26 BOARD OF AGRICULTURE. [Jan., 



especially regarding the effect of forests upon stream flow, 

 upon the conservation of moisture. The last year that I was 

 in the employ of the Division of Forestry I spent considerable 

 time in the San Bernardino Mountains in Southern California. 

 At the base of these mountains land is worth from $500 to 

 $ 1,000 per acre where water can be gotten upon it. If water 

 is not brought upon this land, it is not worth a snap of the 

 finger. The lind is not valuable, it is the water that is 

 valuable. On the watershed of these mountains, in coopera- 

 tion with a private company, we have determined that the in- 

 direct value of the forest is very great. The precipitation has 

 been carefully investigated, and every stream upon the area 

 studied has been accurately gauged, the water has been meas- 

 ured that has run from the watershed, so that we have been 

 able to compare the precipitation and the run-off on areas that 

 are forest covered and areas that are denuded of their forest 

 growth. In a number of instances we have been able to show 

 that at the time of the heavy rains, when the streams rise to 

 great height on the denuded watershed, they immediately re- 

 cede and in a short time reach their normal flow. On the 

 watershed that is covered with timber the flood water rises 

 to a given height, but instead of receding as rapidly as in 

 the other case it gradually recedes, i. e., it takes a longer time 

 for the water to run off. In other words, the run-off is much 

 more gradual from the forest-covered area, showing conclu- 

 sively the greater value of the forest-covered area to hold or 

 conserve the water. 



A MEMBER. I would like to ask if it has been determined 

 whether in the actual run of water there is any difference in 

 the amount of run-off between the naked and tree-covered 

 area throughout a year? 



Professor TOUMEY. Our data on this matter is not en- 

 tirely worked up, but it appears that the annual run-off is 

 more on the wooded areas. We do not comprehend the enor- 

 mous amount of water that is taken from the denuded areas 



