What is the water quality grade for Mirror Lake?

Mirror Lake in Adams County, Wisconsin received a water quality grade of F (Very Poor). Water clarity: 2.1 ft visibility. Chlorophyll-a (algae): 31.6 µg/L. Surface area: 94.33 acres.

Is Mirror Lake safe to swim in?

Avoid swimming, very poor water quality, potential algae toxins. Mirror Lake has an overall water quality grade of F. Algae concentration (chlorophyll-a) is 31.6 µg/L. Always check local health department advisories before swimming.

Mirror Lake

Adams County, WisconsinEutrophic

Mirror Lake is a 94-acre productive, nutrient-rich eutrophic lake in Adams County, ND. Water quality is graded F based on 2 sampling years through 2024. Compared to the 1 other monitored lakes in Adams County, Mirror Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-24. 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 2.1 ft of visibility. Chlorophyll-a: 31.6 µg/L. Trophic State Index: 65.

Metric	Value	Grade
Water Clarity (Secchi Depth)	2.1 ft	F
Phosphorus	No data
Chlorophyll-a (Algae)	31.6 µg/L	F
Trophic State Index (TSI)	65	Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

Characteristic	Value
Surface Area	94.33 acres

Location

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County Ranking

Ranked #2 of 2 lakes in Adams County

Cleaner Lakes Within 30 Miles

Mirror Lake holds Grade F. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Adams County

North Lemmon Lake

Adams County

Indian Creek Dam Lake

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 F Lakes in Wisconsin

J. Clark Salyer Pool 357

Bottineau County · Clarity: 2.2 ft

Western Stump Lake

Nelson County · Clarity: 4.3 ft

Morrison Lake

Ramsey County · Clarity: 1.9 ft

Eastern Stump Lake

Nelson County · Clarity: 4.7 ft

Mchugh Slough Lake

Nelson County · Clarity: 1.6 ft

Buffalo Lake

Pierce County · Clarity: 0.3 ft

Eutrophic Lakes in Wisconsin

Lake Alice J. Clark Salyer Pool 357 E. A. Patterson Lake Lake Irvine

Reservoir Info (USACE NID)

Mirror Lake is a man-made reservoir impounded by the Mirror Lake Dam (completed 1909), built primarily for recreation on the Flat Creek; earth-type dam, 19 ft tall and 800 ft long.

Surface area: 94.33 ac
Normal storage: 573 ac-ft
Max storage: 894.59 ac-ft
Drainage area: 0 sq mi
Hazard class: Significant
Owner: Hettinger Park Board

Source: USACE National Inventory of Dams, NID ID ND00137 · Operator website

EPA Impairment Status

Mirror Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)Oxygen depletion (low DO)

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

Source: EPA ATTAINS assessment unit ND-10130303-001-L_00 · 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: 2024-09-24

Monitoring stations: 2