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
and do not supersede demand projections for individual
water providers or users.
Water use projections for consumptive use and
diversions throughout this report are presented in units of
AFY. An AF of water is approximately 326,000 gallons.
Non-consumptive water uses are indicated in flow-based
units (i.e., the volume of water passing a given point over
a certain time step, such as cfs or AF volumes) as
described elsewhere in this report.
An overview of the methods used to estimate future
water use is provided in the following subsections.
Sections 5.2 and 5.3 present the results of the water use
analyses.
5.1.1 Method for Estimating Municipal
and Industrial Use
In the United States, only Nevada and Arizona grew at a
faster rate than Colorado in the 1990s, and State
Demographer projections suggest that vigorous
increases in population can be expected well into the
future. Projecting the water needs that accompany the
corresponding municipal, industrial, and commercial
uses of water are therefore a key part of addressing the
state's future water needs.
5.1.1.1 Overview of Method for Estimating
M&I Use
The M&I water use analysis methods employed in SWSI
resulted in a summary of baseline water uses (estimated
for year 2000) and a forecast of such water uses for the
year 2030. In SWSI, all publicly-supplied and self-
supplied residential, commercial, institutional, and
industrial water uses are identified as M&I water users. In
addition, major self-supplied industrial (SSI) water users
are also accounted for.
Key terms used in M&I water use projections are
presented in Table 5-1.
~~
Table 5-1 Definition of M&I Demand Terms
M&I Demand All of the water use of a iypical
municipal system, including
residential, commercial, industrial,
irrigation, and firefighting
SSI Demand Larqe industrial water uses that h~
their own water supplies or lease raw

M&I and SSI Demand water from others
The sum of M&I demand and SSI
CU Demand That portion of the water demand for a
specific category of water use that is
consumed and does not return to the
stream svstem throuqh return flow
This water use analysis included the following
components:
^ Collection of available statewide water use,
demographic, and weather data
^ Evaluation of available information to determine
factors that influence M&I water use
^ Review of M&I water use studies conducted
throughout the state
^ Preparation of a statewide forecast of future urban
water use to the year 2030 by county and by basin
^ Assessment of the current level of conservation
efforts by county
The method used for estimating urban water demand is
based on a sample of water providers throughout the
state as described in this section. The estimated per
capita water use rates for each county were multiplied by
the projected population of each county to estimate
current and future municipal water demand (i.e., the
residential, commercial, and industrial water use) of each
county.
Population projections are summarized in
Section 5.1.1.2. Per capita estimates of M&I water use
are discussed in Section 5.1.1.3, and SSI uses are
discussed in Section 5.1.1.4. The effects of Level 1
conservation measures are reviewed in Section 5.1.1.5.
Section 5.1.1.6 provides a discussion of CU factors and
estimated CU given the range of data available on the
subject. The M&I water use forecasts presented in
Section 5.2 represent the baseline SWSI forecasts.
Detailed data and results are included in appendices, as
noted throughout this section.
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Sfvtewide Woter Supoly Initiofive
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