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LakeQuality
B

One Horse Gap Lake

Pope County, WisconsinEutrophic

One Horse Gap Lake is a 29-acre productive, nutrient-rich eutrophic lake in Pope County, IL. Water quality is graded B based on 2 sampling years through 2020. Compared to the 1 other monitored lakes in Pope County, One Horse Gap Lake ranks #1 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-11-09. Grade methodology: LakeGrade methodology.

Swimming Safety

Good for swimming, clear water with low algae levels

Water Quality Grade: B, Good

Murky, only visible to about 4 ft. Phosphorus level: 17 µg/L. Trophic State Index: 51.

MetricValueGrade
Water Clarity (Secchi Depth)4 ftD
Phosphorus17 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)51Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Surface Area29 acres

Location

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County Ranking

Ranked #1 of 2 lakes in Pope County

Nearby Lakes in Pope County

Reservoir Info (USACE NID)

One Horse Gap Lake is a man-made reservoir impounded by the One Horse Gap (completed 1973), built primarily for recreation on the TR-GRAND PIERRE; earth-type dam, 36 ft tall and 443 ft long.

Surface area
29 ac
Normal storage
193 ac-ft
Max storage
304 ac-ft
Drainage area
0 sq mi
Hazard class
Significant
Owner
USDA FS

Source: USACE National Inventory of Dams, NID ID IL50615 · Operator website

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2020-11-09

Monitoring stations: 3