THE BATTLE FOR THE WEEKS BILL 



139 



quency and the height of floods by erod- 

 ing the steep slopes and thereby con- 

 veying the water more rapidly to the 

 streams and at the same time filling 

 them with sand and making them less 

 capable to carry it away. He showed 

 that deforestation decreases the low- 

 water flow, making it lower than under 

 forested conditions, and gave nu- 

 merous concrete examples of this effect. 

 He further showed that the eroded 

 waste filled the stream channels and 

 worked its way down stream, filling the 

 reservoirs of power plants and destroy- 

 ing their value, and ultimately filled 

 the navigable streams, ruining much of 

 the improvement work of the army en- 

 gineers. Dredging, for instance, has to 

 be repeated time and again, while 

 gravel deposits are steadily filling the 

 rivers and harbors. The better policy 

 would be to prevent waste from enter- 

 ing the streams bv keeping the steep 

 mountain slopes forested. Professor 

 Glenn showed how streams so protected 

 scour themselves and are rarely sub- 

 ject to filling, while streams whose 

 watersheds are denuded gradually have 

 their channels silted up and are able 

 to carry less water, and are therefore 

 much more subject to floods and low 

 water. He also showed that much val- 

 uable land has been ruined in the South 

 by floods carrying gravel and sand over 

 the rich bottom-lands and reducing to 

 waste thousands of acres that were for- 

 merly among the most valuable agri- 

 cultural lands of the southern country. 

 Conditions are rapidly becoming worse 

 and the people support eagerly the pro- 

 posed legislation, and are demanding 

 it as the most vital thing for them now 

 before Congress. Professor Glenn, per- 

 sonally, does not think highly of the 

 proposition to regulate Southern Ap- 

 palachian streams by storage reservoirs, 

 regarding reforestaton as preferable in 

 many ways. 



Chairman Scott had interpolated sev- 

 eral questions during Professor Glenn's 

 statement, these questions relating es- 

 pecially to the farm lands on the lower 

 slopes of the mountains, which Mr. 

 Scott holds are the chief sources of ero- 



sion. Professor Glenn said that many 

 of these farm lands should never have 

 been so used, not being suited for cul- 

 tivation. He had found fields cleared 

 and cultivated on slopes of thirty-seven 

 degrees, measured by clinometer. Such 

 slopes are altogether too steep for culti- 

 vation. The problem in the Southern 

 Appalachians is both an agricultural 

 and a forestry problem, which can only 

 be solved by reforesting the steep 

 slopes and saving the gentler ones by 

 terracing, ditching, and better cultiva- 

 tion. But the proportion of suitable 

 agricultural land is not over twenty per 

 cent of the area of the mountain coun- 

 try, as against at least eighty per cent 

 which is profitably available for forest 

 growth only. The statement of Mr. 

 Moore that more of these slopes should 

 be cleared would be followed by dis- 

 aster if carried out under present meth- 

 ods of cultivation. He showed that 

 while the source of flood damage is on 

 the upper slopes, the actual damage is 

 done when the water strikes the gentler 

 slopes where the run-off is not so rapid. 

 The headwaters, so far as flood water 

 and erosion are concerned, are the locus 

 of the chief destruction. Deforestation 

 does increase the height and frequency 

 of floods ; there can be no doubt about 

 this. 



Professor Glenn was the last speaker 

 at the morning session, and the com- 

 mittee reconvened at three o'clock in 

 the afternoon, when Professor Roth, of 

 the University of Michigan, was the 

 first witness. Professor Roth stands in 

 the first rank of American foresters in 

 point of wide experience and profes- 

 sional knowledge. He showed several 

 photographs, reproductions of which 

 appear in connection with this report, 

 illustrating the effect of deforestation 

 in the Southern Appalachian and White 

 Mountains. Mr. Scott took exception 

 to one of these photographs on the 

 ground that it showed conditions in 

 the low rolling country rather than in 

 the mountains. Professor Roth ar- 

 gued that photographs were not reli- 

 able so far as slope was concerned, and 

 that the conditions illustrated there 



