62 LAND DRAINAGE 



89. Reclaiming delta lands. These lands have been 

 built up and are still being added to by the great rivers 

 flowing through them. They are very low, being in many 

 cases only a few feet above sea level. They are lower 

 than the banks of their rivers and in many cases lower 

 than the surface of the rivers at normal flood. Much of 

 the surface of these lands is under water all the year, 

 and in some cases is occupied by shallow lakes. The soil 

 is very deep and rich. In the vicinity of New Orleans, 

 the alluvial deposits are said to reach a depth of 2000 

 feet. In some parts the surface is covered with grass- 

 like growth, in others by great forests of sycamore timber. 



At one time these lands were considered almost worth- 

 less for agricultural purposes, and thousands of acres 

 were purchased at a price as low as 12| cents an acre. 

 At the present time (1915), values have advanced to 

 $10 to $30 an acre. 



Great drainage projects are already in operation, and 

 others are under way. The method is to inclose a tract 

 of this land by dike, in getting the material for which a 

 ditch of considerable size is excavated inside the dike. 

 The ditch therefore encircles the tract. The area to be 

 thus diked in is selected abutting a natural water course, 

 or some large drainage canal. If it is not so located, it 

 must have a ditch or canal dug to it. The ditch encircling 

 the tract is given a fall such that the bottom is lowest at 

 some point adjacent to the water course or drainage canal. 

 Ditches are next cut across the tract at intervals from the 

 encircling ditch, and again other branches are dug back 

 from these, dividing the tract in units of forty acres or 

 less. All the ditches have such fall that the water in 

 them will gravitate from the smaller to the larger and 

 finally to the lowest point in the encircling ditch. 



