72 Prockedings o^ thk 



should assist greatly in removing- difficulties of this 

 nature. 



Mr. Marsten Manston made certain stream measure- 

 ments on the Yuba River, California, for the Geological 

 Survey. In an article, entitled "Features and Water 

 Rights of Yuba River, California," Bulletin No. lOO, 

 United States Department of Agriculture, in discussing 

 the stream flow from certain portions of this basin, he 

 makes the following interesting comparison between 

 a forested and denuded basin. Both of these catch- 

 ment areas are situated on the western slope of the 

 Sierra Nevada, adjoin each other, and have exposures 

 of marked similarity. 



''On the south fork of the north fork we have a 

 watershed area of 139 square miles, which was gaged 

 on September 19, 1900, after three successive seasons 

 of deficient rainfall, and gave a minimum run-off of 

 113 cubic feet per second or 0.8 cubic foot per second 

 per square mile. This area is well covered with timber 

 and brush, and in one hundred and twenty days gives 

 a minimum run-off of i,z^ 1,1 52,000 cubic feet. The 

 drainage basin of the north fork is more heavily 

 timbered than the basin of the other forks, and conse- 

 quently has a deeper soil, and although only one-tenth 

 the total drainage area, it furnishes 75 per cent of the 

 low-water flow of the entire drainage basin above 

 Parks Bar. 



"On the south fork, above Lake Spaulding, there is 

 a watershed of 120 square miles, which has heretofore 

 been described as comparatively bare of timber, and 

 the timbered areas which once existed have been cut 

 off. The run-off of this area is practically nothing 

 for one hundred and twenty days each year, due to 

 this absence of forests and brush. If this area were 

 afforested and gave a minimum run-off of 0.8 cubic 



