic State Index (TSI)	74	Hypereutrophic

Very high nutrients, dense algae, poor clarity

Lake Details

Characteristic	Value
Surface Area	13 acres

Location

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County Ranking

Ranked #2 of 2 lakes in Clarke County

Cleaner Lakes Within 30 Miles

East Lake Osceola holds Grade F. 4 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Clarke County

More Wisconsin Lake Rankings

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Top 25 by overall water quality score

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Grade A/B + low algae filter

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Other Grade F Lakes in Wisconsin

Big Creek Lake

Polk County · Clarity: 2.6 ft

Arrowhead Lake

Pottawattamie County · Clarity: 1.8 ft

White Oak Lake

Mahaska County · Clarity: 1.4 ft

Crystal Lake Max Depth

Hancock County · Clarity: 1.6 ft

Hannen Lake

Benton County · Clarity: 1.2 ft

Briggs Woods Lake

Hamilton County · Clarity: 1.5 ft

Hypereutrophic Lakes in Wisconsin

White Oak Lake Hannen Lake Briggs Woods Lake Union Grove Lake

Reservoir Info (USACE NID)

East Lake Osceola is a man-made reservoir impounded by the East Lake Dam (completed 1915), built primarily for water supply on the TR-WHITE BREAST CREEK; earth-type dam, 41 ft tall and 795 ft long.

Surface area: 13 ac
Normal storage: 98 ac-ft
Max storage: 257 ac-ft
Drainage area: 0.5 sq mi
Hazard class: Significant
Owner: Clarke County Conservation Board

Source: USACE National Inventory of Dams, NID ID IA01337 · Operator website · Matched by proximity (0.08 km)

EPA Impairment Status

East Lake Osceola is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Oxygen depletion (low DO)Turbidity

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit IA 04-LDM-1065 · 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: 2024-09-15

Monitoring stations: 1