DRAINAGE OF WET LANDS OF SOUTHERN LOUISIANA. 



27 



serious matter. The heaviest rainfall that this plant has been called upon to 

 handle since the records were begun occurred in the latter part of April, 1911, 

 when 6.25 inches of rain fell in two days. The plant did not run at full 

 capacity all of the time, so some flooding occurred for about 48 hours in the rear 

 portion of the plantation ; no large damage resulted from it, however. In view 

 of the fact that this plant can not be depended upon always to run at full 

 capacity, its present capacity is just about sufficient. There are a number of 

 factors which make the run-off from this plantation greater in amount and in- 

 tensity than it is from the average district of newly reclaimed wet prairie land. 

 Among these are, first, a fall in the surface from front to rear of the tract of 

 about 10 feet ; second, a heavy and impervious soil on all the front lands, which 

 comprise about half the entire area ; third, a very complete system of ditches ; 

 fourth, complete and intensive cultivation ; and fifth, a well-decayed and com- 

 paratively impervious prairie land in the rear portion of the tract. However, 

 after the average district has been as long reclaimed as this district has been 

 about the only one of the above factors that will differ, when it comes to mak- 

 ing comparisons, will be the surface slope. It seems reasonable to suppose that 

 the percentage of run-off on newly reclaimed districts will gradually increase 

 until it is almost as large as it is on the tract under discussion. 



The cost of operation of this plant in labor and fuel has been carefully kept, 

 but due to inefficient machinery and large run-off from the front lands, it is con- 

 siderably higher than where conditions are more nearly typical. Following is 

 a summary of the cost of operation of the pumping plant on area No. 1 from 

 June, 1909, to December, 1911, inclusive. 



Cost of operating pumping plant on area No. 1, June, 1909, to December, 1911, 



inclusive. 





Rainfall. 



Run-off. 



Cost. 



Date. 



Labor. 



Fuel. 



Total. 



Per acre. 



Per inch 



of water 



removed 



over 



tract. 



Per 



acre-foot 



lifted 



1 foot.i 



1909 2 



Inches. 

 42.32 

 43.08 

 52.32 



Inches. 

 16.33 

 11.58 

 23.42 



$600 

 500 

 753 



$936 



616 



1,267 



$.1,536 

 1,196 

 2,020 



$0.64 

 .50 



.77 



$94. 00 

 103.00 

 101.00 



$0.09 



1910 



.10 



1911 



.08 







i Calculated on basis of 5 feet effective lift. 

 2 June to December only. 



Actual lift 10 feet. 



Condition of Land for Cultivation. 



For two years after this tract of land was reclaimed it was cultivated with 

 only such drainage as was afforded by the reservoir canals. At the end of this 

 time lateral ditches were cut at a spacing of about 400 feet, and good drainage 

 thus secured for a number of years. Not much detailed information was avail- 

 able concerning conditions during this early period. It is known, however, that 

 during this time excellent crops were grown on this prairie land, and that they 

 were uniformly better than those grown on the front lands. Up until the last 

 two or three years the prairie lands were so much better drained than the front 

 lands that plowing could be done on them when the water stood on the surface 

 of the latter. As is shown by figure 5, the depth of drainage is now very small 

 on these lands, hardly more than a foot. However, crops were reported as being 



