What is the water quality grade for Posey Lake?

Posey Lake in Lenawee County, Wisconsin received a water quality grade of D (Poor). Water clarity: 4.5 ft visibility. Surface area: 150 acres.

Is Posey Lake safe to swim in?

Swimming not recommended, poor water quality with high algae risk. Posey Lake has an overall water quality grade of D. Always check local health department advisories before swimming.

Posey Lake

Lenawee County, WisconsinLimited DataEutrophic

Posey Lake is a 150-acre productive, nutrient-rich eutrophic lake in Lenawee County, MI. Water quality is graded D based on 1 sampling years through 2022. The lake supports 7 documented fish species including Bluegill, Common carp, and Golden redhorse. Compared to the 7 other monitored lakes in Lenawee County, Posey Lake ranks #8 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-09-16. Grade methodology: LakeGrade methodology.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Murky, only visible to about 4.5 ft. Trophic State Index: 55.

Metric	Value	Grade
Water Clarity (Secchi Depth)	4.5 ft	D
Phosphorus	No data
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	55	Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

Characteristic	Value
Surface Area	150 acres

Fish Species

Bluegill Common carp Golden redhorse Largemouth bass Pumpkinseed White sucker Yellow bullhead

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for Posey Lake (14-day solunar calendar)

→ Is it safe to eat fish from Posey Lake? (mercury & PFAS guide)

→ Posey Lake fishing regulations (limits, seasons, special rules)

Location

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County Ranking

Ranked #8 of 8 lakes in Lenawee County

Cleaner Lakes Within 30 Miles

Posey Lake holds Grade D. 3 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Lenawee County

Sand Lake Central Basin; Cambridge Township

Lenawee County

Devils Lake Central Basin North

Lenawee County

Round Lake Central Basin

More Wisconsin Lake Rankings

Cleanest lakes in Wisconsin

Top 25 by overall water quality score

Best swimming lakes in Wisconsin

Grade A/B + low algae filter

Family fishing lakes in Wisconsin

Panfish-rich, public access

All Wisconsin lakes

Full state directory

Other Grade D Lakes in Wisconsin

Kimball Lake

Newaygo County · Clarity: 4.5 ft

Community College Pond

Chippewa County · Clarity: 1.5 ft

Little Beaver Lake

Alger County · Clarity: 6.2 ft

Van Etten Lake

Iosco County · Clarity: 5.5 ft

South Pond

Chippewa County · Clarity: 1.3 ft

Eagle Lake

Cass County · Clarity: 6 ft

Eutrophic Lakes in Wisconsin

Kimball Lake Van Etten Lake North Central Basin; Oscoda Township Community College Pond Pentwater Lake Northwest Basin; Pentwater Township

Reservoir Info (USACE NID)

Posey Lake is a man-made reservoir impounded by the Posey Lake Level Control Structure (completed 1955), built primarily for recreation on the Posey Lake Drain; gravity-type dam, 7 ft tall and 15 ft long.

Surface area: 150 ac
Normal storage: 190 ac-ft
Max storage: 715 ac-ft
Drainage area: 0 sq mi
Hazard class: Low
Owner: Lenawee County Drain Commissioner

Source: USACE National Inventory of Dams, NID ID MI02265 · Operator website

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2022-09-16

Monitoring stations: 1