Urrigatfon, 6 9 



A dam of piles and riprap was thrown across the river at a point where 

 it is about 1500 feet wide at flood. From this dam the line of the 

 main canal was traced to the entrance of the Tlahualilo, a distance 

 of 39 miles. The canal terminated in a distributing tank at the en- 

 trance to the irrigable area, whence it bifurcated, one arm being car- 

 ried along the western side of the basin. 



The rainfall in the Bolson of Mapimi is confined to a few days of 

 heavy showers about the beginning of June and the beginning of De- 

 cember. But up in the mountains of Durango, where the Nazas takes 

 its rise, the rainfall at the same season is very heavy and protracted, 

 resulting in high water in the river, which lasts for several weeks at a 

 time. It is during these freshets that the cultivated lands in the Nazas 

 district are irrigated. For the rest of the year they receive no water, 

 except from occasional brief showers. In the Tlahualilo basin, a week 

 or ten days of irrigation is all that is needed in the course of a year, 

 the water soaking easily and quickly through the almost impalpable 

 silt, and the hot sun forming a protecting crust which checks evapora- 

 tion, and retains the moisture in the subsoil for a surprisingly long 

 time. In fact, owing to their long roots, the cotton plants strictly re- 

 quire irrigation only once every other year, but corn and wheat, of 

 course, must receive it at each planting. The distribution of the 

 waters is regulated by government schedule, each property on the 

 river being allotted its proportion of water, according to priority of 

 settlement. Each canal on the river is permitted to take as many irri- 

 gations as it desires during the season of high waters, but in strict 

 rotation. That is, after a property has taken one quota, it cannot re- 

 peat the process until all the others have taken theirs, when its second 

 quota is available. Where another property, as often happens, does 

 not care to use all the water to which it is entitled, its further allot- 

 ments may be used by its neighbor. The waters, on leaving the river, 

 are heavily charged with sediment largely volcanic in its origin, and 

 this is deposited on the lands at each flooding in the shape of extremely 

 fine mud. 



Six years of experience with this property demonstrates the fact 

 that irrigation, when applied to fertile land under a carefully planned 

 and thoroughly executed system, where the water supply is owned by 

 the user, puts agriculture among the least dubious of industries. The 

 system adopted by the Tlahualilo Company is especially worthy of atten- 

 tion, because of the notable unity of plan pursued from the inception 

 of the enterprise to its fullest development, and of its resultant econo- 

 mies. It was on this property that a disastrous experiment of colo- 

 nization from Alabama took place in the year 1896, when hundreds of 

 negroes were taken from Alabama and other points of the southern 

 portion of the United States under the supposition that they could 



