Forest Influences 311 



The detritus washed from the lands above is deposited 

 on the fertile lands in the valleys below. Thousands of 

 families were driven from their homes in the most fertile 

 valleys of France along the foothills of the Alps because 

 two and three feet of sterile debris from the mountains 

 were spread over their fields. In our own country the 

 floods in the Missouri and Mississippi rivers have many 

 times buried the overflowed lands along their banks with 

 many feet of sand that absolutely destroys the value 

 of the lands for several years to come. This is taking 

 place along all our foothill streams and rivers. 



When this sand and debris is not deposited on the over- 

 flow lands, it is deposited in the stream bed or along the 

 coast near the mouth of the river. Hundreds of miles of 

 rivers in the United States have been lost to navigation 

 in this way, and the government has spent millions and 

 millions of dollars in keeping others open. The govern- 

 ment experts estimate that one billion cubic feet of debris 

 are carried to the sea by the streams annually. It is the 

 heaviest tax that the farmer has to pay and most of it 

 comes from areas from which the forests should never 

 have been cut; 



This sediment carried by the streams does the greatest 

 amount of damage in the irrigated districts. Here vast 

 reservoirs are constructed at enormous expense, and to 

 make the work economical these structures must last a 

 long time. If the forests are cut away from the drainage 

 basins of the streams that feed these reservoirs and erosion 

 sets in, these expensive reservoirs are filled in a few 

 years and their value destroyed. Not only is the reservoir 

 destroyed, but the natural reservoir site — probably the 



