S5_11-15-04

• Basin: Statewide
• Title: SWSI Phase 1 Report - Section 5 Projected Water Use
• Date: 11/15/2004
• Author: CWCB
• SWSI - Doc Type: Final Report

Section 5
Projected Water Use
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Statewide Water Supply Initiafive
Water is managed in Colorado to meet the many
important needs of our citizens and our environment, and
is vital to Colorado's present and future. Our economy,
our quality of life, our recreational opportunities, the
environment, and human life itself are all dependent on
water. The broad diversity of water uses in Colorado is
indicative of the many ways in which we are affected by
the water that is available to us and our environment,
and how we choose to use it. Severe and continuing
drought conditions throughout the state in the early
2000s in conjunction with rapid growth and concern over
compact obligations have brought focus to the
constraints on our state's water resources and the
challenges associated with meeting multiple objectives
and needs.
As a significant step toward reaching SWSI's goal of
helping Colorado maintain an adequate water supply for
our citizens and the environment, SWSI evaluated water
use in 2030 in each of the state's major river basins for
the following categories of water use (as described in
Section 4):
^ M&I
^ Agricultural
^ Recreation and Environmental
A consistent and comprehensive method was developed
in SWSI to estimate baseline (year 2000) and future
(2030) water uses in the state. M&I and agricultural water
projections represent "traditional" uses in water planning,
and are generally associated with off-stream uses that
have a consumptive component. In order to estimate
current and future water needs for these uses, SWSI
obtained historical water use data, population
projections, and irrigated acreage data for each of the
state's major river basins. Decreed CWCB instream flow
and RICD water rights were inventoried, and a process
for evaluating environmental and recreational uses was
initiated - recognizing that these uses differ significantly
from M&I and agricultural needs in that they are non-
consumptive, flow-related uses. Approaches to defining
water needs for environmental and recreational uses are
described in Section 6.
Demands on Colorado's water resources are projected to
increase dramatically through 2030. In large part, this will
be driven by continuing population increases, while
agricultural uses remain high, environmental water uses
continue, and more people participate in water-based
recreational activities. The following sections describe
the methods used in determining reconnaissance level
water use projections for 2030, and the results of those
analyses.
5.1 Overview of Projection
Methods
Standard methods were adapted for use in SWSI for
projecting future M&I and agricultural uses throughout
Colorado, then aggregated by the state's eight major
river basins. Because of the unique, in-channel flow and
non-consumptive nature of environmental and
recreational uses - and some inherent conflicts even
between different environmental and recreational uses in
the types and timing of flows desired - Colorado's
statutory framework for CWCB minimum instream flows
was used as the initial basis for estimating future uses for
recreation and the environment. Further enhancement of
flows was considered in the options analysis phase of
SWSI.
The objectives of the SWSI water use analysis efforts
were to:
^ Develop a reconnaissance-level water use forecast
^ Use consistent data and method throughout the state
^ Maximize the use of available data
While numerous past evaluations and reports have
projected future water use in the state, a standard
method for SWSI was deemed important. Past efforts
vary widely in their method and demographic projections,
and do not provide complete coverage of the state.
Nonetheless, past evaluations and databases were
referenced in the development of SWSI water use
projections to help guide the evaluation and validate
results. The estimates developed in SWSI are intended
to be reconnaissance-level estimates to guide a
discussion of addressing the state's future water needs,
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