Iowa DNR

Water Quality Assessments

Impaired Waters List

East Nishnabotna River IA 05-NSH-1415

from confluence with Fisher Cr. (S27, T69N, R40W, Fremont Co.) to Page/Montgomery county line

Assessment Cycle
Release Status
Result Period
1990 - 1992
Assessment Type
Integrated Report
Category 0
Legacy ADBCode
IA 05-NSH-0020_2
Overall Use Support
Aquatic Life Use Support
Fish Consumption
Not assessed
Assessment Comments

Assessment is based on results from the DNR monthly water quality monitoring station at Hwy 59 near Shenandoah.

Basis for Assessment

No violations of Class B(WW) WQC during biennial period; thus, should assess as FST due to known threats due to agricultural NPS.   Rivers in this region, however, are impaired by stream channelization, removal of riparian vegetation (especially trees), streambank destabilization, and by agricultural development.   These impairments cause habitat alterations (i.e., loss of amount and quality of habitat due to siltation, stream widening, and unfavorable flow regimes in wide, silt/sand channels.)  Thus, assess this reach as PS its aquatic life uses.

Monitoring and Methods
Assessment Key Dates
230 Fixed station physical/chemical (conventional plus toxic pollutants)
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 3
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