THE IRRIGATION AGE. 



DEVELOPMENT OF THE UNDERFLOW. 



The Experiment Station Well. 



PROFESSOR J. J. VERNON, 

 Mesilla Park Agricultural Experiment Station, New Mexico. 



The development of the underflow for irrigation 

 is one of the methods that has been adopted in certain 

 sections for relief during drouthy seasons. 



The people of the Territory fully appreciate the 

 value of any investigations which are intended to assist 

 in the solution of the difficult problems connected with 

 the development of the underflow for irrigation in New 

 Mexico, and it is, therefore, unnecessary to dwell upon 

 this feature of the question. 



The great necessity for information along this line 

 led the authorities of the Territorial Experiment Sta- 

 tion to. inaugurate experimental work. One feature of 

 the question taken up for solution was that of pumping 

 for irrigation. While an abundance of water was to 

 be had at fifteen feet below the surface of the groundj 

 to secure a well that would furnish a sufficiently large 

 quantity of water for irrigation purposes seemed, at 

 first thought, to be impossible, if the cost was to be 

 kept within the limits of practicability, since the water- 

 bearing beds under the experiment station farm, as 

 well as those under the whole of the Rio Grande Val- 

 ley, were thought to be composed of almost pure sand. 

 An open well situated only a few miles from the ex- 

 periment station farm had cost upward of $10,000 and 

 was capable of supplying only from 1,000 to 1,200 gal- 

 lons per minute. 



Before the experiment station well was begun an 

 investigation was made of some wells of the valley, 

 in order that we might profit by a knowledge of the 

 difficulties encountered by others. This investigation 

 led us to believe that in the formation of the valley 

 lands gravel strata had been laid down, and that pos- 

 sibly a gravel stratum might be found of sufficient 

 thickness to make the development of large quantities 

 of water possible at a reasonable cost. The well on the 

 experiment station farm was begun with the avowed 

 purpose of proving or disproving this supposition. The 

 theory proved correct. 



A standard pipe, six inches in diameter, was sunk 

 to a depth of forty-eight feet, penetrating a stratum 

 of gravel twelve feet thick, which was intermixed with 

 from 20 to 50 per cent of sand. A slotted strainer, 

 made from 16-gauge galvanized iron, closed at the bok 

 torn, was lowered inside of the pipe. The pipe was 

 then jacked up until the whole slotted portion of the 

 strainer was exposed. Each of the slots in the strainer 

 was 1%-inch long by l^-inch wide, the intervening 

 spaces being of the same dimensions. This form of 

 strainer allows water and sand 'to freely enter the well, 

 but restrains the gravel, which, after the sand is re- 

 moved, as is indicated below, forms a very porous water- 

 bearing stratum. 



When water was first pumped from the well it 

 was loaded with sand. This continued for several days. 

 Probably two carloads of sand were pumped from the 

 well before the water became clear. From this we con- 

 clude that the sand mixed with gravel around the 

 strainer had been removed for several feet in every 

 direction. 



The quantity of water furnished by this small 



well has been far beyond our most sanguine expecta- 

 tions. We hoped to secure a flow of from -100 to 500 

 gallons per minute, but one of the pumps, being tested, 

 produced 1,085 gallons per minute. This quantity of 

 water, supplied by only a 6-inch well, at first thought 

 seems almost incredible, but upon looking into matters 

 a little more carefully the reasons for this large flow 

 are readily understood. Since the slots in the strainer 

 occupy nearly one-half of the total area of the walls 

 of the strainer, it is evident that the strainer offers 

 little obstruction to the passage of the water through its 

 walls, and since the sand mixed with the gravel has 

 been removed for several feet, perhaps ten, possibly 

 twenty-five feet, in every direction, we may reasonably 

 say that we have, in a measure, the results that would 

 be obtained by an open well from twenty to thirty feet 

 or more in diameter, twelve feet deep. 



When the matter is looked at in this light we can 

 readily understand that the quantity of water which 

 can be secured from such a well is enormous and the 

 flow is probably only limited by the carrying capacity 

 of the pipe through which the water must be drawn. 



The total cost of the well, including curbing, pipe, 

 strainer and sinking, was not to exceed $150. This 

 very small cost, in consideration of the large quantity 

 of water secured, seems to indicate that what was con- 

 sidered a very difficult problem that of securing large 

 quantities of water for irrigation from the underflow 

 has been solved for all localities where a gravel stratum 

 of sufficient thickness can be found. For sections where 

 no gravel strata can be found, other methods must be 

 tried. 



IRRIGATION IMPLEMENTS. 



The Department of Agriculture recently issued a 

 pamphlet containing a very interesting article by El- 

 wood Mead, chief of irrigation investigations, concern- 

 ing the preparation of land for irrigation and methods 

 of applying water. Not the least interesting feature 

 is a series of illustrations, which are reproduced else- 

 where, showing some of the novel implements used. 

 Mr. Mead finds a diversity of irrigation methods in 

 use on Western farms, which he attributes to the 

 early training and environment of the irrigators, and 

 further says : 



"Among the 120,000 irrigators of Western Amer- 

 ica are to be found nearly all classes and nationalities. 

 Each settler from another State or from a foreign 

 country introduces on his farm some custom or prac- 

 tice common to his old environment. This is particu- 

 larly noticeable in the conservative Chinese, who irri- 

 gate the truck gardens near towns and cities in Chi- 

 nese fashion. The same is true of the Italians, Span- 

 iards and Mexicans, who imitate for a time at least 

 the ways of their forefathers. It also applies, but to 

 a less degree, to those who come from humid States. 

 The farmer who lives until maturity in the Mississippi 

 Valley and then moves West onto an irrigated farm 

 does not as a general thing adopt new ways of farm- 

 ing until crop failures compel him to do so. Even 

 then the old ways of doing things are mixed with 

 the new. 



"Then, apart from the influence which early train- 

 ing may exert, there is always present the vital question 

 of money. Many new settlers have not the means 

 to prepare fields for easy and efficient irrigation. They 



