466 



Irrigation and Drainage 



underdrains, and the small squares cover 40 acres 



each. 



Another drainage system of this sort in the same 

 state is found in Mason and Tazewell counties, where 

 by a cooperative plan the open ditches have been dug 



Fig. 151. Plan of drainage of lands of the Illinois Agricultural Company, 

 Rontoul, Illinois. After J. O. Baker. The smallest squares are 40 

 acres; double lines show open ditches; single lines are tile drains. 



and the expense divided among the landowners in 

 proportion to the benefits derived. The work was 

 begun in 1883, completed in 1886, and has 17.5 miles 

 of main ditch 30 to 60 feet wide at the top and 8 to 11 

 feet deep. Leading into these mains there are five 

 laterals 30 feet wide at the top and from 7 to 9 feet 

 deep, the whole system embracing 70 miles of open 

 ditch, excavated for the express purpose of providing 

 outlets for underdrains after the manner of Fig. 151. 



