Missouri River IA 06-WEM-1708

from confluence with Platte R. (Mills Co.) to the water supply intake at Council Bluffs near River Mile 619 in SE 1/4 S22 T75N R44W Pottawattamie Co.

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

Assessment Cycle

2002

Result Period

1998 - 2000

Designations

Assessment Methodology

2002 Methodology Document

Assessment Type

Evaluated

Integrated Report

Category 0

Legacy ADBCode

IA 06-WEM-0020_1

Overall Use Support

Partial

Aquatic Life Use Support

Partial

Fish Consumption

Fully

Primary Contact Recreation

Not assessed

Documentation

Assessment Comments

Assessment is based on (1) USGS NASQAN monitoring at Omaha, (2) surveys of Nebraska fisheries biologists, (3) consultation with IDNR staff and (4) results of fish tissue monitoring.

Basis for Assessment

SUMMARY: The Class A (primary contact recreation) uses remain "not assessed." The Class B(WW) aquatic life uses remain assessed as "partially supported." The fish consumption uses are assessed as "fully supported." EXPLANATION: The Class A uses remain "not assessed" due to the lack of monitoring data for indicator bacteria for this reach of the Missouri River. The Class B(WW) uses remain assessed as "partially supported" based on the assessment developed for the 1998 and 2000 reports (i.e., habitat alterations and flow modifications that resulted from development of the river for navigation uses in the mid-Twentieth Century). This assessment was developed in consultation with the Missouri River fisheries biologist for the state of Nebraska. Fish consumption uses remain assessed as "fully supported" based on EPA/DNR fish tissue (RAFT) monitoring just south of Council Bluffs in 1999 (see assessment for the 2000 report).

Monitoring and Methods

Assessment Key Dates

9/28/2000	Fixed Monitoring End Date
10/12/1999	Fixed Monitoring Start Date
9/1/1999	Fish Tissue Monitoring

Methods

120	Surveys of fish and game biologists/other professionals
230	Fixed station physical/chemical (conventional plus toxic pollutants)
260	Fish tissue analysis

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
Flow alteration	Overall Use Support	Moderate	Flow Regulation/Modification	Moderate
Flow alteration	Aquatic Life Support	Moderate	Flow Regulation/Modification	Moderate
Other habitat alterations	Overall Use Support	Moderate	Channelization	Moderate
Other habitat alterations	Aquatic Life Support	Moderate	Channelization	Moderate