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LakeQuality
F

Borah Lake

Richland County, WisconsinHypereutrophic

Borah Lake is a highly nutrient-loaded hypereutrophic lake in Richland County, IL. Water quality is graded F based on 2 sampling years through 2022. Compared to the 2 other monitored lakes in Richland County, Borah Lake ranks #3 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2022-10-13. 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 2.2 ft of visibility. Phosphorus level: 131 µg/L. Trophic State Index: 70.

MetricValueGrade
Water Clarity (Secchi Depth)2.2 ftF
Phosphorus131 µg/LF
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)70Hypereutrophic

Very high nutrients, dense algae, poor clarity

Location

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County Ranking

Ranked #3 of 3 lakes in Richland County

Cleaner Lakes Within 30 Miles

Borah Lake holds Grade F. 3 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Richland County

C
Olney East Fork Lake
Richland County
D
Vernor Lake
Richland County
D
Newton Lake
Jasper County
F
Fairfield Lake
Wayne County
F
Sam Dale Lake
Wayne County
D
Sara Lake
Effingham County

More Wisconsin Lake Rankings

Cleanest lakes in Wisconsin

Top 25 by overall water quality score

Best swimming lakes in Wisconsin

Grade A/B + low algae filter

Family fishing lakes in Wisconsin

Panfish-rich, public access

All Wisconsin lakes

Full state directory

Other Grade F Lakes in Wisconsin

Lake Charlemagne

Cook County · Clarity: 2 ft

Bode Lake North

Cook County · Clarity: 1.5 ft

Great Lakes Quarries West

Cook County · Clarity: 2.5 ft

Bull Frog Lake

Cook County · Clarity: 3 ft

Belly Deep Slough Lake

Cook County · Clarity: 0.7 ft

Sauk Lake

Cook County · Clarity: 1 ft

Hypereutrophic Lakes in Wisconsin

Bode Lake NorthBelly Deep Slough LakeSauk LakeWashington Park Lagoon Lake

Reservoir Info (USACE NID)

Borah Lake is a man-made reservoir impounded by the M. D. Borah Lake Dam (completed 1953), built primarily for recreation on the TRIB FOX RIVER; earth-type dam, 36 ft tall and 960 ft long.

Normal storage
2,060 ac-ft
Max storage
4,720 ac-ft
Hazard class
High
Owner
CITY OF OLNEY

All listed purposes: Recreation;Water Supply.

Source: USACE National Inventory of Dams, NID ID IL00331 · Operator website · Matched by proximity (0.87 km)

EPA Impairment Status

Borah Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

MercuryNutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit IL_RCB · Official waterbody report · Matched by proximity (0.17 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: 2022-10-13

Monitoring stations: 3