522 



SCIENCE 



[Vol. LVI, No. 1454 



Beneficial use of the waters of Colorado 

 Kiver commenced many j'ears ago. No attempt 

 will be made in this sketch to do more than 

 to give the briefest outline of historical facts. 



The extent to which the water of Colorado 

 River is being used for irrigation will appear 

 from the following figures compiled by Mr. 

 E. C. LaRue for 1913. 



Colorado; area irrigated in 1913 was 440,000 

 acres. 



Wj-oming; area irrigated in 1913 was 280,000 

 a,cres. 



Utah; area irrigated in 1913 was 204,000 

 acres. 



Nevada; area irrigated in 1913 was 5,000 

 acres. 



New Mexico; area irrigated in 1913 was 40,000 

 acres. 



Arizona; area irrigated in 1913 was 315,000 

 acres. 



California; area irrigated in 1913 was 297,000 

 acres. 



Mexico; area irrigated in 1913 was 50,000 

 acres. 



In California the irrigated area now ap- 

 proaches 500,000 acres and in Mexico it is 

 about 190,000 acres. There has, of course, 

 also, been extension of irrigation in the upper 

 states but later figures are not at hand. 



No Colorado River water was used for ir- 

 rigation in Mexico prior to the construction of 

 the Imjjerial Canal from which water ibegan 

 to be used in 1901. By 1905 there were about 

 5,000 acres of land in Lower California being 

 irrigated. In 1910 the area was probably 

 about 20,000 acres and in 1920 had reached 

 about 150,000 acres. 



The potential use of water from this river 

 and its tributaries can not be stated with any 

 great degree of precision. Some allowances 

 must be made for the fact that just at present 

 each of the several interested states is endeavor- 

 ing to secure recognition of extreme ultimate 

 possibilities in this connection rather than of 

 early future probabilities. For the purpose of 

 a guide in this discussion the following figures 

 are noted — the endeavor being to include in 

 the areas noted as irrigable only such as would 

 seem to justify construction of works within 

 the next thirty years. 



In the Green River Basin the extent of ir- 

 rigation in 1913 was about 500,000 acres and 



expansion within thirty years to about 900,000. 

 acres is to be expected; in the Grand River 

 Basin from about 300,000 to about 420,00O. 

 acres; on the lower Colorado from about 

 400,000 acres to 1,500,000 acres; in the Gila 

 River Basiu from 280,000 to some uncertain 

 extent possibly 400,000 acres ; in the San Juan 

 River Basin from 117,000 to 500,000 acres; in 

 the basins of the lesser tributaries of Colorado 

 River from about 61,000 acres in 1913 to about 

 160,000 acres, and in Mexico from 50,000 in 

 1913 and 190,000 in 19~21 to 600,000 acres. 



After the war between the United States and 

 Mexico the boundary line between the two. 

 countries had to be fixed. This was done in a 

 conference resulting in a boundary line treaty 

 consummated in 1848. But it was soon found 

 that portions of the line westerly from the Rio 

 Grande should have been placed further south 

 and negotiations were commenced for a modifi- 

 cation of the line. The result of these negotia- 

 tions (in 1853) was the acquisition of a strip 

 of land, now the south portion of New Mexica 

 and Arizona known as the Gadsden Purchase. 

 There is a story current, though probably im- 

 Ijossible of verification and to be cons'idered 

 for the present as without foundation in fact,, 

 to the effect that the Commissioners of the^ 

 United States who made the purchase were 

 given the choice of three locations for a new 

 line. According to this story the line furthest 

 to the south touches the head of the Gulf; but 

 the payments to be made by the United States 

 to ^lexico were graded according to the dis- 

 tance that the boundary would be shifted south- 

 ward and the line requiring the least payment 

 was selected by the United States Commission- 

 ers. Whether this story be true or not we can 

 now see how unfortunate it was to have fixed 

 the line in its established position. It should 

 have been as far south as the head of the Gulf 

 of California so that the entire delta of the 

 Colorado River would have been in the United 

 States. The Commissioners accepted a loca- 

 tion of the line which may at any time become 

 a source of friction and which has already be- 

 come a matter of great inconvenience and some 

 embarrassment to the United States. The 

 boundary divides the delta of the river not 

 along a channel, which would be bad enough, 

 but in such a way that most of the delta slope 



