WSPC03421

• File Number: 8230.100.10
• Description: Colorado River - Interstate Litigation - Arizona Vs California
• State: AZ
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1964
• Title: AZ Vs CA - Arizona V California and Pacific Southwest Water Problems - California Assembly Interim Committee Reports - 1963-1965 - Volume 26-Number 13
• Water Supply Pro - Doc Type: Report/Study

002058

ARIZONA V. O.!.L!FORNL~ AND P~",CIFIC SOUTHV.'EST VtATEI:. r~CDLE1fS

a1
V~

TABLE XVIII

SOUTHEASTERN CALIFORNIA
PRESENT AND ESTIMATED FUTURE SUPPLY FROM THE COLORADO RIVER
(1,000 acre.feet)

Present uses
3,850.0
( Prioriti~s
I-III )
300.0 t
(Priority
VII)

4,150.0
* District also has state contract for 20,000 acre-feet of water per year.
t Not all being used at present.

Imperial Irrigation District }
Cotlchella County Water District *
Palo Verde Irrigation District
Yuma Project

With California
limited to 4.4
million acre-
feet a year
3,850.0
(Priorities
I-III)

3,850.0

In summarizing the water supply and requirements data for south-
eastern California and of southern California, it can be seen that
through 1990 (Msuming a 4.4 million aere-foot supply of water for
California from the Colorado water supply) requirements are basically
in balanee. 'l'he data in the Pacifie Southwest Water Plan indieating the
present and expeeted futurc deficiencies in water supply for the Pacific
Southwest shows the deficiencies in Arizona. Although the entire Pacific
Southwest is an area of defieieney, the the situation in individual areas
varies greatly because of the activity of the loeal areas in providing
sufficient imported water supplies.

ARIZONA

'fhe area of principal water defieiency in the Pacific Southwest at
the present is Arizona and specifically thc service arca of the Central
Arizona Project.
In the August 1963 Pacific Southwest Water Plan the Bureau of
Reclamation estimated that in the Central Arizona Project service area
the present pumpage is exceeding the available rceharge by approxi-
mately 2.2 million acre-feet per year at the headgate.4
In the Supplemental Report on the Central Arizona Project, how-
ever, these estimates were revised:

The indicated headgate deficiency of 2,190,000 acre-feet annnally,
. . . had to be met by ground-water pumping. A portion of this
deficiency became return flows on application. 'What portion of the
return flows was and will be utilizable at the present or in the
future is unknown. It is basic, through, that most of these waters
are "in transit" and must be classified as recharge'; however, in
some instances it may be years before this snpply is available for
reuse. Therefore, the net overdraft may range from a quantity
substantially lower than 2,190,000 acre-feet or closely approach it.
On the basis of limited data pl"eSently available, it is estimated
that 30 percent of the applied water became return flow, thereby

"Pacific SouthWest Water Plan~ R6vi8ed~ at 1II-4. III-6.