Iowa Impaired Waters and TMDL Information

Assessed Waters of Iowa by Watershed

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Display impaired waters and TMDL information only




Iowa Previously 303(d)-Listed Waters Now Attaining All Applicable Water Quality Standards

Description of this table
NOTE: Click on the underlined "Number of Waters Attaining" value for a detailed list of those previously 303(d)-listed waters now attaining all applicable water quality standards.
2008 color.gif 19 29
2010 color.gif 17 19
2011 color.gif 2 4
2013 color.gif 14 16
2015 color.gif 13 22

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Iowa 2014 Causes of Impairment for 303(d) Listed Waters

Description of this table
NOTE: Click on a cause of impairment (e.g. pathogens) to see the specific state-reported causes that are grouped to make up this category. Click on the "Number of Causes of Impairment Reported" to see a list of waters with that cause of impairment.
Pathogens color.gif 347
Cause Unknown - Impaired Biota color.gif 126
Cause Unknown - Fish Kills color.gif 56
Mercury color.gif 45
Algal Growth color.gif 39
Turbidity color.gif 29
Organic Enrichment/Oxygen Depletion color.gif 25
pH/Acidity/Caustic Conditions color.gif 17
Metals (other than Mercury) color.gif 7
Temperature color.gif 7
Other Cause color.gif 5
Ammonia color.gif 3
Polychlorinated Biphenyls (PCBs) color.gif 2
Salinity/Total Dissolved Solids/Chlorides/Sulfates color.gif 1
Toxic Organics color.gif 1

Total: 710 Causes of Impairment

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Iowa Cumulative TMDLs by Pollutant

This chart includes TMDLs since October 1, 1995.

Description of this table
NOTE: Click on the underlined "Pollutant" value to see associated listed waters for which a TMDL was developed. Click on the underlined "Number of TMDLs" value to see a listing of those TMDLs for the pollutant.
Number of Causes of
Impairment Addressed
Escherichia Coli (E. Coli) color.gif 57 73
Turbidity color.gif 30 34
Siltation color.gif 23 23
Algae color.gif 18 21
Phosphorus, Total color.gif 15 22
Nutrients color.gif 14 14
Nitrate color.gif 6 6
Organic Enrichment color.gif 6 6
Sediment color.gif 5 5
Ammonia color.gif 4 5
Chlorophyll-A color.gif 4 4
Pathogens color.gif 4 5
Atrazine color.gif 3 3
Dissolved Oxygen color.gif 3 5
Noxious Aquatic Plants color.gif 3 3
Phosphorus color.gif 3 3
pH color.gif 3 4
Algal Growth color.gif 2 3
Excess Algal Growth color.gif 2 3
Suspended Solids color.gif 2 2
Chlordane color.gif 1 1
Chlordane in Fish Tissue color.gif 1 1
Clarity color.gif 1 2
Nitrous Oxide (NOX) color.gif 1 1
Other Nutrients color.gif 1 2
Oxygen Demand color.gif 1 1
Priority Organics Compounds color.gif 1 1
Thermal Modifications color.gif 1 1
Total Suspended Solids (TSS) color.gif 1 2
pH, High color.gif 1 1

Total: 217 TMDLs; 257 Causes of Impairment Addressed


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Iowa Cumulative Number of TMDLs

EPA Fiscal Year starts October 1 and ends September 30.


Description of this table
NOTE: Click on the underlined "Number of TMDLs Completed" value for a detailed list of the TMDLs for the fiscal year.
2001 color.gif 11 11
2002 color.gif 10 10
2003 color.gif 16 16
2005 color.gif 36 36
2006 color.gif 18 19
2007 color.gif 13 14
2008 color.gif 21 26
2009 color.gif 13 16
2010 color.gif 27 38
2011 color.gif 8 17
2012 color.gif 18 27
2013 color.gif 13 13
2014 color.gif 8 9
2015 color.gif 5 5

Total: 217 TMDLs; 257 Causes of Impairment Addressed

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TMDL Document Search


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