7916

• UCREFRP Catalog Number: 7916
• Author: Stalnaker, C. B.
• Title: Methodologies for Preserving Instream Flows, The Incremental Method, ‎(from a syposium by the Upper Mississippi River Basin Commission, Nov. 14, 1978)‎
• USFW Year: 1978
• USFW - Doc Type: Instream Flow Management State of the Art Proceedings
• Copyright Material: YES

4. Does the IFG incremental methodology
require advanced training for its use?

The IFG incremental methodology combines field
techniques (stream measurements) with computer
analysis of data. Therefore, implementation requires a
certain minimum knowledge of technology. Most
professional fishery biologists already possess the
essential skills for stream measurement. The IFG
incremental methodology utilizes those stream
measurements which are standard in most fishery and
engineering agencies. Computer programs are
available which require minimal training for someone
who has experience with computer analyses.

5. What agencies will benefit most from the IFG
incremental methodology?

The IFG incremental methodology will be most
useful to the following types of agencies:

A. Fish and wildlife management agencies

B. Water planning agencies

C. Water development agencies

D. Agencies involved with stream channel relocation
or alteration

6. What kinds of questions can the IFG incremen-
tal methodology be used to address?

The IFG incremental methodology will help answer
the following kinds of questions:

A. What will be the effect on potential trout habitat of
a reduction of flow levels in Squaw Creek from 50
cis to 25 cis during the low flow season?

B. What is the best pattern of stream flows through-
out the year (expressed as monthly discharges) to
give smallmouth bass a competitive advantage
over white suckers?

C. Is it less damaging to the fish to take water for
development purposes from Red Creek than from
Cabin Creek?

D. \Vhich time of the year is the flow level most
limiting to trout and which life stage is most
severely affected?

E. What is the optimum habitat maintenance flow
regime for small mouth bass in Eagle Creek?

H ow does the IFG incremental methodology
..1ate to water planning? .

i FG incremental methodology is well suited for
. ili~g requiremehts under the Water
'{:~~ Council's Principles and Standards. It can

..

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be used both for the National Economic Development
(NED) account and for the Environmental Quality
(EQ) account. For the NED account, the IFG
Incremental methodology quantifies benefits to fish
which would result from alternative flow regimes.
These may then be translated into monetary benefits
by water planners. For the EQ account, the IFG
incremental methodology provides a meaningful
measurement of impacts on fish in non-monetary
terms.

Further, the IFG incremental methodology can be
used as a tool for planning fish and wildlife
management of streams. As decision-makers develop
objectives or desired outcomes for fishery manage-
ment, the methodology can demonstrate what those
objectives mean in terms of stream flow requirements.

8. How does the IFG incremental methodology
improve communication among fishery
managers, water users and water planners?

The IFG incremental methodology provides a direct
link between fishery biologists, hydrologists and
hydraulic engineers. Engineers have been working
for several years with hydraulic simulation models of
streams. Hydrologists have been displaying water
supply information as flow duration or frequency of
occurrence graphs. Similarly, fishery biologists have
been collecting data on stream fishes. The IFG incre-
mental methodology arranges the fishery data in such
a way to be directly analyzed in conjunction with the
stream simulation moqels and monthly time series of
flow events. As a result, both river engineers and
fishery biologists now have a common ground to
display and discuss the interrelationships of their
professions.

9. What can the IFG incremental methodology
NOT do?

The IFG incremental methodology is NOT designed
to provide solutions to the following types of problems:

A. It does not address reservoir, lake, or estuarine
problems. It is specifically intended for use in
streams and rivers.

B. It is not designed to generate a "minimum flow"
recommendation. It will quantify and predict
impacts associated with various flows, thereby
permitting the decision-maker to choose among
alternatives.

C. It does not predict the actual number or production
of fish that will occur in a stream under given con-
ditions. It does predict and quantify the changes in
suitability of the physical habitat for various
species and life stages under differing flow
conditions.

D. To date, only physical aspects of a stream are
treated by the IFG incremental methodology. The

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