Arrowhead Lake
Pottawattamie County, WisconsinEutrophic
Arrowhead Lake is a 16-acre productive, nutrient-rich eutrophic lake in Pottawattamie County, IA. Water quality is graded F based on 2 sampling years through 2024. Compared to the 1 other monitored lakes in Pottawattamie County, Arrowhead Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-30. 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 1.8 ft of visibility. Chlorophyll-a: 53.6 µg/L. Trophic State Index: 69.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 53.6 µg/L | F |
| Trophic State Index (TSI) | 69 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 15.7 acres |
Location
County Ranking
Ranked #1 of 2 lakes in Pottawattamie County
Cleaner Lakes Within 30 Miles
Arrowhead Lake holds Grade F. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Pottawattamie County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Arrowhead Lake is a man-made reservoir impounded by the Arrowhead Lake Dam (completed 1959), built primarily for fire protection, stock, or small fish pond on the TR-MOSQUITO CREEK; earth-type dam, 47 ft tall and 615 ft long.
- Surface area
- 15.7 ac
- Normal storage
- 139 ac-ft
- Max storage
- 348 ac-ft
- Drainage area
- 1.63 sq mi
- Hazard class
- Low
- Owner
- Pottawattamie County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA00955 · Operator website
EPA Impairment Status
Arrowhead 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 06-WED-1702 · 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: 2024-09-30
Monitoring stations: 1