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 Stream Quality: Adaptive Management Approach




The Illinois Environmental Protection Agency is responsible for assessing stream health in Illinois. These assessments are published on a two year cycle in a newly titled report: Illinois Integrated Water Quality Report and Section 303(d) List – 2012. This report describes the designated uses for each water body and how well those uses are being supported. The report also lists the possible causes and sources of water quality impairments. This information is used to develop the Section 303(d) otherwise known as the List of Impaired Waters or simply the TMDL list. The table below lists the potential reasons or causes why our streams are not fully supporting the General Use and/or Aquatic Life Use.


Causes and Sources of Impairment for the
DuPage River Watershed
Based on the 2012 (draft) 
ntegrated Water Quality Report and Section 303(d) List

Potential Causes of Impairment

Potential Sources of Impairment

In-stream Effect


Site Clearance (Land Development or Redevelopment), Urban Runoff/Storm Sewers, Highways, Road, Bridges, Infrastructure (New Construction), impacts from Hydro-structure Flow Regulations/Modifications

Covering of stream bottom habitat with silt, cloudy water, difficult for fish to see prey, depletion of Oxygen needed by fish and macroinvertebrates

Total Phosphorus

Municipal Point Source Discharges, Urban Runoff/Storm Sewers, Runoff from Forest/Grassland/Parkland, Waterfowl, Specialty Crop Production,

Increased Algal Growth, Depletion of Oxygen needed by fish and macroinvertebrates


Road deicing operations    Urban Runoff/Stormsewers, Municipal Point -Source Discharges

Reduction of flora and fauna diversity as salt intolerant species are pushed out

Low Dissolved Oxygen

Excess nutrients, Excess algal or macrophyte growth, Excess sediment, Impoundments,

Needed by aquatic life to "breath"

In Stream Habitat Problems: Changes in stream depth and velocity, Alteration of streamside vegetation, flow regime

Urban Runoff, Land Development, loss of riparian habitat, instream infrastructure (bridges, culverts), flashy storm fllows

Reduced habitat diversity leads to reduced biological diversity

Fecal Coliform

Urban Runoff/Storm Sewers, Source Unknown

Bacteria, Public Health/Primary Contact with water


Contaminated Sediments

Toxic Substance - Pesticide


Contaminated Sediments

Toxic Substance - Heavy Metal


Contaminated Sediments

Toxic Substance - Industrial Waste




Contact Us

10S404 Knoch Knolls Road

Naperville, IL 60565

Phone: 630-428-4500

Fax: 630-428-4599

E-mail: Jennifer Hammer



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