Pony Express Lake
DeKalb County, WisconsinEutrophic
Pony Express Lake is a 164-acre productive, nutrient-rich eutrophic lake in DeKalb County, MO. Water quality is graded D based on 3 sampling years through 2024. Compared to the 5 other monitored lakes in DeKalb County, Pony Express Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-08-07. 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 1.3 ft of visibility. Phosphorus level: 53.2 µg/L. Chlorophyll-a: 26.3 µg/L. Trophic State Index: 66.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | F |
| Phosphorus | 53.2 µg/L | C |
| Chlorophyll-a (Algae) | 26.3 µg/L | D |
| Trophic State Index (TSI) | 66 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 164 acres |
Location
County Ranking
Ranked #1 of 6 lakes in DeKalb County
Nearby Lakes in DeKalb County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
St. Louis city County · Clarity: 2.3 ft
Shelby County · Clarity: 3.2 ft
Macon County · Clarity: 1.8 ft
Harrison County · Clarity: 1.7 ft
Stone County · Clarity: 2.3 ft
Knox County · Clarity: 2.1 ft
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Pony Express Lake is a man-made reservoir impounded by the Pony Express Lake Dam (completed 1963), built primarily for recreation on the TR-WEST FORK LOST CREEK; earth-type dam, 40 ft tall and 1,600 ft long.
- Surface area
- 164 ac
- Normal storage
- 2,400 ac-ft
- Max storage
- 3,560 ac-ft
- Drainage area
- 4.14 sq mi
- Hazard class
- High
- Owner
- MO DEPT OF CONSERVATION
Source: USACE National Inventory of Dams, NID ID MO10171 · Operator website
EPA Impairment Status
Pony Express 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_7118.00 · 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: 2024-08-07
Monitoring stations: 2