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LakeQuality
C

Railroad Lake

Scott County, WisconsinEutrophic

Railroad Lake is a 29-acre productive, nutrient-rich eutrophic lake in Scott County, IA. Water quality is graded C based on 2 sampling years through 2024. Compared to the 4 other monitored lakes in Scott County, Railroad Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2024-09-10. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Murky, only visible to about 5.1 ft. Chlorophyll-a: 8.3 µg/L. Trophic State Index: 53.

MetricValueGrade
Water Clarity (Secchi Depth)5.1 ftD
PhosphorusNo data
Chlorophyll-a (Algae)8.3 µg/LB
Trophic State Index (TSI)53Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Surface Area29 acres

Location

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County Ranking

Ranked #2 of 5 lakes in Scott County

Cleaner Lakes Within 30 Miles

Railroad Lake holds Grade C. One nearby lake has a higher grade.

See full comparison →

Nearby Lakes in Scott County

Reservoir Info (USACE NID)

Railroad Lake is a man-made reservoir impounded by the Railroad Lake Dam (completed 1983), built primarily for recreation on the TR- BLACK HAWK CR.; earth-type dam, 35 ft tall and 525 ft long.

Surface area
29 ac
Normal storage
360 ac-ft
Max storage
750 ac-ft
Drainage area
1.11 sq mi
Hazard class
Significant
Owner
Scott County Conservation Board

Source: USACE National Inventory of Dams, NID ID IA02208 · Operator website

EPA Impairment Status

Railroad Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Algal growth

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

Source: EPA ATTAINS assessment unit IA 01-NEM-68 · Official waterbody report · Matched by proximity (0.54 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: 2024-09-10

Monitoring stations: 1