Cottontail Lake
Jackson County, WisconsinEutrophic
Cottontail Lake is a 21-acre productive, nutrient-rich eutrophic lake in Jackson County, MO. Water quality is graded F based on 3 sampling years through 2023. Compared to the 26 other monitored lakes in Jackson County, Cottontail Lake ranks #12 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2023-10-03. 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 1.6 ft of visibility. Phosphorus level: 86.5 µg/L. Chlorophyll-a: 39.4 µg/L. Trophic State Index: 68.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | F |
| Phosphorus | 86.5 µg/L | D |
| Chlorophyll-a (Algae) | 39.4 µg/L | F |
| Trophic State Index (TSI) | 68 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 21 acres |
Location
County Ranking
Ranked #12 of 27 lakes in Jackson County
Cleaner Lakes Within 30 Miles
Cottontail Lake holds Grade F. 2 nearby lakes hold higher grades.
- CLotawana Lk. LakeJackson County · 5.1 mi · Two grade letters higher (F → C)
- DPrairie Lee Lake Nr. DamJackson County · 4.2 mi · Higher grade (F → D)
Nearby Lakes in Jackson County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
St. Louis County · Clarity: 1.6 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
Callaway County · Clarity: 1.7 ft
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Cottontail Lake is a man-made reservoir impounded by the Cottontail Lake Dam (completed 1966), built primarily for recreation on the TR-EAST BR-BIG CREEK; earth-type dam, 25 ft tall.
- Surface area
- 21 ac
- Normal storage
- 154 ac-ft
- Max storage
- 281 ac-ft
- Drainage area
- 1,200 sq mi
- Hazard class
- Low
- Owner
- MO DEPT OF CONSERVATION
Source: USACE National Inventory of Dams, NID ID MO20025 · Operator website
EPA Impairment Status
Cottontail Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7379.00 · 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: 2023-10-03
Monitoring stations: 2