Lake Pahoja
Lyon County, WisconsinEutrophic
Lake Pahoja is a 72-acre productive, nutrient-rich eutrophic lake in Lyon County, IA. Water quality is graded F based on 2 sampling years through 2024.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-09. 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 1.7 ft of visibility. Chlorophyll-a: 44.8 µg/L. Trophic State Index: 69.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.7 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 44.8 µg/L | F |
| Trophic State Index (TSI) | 69 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 71.5 acres |
Location
County Ranking
Ranked #1 of 1 lakes in Lyon County
Nearby Lakes in Lyon County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Lake Pahoja is a man-made reservoir impounded by the Lake Pahoja Dam (completed 1974), built primarily for fire protection, stock, or small fish pond on the TR-KLONDIKE CREEK; earth-type dam, 50 ft tall and 1,305 ft long.
- Surface area
- 71.5 ac
- Normal storage
- 893 ac-ft
- Max storage
- 2,283 ac-ft
- Drainage area
- 6.09 sq mi
- Hazard class
- Significant
- Owner
- Lyon County Conservation Board
All listed purposes: Fire Protection, Stock, Or Small Fish Pond;Recreation.
Source: USACE National Inventory of Dams, NID ID IA00604 · Operator website
EPA Impairment Status
Lake Pahoja is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 06-BSR-1532 · 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: 2024-09-09
Monitoring stations: 1