40 BULLETIN 71, U. S. DEPARTMENT OF AGRICULTURE. 



Ditches. 



In this district, as in area No. 3, the collecting ditches have been used in con- 

 nection with the lateral ditches to drain the ground. The collecting ditches 

 have been placed along the roads and this has made it less difficult to keep them 

 in good condition and also to see when they were in need of cleaning. However, 

 these collecting ditches have not been easy to maintain, and it has been neces- 

 sary to clean them out a number of times. It was the plan at first to place 

 the laterals every 210 feet, but later they were placed at twice that distance. 

 When the ground was first drained this greater distance was not found to be 

 too great. In 1912, after two years of drainage and cultivation, a distance of 

 210 feet is considered by the landowners to be about as great as is safe. The 

 laterals were at first 3 feet deep. This depth is not considered sufficient when 

 the spacing between the laterals is as much as 210 feet. At times of heavy 

 rains it has been found that the land between the ditches became too wet for 

 best growth of crops. 



Most of the laterals on this tract carry drainage water for at least 2,000 

 feet. This length seems to be allowable if the ditch is kept in fairly good condi- 

 tion. When ditches longer than a half mile are used, they must be increased 

 in width and depth at the lower end. unless they are kept in perfect condition 

 all of the time. On the lower and softer portion of this tract, unless some 

 further collecting ditches are cut, the length of lateral will be nearly a mile ; in 

 view of the fact that this ground is almost level it is likely that this length will 

 be too great. The percentage of land consumed in ditches and canals on this 

 tract is quite small, considering the large area in reservoir. When all of the 

 ditches are spaced 210 feet apart the area of land so consumed will be a little 

 more than 2\ per cent. 



Pumping Plant. 



The pumping plant is quite well located to draw water from all parts of the 

 district. The discharge is into Bayou False, which is about 60 feet wide at 

 this point and so affords an excellent outlet. As this plant is of much better 

 construction than any of the others of this group, a somewhat detailed descrip- 

 tion of it will be given (see fig. 11). The block of concrete which forms the 

 foundation for the pumps and engines is about 17 feet wide and 50 feet long, 

 and was placed approximately on the center of the levee with its greatest length 

 parallel to the levee. This block is 8 feet thick and so extends below the plane 

 of permanent water level, thus protecting from decay the piling that supports 

 it. Around this foundation was driven a double row of sheet piling, and at 

 each end a double row was extended some 15 feet into the levee. The sides of 

 the intake basin also were protected by a double row of sheet piling, supported 

 by a timber frame bolted to a number of round piles. The short length of dis- 

 charge canal necessary to reach to the bayou was protected in a similar manner. 

 Across the front of the intake basin a wooden screen prevents any floating 

 matter of size from entering the pumps. The base of the pumps is set at about 

 extreme low water in the bayou, and to protect the foundation from being 

 flooded the concrete is raised in a wall about a foot thick along the outside to a 

 height of 3 feet above mean tide. The whole of the foundation is well rein- 

 forced with steel, and the round piling under the concrete extends into it about 

 2 feet, thus insuring a perfect bond. 



One 30-inch cast-iron centrifugal pump was installed in March. 1910. and a 

 duplicate unit was added July. 1912. The arrangement and size of piping of 

 the first unit is shown in figure 11. The important features are the enlarging 

 and tapering of the pipes at the intake and discharge ends, the freedom from 

 bends or elbows, and the horizontal cutting of the intake end of the pipe, the 



