Dead Colt Creek Dam Lake
Ransom County, WisconsinEutrophic
Dead Colt Creek Dam Lake is a 124-acre productive, nutrient-rich eutrophic lake in Ransom County, ND. Water quality is graded F based on 2 sampling years through 2020.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-10-02. 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 3.3 ft of visibility. Chlorophyll-a: 32.3 µg/L. Trophic State Index: 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 32.3 µg/L | F |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 124 acres |
Location
County Ranking
Ranked #1 of 1 lakes in Ransom County
Cleaner Lakes Within 30 Miles
Dead Colt Creek Dam Lake holds Grade F. 2 nearby lakes hold higher grades.
- CSilver LakeSargent County · 24.1 mi · Two grade letters higher (F → C)
- CAlkali LakeSargent County · 26.3 mi · Two grade letters higher (F → C)
Nearby Lakes in Ransom County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Dead Colt Creek Dam Lake is a man-made reservoir impounded by the Dead Colt Creek Dam (completed 1984), built primarily for flood risk reduction on the Dead Colt Creek; earth-type dam, 92 ft tall and 1,200 ft long.
- Surface area
- 124 ac
- Normal storage
- 2,208.6 ac-ft
- Max storage
- 8,901.2 ac-ft
- Drainage area
- 60 sq mi
- Hazard class
- Significant
- Owner
- Ransom County WRB
All listed purposes: Flood Risk Reduction;Recreation.
Source: USACE National Inventory of Dams, NID ID ND00412 · Operator website
EPA Impairment Status
Dead Colt Creek 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-09020204-005-L_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: 2020-10-02
Monitoring stations: 1