WSP01731

• File Number: 8281.650
• Description: Colorado River Studies and Investigations -- Colorado River Basin Quality Study
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 7/1/1999
• Title: A Watershed Approach to the Upper Colorado River Basin
• Water Supply Pro - Doc Type: Project Overview

" ...Ir
"cWo? I.Vlf oJ'-<,
~, r~ '~'1'

P J\-" N

r~' I 't1&;c.-'.., I r~~ S
A_l~ .
at.. ':'"~u.",~)

o
"-')
..)
*'1
C,j
~

A WATERSHED APPROACH TO THE
UPPER COLORADO RIVER BASIN
Julyl999

Summary: Local stakeholders in the Upper Colorado basin have organized a basinwide study of
the water quantity and quality issues related to growth on both the Front Range and West Slope.
The study will focus on existing and projected conditions in the Upper Colorado River basin,
examining the impacts to water quality and quantity resulting from the exercise of existing and
future transmountain diversion water projects and in-basin uses.

Background: Since Colorado has a semi-arid climate, most of the state's water falls as snow in
the Rockies, contributing to Colorado's winter economy. The spring snowmelt then provides the
Front Range cities with a significant portion of their water supply via transmountain diversions
from the West Slope. Due to their relative proximity to the Front Range, Grand and Sununit
counties have historically been a primary source for such diversions. Based on a ten year
average, the Front Range, including agricultural users, diverts approximately 368,000 acre feet of
water per year from Grand County and 67,000 acre feet from Sununit County (an acre foot equals
one acre, one foot deep in water). The Front Range owns the water rights to divert more than this
amount. With rapid growth, the Front Range municipalities and counties are depending on
additional West Slope water to meet these groWth needs.

Simultaneously, West Slope communities are also growing at an average ofA% a year. These
two basins include the towns of Breckenridge, Frisco, Silverthorne, Winter Park, Fraser, and
Kremmling, Granby, and Grand Lake as well as the Keystone area. All of these areas are facing
tremendous development pressures and are also looking for a way to preserve enough water for
their future.

Facing water needs from both sides of the Divide, the Upper Colorado River basin must also
contend with environmental, recreational, and economic effects caused by the state's dependency
on Colorado River water. The impacts of increasing diversions from these basins must be
identified and considered. This requires knowledge of the watershed and a clear understanding
of the hydrology of the basins. Further, information generated in this project could assist in
identifYing solutions to problems associated with reduced stream flows in the basin.

Specific Issues to be Addressed: The project will have three phases. The first phase entails a
Scope of Work. The second phase involves the collection and analysis of relevant data. Finally,
the Third Phase will seek mutually agreeable solutions to problems identified by the study. Basin
stakeholders will hopefully be able to address specific issues in the basin which may include:
water supply; water quality; instream flow needs; recreational uses; water rights; and agricultural
to municipal use conversions. The stakeholders believe that cooperative solutions will be
discovered that were not apparent before due to lack of information and knowledge. Both Front
Range and West Slope needs must be considered. This analysis will also evaluate how much
water needs to remain in the stream for instream uses while balancing competing demands for
water out of the stream. As part of this analysis, the study will look at water supply strategies for
meeting future West Slope needs to the year 2030. Future industrial and local economic needs

1