7925

• UCREFRP Catalog Number: 7925
• Author: Smith, G. L., ed.
• Title: Proceedings, Workshop In Instream Flow Habitat Criteria And Modeling, December 1979.
• USFW Year: 1979.
• USFW - Doc Type: Info. Series No. 40,
• Copyright Material: NO

A hierarchical analytical approach was proposed for IFGIM toward

quantification of watershed processes and sedimentation as integral components

of the riverine ecosystem. The workshop set forth the sequential levels of

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analysis required to develop and conduct an integral analysis of watershed

processes and sedimentation, A given level of analysis is to be formulated,

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verified and utilized depending on level of accuracy required; available data;

constraints; magnitude of projected channel changes; etc.

The module for instream water quality, recommended that incremental

development be undertaken that would introduce water quality aspects to

instream flow needs assessments. To be useful, such development must be

applicable to the following problems: (1) the redistribution of water over a

year (or periods of years) to increase low flows and/or reduce flood flows;

and (2) the installation of major diversions up stream which decrease

available flows. The context of these problems could be: (1) the need to

establish instream flows as a part of a long range planning process; (2) the

need to make operatinal decisions on f real-time basis to maintain minimum low

flows; and (3) the evaluation of Environmental Impact Statements of projects
that would change instream flows. No limit is specified for the site of a

river system,

This group stressed the introduction of water quality methodologies must

be an evolutionary process that will improve as the IFG staff develops

in-house skills in water quality analyses. The workshop also proposed that

the methodologies be classified according to their cost, required knowledge,

data needs, and ability to resolve a basic low flow/water quality issues.

Four classes were identified: (1) level one - will be to provide low cost,

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crude estimates of potential water quality problems, Text book concepts and

heuristic approaches will be used; (2) level two - will estimate changes in

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