F

Sweet Briar Dam-Mid Reservoir

Morton County, WisconsinEutrophic

Sweet Briar Dam-Mid Reservoir is a productive, nutrient-rich eutrophic lake in Morton County, ND. Water quality is graded F based on 2 sampling years through 2024. Compared to the 3 other monitored lakes in Morton County, Sweet Briar Dam-Mid Reservoir ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-08-06. 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 3 ft of visibility. Chlorophyll-a: 36.9 µg/L. Trophic State Index: 64.

Metric	Value	Grade
Water Clarity (Secchi Depth)	3 ft	F
Phosphorus	No data
Chlorophyll-a (Algae)	36.9 µg/L	F
Trophic State Index (TSI)	64	Eutrophic

High nutrients, frequent algae, reduced clarity

Location

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County Ranking

Ranked #3 of 4 lakes in Morton County

Cleaner Lakes Within 30 Miles

Sweet Briar Dam-Mid Reservoir holds Grade F. 4 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Morton County

Nygren Dam Lake

Sweetbriar Dam Lake

East Arroda 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

Ramsey County · Clarity: 1.9 ft

Eastern Stump Lake

Nelson County · Clarity: 4.7 ft

Mchugh Slough Lake

Nelson County · Clarity: 1.6 ft

Pierce County · Clarity: 0.3 ft

Eutrophic Lakes in Wisconsin

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

EPA Impairment Status

Sweet Briar Dam-Mid Reservoir 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)

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

Source: EPA ATTAINS assessment unit ND-10130203-005-L_00 · Official waterbody report · Matched by proximity (0.43 km)

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: 2024-08-06

Monitoring stations: 1