2 BULLETIN 304, U. S. DEPARTMENT OF AGRICULTURE. 



hence can not generally be used for growing ordinary crops. In this 

 natural condition they are, therefore, good for nothing but pasture, 

 and have accordingly but little agricultural value. 



Similarly, extensive marshy areas along our coasts may be for a 

 part of the time above water level, but are subject to overflow at 

 high tide, especially during spring tides and when the river channels 

 which form their natural drainage outlets are in flood. All such 

 low lands are, in general, formed by alluvial deposit and possess a 

 high degree of fertility when relieved of their excess of water and 

 changed from their original saturated condition to a degree of mois- 

 ture content suitable for ordinary dry-land crops. 



As a physical proposition it is possible to reclaim all such areas 

 for agriculture by first constructing levees to keep them from being 

 overflowed, and then, where necessary, by installing pumping plants 

 to pump out from the interior of the district the excess rainfall and 

 such water as may seep through or under the levees in injurious 

 amounts. But as such work is expensive both for the first con- 

 struction and for its subsequent maintenance and operation, the 

 really difficult and fundamental question for the landowner is 

 whether the value of the land after its reclamation will be sufficient 

 to justify the expenditures necessary to carry out the work. 



So long as there exists in a locality any unoccupied or unutilized 

 higher land suitable for agriculture there is little demand for the 

 use of lands lying so low as to require drainage by pumps. But the 

 present high price of agricultural land justifies a heavy expenditure 

 for the conversion to a productive state of areas formerly considered 

 almost valueless, especially in those regions where agricultural land 

 values are, particularly high, either on account of unusually favorable 

 natural conditions or the proximity of large centers of population. 



EFFECTIVENESS OF DRAINAGE RECLAMATION. 



Some areas are so favorably situated that, when once protected 

 by levees from inundation, satisfactory interior drainage without the 

 use of pumps may be secured by a natural or gravity flow of their 

 drainage waters, either through sluice gates or through ditches or 

 natural streams other than those producing the overflow. Exam- 

 ples of such lands are many tidal marshes and the large areas in 

 Arkansas, Mississippi, and northern Louisiana, where the land, pro- 

 tected from the Mississippi River by great levees, has good gravity 

 drainage outlets through other streams. 



But much overflowed land is not so fortunately located. Fre- 

 quently, in addition to a protective levee system, a pumping plant 

 is required for lifting the interior drainage water out over the levee. 

 In fact, numerous cases may be found in which, when the levee sys- 

 tem was first constructed, reliance was placed solely upon gravity 



