Mormon Trail Lake
Adair County, WisconsinEutrophic
Mormon Trail Lake is a 33-acre productive, nutrient-rich eutrophic lake in Adair County, IA. Water quality is graded C based on 2 sampling years through 2024. Compared to the 4 other monitored lakes in Adair County, Mormon Trail Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-29. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 6.2 ft. Chlorophyll-a: 9.7 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.2 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 9.7 µg/L | B |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 33 acres |
Location
County Ranking
Ranked #1 of 5 lakes in Adair County
Nearby Lakes in Adair County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Mormon Trail Lake is a man-made reservoir impounded by the Mormon Trail Lake Dam (completed 1965), built primarily for recreation on the TR-WEST FORK NODAWAY; earth-type dam, 46 ft tall and 928 ft long.
- Surface area
- 33 ac
- Normal storage
- 394 ac-ft
- Max storage
- 585 ac-ft
- Drainage area
- 0.65 sq mi
- Hazard class
- Low
- Owner
- Adair County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA00021 · Operator website
EPA Impairment Status
Mormon Trail Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit IA 05-NOD-1404 · 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: 2024-09-29
Monitoring stations: 1