78 



The Dawn of a New Constructive Era 



Two Kinds 

 of Natural 

 Drainage 



Some Factors fo be Consid- 

 ered in the Drainage of the 

 Cut-Over Lands 6>///f^ South 



By S. H. McCrory 



Chief of Drainage Investigations 



Office of Public Roads and Rural Engineering 

 U. S. Department of Agriculture 



One of the fundamental requirements of any soil that is to 

 be used profitably for agriculture is that it be well drained. It 

 matters little how much inherent fertility the soil may possess, 

 or how favorably located the land may be with respect to mar- 

 kets, if there is insufficient drainage agricultural operations can- 

 not be conducted successfully. It is hardly necessary for me to 

 say that in all the Southern States there are large areas of cut- 

 over lands, which, before they can be made available for the 

 practice of agriculture on a paying basis, must have existing 

 drainage improved. These areas may be divided roughly into 

 two classes. In the one class may be placed wide stretches of 

 low-lying level lands with poorly developed natural drainage 

 channels. In the other may be placed rolling and hilly land 

 where the natural drainage is ample — if not too ample — only the 

 narrow valleys along the streams needing drainage. 



The low level lands are usually found in the coastal plain 

 region or the Mississippi Valley. The drainage channels of these 

 lands are usually shallow, poorly defined. depressions that vary 

 in width front a few feet to several miles, and are generally cov- 

 ered with stumps and a heavy growth of small trees, brush, and 

 vines. Occasionally there is a poorly defined stream channel that 

 winds its way through the depression. Usually, however, the 

 water finds its way slowly down the swamp through the trees 

 and natural growth or stands until it sinks into the earth or is 

 evaporated. Between the drainage channels are low ridges which 

 usually rise only a few feet above the channels. The first at- 

 tempts at cultivation are generally made on these ridges. Dur- 

 ing periods of heavy rain the water rises and the ridges become 



