WSP10841

• File Number: 8200.760
• Description: Yampa River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 1/1/1993
• Author: Hydroshpere
• Title: Yampa River Basin Alternatives Feasibility Study - Executive Summary - Draft - January 1993
• Water Supply Pro - Doc Type: Report/Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

000428

Executive Summary

EVALUATION OF POTENTIAL RESERVOIR SITES

Site Identification and Screening

Past studies of the Yampa River Basin have identified and examined numerous sites for
new water storage projects. In the Feasibility Study, sixty-four reservoir sites were identified
from an extensive review of documents, through discussions with local water managers and
members of the Study Technical Steering. Group (TSG) and by map and field reconnaissance by
the consultant team. These sites appeared, from the information initially available, to have
some potential to support a reservoir meeting either the near term (2015) or long term (2040)
projected deinand requirements.

A two-stage screening process was performed to reduce this list of 64 sites down to eight
sites that would be the object of field evaluations. Estimates of inflow hydrology were made
based on approximate site drainage area and regional precipitation data or on gaged flow data
where available. Those sites which exhibited average annual inflows less than 20,000 af were
excluded from further consideration. This inflow criteria was based on the inflow estimated to
be necessary to support a reservoir with a minimum capacity of 10,000 acre-feet. For
screening purposes, a 10,000 af reservoir was considered the minimum size necessary to meet
near and long term demands in the area. Other screening criteria included presence of known
fatal geotechnical and environmental flaws, recreation use potential, and the ability of a
reservoir at the site to deliver water to meet existing and projected future demands. Project
costs were not developed or used as an evaluation criterion at this stage, however factors which
could significantly affect the cost of a project, such as relocation of a major road, were noted.

A list of eight potential reservoir sites recommended for field study was reviewed by the
TSG and the Study's Public Advisory Group (FAG) and was presented at a public meeting held
in Craig on February 21, 1991. Based on substantial public comment received at and
subsequent to the public meeting, the TSG determined that the Ralph White. and Mad Creek
sites should be deleted from further consideration and that a new site on Fortification Creek,
called Cedar Mountain, should be reviewed for fatal flaws.

In addition to the sites identified as near-term storage candidates, it was also determined
that alternative long-term storage sites in the upper basin be identified and screened through a
review of previous work in the Study. A total of 11 reservoir sites were identified and re-
. reviewed for consideration as a long-term storage project. The 11 sites included seven that
were previously reviewed, the new site on Fortification Creek (Cedar Mountain), a Yampa
River mainstem site near the Mount Harris Mine, and two new sites above Steamboat Springs
that had not been previously considered because of their distance from Craig. These eleven
sites were then screened using a process similar to short-term site screening process.

Based on these screening and review processes, a total of nine sites were identified for
field evaluation. These sites are listed in Table S-2.

S-7