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<br />In cases of extraordinary drought or of serious accident
<br />to the irrigation system of the United States, which might
<br />make it difficult for the latter to deliver the guaranteed
<br />amount of l,850,234,000 cubic meters (l,500,000 acre-feet)
<br />per year the water assigned to Mexico, per clause a of this
<br />article, will be reduced in the same proportion as the consump-
<br />tions are reduced in the united States.
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<br />As is seen by the above article, Mexico is guaranteed
<br />by the Treaty a volume of l,850,234,000 cubic meters (1,500,000
<br />acre-feet) as a minimum, a volume which in many years will be
<br />2,097,000,000 cubic meters (l,700,000 acre-feet).
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<br />NOW then, before negotiating the Treaty a precise esti-
<br />mate was made of the net area in Mexican territory irrigable
<br />with water from the Colorado River under economically practi-
<br />cal conditions. Accordingly, this estimate found that there
<br />was an area of 200,000 net irrigable hectares (494,200 acres)
<br />equivalent to a gross area of 300,000 hectares. This gross
<br />area of 300,000 hectares (74l,300 acres) is less than that
<br />estimated as irrigable by our engineers during the inter-
<br />national conferences of 1929 to which we referred at the
<br />beginning of this report. The difference between these two
<br />estimates is that in the latter, great areas, considered in
<br />the estimate of 1929, are eliminated as being useless for
<br />agricultural operations due to the large amount of salts
<br />that the lands contain. For example, the basin of the Laguna
<br />Salada and the lands adjacent to the Gulf were eliminated.
<br />There were also eliminated some other areas of lands of poor
<br />quality where heavy pumping would be required.
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<br />Now then for irrigation of the net 200,000 hectares
<br />(494,200 acres), in accordance with the coefficient of irri-
<br />gation observed as an average since the commencement of
<br />agricultural work in the Mexicali Valley (l.25 meters or
<br />4.l feet), a volume of 2,500,000,000 cubic meters (2,026,700
<br />acre-feet) would be needed.
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<br />This volume can be obtained with the amount guaranteed
<br />by the Treaty of 1,850,234,000 cubic meters (l,500,000 acre-
<br />feet) in the minimum years or 2,097,000,000 (l,700,000 acre-
<br />feet) in the majority of the years plus the water that is
<br />pumped from wells -- similar to those existing on the Laguna
<br />which will more than supply the deficiency between the quan-
<br />tity required and the quantity guaranteed by the Treaty.
<br />
<br />If the coefficient of irrigation in Mexicali Valley
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<br />Information Bulletin #l8
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<br />-13-
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<br />January l2, 1962
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