WSP10867

• File Number: 8278.400
• Description: Title I - Mexican Treaty
• Basin: Colorado Mainstem
• Date: 3/1/1962
• Author: IBWC
• Title: Mexican Water Treaty -Appendix E -Water Supply
• Water Supply Pro - Doc Type: Publication

J. R. Riter, Hydraulic Engineer for the Bureau or Reclamation, made further

explanation of the source 0:1 water in the Colorado River below Imperial Dam. His

statement is as follows from page 347:

"Mr. RITER. The imperial Dam, located on the Colorado River 15
miles upstream from Yuma, Ariz., is the lowest pOint of diversion for
use for the United States. Below this point the river now receives
return flow from the Yuma project, seepage losses from the Imperial
Dam to the Pilot Knob portion of the All-American Canal and, occasionally,
floodwaters from the Gila River.
"To determine the future return flow it is necessary to make assump-
tions regarding the future development in that part of Arizona which
will drain into the Colorado River below the Imperial Dam.
"I will first discuss return flow from the Yuma proj ect. This proj ect
embraces 15,000 acres in southeastern California and 52,000 acres in
southwestern Arizona. It is one of the old projects of the Bureau of
Reclamation. The first vlater was delivered in the year 1907. Water
was originally diverted from Laguna Dam, which is also on the Colorado
River, 10 miles northeast of Yuma. It was carried in a canal along the
California side of the river lO serve the lands located in that State, and
a'l Yuma there is a siphon which carries water across the river to serve
the lands on the Arizona sIde.
"Since August 1941, th8 water for the Yuma project is being diverted
at Imperial Dam, which is located 5 mdes above the old Laguna Dam, and
its service is through the All-AmerIcan Canal which has replaced a portion
of the Yuma main. cana".
* * *

"Mr. RITER. It (the All-American Canal) serves lands in the Imperial
and Coachella_\Lq.ll~y:s_in_Caliiornirl Howe\lBl',-i-n-the-process-of-buHdtn'd,
in the upper reaches of the cana l, it was more convenient to have that
canal also carrying water for the Yuma project. So for that reason, when
the caned was constructed, the upper 15 miles of-the canal was made
2,000 second-feet larger than the needs by the Imperial dIstrict, in order
that the Yuma projecl water could be carried in that canal instead of in
the Yuma Canal.
* * *

"At the present time the annual diversion of water from the river
forche Yuma project is 1,400,000 acre-feet. One million acre-feet
of this water is used for power production at the Siphon Drop plant, but
that is entirely returned to the river. Four hundred thousand acre-feet
are diverted for irrigation purposes, and of that amount 200,000 acre-
feet are applied to the land and the remaining 200,000 acre-feet returns
as waste or return flow through the drains.

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