KECLAMATIOX OF LOUISIANA WET PRAIRIE LANDS. 419 



among those are the Bayou L'Ourse, in the southeastern part of La Fourche Parish, 

 and the Wax and Little Wax bayous, in St. Mary Parish. Bayou L'Ourse is an insig- 

 nificant stream, occupying the center of a long and important ridge. It is probable 

 that at one time this bayou served as an outlet for the La Fourche or possibly of some 

 predecessor of the latter bayou, draining in a more easterly direction through Bayou 

 T>' -t, I ''ke Fields, and Long Lake. Wax and Little Wax bayous are streams of erosion 

 rather than of sedimentation and have been formed wholly or in part by the action 

 of storms and the tidal flow which is quite strong along this portion of the coast. As a 

 result, the bayous are bordered by the marsh or by very low ridges. Both streams are 

 from 10 to 50 feet in depth and 100 to 200 feet in width. 



From the fore^jomg discussion it is seen that these lands may not 

 in general be drained through gravity outlets in the ordinary way, 

 but that it is necessary to surround them by levees or embankments 

 and then, by the construction of an interior drainage system of ditches, 

 lead the drainage water to some convenient point from which it is 

 pumped over the embankment into the adjacent stream or bayou. 



PURPOSE OF INVESTIGATIONS. 



The development of these lands is now progressing with such 

 rapidity that the United States Department of Agriculture, through 

 Drainage Investigations of the Office of Experiment Stations, decided 

 in the spring of 1909 to make a study of the various conditions 

 entering into the reclamation of these most valuable lands. 



The engineers makmg the investigation were charged to deter- 

 mine the volume of water, or percentage of the rainfall, which it is 

 necessary to pump from the fields in order to secure adequate drain- 

 age of these soils; the area of the field surface occupied by ditches, 

 and the depth, width, and arrangement of the ditches and the levees 

 required in a drainage system; the influence of bad physical condi- 

 tion of ditches upon the efficiency of the system; the distance from 

 the ground surface at which the water table should be maintained; 

 the difference in the level of the water in the ditches while the pumps 

 were in operation; the percentage of saturation or the quantity of 

 water which the soil should contain when in the best condition for 

 growing crops. 



Accordingly, four reclaimed tracts of land were chosen in the 

 vicinity of New Orleans, which were regarded as having good ditch 

 systems, couj)led with ample pumj)ing capacities, and, as practically 

 no information was extant as to the relation of rainfall to the result- 

 ing run-off from these lands, rain gauges were established on each 

 tract and continuous rainfall records kept, in order to compare them 

 with the pumping records for the same period. 



The following gives a brief description of the tracts in question, 

 including their punij)ing maclunery equipment, and also describes 

 a new tract, District No. 3, which is being reclaimed in the spring 

 of 1910. 



