338 MAN'S USE AND CONSERVATION OF SOILS 



But there are other sections where by another sort of work 

 millions of acres of exceptionally fertile soil may be re- 

 claimed. Rich flood plains must be protected against 

 periodic overflows that often ruin crops and sometimes 

 ruin even the soil itself. The building of systems of levees 



CYPRESS SWAMP RECLAIMED 



This is the same section that was shown in the preceding illustration, after 

 the land had been drained, cleared, and staked out for cultivation. 



would prevent this, and the establishment of flood basins 

 to catch the overflows from the rivers would furnish farmers 

 in these sections with water for irrigation during the dry 

 months that often succeed floods. The United States may 

 well profit by the examples of ancient peoples in reclaiming 

 such lowlands. Undrained areas of the Great Lakes region 

 and of the coastal plains may also be reclaimed, as Holland 



