DRAINAGE OF WET LANDS OF SOUTHERN LOUISIANA. 



43 



vent flooding. In these soft spots the levee is only about a foot above mean tide 

 and considerable work will have to be done to bring it to grade. Additions are 

 being made to these portions with hand labor, and at present subsidence has 

 practically ceased. 



On a portion of the levee where the old bank was used for a foundation some 

 peculiar • seepage conditions have become apparent. Water appeared in the 

 interior of the district some 20 to 40 feet from the levee, and an examination 

 showed that the subsoil of the impervious Sharkey clay was filled with holes 

 that varied in size from that of the usual crawfish hole, about 1 inch in diam- 

 eter, up to several inches, the latter probably being muskrat holes. This was in 

 a place where the underlying subsoil was very solid. It will be necessary to cut 

 a deep muck ditch along this levee and fill it with puddled earth. 



Fig. 12 



-Sketch map of area No. 5, Des Allemands, La Fourclie Parish, La., showing 

 arrangement of levee and ditches. 



Reservoir Canals. 



As shown in figure 12, the reservoir canals were all cut in the interior of the 

 district. By extending the canals to all parts of the tract the necessity of 

 small collecting ditches was eliminated. A small canal gives much better out- 

 let to the laterals than a collecting ditch and is easier to maintain in good 

 condition. These canals were cut with a dipper dredge and tlie material was 

 deposited rather close to the sides of the canal. This resulted in a small 

 amount of shrinkage in the size of the canals, there having been, in February, 

 1912, about 4 feet of soft mud in the bottom of each of them ; part of this was 

 perhaps left by the dipper dredge when cutting the canal. It was expected 

 that an attempt would soon be made to remove this mud with a small hydraulic 

 dredge ; this should be a very favorable situation for its use. At the time of 

 the examination the cross section of the main canal was so far reduced that 

 the pumping plant could not be operated at full capacity after the water was 



