Mud Creek IA 02-CED-488

mouth (S10 T78N R2W Muscatine Co.) to confluence with unnamed tributary in S5 T78N R1E Muscatine Co.

This is a Legacy Assessment. Prior to 2004, assessments were developed under a methodology that pre-dated the Integrated Report guidelines.

Assessment Cycle

1998

Result Period

1994 - 1996

Designations

Assessment Type

Monitored

Integrated Report

Category 0

Legacy ADBCode

IA 02-CED-0160_0

Overall Use Support

Not supporting

Aquatic Life Use Support

Not supporting

Documentation

Assessment Comments

Habscrs/fshscrs: 26/12; 16/10. (1997v.) Fish IBI scores: 18,20,18,18,32,34. Downstr>Upstr. 1996 Biocriteria: Fish (1999v.) IBI= 43,38 (fair), 18,18,16,13 (poor); BM-IBI= 33,34 (fair), 20,20,27 (poor), 34(fair).

Basis for Assessment

Used results from 6 stream bioassessments of Mud Creek conducted in Sept. 1996. Fish community IBI scores ranged from 0%-75% of stream reference sites located in the same ecoregion. B(LR) aquatic life use assessed as non-supporting due to high level of diseased fish (11.4%) in Mud Cr. below Durant STP, mostly likely caused by high organic waste loading from the STP. Fish community health (IBI) scores were low in Mud Cr. adjacent to Durant and Wilton STP outfalls. Recovery to expected IBI levels occurred downstream from City of Wilton. Physical habitat scores at bioassessment locations ranked from poor to fairly good.

Monitoring and Methods

Assessment Key Dates

9/24/1996	Biological Monitoring

Methods

220	Non-fixed station physical/chemical monitoring (conventional pollutant only)
315	Regional reference site approach
320	Benthic macroinvertebrate surveys
330	Fish surveys
380	Quan. measurements of instream parms-- channel morphology-- floodplain-- 1-2 seasons-- by prof

Monitoring Levels

Biological	0
Habitat	0
Physical Chemistry	0
Toxic	0
Pathogen Indicators	0
Other Health Indicators	0
Other Aquatic Life Indicators	0
# of Bio Sites	6
BioIntegrity	N/A

Causes and Sources of Impairment

Causes	Use Support	Cause Magnitude	Sources	Source Magnitude
Organic enrichment/Low DO	Overall Use Support	High	Agriculture Crop-related Sources Grazing related Sources Municipal Point Sources Pasture grazing - Riparian	Moderate Moderate Moderate High Moderate
Organic enrichment/Low DO	Aquatic Life Support	High	Agriculture Crop-related Sources Grazing related Sources Municipal Point Sources Pasture grazing - Riparian	Moderate Moderate Moderate High Moderate
Nutrients	Overall Use Support	Moderate	Agriculture Crop-related Sources Grazing related Sources Municipal Point Sources Pasture grazing - Riparian	Moderate Moderate Moderate High Moderate
Nutrients	Aquatic Life Support	Moderate	Agriculture Crop-related Sources Grazing related Sources Municipal Point Sources Pasture grazing - Riparian	Moderate Moderate Moderate High Moderate
Other habitat alterations	Overall Use Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Channelization Grazing related Sources Habitat Modification (other than Hydromodification) Hydromodification Pasture grazing - Riparian Removal of Riparian Vegetation	Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate
Other habitat alterations	Aquatic Life Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Channelization Grazing related Sources Habitat Modification (other than Hydromodification) Hydromodification Pasture grazing - Riparian Removal of Riparian Vegetation	Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate
Siltation	Overall Use Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Channelization Crop-related Sources Grazing related Sources Habitat Modification (other than Hydromodification) Hydromodification Pasture grazing - Riparian Removal of Riparian Vegetation	Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate
Siltation	Aquatic Life Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Channelization Crop-related Sources Grazing related Sources Habitat Modification (other than Hydromodification) Hydromodification Pasture grazing - Riparian Removal of Riparian Vegetation	Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate Moderate