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Dividing the Water: Basic Precepts of Colorado River Water Law
David L. Hegner
1
2
The extent of riparian vegetation development along the
rivers and streams which comprise the Colorado River System
is a function of a myriad of legal and operational factors.
The utilization of Colorado River water can be identified
with several key issues, federal acts, and treaties. This
paper ~vill outline the major arguements and perceptions
which define the present day levels of water and hence the
extent of riparian vegetation along the river corridors of
the Colorado River System.
INTRODUCTION
The "Law of the River" as applied to the Colorado
River, has evolved out of a combination of both
Fedeual and State statutes, inter-state compacts,
court decisions, contracts, an international treaty,
operating criteria, and administrative decisions.
The cummulative effect of all these apportionments
have defined the development and extent of the
riparian vegetation along the river corridors of
the Colorado River System.
The Colorado River begins its journey in the mountains of Colorado and flows nearly 1400 miles before
it terminates in the Gulf of California. The
Colorado River is the second longest river in the
United States and holds the dubious distinction of
being the most closely regulated of the major rivers.
The 900 mile long basin can be seperated into two
distinct basins: the Upper Basin, consisting of
portions of Hyoming, Colorado, Utah and New Mexico;
and the Lower Basin, consisting of portions of
Nevada, Arizona and California. Numerous Federal,
State, and private water projects utilize the river
basin water both directly and indirectly. For the
period of time from 1976 through 1980, the states
of the Colorado River Basin collectively utilized
over 15 million acre-feet of water (BOR, 1984).
1
Paper presented at the North American
Riparian Symposium. Tucson, Arizona, April 16-18,
19"85.
Thff main objective of this paper is to outline the
legal and operational decisions and constraints
whith define the flow levels that have shaped and
continue to regulate the extent of the riparian
community.
Prior to exploring the law of the Colorado River,
it is necessary to understand the underlying logic
which defines ~·Jestern r1ater law. Specifically, the
"appropriated right'" to water and the percieved
neces-sity to hold the right to water use have
defined the entire development of water in the
\Vest. Hhen the first settlers made their way into
the Basin, they quickly realized that the key to
development and control centered around who had
the ultimate control of the water. In contrast to
the water law of the East, the developers initiated
a reservation system of water that defined that
use had to be beneficial to development and in
most cases led to complete diversion from the
river channel. Since water 'vas of very limited
supply, the user had to hold a legal right to
beneficially utilize the 'vater. The right was
allocated on a first in time logic and as such
the first ones on the scene laid claim to the
primary use of the water and were defined as the
"senior"' water right holders. The initial users
of the river generally gained the major control of
the water resource, With this basic concept in
mind, the remainder of the paper will outline some
of the major development issues associated with
tha Colorado River.
EARLY DEVELOPMENT (PRE-1900)
2 Grand Canyon Study Manager, U.S. Bureau o f
Reclamation, Division ·Of Water and Land, Salt
Lake City, Utah 84147
The first non-native irrigators in the Colorado
River Basin were the Jesuit missionaries in the
Tucson area around 1732 (U,S. Dept. Int., 1946).
After the Civil 1-lar had ended, a number of people
began to move into the Colorado River Basin and
specifically the California and Arizona areas.
453
1925 TO PRESENT
Thomas Blythe recorded the first use of Colorado
River water for irrigation purposes in the Palo
Verde Valley in 1856 (U.S. Dep~. Int., 1946)
By
1877, Blythe made the first legal filing for
Colorado River water in California. Within this
same time period of the late 1800's, the Mormon
pioneers were developing and designing extensive
irrigation works in Hyoming, Colorado, and Utah.
By 1883, the Grand Valley Canal had been built and
was supplying irrigation water to a large area of
the Western Slope area of Colorado.
1900 TO 1925
In the history of the Colorado River water development, the early 1900's were the most significant.
During this period, the use of water in the Lower
Basin had reached the maximum possible without the
development of extensive storage and regulation.
The passage of the Reclamation Act of 1902 signaled
the beginning of the investigations. into to feasibility of building large regulation and irrigation
works in the West. Several reports and studies were
conducted and analyzed. Several of these plans led
to the development of the modern day Bureau of
Reclamation.
By the 1920's, the development of the Upper B.asin
was considerably lagging behind that of the Lower
Basin. However, mainstem development in both basins.
was impeded by the lack of storage facilities, water
shortages, and the continual threat of floods and
the aggravated siltation problems. During this
time period, several public and private agencies and
groups were seeking the rights to develop hydroelectric power and were proposing to provide storage
and flood control on only an incidental basis.
These recommendations were analyzed, but the Upper
Basin states regarded any development in the Lower
Basin as threatening to their established priorities
to the water and could preclude future use of the
resource. The states thought that they s.hould
control the use of water within their own states,
but the Federal government claimed the ultimate
jurisdiction over the water based on it being an
interstate waterway. Some form of agreement was
obviously needed before any comprehensive development of the Colorado River Basin could proceed.
