Blue Grass Lake
Scott County, WisconsinEutrophic
Blue Grass Lake is a 14-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, Blue Grass Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-10. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 4.5 ft. Chlorophyll-a: 12.7 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.5 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 12.7 µg/L | C |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 13.8 acres |
Location
County Ranking
Ranked #4 of 5 lakes in Scott County
Cleaner Lakes Within 30 Miles
Blue Grass Lake holds Grade C. 2 nearby lakes hold higher grades.
- BLambach LakeScott County · 0.7 mi · Higher grade (C → B)
- CRailroad LakeScott County · 0.3 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)
Blue Grass Lake is a man-made reservoir impounded by the Blue Grass Lake Dam (completed 1974), built primarily for recreation on the BLACK HAWK CREEK; earth-type dam, 28 ft tall and 850 ft long.
- Surface area
- 13.8 ac
- Normal storage
- 93 ac-ft
- Max storage
- 490 ac-ft
- Drainage area
- 0.8 sq mi
- Hazard class
- Significant
- Owner
- Scott County Conservation Board
All listed purposes: Recreation;Other.
Source: USACE National Inventory of Dams, NID ID IA01970 · Operator website
EPA Impairment Status
Blue Grass 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 01-NEM-68 · Official waterbody report · Matched by proximity (1.08 km)
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: 2024-09-10
Monitoring stations: 1