Cleanest/Best States

National Average

Dirtiest/Worst States

0%					50%					100%

Percentage of Surface Waters with Impaired or Threatened Uses (state + EPA data):

Number of Impaired Waterbodies (as reported by the state):

NOTE: Data limitations affect the accuracy of these rankings.

Rank counties in IOWA or in the U.S. by assessed use impairments.
Rank watersheds in IOWA by assessed use impairments
Rank states by assessed use impairments, impairments due to specific causes, or impairments due to specific sources

IOWA contains a portion of 55 watersheds.

Percentage of Surface Waters with Reported Problems (state + EPA data): 6%

Number of Waterbodies with Reported Problems (as reported by the state): 159

Beneficial Use Most Frequently Impaired	Percent of All Impairments
Aquatic Life Support	51%
Primary Contact Recreation (Swimming)	22%
Overall Use	5%
Drinking Water Supply	4%

Beneficial uses not reported for 100% of waterbodies.

Priority for Regulation	Number of Waterbodies
Targeted	2
High	12
Medium	9
Low	28
Not Assessed for TMDL Priority	68
Not Reported to US EPA for TMDL Priority	40

Rivers, Streams, and Creeks
Number of impaired waterbodies: 56
Percent of Rivers, Streams and Creeks in IOWA assessed by agencies for 1997-98 reporting period: 14%

	Percent Waterbodies Affected
Sediments	36%
Pathogens	32%
Unknown	29%
Nutrients	11%
Low Dissolved Oxygen/Organic Enrichment	5%
More...

NOTE: Possible inconsistencies between data on (a) impaired waterbodies and (b) percentage of waterbodies assessed.

Rivers, Streams, and Creeks
Number of impaired waterbodies: 56 (cause not reported for 66%)
Percent of Rivers, Streams and Creeks in IOWA assessed by agencies for 1997-98 reporting period: 14%

	Percent Waterbodies Affected
Impairment source not reported	66%
Unknown Sources	23%
Agriculture	4%
Municipal Point Sources	4%
Industrial Point Sources	2%
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NOTE: Possible inconsistencies between data on (a) impaired waterbodies and (b) percentage of waterbodies assessed.