174 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



the entire scheme for the Ohio watershed will be completed during 

 the coming year. 



There is still need of some further extension in the line of direct 

 flood work, notably in Oklahoma, Indiana, and Illinois, and along 

 some of the upper tributaries of the Mississippi River, but little can 

 be accomplished during the next fiscal year, as projects already under 

 way will consume any funds that might otherwise have been available. 

 ^ Over a year ago it was recognized that the approaching comple- 

 tion of the irrigation projects in the Far West by the Reclamation 

 Service imposed new responsibilities upon the Weather Bureau, 

 namely, the obtaining of accurate snow measurements at the sources 

 of water supply, the determination of the water equivalent of the 

 accumulated snows of winter, and the gauging of the streams for the 

 benefit of the water users; and it has become a part of the duty of 

 the River and Flood Division to determine as nearly as possible the 

 amount of water that will be available each season for irrigating 

 purposes. A sufficient suppl}^ of funds for the entire project has not 

 yet been provided, but it has been proposed to conduct during the 

 coming year at least one series of observations, probably in northern 

 Utah, along certain definite lines. From the experience thus ob- 

 tained it will be possible to pass intelligently upon the feasibility of 

 the general plan and to prepare reasonable estimates of the annual 

 cost of the entire project for submission to Congress. For a time, at 

 least, this work must be limited to the smaller watersheds. 



EFFECTS OF FOREST ON CLIMATE AND STREAM FLOW. 



There remains one other problem that will engage the special at- 

 tention of the River and Flood Division. The widespread discussion 

 during the last two or three years as to the effect of forest cover on 

 climate, stream flow, etc., has developed such differences of opinion 

 in the minds of those chiefly interested as to necessitate a searching 

 inquiry into the subject. After an elaborate research into all avail- 

 able data, the Weather Bureau, in company with many eminent engi- 

 neers, concludes that on the principal rivers the floods are not higher 

 or longer continued or the low water lower than forty years ago, 

 while other persons hold to the opposite. But there are other ques- 

 tions with regard to which all appear to agree that available data 

 are at best insufficient; consequently, to quote from my report of 

 February, 1910, to the Committee on Agriculture of the House of 

 Representatives on " The influence of forests on climate and on 

 floods:" 



We mnst therefore reason empirically from the best information at hand, and 

 this iusnfliciency of data renders less positive the conclusions of all investigators, 

 no matter which side of the question they may be on. 



Therefore the Weather Bureau and the Forest Service, with the 

 permission of the Secretary of Agriculture, have agreed to cooperate 

 in an exhaustive study of the entire question of forest effects upon 

 climate and stream flow, and have selected as a suitable field for op- 

 eration the Rio Grande National Forest, in southwestern Colorado. 

 Representatives of the Weather Bureau and the Forest Service are 

 already in the field making preliminary arrangements, and active work 

 will begin as soon as the Weather Bureau can supply and install the 

 necessary equipment and the Forest Service can provide the necessary 



