DEAINAGE OP WET LANDS OP SOUTHERN" LOUISIANA. 



31 



about $0.75 per " acre " ^ of ditch. With the present spacing of 160 feet the 

 annual cost of ditch maintenance per acre of area drained is about $1. 



During the summer of 1910 some measurements of the depth of the water 

 table below the surface were made. The results of these measurements are 

 shown graphically in figures 8 and 8a. It is evident that after long and heavy 



^ The term " acre " is in common use in the section under discussion as a unit of length 

 in rough land measurements. Its value is the length of one side of a square whose area 

 is 1 acre, or about 209 feet. 



