BOARD01455

• Board Meeting Date: 6/9/1942
• Description: Table of Contents and Minutes
• Board Meetings - Doc Type: Minutes

1~1

Conditions in Mexico.

The area in the Colorado River delta in Mexico may be divided into two
classes I (a) that part which may be considered as possible or reasonably
permanent development without a controlled river, and (b) that part which
could be permanently developed only with the river controlled.

Under the rirst class (a) may be considered the area developed prior to
the construction or Boulder Dam, totaling a gross or about 300,000 acres or
which a net or about 200,000 acres would be cropped annually and uhder the
second class (b) the balance of the irrigable area which includes that
developed since 1935.

The reason class (b) lands were not developed prior to 1935 was due to
flood conditions and the fact that these areas were in what is known as the
"live". delta where 140,000 acre feet or silt carried by the river was being
deposited eaoh year. Several attempts were made to develop these areas, but
had to be abandoned. Thererore, only by reason of control works which were
built in the U. S. could class (b) lands be put under irrigation.

Prior to control of the river by Boulder Dam, the irrir,ation of class
(a) area was dependent upon the natural flow. Since 1920, by which time most
of this area had been developed, the maximum diversion was 745,000 acre reet
in 1925 and the minimu11l 452,000 acre reet in 1934. Only 228,000 acre reet
was used in 1932, but this was due largely to a smaller acreage in orop
rather than a shortage of river flow. This would seem to indicate that under
natural rlow conditions Mexican lands were not assured of a dependable rlow
or 750,000 acre reet.

Between 1920 and 1930 (to eliminate depression years) the diversion of
water in Mexico averaged 603,000 acre feet per year and included only one
year of considerable shortage (1924).

ThrouGhout all the years since development commenced, lands in Mexico
have depended on diversion works located in the United States. As to the
ruture, it is not believed that Mexico Oan successfully maintain diversion
works at any point in the twenty mile stretch of the river, which is a
common boundary between.Arizona and Mexico, south of the California boundary.
It appears that the most practical diversion, for the major part of the land
to be irrigated, would be located in the United States.

Prior to control at Boulder Dam, protective works in Mexico were construct-
ed and maintained by United States interests in the cost of which the Mexican
Government did not participate, Following control of the river, Mexico has
fOlir.d it necessary to take over the maintenance of the levee system to protect
adjacent land. The levee Syst8~ must be raised, strengthened and extended to
protect the areas in which recent development has been attempted. Mexico will
no doubt expect the United States to share in the cost of this work, which
will cost several millions of dollars over a period of years and which fact
should be fully considered by our Government in any treaty negotiations.

The recent development has been of a hit and miss type. Temporary pumps
are installed and vmter used from sloughs and side channels - it is not a