Willow Lake
Harrison County, WisconsinEutrophic
Willow Lake is a 19-acre productive, nutrient-rich eutrophic lake in Harrison County, IA. Water quality is graded C based on 2 sampling years through 2024. Compared to the 1 other monitored lakes in Harrison County, Willow Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-03. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 4.8 ft. Chlorophyll-a: 9.5 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 9.5 µg/L | B |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 19 acres |
Location
County Ranking
Ranked #1 of 2 lakes in Harrison County
Nearby Lakes in Harrison County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Willow Lake is a man-made reservoir impounded by the Willow Lake Dam (completed 1976), built primarily for debris control on the TR-WILLOW CREEK; earth-type dam, 31 ft tall and 390 ft long.
- Surface area
- 19 ac
- Normal storage
- 21 ac-ft
- Max storage
- 44 ac-ft
- Drainage area
- 0.21 sq mi
- Hazard class
- Low
- Owner
- Harrison County Conservation Board
All listed purposes: Debris Control;Recreation.
Source: USACE National Inventory of Dams, NID ID IA01566 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-09-03
Monitoring stations: 1