110 OUR USE OF THE LAND 



rather than to cure the causes of the destructive power of un- 

 controlled waters. For example, the people of Portsmouth, Ohio, 

 decided to build a great concrete dike around the city to pro- 

 tect them from the periodic floods of the Ohio river. Even if 

 they had wanted to, it would have been impossible for them 

 to attempt to cure the causes of these floods. No one could stop 

 abnormal precipitation, and the citizens of Portsmouth had no 

 more control over the deforestation and over-cultivation of 

 sloping lands in the basin of the Ohio. 



The solution of this flood problem must in part be to con' 

 trol, so far as they are controllable, the causes of excessive 

 run'off. This is a bigger task than any local community can 

 undertake. The other part of the solution is a unified engineer 

 ing program for the whole river basin, which is also beyond 

 the power of an individual community to undertake. The con 

 trol of water, therefore, is a regional, not a local problem. 



A map of the United States will show that each of the- great 

 river systems like the Colorado, the Connecticut, or the Mis 

 sissippi flows through many states. The largest of these systems, 

 the Mississippi, covers twenty-four states which contain about 

 one-third of the total population and a little less than 41 per 

 cent of the total land area of the United States. 8 The methods 

 of land-use of the people at the headwaters of the Mississippi 

 in Minnesota, or the Dakotas, or Pennsylvania are very impor 

 tant to the citizens of St. Louis and Vicksburg and New 

 Orleans. Scores of millions of acres of denuded forests, of 

 barren fields, of eroding hillsides in the vast basin of the Mis 

 sissippi pour their quotas of racing rain water into the rivulets, 

 brooks, creeks, and rivers that go to swell the mighty Missis 

 sippi floods. 



In the West the problem of flood control is vastly different 



8 Report of the Mississippi Valley Committee of the Public Wor\s Adminis* 

 tration, October 1, 1934, United States Government Printing Office, Washington, 

 1934, p. 14. 



