WSP07095

• File Number: 8281.960
• Description: Colorado River Studies and Investigations -- Lower Colorado Comprehensive Framework Study
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1971
• Title: Lower Colorado Region Comprehensive Framework Study -- Appendix V - Water Resources
• Water Supply Pro - Doc Type: Report/Study

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SUMMARY OF FINDINGS

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':Chis appendix presents the evaluation of water resources of the
Lower Colorado Region and summarizes the requirements for the use of
water 'under present (1965) and projected future (1980, 2000, and 2020)
conditions leading to the formulation of framework plans to provide
a broad guide to the best use, or combinations of uses, of water
resources to meet foreseeable short- and long-term needs of the Region.

The Lower Colorado Region includes most of Arizona and parts
of Nevada, New Mexico, and utah, comprising a total area of over
141,000 square miles. For purposes of analysis and pianning, the
Lower Colorado Region has been divided into three subregions com-
prisiQg the major drainage areas of the Lower Main Stem, the Little
Colorado River, and the Gila River above Painted Rock Dam.

':Che Region is richly endowed with favorable climate, abundant
land, 'mineral, and other resources, and leads the Nation in population
growth rate. Though other resources are abundant, the Region probably
comes closer than most any other to using the last available drop of
water'-resources for man's needs. Water is used for irrigation,
municipal-iridustrial-domestic purposes, livestock watering, thermal
and hYdroelectric power generation, mineral activity, fish and wildlife
facilities, and recreation. Large amounts of water are also exported
from the Lower Colorado River to the adjoining California Region and
to Mexico for multiple-purpose uses.

The Region I s econOIny is sustained by utilizing ground-water
reserves, especially in the areas of population concentration such
as central Arizona and the Las Vegas area in Nevada. The depletion
rate of these reserves has reached well over 2 million acre-feet
annually due largely to the imbalance between location of supply and '
location of demand, and to the lack of facilities which would enable
the Region to ut;l.lize its unused share of Colorado River water. The
Southern Nevada Water Project, currently under construction, the
Dixie:Project in utah, and the Central Arizona Project would enable
the Region to utilize its remaining available water supplies.

The regional water supply deficiency, even with the above pro-
jects, is projected to exceed 4 million acre-feet by year 2020. Expan-
sion of water conservation management practices, more intensive water
reuse, vegetative management for increased water yields, and treatment
of brackish water are all possible W8lfS ,to lessen the effects of rising
water deficiencies until augmentation of the Region's water supplies
can be accomplished in sufficient amounts to meet future water require-
ments ,and reduce ground-water overdraft.

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