Eagle Lake West Central Basin; Ontwa Township
Cass County, WisconsinMesotrophic
Eagle Lake West Central Basin; Ontwa Township is a mesotrophic lake in Cass County, MI. Water quality is graded B based on 2 sampling years through 2023. Compared to the 22 other monitored lakes in Cass County, Eagle Lake West Central Basin; Ontwa Township ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2023-09-21. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Murky, only visible to about 6.3 ft. Chlorophyll-a: 4.7 µg/L. Trophic State Index: 48.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.3 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 4.7 µg/L | A |
| Trophic State Index (TSI) | 48 | Mesotrophic |
Moderate nutrients, good water quality
Location
County Ranking
Ranked #9 of 23 lakes in Cass County
Nearby Lakes in Cass County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Lapeer County · Clarity: 9.5 ft
Livingston County · Clarity: 13 ft
Manistee County · Clarity: 11 ft
Lake County · Clarity: 14 ft
Genesee County · Clarity: 10 ft
Lake County · Clarity: 8 ft
Mesotrophic Lakes in Wisconsin
EPA Impairment Status
Eagle Lake West Central Basin; Ontwa Township is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MI040500011403-04 · Official waterbody report · Matched by proximity (0.32 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: 2023-09-21
Monitoring stations: 1