but in a thickly populated country the same freedom soon 

 results in destruction of all useful wildlife. Likewise, prac- 

 tices in respect to the development and use of water resources 

 which in an earlier period of sparse settlement were an ad- 

 vantage to the individual and did no harm to his society, 

 have in a later period of denser settlement proved to be 

 destructive and harmful. In a sparsely settled section of 

 the upper Mississippi Basin a few farmers may turn their 

 prairie sod cover under, and a few small lumber companies 

 remove the forest cover from small areas, with profit to 

 themselves and without disturbing the natural balance in 

 the basin; but when with denser settlement these practices 

 become wide-spread, the natural balance may become so up- 

 set as seriously to impoverish or destroy outright those phys- 

 ical characteristics on which prosperity is based. It is our 

 purpose in this section to indicate the more important prac- 

 tices in numerous areas of small headwater streams which 

 have upset Nature's balance of factors and now endanger 

 the prosperity of the United States. 



1. RUSHING THE WATERS TO THE SEAS 



BEFORE the United States was discovered and settled, Nature 

 through many thousands of years, as has been explained, 

 employed every possible device to promote absorption and 

 infiltration of the rains and melting snows. Grasses, herbs, 

 shrubs, trees, rotting logs, twigs, leaves, stones, and pebbles 

 were retarding instruments; grass, herb, shrub, and tree roots 

 kept the surface soils porous and permeable; the humus 

 blanket kept many soils readily absorbent. Low-lying flat 

 lands became swamp, marsh, or wet lands; pockets and 

 depressions in the sloping surface became ponds and lakes; 

 the underground became a great reservoir. These agencies 

 served to retard the flow of water to the seas, to extend the 

 duration, increase the evaporation, and reduce the crests of 

 floods, and in dry seasons to sustain by springs and seepage 

 the normal flow of streams. 



Speaking broadly, the first settlers in a forested region 

 selected fertile, high and dry rolling lands; those easiest to 



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