Lake of the Hills
Scott County, WisconsinEutrophic
Lake of the Hills is a 657-acre productive, nutrient-rich eutrophic lake in Scott County, IA. Water quality is graded C based on 2 sampling years through 2024. Compared to the 4 other monitored lakes in Scott County, Lake of the Hills ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-08-26. Grade methodology: LakeGrade methodology.
Swimming Safety
Swim with caution, moderate algae may be present
Water Quality Grade: C, Fair
Murky, only visible to about 5.1 ft. Chlorophyll-a: 16.8 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.1 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 16.8 µg/L | C |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 657 acres |
Location
County Ranking
Ranked #5 of 5 lakes in Scott County
Cleaner Lakes Within 30 Miles
Lake of the Hills holds Grade C. 2 nearby lakes hold higher grades.
- BLambach LakeScott County · 0.3 mi · Higher grade (C → B)
- CRailroad LakeScott County · 0.4 mi · Higher overall water quality score
Nearby Lakes in Scott County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Lake of the Hills is a man-made reservoir impounded by the Lake of The Hills Dam (completed 1972), built primarily for other on the BLACKHAWK CREEK; earth-type dam, 48 ft tall and 2,400 ft long.
- Surface area
- 657 ac
- Normal storage
- 613 ac-ft
- Max storage
- 1,950 ac-ft
- Drainage area
- 2.6 sq mi
- Hazard class
- High
- Owner
- Iowa Department of Transportation,SCOTT COUNTY CONSERVATION
All listed purposes: Other;Recreation.
Source: USACE National Inventory of Dams, NID ID IA00978 · Operator website
EPA Impairment Status
Lake of the Hills 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 01-NEM-68 · 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: 2024-08-26
Monitoring stations: 1