What is the water quality grade for Coldwater Lake?

Coldwater Lake in Isabella County, Wisconsin received a water quality grade of B (Good). Water clarity: 10 ft visibility.

Is Coldwater Lake safe to swim in?

Good for swimming, clear water with low algae levels. Coldwater Lake has an overall water quality grade of B. Always check local health department advisories before swimming.

What fish are in Coldwater Lake?

Fish species found in Coldwater Lake include Lake herring. Coldwater Lake is located in Isabella County, Wisconsin.

Coldwater Lake

Isabella County, WisconsinLimited DataMesotrophic

Coldwater Lake is a mesotrophic lake in Isabella County, MI. Water quality is graded B based on 1 sampling years through 2023. The lake supports 1 documented fish species including Lake herring. Compared to the 1 other monitored lakes in Isabella County, Coldwater Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2023-06-14. Grade methodology: LakeGrade methodology.

Swimming Safety

Good for swimming, clear water with low algae levels

Water Quality Grade: B, Good

Good clarity, visible to about 10 ft. Trophic State Index: 44.

Metric	Value	Grade
Water Clarity (Secchi Depth)	10 ft	B
Phosphorus	No data
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	44	Mesotrophic

Moderate nutrients, good water quality

Fish Species

Lake herring

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

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

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

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

Location

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County Ranking

Ranked #2 of 2 lakes in Isabella County

Cleaner Lakes Within 30 Miles

Coldwater Lake holds Grade B. 3 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Isabella County

Coldwater Lake Southeast Basin; Nottawa Township

Isabella County

Lake George

Clare County

Lake George; Central Deep Basin; Lincoln Township

Clare County

Windover Lake South Basin; Freeman Township

Clare County

Windover Lake

Clare County

Shingle Lake South Basin; Lincoln Township

Clare County

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 B Lakes in Wisconsin

Middle Lake; Elba Township; Section 13

Lapeer County · Clarity: 9.5 ft

Portage Lake

Livingston County · Clarity: 13 ft

Bear Lake East Basin; Pleasanton Township

Manistee County · Clarity: 11 ft

Bass Lake

Lake County · Clarity: 14 ft

Long Lake

Cass County · Clarity: 10.5 ft

Byram Lake West Central Basin; Fenton Township

Genesee County · Clarity: 10 ft

Mesotrophic Lakes in Wisconsin

Middle Lake; Elba Township; Section 13 Portage Lake Shavehead Lake East Basin; Porter Township Chippewa Lake Northeast Basin; Chippewa Township

EPA Impairment Status

Coldwater Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

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

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

Source: EPA ATTAINS assessment unit MI040802020204-07 · 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: 2023-06-14

Monitoring stations: 1