Back Bay Deep Lake
Chippewa County, WisconsinMesotrophic
Back Bay Deep Lake is a mesotrophic lake in Chippewa County, MI. Water quality is graded B based on 3 sampling years through 2025. Compared to the 17 other monitored lakes in Chippewa County, Back Bay Deep Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2025-10-15. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 8.2 ft. Phosphorus level: 15 µg/L. Chlorophyll-a: 1.9 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.2 ft | C |
| Phosphorus | 15 µg/L | A |
| Chlorophyll-a (Algae) | 1.9 µg/L | A |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Location
County Ranking
Ranked #9 of 18 lakes in Chippewa County
Cleaner Lakes Within 30 Miles
Back Bay Deep Lake holds Grade B. 2 nearby lakes hold higher grades.
- ASaint Mary'S River Offshore LakeChippewa County · 2.1 mi · Higher grade (B → A)
- ASaint Mary'S River Shore LakeChippewa County · 2.1 mi · Higher grade (B → A)
Nearby Lakes in Chippewa 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
Cass County · Clarity: 10.5 ft
Genesee County · Clarity: 10 ft
Mesotrophic Lakes in Wisconsin
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-10-15
Monitoring stations: 1