North Skunk River IA 03-NSK-859

from the Mahaska/Poweshiek line to confluence with Sugar Cr. in S20 T78N R16W Poweshiek Co.

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

Assessment Cycle

1996

Result Period

1992 - 1994

Designations

Assessment Type

Monitored

Integrated Report

Category 0

Legacy ADBCode

IA 03-NSK-0020_2

Overall Use Support

Partial

Aquatic Life Use Support

Partial

Documentation

Assessment Comments

Stream use assessment in Poweshiek county.

Basis for Assessment

Used results of the November 1994 DNR stream use assessment to assess support of the Class B(LR) aquatic life uses as PS due to (1) habitat score (20) worse than the overall median score (22) for DNR stream use assessments and (2) indications on field sheet of little diversity of substrates, no pool/riffle developement, extensive channel alterations due to channel straightening and pasturing of riparian area. Relatively low number of fish species captured (6) with most turbidity-tolerant cyprinids.

Monitoring and Methods

Assessment Key Dates

11/1/1994	DNR Stream Use Assessment

Methods

330	Fish surveys
375	Visual observation-- may not quantify some parameters-- single season-- by prof.

Monitoring Levels

Biological	3
Habitat	3
Physical Chemistry	0
Toxic	0
Pathogen Indicators	0
Other Health Indicators	0
Other Aquatic Life Indicators	0
# of Bio Sites	0
BioIntegrity	N/A

Causes and Sources of Impairment

Causes	Use Support	Cause Magnitude	Sources	Source Magnitude
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	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	Moderate Moderate Moderate Moderate Moderate Moderate Moderate
Siltation	Overall Use Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Grazing related Sources Pasture grazing - Riparian	Moderate Moderate Moderate Moderate
Siltation	Aquatic Life Support	Moderate	Agriculture Bank or Shoreline Modification/Destabilization Grazing related Sources Pasture grazing - Riparian	Moderate Moderate Moderate Moderate
Suspended solids	Overall Use Support	Moderate	Agriculture Grazing related Sources Pasture grazing - Riparian	Moderate Moderate Moderate
Suspended solids	Aquatic Life Support	Moderate	Agriculture Grazing related Sources Pasture grazing - Riparian	Moderate Moderate Moderate