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LakeQuality
C

George Lake

Rock Island County, WisconsinEutrophic

George Lake is a 167-acre productive, nutrient-rich eutrophic lake in Rock Island County, IL. Water quality is graded C based on 2 sampling years through 2021.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2021-10-19. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Murky, only visible to about 4.2 ft. Phosphorus level: 22.5 µg/L. Trophic State Index: 53.

MetricValueGrade
Water Clarity (Secchi Depth)4.2 ftD
Phosphorus22.5 µg/LB
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)53Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Surface Area167 acres

Location

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County Ranking

Ranked #1 of 1 lakes in Rock Island County

Nearby Lakes in Rock Island County

Reservoir Info (USACE NID)

George Lake is a man-made reservoir impounded by the Lake George Dam (completed 1962), built primarily for recreation on the BIG BRANCH CREEK; earth-type dam, 78 ft tall and 1,090 ft long.

Surface area
167 ac
Normal storage
4,014 ac-ft
Max storage
6,355 ac-ft
Drainage area
7.27 sq mi
Hazard class
High
Owner
ROCK ISLAND COUNTY FOREST PRESERVE DIST.

Source: USACE National Inventory of Dams, NID ID IL00136 · Operator website

EPA Impairment Status

George 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)Turbidity

Source: EPA ATTAINS assessment unit IL_RML · Official waterbody report · Matched by proximity (0.28 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: 2021-10-19

Monitoring stations: 3