Three Mile Lake
Union County, WisconsinEutrophic
Three Mile Lake is a 880-acre productive, nutrient-rich eutrophic lake in Union County, IA. Water quality is graded D based on 2 sampling years through 2024. Compared to the 5 other monitored lakes in Union County, Three Mile Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-06-26. Grade methodology: LakeGrade methodology.
Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Very murky, less than 2.7 ft of visibility. Chlorophyll-a: 28.4 µg/L. Trophic State Index: 63.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.7 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 28.4 µg/L | D |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 880 acres |
Location
County Ranking
Ranked #1 of 6 lakes in Union County
Nearby Lakes in Union County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Three Mile Lake is a man-made reservoir impounded by the Three Mile Reservoir Dam (completed 1995), built primarily for flood risk reduction on the THREE MILE CREEK; earth-type dam, 63 ft tall and 1,850 ft long.
- Surface area
- 880 ac
- Normal storage
- 14,091 ac-ft
- Max storage
- 29,950 ac-ft
- Drainage area
- 36.3 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
All listed purposes: Flood Risk Reduction;Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID IA02944 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-06-26
Monitoring stations: 1