Shabbona Lake
DeKalb County, WisconsinEutrophic
Shabbona Lake is a productive, nutrient-rich eutrophic lake in DeKalb County, IL. Water quality is graded C based on 2 sampling years through 2022.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-10-03. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 4.9 ft. Phosphorus level: 27.5 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.9 ft | D |
| Phosphorus | 27.5 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Location
County Ranking
Ranked #1 of 1 lakes in DeKalb County
Cleaner Lakes Within 30 Miles
Shabbona Lake holds Grade C. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in DeKalb County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Cook County · Clarity: 9 ft
Cook County · Clarity: 8.5 ft
Williamson County · Clarity: 3.2 ft
Johnson County · Clarity: 4.5 ft
Gallatin County · Clarity: 3.9 ft
Rock Island County · Clarity: 4.2 ft
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Shabbona Lake is a man-made reservoir impounded by the Shabbona Lake Dam (completed 1974), built primarily for other on the INDIAN CREEK; earth-type dam, 56 ft tall and 2,570 ft long.
- Normal storage
- 4,275 ac-ft
- Max storage
- 6,387 ac-ft
- Hazard class
- Low
- Owner
- ILLINOIS DEPARTMENT OF NATURAL RESOURCES
All listed purposes: Other;Recreation.
Source: USACE National Inventory of Dams, NID ID IL01202 · Operator website
EPA Impairment Status
Shabbona Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit IL_VTU · 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: 2022-10-03
Monitoring stations: 3