Harrison County Lake
Harrison County, WisconsinHypereutrophic
Harrison County Lake is a 292-acre highly nutrient-loaded hypereutrophic lake in Harrison County, MO. Water quality is graded F based on 3 sampling years through 2021. Compared to the 2 other monitored lakes in Harrison County, Harrison County Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2021-09-01. 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 1.5 ft of visibility. Phosphorus level: 70 µg/L. Chlorophyll-a: 134.4 µg/L. Trophic State Index: 72.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.5 ft | F |
| Phosphorus | 70 µg/L | D |
| Chlorophyll-a (Algae) | 134.4 µg/L | F |
| Trophic State Index (TSI) | 72 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 292 acres |
Location
County Ranking
Ranked #3 of 3 lakes in Harrison County
Cleaner Lakes Within 30 Miles
Harrison County Lake holds Grade F. 4 nearby lakes hold higher grades.
- BNorth Bethany City ReservoirHarrison County · 6.5 mi · Two grade letters higher (F → B)
- BLake MarieMercer County · 28.6 mi · Two grade letters higher (F → B)
- DHarrison County Lake IntakeHarrison County · 0.1 mi · Higher grade (F → D)
- DLake PahoMercer County · 22.8 mi · Higher grade (F → D)
Nearby Lakes in Harrison County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
St. Louis County · Clarity: 1.6 ft
Jackson County · Clarity: 2 ft
St. Charles County · Clarity: 2.3 ft
St. Francois County · Clarity: 1.1 ft
Saline County · Clarity: 2.3 ft
Polk County · Clarity: 1.2 ft
Hypereutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Harrison County Lake is a man-made reservoir impounded by the West Fork of Big Creek C-1 Dam (completed 1992), built primarily for flood risk reduction on the LITTLE CREEK; earth-type dam, 49 ft tall and 1,500 ft long.
- Surface area
- 292 ac
- Normal storage
- 2,842 ac-ft
- Max storage
- 9,994 ac-ft
- Drainage area
- 17.2 sq mi
- Hazard class
- High
Source: USACE National Inventory of Dams, NID ID MO12370 · Operator website · Matched by proximity (0.24 km)
EPA Impairment Status
Harrison County Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MO_7386.00 · 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: 2021-09-01
Monitoring stations: 1