Larimore Dam Lake
Grand Forks County, WisconsinEutrophic
Larimore Dam Lake is a 72-acre productive, nutrient-rich eutrophic lake in Grand Forks County, ND. Water quality is graded D based on 2 sampling years through 2025. Compared to the 3 other monitored lakes in Grand Forks County, Larimore Dam Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2025-10-13. 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 3 ft of visibility. Chlorophyll-a: 13.3 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 13.3 µg/L | C |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 72 acres |
Location
County Ranking
Ranked #2 of 4 lakes in Grand Forks County
Cleaner Lakes Within 30 Miles
Larimore Dam Lake holds Grade D. 3 nearby lakes hold higher grades.
- CFordville Dam LakeGrand Forks County · 18.6 mi · Higher grade (D → C)
- CNorth Golden LakeSteele County · 24.2 mi · Higher grade (D → C)
- CSouth Golden LakeSteele County · 25.1 mi · Higher grade (D → C)
Nearby Lakes in Grand Forks County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Larimore Dam Lake is a man-made reservoir impounded by the Upper Turtle River Flood Ret. 9 (completed 1979), built primarily for flood risk reduction on the South Branch Turtle River; earth-type dam, 71 ft tall and 1,040 ft long.
- Surface area
- 72 ac
- Normal storage
- 823 ac-ft
- Max storage
- 10,410 ac-ft
- Drainage area
- 64.9 sq mi
- Hazard class
- High
- Owner
- Grand Forks County WRB
All listed purposes: Flood Risk Reduction;Recreation.
Source: USACE National Inventory of Dams, NID ID ND00391 · Operator website
EPA Impairment Status
Larimore Dam Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit ND-09020307-001-L_00 · Official waterbody report · Matched by proximity (0.06 km)
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: 2025-10-13
Monitoring stations: 3