WSP07211

• File Number: 8149.911
• Description: Miscellaneous Small Projects and Project Studies - SE Needs Assessment and PSOP
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 4/1/1999
• Author: AK River Basin Water
• Title: Preliminary Findings Arkansas River Water Needs Assessment
• Water Supply Pro - Doc Type: Report/Study

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deer, rurke::. and waterfowl. while :uso protecting
and enhancing blue herons, peregrine falcons, and
bald eagles. For the uppet reservoirs, the objective
is ro develop and sustain lake trour populations.
The objective for Pueblo Reservoir is to optimize
the production of warm warer fish population.

E. Study Methodology

The assessment was J. six-year effort involving a
ream of Federal and Srate agency professionals.
Early phases of rhe srudy focused on literarure
and data collecrion, while latter phases of rhis
effort de,jt with analysis of data and reporting on
the team's findings. The approach ro rhe overall
assessment involved five steps: ,( 1) preliminary
evaluarion and design of specific studies; (2)
hydrologic investigation for stream flows and
teservoir levels; (3) evaluarion of river flow- and
reservoir level-dependenr v,jues and rhe Water
required [Q support rhose v,jues; (4) an,jysis of
the legal and institutional framework governing
stream Hows and reservoit levels; and (5) presenta-
rion of findings, including examples/scenarios
that illustrate the rradeoffs associated wirh Water
management oprions. The following describes
each 0 f these steps:

(1) Pteliminary Assessment
The preliminary assessment involved a thorough
review of !irc:rarure, discussions with perrinenr
field personnel, and a reconnaissance-level field
assessment. Aerial phorogtaphs and maps were
used to assist with designing specific srudies.
Outing this step, interagency cooperative agree-
ments were arranged, and specific techniques or
methods were sdeered. This step involved careful
coordination between MOU agency's field person'
nel and other affected agencies, including offices
of the u.s. Geological Survey, U.S. Environmental
Protection Agency, U.S. Fish and Wildlife Service,
and Colorado Department of Human Health and
Environment. The result of the preliminary assess.
menr provides documented summaries of lirer:1-
cure reviews and selected methods.

(2) Hydrologic Investigation
The hydrologic investigation included analysis of

historic srreamflow and reservoir operations dara
to detetmine cypical and extreme levels of river
Rowand reservoir storage contenrs. This dara is
relatively abundant in rhe basin and was anal)"led
to derermine rusrorical [rends reflecrive of warer
managemenr and use. Reservoir operarion and
river flow models were used to imulate various
managemenr opporruniries. The hydrologic inves-
tigation provided the physical resource back,
ground for anal)"ling the Water, both rivet and
reservoir, dependency of che resource values iden-
rified in the nexr step. The tesults of the hydro.
logic investigation are documented in the section
on analysis of existing Water management.
All river flow measurements were taken at the
Wellsville srream flow gage, loca<ed jUst east of
Salida. Flows upstream and downstream from ,his
poinr are differenr from rhis gage. due co input
from triburaries and river gains and losses from
irrigation (erurn flows, seepage. and evaporation.
Furrher information on hydrologic assumptions is
available in the primary hydrology chapter of the
Warer Needs Assessment.

(3) Resource Values Assessment
Significant resource values were evaluated relative
co dependence on reservoir levels. river flows or
other water-related conditions. This step involved
dose interaction be['\Veen project [e:lffi members
with different types of expertise. Results of rhe
hydrologic investigation, including hydtaulic and
geomorphic analyses, were examined in conjunc-
tion with evaluations of resource v,jues to develop
resource specific river flow and reservoir level
needs. This assessment documenrs rhe need fot
Water to maintain, as well as enhance, fish and
wildlife habitat. and recreational pursuits. such as
rafting and fishing (i.e. flyfishing. spincasting, and
float fishing).
For purpose of this assessment, the term "resource
values" incorporates a multitude of objective nar-
Ur:tl resource related requitements (e.g., species
such as brown trour ne~d specific river conditions
to survive) and subjective user preferences (e.g_.
activities such as rafting and fishing need Hows to
support user experiences). Data collecrion needed
to supplement available literature and other infoto
marion was performed during this Step. Flow

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