EECLAIMIITG OVEEFLOWED LANDS IN MISSISSIPPI. 31 



FLOODWAYS. 



In floodways all trees and underbrush should be cut and removed 

 and all drift disposed of; stumps should be cut level with the ground. 

 The heights of the levees have been computed upon a basis which 

 requires that everything that will seriously impede the flow of water 

 shall be removed from the floodway, the latter including the river 

 channel itself; the widths to be cleared are given in Appendix II. 



It is reconunended that a separate organization be formed to clear 

 the entire river floodway, since, to be effective, this must be cleared 

 through the length of the levee improvements. It is not believed 

 that the clearing can be advantageously handled by the separate 

 levee districts, working independently. To clear this floodway, the 

 entire valley between the lower end of district No. 1 and Cox Ferry 

 should be organized into one drainage district. The cost of the 

 work should be assessed, according to the benefits to result, to all of 

 the land that at present is subject to overflow, excepting that within 

 the floodway itself. The floodway should be cleared to a point 2 

 miles below Cox Ferry in order to prevent the increase of flood height 

 at the Ferry that otherwise would result from the more rapid dis- 

 charge of the upper river. 



SEDIMENTATION AREAS. 



The smaller streams and ravines which enter the valley from the 

 surrounding hills usually carry a large amount of sediment and 

 drift, which bemg deposited is continually filling up the lands where 

 the streams enter the bottoms. For this reason many of these 

 smaller streams have not established channels for themselves, but 

 have filled up and spread over the bottom. If ditches are con- 

 structed to connect these small streams with the main drainage 

 channels, the same process of sedimentation wiU continue and the 

 ditches will soon become fiUed. 



To overcome this difficulty in the ditches that are to be constructed, 

 it will be necessary to provide sedimentation areas, each bounded by a 

 levee on the lower or downstream side that will servo to impound the 

 water and decrease its velocity, thus causing the suspended matter 

 to be deposited. In this manner the excess sediment and drift can 

 be confined to a limited area and damage to ditches prevented. 

 When an area has become filled to such a height that storage is 

 no longer possible, a new levee can bo constructed a little farther 

 upstream or downstream; thus a new sedimentation area is formed, 

 leaving the old one, filled with fertile soil, available for cultivation. 



These areas are of the utmost importance in the reclamation of a 

 river valley of the character of that of the Big Black, and as tliey make 

 it possil>le for tlu; furrncr to nitaiii the most fertile soil on his farm, 

 they should l>e constmctcd by him regardless of whether the larger 



