THE IRRIGATION AGE. 



153 



Fig. 5 The corn grown in 1914 showed many bare spots. 



lateral system, consisting of eight parallel laterals 

 on the east and nine on the west side of the main, 

 is composed of 6-inch tile at an average depth of 

 five and three-quarters feet. The laterals are 315 

 feet apart, those on the east of the main drain being 

 900 feet long, while those on the west, due to the 

 topography, vary from 500 feet to ( 1,700 feet long. 

 Branch No. 7 differs from the others in that it ex- 

 tends north along the west line in order to reach 

 the deep depression at the northwest corner of the 

 tract. The tile, with the exception of 640 feet of 

 12-inch sewer pipe, was ordinary hard-burned clay 

 drain tile in two-foot lengths. Each piece was laid 

 to grade with abutting joints. No protection was 

 provided at the joints for keeping out silt. 



.Concrete silt wells were placed along the main 

 drain at the points where the laterals enter, and at 

 distances of not more than 500 feet apart on the 

 laterals. These silt wells vary in size from 4X4 

 feet to 2 l /2 X 4 feet and have an average depth of 

 about eight feet. The bottom is in each case one 

 and one-half feet below the tile grade. The sump 

 at the southeast corner of the tract consists of a 

 reinforced concrete pit five and one-half feet square 

 and sixteen feet deep, with the inlet tile four feet 

 from the bottom. The water was originally pumped 

 from this sump with a 3^-inch vertical centrifugal 

 pump operated by a 5 H. P. direct-connected motor. 

 The irrigation laterals were lined with concrete at 

 all points where they crossed the tile lines to pre- 

 vent excessive seepage into the new trenches. Fig. 

 2 shows the plan of the system. 



Construction and Cost in 1913 

 Construction was done by contract, the con- 

 tractor receiving a commission of 10 per cent on 

 the labor and materials, exclusive of tile and pump- 

 ing equipment. This arrangement, however, was 

 not strictly adhered to as both labor and materials 

 were furnished without commission. The trenches 

 were all dug by hand and at no place except in the 

 vicinity of the sump was any water or serious cav- 

 ing encountered. 



The system consists of 21,842 

 feet of drain varying in size from 

 6-inch to 12-inch tile, including 640 

 feet of 12-inch sewer pipe used for 

 the lower end of the main line be- 

 cause of the deep cut here. The 

 tile cost 7^4 cents per foot for 6- 

 inch, 13 cents per foot for 8-inch, 

 and 26 cents per foot for 12-inch, 

 totaling $2,018.55 or an average of 

 $0.0924 per foot, f. o. b. Kearney 

 Park. Distributing the tile, dig- 

 ging trenches, laying, backfilling, 

 tools and repairs amounted to $4,- 

 352.38, divided as follows : 



Digging and laying $2,935.42 



Backfilling 293.99 



Supplies and blacksmith- 

 ing 821.17 



Commission 301.80 



$4,352.38 



The structure, including the ma- 

 terial and work on the silt wells, 

 irrigation crossings and sump, 

 amounted to $2,066.24, of which $1,015.34 was for 

 materials and $164.45 for commission. This was 

 divided approximately as follows : 



Sump $ 500.00 



Thirty-four silt wells 1,258.00 



Twenty-eight crossings 308.24 



The pump equipment cost $561.35, divided as 

 follows : 



Transformers $160.00 



Pump, motor, etc 401.35 



A summary of the cost of the drainage plant 

 as installed in December, 1913, on a basis of 151 

 acres of arable land, is given in the following table : 

 Item Total Per acre 



Tile $2,018.55 $13.37 



Digging and laying 2,750.67 18.23 



Distributing tile 184.75 1.22 



Backfilling 293.99 -1.94 



Supplies and blacksmithing. . . 821.17 5.44 



Sump 460.00 3.05 



Silt wells 1,163.55 7.70 



Crossings 278.24 1.84 



Pump equipment 561.35 3.71 



Commission 466.25 3.09 



$8,998.52 $59.59 

 The cost of installing the tile was : 



Cost per foot 



Item Total of drain 



Tile $2,018.55 $.0924 



Digging and laying 2,750.67 .1259 



Distributing 184.75 .0085 



Backfilling 293.99 .0135 



Supplies and blacksmithing. .. 821.17 .0376 



$6,370.93 $.2917 



Immediately after the completion of the drain- 

 age system, steps were taken to prepare the land 

 for flooding. This work consisted of repairing the 

 irrigation system and rechecking the field, both of 

 which had become neglected through disuse. The 

 repairs to the irrigation system cost $235.17, or 



