THE IRRIGATION AGE. 



117 



The Drainage Problem in the San Luis Valley. 



Why it will be necessary for the state law to provide for the drainage of the region. The raising of 

 grain and potatoes in the valley and some of the enormous crops of each. 



W. A. Anderson. 



Some years ago careless methods of farming and irri- 

 gating brought into the eastern portion of the San Luis 

 valley a vast amount of alkali. As is always the case 

 where this bane of the irrigation farmer is found unless 

 an effort is made to get rid of it, the alkali conquered 

 the farmers and many finely situated ranches were aban- 

 doned. For several years thereafter no effort was, made 

 by property owners to raise crops on the land, and each 

 year the alkali became thicker and the land less valuable. 

 Much of this land is around Hooper and Mosca on the 

 narrow gauge line of the Denver & Eio Grande railroad 

 from Salida to Alamosa. Naturally the news of the 

 abandonment of San. Luis valley farms was not limited 

 to the comparatively few who were compelled to move 

 out and unfavorable reports which spread from this 

 movement did much to seriously interfere with the rapid 

 settlement of the district. Ill news travels much faster 

 and is much more widely published than news of a 

 favorable character and it was some years after the 

 emigration of the agriculturists from the eastern por- 

 tion before the valley "boosters" and real estate men 

 were able to overcome the prejudice against the valley 

 as a whole. Even today it is not unusual to hear people 

 remark that they would not take valley land as a gift, 

 when if they knew the true state of affairs and the real 

 value they would be only too glad to purchase a sec- 

 tion or a half-section if for nothing more than a purely 

 money making investment. 



But even that section of the valley where the alkali 

 deposits drove settlers out will in time be exceedingly 

 valuable property again. Land there at one time sold 

 as high as $50 an acre. Today it can be bought for 

 $10 or $12, but unless all signs fail it will not be many 

 years before it again reaches its high water mark and 

 even goes above it. This is because of the "re-reclama- 

 tion" of this land by means of drainage ditches. About 

 three years ago some interested parties got the govern- 

 ment reclamation service interested in the alkali lands 

 of the San Luis valley, and in the summer and fall of 

 1906 government experts were sent out who showed the 

 farmers, by a series of lectures, how the land could be 

 reclaimed from its alkaU, for without this plague the 

 soil is as fertile as in any other section of the valley or 

 in any other section of the state. Following this, in the 

 summer of 1907, civil engineers were sent out by the 

 government service who surveyed the land and ran 

 levels for main and lateral drainage ditches. 



What the valley really needs, however, more than 

 any other thing, and what must of necessity come within 

 a few years if it is not to be had now, is a district 

 drainage law.' This is the one thing at the present time 

 which stands in the way of the rapid and complete de- 

 velopment of the region. The geography and geology 

 of the valley must be recalled for an understanding of 

 the difficulties that confront the people of this region 

 and their need of the co-operation of the rest of the 

 state. 



The irrigators of the San Luis valley require no 

 financial assistance nor propose any plan of public im- 

 provements to be undertaken by means of funds drawn 



from the state treasury. Although such a use of the 

 public improvement fund might be justifiable under 

 the circumstances, all that the people of the valley are 

 asking is that the laws of the state be put in such shape 

 that they can undertake this work for themselves and 

 pay for it themselves. 



The San Luis valley is a great saucer or basin, the 

 bed of an ancient lake, with the slope of the rock strata 

 following closely the surface contours. When sediment 

 bearing streams discharge into a body of water, the 

 coarser and heavier materials are deposited nearer the 

 shores, while the lighter and finer clays and sands are 

 carried farther toward the middle of the lake. The 

 sediments are also much thicker near tLd shore than they 

 are farther out. In the San Luis valley the gravels and 

 sands are coarsest and thickest along the northern and 

 eastern and western sides near the foot of the moun- 

 tains, while in the center the soil is composed of fine 

 silt, and the rocks beneath are made up of thin layers 

 of fine grained and closely compacted shales. 



A writer in the Pueblo Chieftain of September 8, 

 1907, gives a comprehensive explanation of how the 

 lands are alkalied and the means of remedying the evil. 

 Here is what he says: 



"On the rim of the valley where the rainfall is 

 heavy and the soil porous, the water from the natural 

 precipitation or from irrigatioon sinks into the soil and 

 is carried away by natural drainage! In the center of 

 the valley, on the contrary, where the rainfall is very 

 light, where the evaporation is very rapid and where 

 the natural drainage is obstructed by impervious lay- 

 ers of fine grained and closely compacted soil, the 

 course of the water is not downward, but upward by 

 evaporation into the air. And as water in evaporation 

 leaves behind it the mineral salts that ground waters 

 carry in solution, the surface of the ground soon be- 

 comes coated with a deposit of lime and magnesia salts 

 that have been leached out of the soil and deposited 

 upon the surface by the evaporated waters. And as a 

 surplus of these salts at the surface makes the ground 

 unsuitable for the growth of many valuable crops, there 

 are in the middle of the San Luis valley thonsands of 

 acres of land, much of which was at one time under 

 cultivation, but which has now been abandoned and has 

 reverted to the wilderness in worse than its original 

 condition. 



"Now it is evident that in order to restore these 

 alkali lands to fertility, all that is necessary is to 

 change the course of the ground waters so that they 

 will carry these alkali salts downward and distribute 

 them through the soil instead of leaving them in a crust 

 upon the surface. That this can be done has already 

 been established by experiments in the region near 

 Mosca and Hooper. 



"The even slope of the valley lends itself readily 

 to drainage works, and the water taken from the sub- 

 soil of one area may readily be used for the irrigation 

 of the next lower level, and so on successively until it 

 finally reaches the level of the central stream. 



