What is the water quality grade for Stephens Lake?

Stephens Lake in Boone County, Wisconsin received a water quality grade of D (Poor). Water clarity: 2.6 ft visibility. Phosphorus: 39.7 µg/L. Chlorophyll-a (algae): 19.9 µg/L. Surface area: 11 acres.

Is Stephens Lake safe to swim in?

Swimming not recommended, poor water quality with high algae risk. Stephens Lake has an overall water quality grade of D. Algae concentration (chlorophyll-a) is 19.9 µg/L. Always check local health department advisories before swimming.

Stephens Lake

Boone County, WisconsinEutrophic

Stephens Lake is a 11-acre productive, nutrient-rich eutrophic lake in Boone County, MO. Water quality is graded D based on 3 sampling years through 2020. Compared to the 11 other monitored lakes in Boone County, Stephens Lake ranks #7 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-09-04. Grade methodology: LakeGrade methodology.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Very murky, less than 2.6 ft of visibility. Phosphorus level: 39.7 µg/L. Chlorophyll-a: 19.9 µg/L. Trophic State Index: 60.

Metric	Value	Grade
Water Clarity (Secchi Depth)	2.6 ft	F
Phosphorus	39.7 µg/L	C
Chlorophyll-a (Algae)	19.9 µg/L	C
Trophic State Index (TSI)	60	Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

Characteristic	Value
Surface Area	11 acres

Location

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County Ranking

Ranked #7 of 12 lakes in Boone County

Cleaner Lakes Within 30 Miles

Stephens Lake holds Grade D. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Boone 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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Panfish-rich, public access

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Other Grade D Lakes in Wisconsin

Boathouse Lake

St. Louis city County · Clarity: 2.3 ft

Hunnewell Lake

Shelby County · Clarity: 3.2 ft

Long Branch Lk. Lake

Macon County · Clarity: 1.8 ft

Harrison County Lake Intake

Harrison County · Clarity: 1.7 ft

Table Rock L. Bl. Hwy. 173 Lake

Stone County · Clarity: 2.3 ft

Henry Sever Lake

Knox County · Clarity: 2.1 ft

Eutrophic Lakes in Wisconsin

Aspen Lake Along Southern Arm Boathouse Lake Hunnewell Lake Long Branch Lk. Lake

Reservoir Info (USACE NID)

Stephens Lake is a man-made reservoir impounded by the Stephens Lake Dam (completed 1939), built primarily for recreation on the TR HINKSON CREEK; earth-type dam, 23 ft tall.

Surface area: 11 ac
Normal storage: 63 ac-ft
Max storage: 135 ac-ft
Drainage area: 40 sq mi
Hazard class: High
Owner: STEPHENS COLLEGE

Source: USACE National Inventory of Dams, NID ID MO11172 · Operator website

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2020-09-04

Monitoring stations: 1