for specific small drainage areas. We may profitably calcu- 

 late in terms of small headwater drainage areas. While the 

 governing objectives are the same for all such areas, each is 

 a problem by itself because it has its unique combination of 

 factors. There may be an inspiring list of detailed things to 

 be done common to all small drainage areas this section will 

 present such a list but what particular combination of these 

 things should be done in a particular area can be known only 

 after a competent study of that area. 



The program of any drainage area must be comprehensive; 

 must take into consideration the entire area, and must 

 include all the things to be done, each in its proper relations 

 to the others, as required by the problem of the area. Indi- 

 vidual programs should, where possible, be part of such a 

 larger program. There are two principal reasons for this. 

 The skill of soil and water specialists can be available to the 

 individual if his is part of a larger program specialized skill 

 brings much more effective and economical results than the 

 most intelligent amateur efforts and the program of one 

 individual or neighborhood can be interlocked with those of 

 others, with greater individual as well as total benefit. 

 When the main objective and the means and modes of their 

 achievements have been determined for an area by competent 

 specialists, each individual or community can then go ahead 

 understandingly. 



A comprehensive plan for even a small drainage area 

 would involve numerous factors to which erosion specialists 

 and other professional groups are accustomed to give atten- 

 tion. Among them are the amount and distribution of the 

 precipitation of the area; the measured flow through its 

 streams; the depth of the water table; the topography; the 

 varieties of soils and to what crops each is best adapted; the 

 areas of tilled soils and the proportions devoted to various 

 crops; the distribution of forests, pastures, and other vegeta- 

 tive cover; the extent and nature of grazing by animals; the 

 methods of cultivation; the extent of erosion and its causes. 

 On the basis of complete information of this kind there can 

 be laid out a plan of land use and agricultural practices for 



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