Smith Lake
Kossuth County, WisconsinEutrophic
Smith Lake is a 53-acre productive, nutrient-rich eutrophic lake in Kossuth County, IA. Water quality is graded F based on 2 sampling years through 2024.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-19. Grade methodology: LakeGrade methodology.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2.4 ft of visibility. Chlorophyll-a: 39.1 µg/L. Trophic State Index: 65.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.4 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 39.1 µg/L | F |
| Trophic State Index (TSI) | 65 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 53 acres |
Location
County Ranking
Ranked #1 of 1 lakes in Kossuth County
Nearby Lakes in Kossuth County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Smith Lake is a man-made reservoir impounded by the Lake Smith Dam (completed 1965), built primarily for recreation on the TR-BLACK CAT CREEK; earth-type dam, 21 ft tall and 570 ft long.
- Surface area
- 53 ac
- Normal storage
- 245 ac-ft
- Max storage
- 463 ac-ft
- Drainage area
- 1.8 sq mi
- Hazard class
- Significant
- Owner
- Kossuth County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA00570 · Operator website
EPA Impairment Status
Smith Lake 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 IA 04-EDM-981 · 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: 2024-09-19
Monitoring stations: 1