The Lower Basin favored a compact becaus.e they
desired to enlist the support of the Upper Rasin
states in securing federal legislation for main-stem development. The Upper Basin states favored
any type of decision which would secure their
rights to future development of the water. Thes:e
concerns and hopes were consumated through. the
development and passage of the Colorado River
Compact in December of 1922. The divisi.on point
between the basins was set at Lees Ferry, Ariioha
and it was determined (based on existing annual
flow information) that the Upper; Basin must guarantee to the Lower Basin statesl an aggregate of
75,000,000 acre-feet of water for any period of
te~ consecutive years.
The passage of the Colorado
River Compact cleared the way for legislation that
authorized the constuction of major water projects
and removed a major cause of rivalry between the
two basins.
454
With the passage of the Compact, the Lower Basin
immediately took advantage of several studies
investigating mainstem storage and irrigation
The
Kincaid Act (1924) and the Fall-Davis Report (1922)
documented the need for flood control and storage
to provide water for the Imperial Valley of southern California (U.S. Dept. Int., 1978). Out of
these studies, irrigation canals were recommended
for the Imperial Valley and the need was seen to
develop a storage dam in the Lower Basin, These
and other recommendations led to the Federal government pass·ing the Boulder Canyon Project A'ct in 1928.
This· Act provided for the building of Hoover Dam
and the definition of the amount of water that
California could legally utilize. To finance the
project, irrigation and hydroelectric power contracts
were initiated to repay the development over time.
The major component of the Boulder Canyon Project
Act, Hoover Dam, was completed in 1935.
The country of Mexico became concerned that the
development in the United States would utilize all
of the Colorado River water before it had a chance
to get to Hexico, In 1944, a treaty was signed
between the United States and Mexico to provide
on an annual basis, a quantity of 1,500,000 acrefeet of water to be supplied to Mexico, The treaty
required that ~1exico construct a diversion structure and that the United States would build the
Davis storage dam and reservoir for regulatory
and flood control purposes.
In 1948, the Upper Basin States entered into a
compact of their own defining'· individual state
percentages of water available for development and
established a commission to explore the potential
for developing water and irrigation projects within
the Upper Basin. After numerous studies and
investigations, the federal government, at the
insistance and pushing of the rpper Basin states,
passed the Colorado River Storage Act of 1956. The
major features of this act were to provide for the
development of four major storage projects within
the Upper Basin ( Glen Canyon, Flaming Gorge,
the three reservoirs of the Currecanti Unit, and
Navajo)J for the establishment of repayment contracts
for the structures and for the future development
of other storage and irrigation features within the
basin. Glen Canyon Dam was initiated in 1956 and
completed in 1963. The primary purpose of Glen
Canyon Dam and Lake Powell is for the regulation
of water to the Lower Basin and to provide for
hydro~owe~ revenues for the Upper Basin.
As the m~in features of the Colorado River Storage
Act were being built , the State of Arizona was
pushing for the full recognition of their water
rights and to restrict California from excessive
us·age of the the Colorado River water. California
had been developing and expanding far faster than
any other s·tate of the Colorado River Basin and
has: 5.een utilizing any excess water that ~.vas not
utilized by the other states. This worried the
other States and still is a sore point in regards
to future development. Several legal scuffles over
these rights and future usage were entered into
and led to the legal definition of how much water
Arizona and California were legally entitled to.
Once the legal aspects were resoled, the State
of Arizona quickly pushed for the development and
funding of the Central Arizona Project for irrigation and municipal and industrial water for the
state. In 1968, the Colorado River Basin Project
Act was passed which authorized the Central
Arizona Project, defined priority rights, authorized the Navajo Generation Station, established
the Mexican Water Treaty as a national obligation,
and established the need to define operating
criteria between the basins. Operating criteria
were developed between the basins and were based
on the legal needs of the Colorado River Compact,
the Mexican Water Treaty, and the need to maintain
parity between the levels of Lake Powell and
Lake Mead.
traints which ultimately control the quantity and
quality of the river water. To say that the
development of the water resources of the Colorado
River Basin is complex would be an understatement.
Before any thought can be given to future changes
that will occur along the vegetation corridors,
it is necessary to understand the precepts and
attitudes which define and limit the amounts of
water available. This paper was not intended to
define every decision point that has been reached
in the regulation of the Colorado River. Instead
the intent was to define the major decisions and
logic patterns which shape the Colorado River of
today.
LITERATURE CITED
SUMMARY
Water holds the. key to the development of the
resources of th~ Colorado River B~sin. In very
simplistic terms, it represents the "critical"
element in any development that has occurred. The
development of the riparian vegetation that occurs
along the Colorado River Basin corridors, is the
result of the amount of water that has his.torically
and is currently available. The vegetation is
regulated by the legal and jurisdictional cons-
455
U.S. Department of the Interior. 1946, The
Colorado River. Planning Report No. 348-2. 392 p.
U.S. Department of the Interior.
the Hoover Dam Documents.
1978.
Updating
U.S. Department of the Interior. 1984, Operation
of the Colorado River Basin~ 1983 Project
Operation. 32p.