What is the water quality grade for Izaak Walton Lake?

Izaak Walton Lake in Vernon County, Wisconsin received a water quality grade of F (Very Poor). Water clarity: 1.5 ft visibility. Phosphorus: 280 µg/L. Chlorophyll-a (algae): 123.1 µg/L. Surface area: 10 acres.

Is Izaak Walton Lake safe to swim in?

Avoid swimming, very poor water quality, potential algae toxins. Izaak Walton Lake has an overall water quality grade of F. Algae concentration (chlorophyll-a) is 123.1 µg/L. Always check local health department advisories before swimming.

Izaak Walton Lake

Vernon County, WisconsinHypereutrophic

Izaak Walton Lake is a 10-acre highly nutrient-loaded hypereutrophic lake in Vernon County, MO. Water quality is graded F based on 3 sampling years through 2020.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-08-21. 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 1.5 ft of visibility. Phosphorus level: 280 µg/L. Chlorophyll-a: 123.1 µg/L. Trophic State Index: 78.

Metric	Value	Grade
Water Clarity (Secchi Depth)	1.5 ft	F
Phosphorus	280 µg/L	F
Chlorophyll-a (Algae)	123.1 µg/L	F
Trophic State Index (TSI)	78	Hypereutrophic

Very high nutrients, dense algae, poor clarity

Lake Details

Characteristic	Value
Surface Area	10 acres

Location

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County Ranking

Ranked #1 of 1 lakes in Vernon County

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Izaak Walton Lake holds Grade F. 5 nearby lakes hold higher grades.

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Reservoir Info (USACE NID)

Izaak Walton Lake is a man-made reservoir impounded by the Izaak Walton Lake Dam (completed 1926), built primarily for recreation on the TR TO WHITE BRANCH; earth-type dam, 25 ft tall.

Surface area: 10 ac
Normal storage: 67 ac-ft
Max storage: 134 ac-ft
Drainage area: 1,000 sq mi
Hazard class: High
Owner: CITY OF NEVADA

Source: USACE National Inventory of Dams, NID ID MO20048 · Operator website

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2020-08-21

Monitoring stations: 1