Koontz Lake
Starke County, WisconsinLimited DataEutrophic
Koontz Lake is a 324-acre productive, nutrient-rich eutrophic lake in Starke County, IN. Water quality is graded D based on 1 sampling years through 2020. Compared to the 1 other monitored lakes in Starke County, Koontz Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-07-10. Grade methodology: LakeGrade methodology.
Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 4.9 ft. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.9 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 324.43 acres |
Location
County Ranking
Ranked #2 of 2 lakes in Starke County
Cleaner Lakes Within 30 Miles
Koontz Lake holds Grade D. 4 nearby lakes hold higher grades.
- AUmk-04 LakeLaPorte County · 19.8 mi · Two grade letters higher (D → A)
- BWti-06 LakeStarke County · 16.3 mi · Two grade letters higher (D → B)
- CUmk-05 LakeMarshall County · 9.4 mi · Higher grade (D → C)
- CUmk-02 LakeLaPorte County · 10.7 mi · Higher grade (D → C)
Nearby Lakes in Starke County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Koontz Lake is a man-made reservoir impounded by the Koontz Lake Dam (completed 1849), built primarily for recreation on the LAWRENCE PONTIUS DITCH; concrete-type dam, 24 ft tall and 271 ft long.
- Surface area
- 324.43 ac
- Normal storage
- 2,980 ac-ft
- Max storage
- 4,820 ac-ft
- Drainage area
- 6.25 sq mi
- Hazard class
- High
- Owner
- DEPARTMENT OF NATURAL RESOURCES
Source: USACE National Inventory of Dams, NID ID IN00782 · Operator website
EPA Impairment Status
Koontz 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 INK01P1036_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: 2020-07-10
Monitoring stations: 1