PUB00022

• Year: 2000
• Title: Layperson's Guide to California Water
• CWCB Section: Interstate & Federal
• Author: California Water Education Foundation
• Description: Layperson's Guide to California Water
• Publications - Doc Type: Other

Colorado River

The turbulent Colorado River is one of the most
controversial and heavily regulated rivers in the
world. From its beginning northwest of Denver, the
1 ,450-mile long river and its tributaries pass through
parts of seven states: four in the Upper Basin -
Colorado. New Mexico, Utah and Wyoming - and
three in the Lower Basin - Arizona, California and
Nevada. Its water also is shared by several Ameri-
can Indian tribes in the basin states and the Repub-
lic of Mexico. The Colorado is the only reliable water
source for much of the desert Southwest but ranks
behind the Sacramento River in tlow. Allocations of
the river are based on an average annual supply of
15 million acre.feet

The first Californians to tap the Colorado River were
settlers in the Palo Verde and Imperial valleys.
Although the area was a desert. they recognized its
agricultural potential and began building canals to
deliver the river water to farmlands. In 1905, the river
broke through a series of dikes, flooding a salty basin
in the Imperial Valley and forming the Salton Sea.
Monumental effort was required to divert the river
back into its customary channel, a feat accomplished
in 1907.

Continued problems with water supply prompted
settlers to form the Imperial Irrigation District (110) in
1911. Because the main canal and levees supplying
river water were located in Mexico and offered little
security, valley pioneers and the district lobbied for
an "All-American" canal north of the border.

Dividing use of the Colorado River's waters has been
no easy task and has involved compromises, inter-
state compacts, a U.S. Supreme Court decree, a
treaty with Mexico and federal and state legislation.
The interstate 1922 Colorado River Compact divided
the watershed into Upper and Lower basins and
apportioned the right to use 7.5 million acre-fee per
year to each basin.

Subsequently, Congress approved the Boulder
Canyon Project Act, dividing the water between the
three Lower Basin states and authorizing construc-
tion of Hoover and Imperial dams and the
All-American Canal. Under this act, California agreed
to limit itself to no more than 4.4 million acre-feet of
water per year, plus half of any surplus.

In 1924, Los Angeles applied to divert 1.1 million
acre-feet annually from the Colorado. Los Angeles
and other south coast cities promoted the formation
of the Metropolitan Water District of Southern
California (MWD) to build an aqueduct and serve as
a water wholesale. MWD was created by the Legis-

lature and approved by public vote in 1928. A $220
million bond issue for a 242-mile long Colorado River
Aqueduct was passed in 1931 and 10 years later it
was completed. The aqueduct was later expanded
to its current 1.2 million acre-feet capacity.

By 1952, disagreement erupted over apportionment
of the Colorado River in the form of Arizona v.
California. Arizona, with its growing population,
wanted to ensure its share of the river allocated to it
under the 1922 Compact remained intact. Arizona
appealed to the U.S. Supreme Court to confirm
California's right to use only 4.4 million acre-feet of
Colorado River water annually, plus half of any water
determined surplus (including a state's apportioned
but unused water) by the secretary of the Interior.
The 1963 ruling confirmed this and entitled Arizona
to receive 2.8 million acre-feet, not counting supply
from tributary streams.

Southern California, in recent years, has continually
used more than its 4.4 million acre-feet share of
Colorado River water - up to 5.3 million acre feel in
some years. However, in December 1996, Interior
Secretary Bruce Babbitt warned California that it
could no longer rely on receiving more than its annual
allocation because of growing demands in Arizona
and Nevada. Babbitt has urged California to develop
a conservation plan to avoid continually exceeding
its allocation or else be subject to federally imposed
water supply cuts.

To date, what has been formed is called the
California's Colorado River Water Use Plan, known
colloquially as the "4.4 Plan." The plan is intended to
reduce California's use ot the Colorado River by
approximately 800,000 acre-feet annually. The plan
uses a combination of water conservation, water
transfers, dry-year fallowing agreements, canal
seepage recovery (lining sections of the All-American
Canal using $235 million in taxpayer dollars). ground-
water banking, special surplus conditions, and
possibly. desalination ot drainage water. It also
includes a water settlement for the San Luis Rey
Indian Tribe.

Along the way have been countless sessions of
intense negotiations between stakeholders. A key
component of the plan is a proposed long term
ag-to-urban water transfer between San Diego
County Water Authority and 110 (see page 21).
Another key component, the interim surplus criteria,
would allow California to continue using surplus
water from the river as it ramps down its use. A draft
of the plan was released in May 2000, with the final
plan slated to go into effect in 2001.

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