FOREST LANDS FOE THE PROTECTION OF WATERSHEDS. 113 



diminution of the floods in the river Seine with the settlement of the country 

 being particularly noticeable. This practical example of what the real technical 

 thought of river engineers on this subject was has been followed ever since. 

 So far as I am aware, no project of river improvement, either for flood pro- 

 tection or low water in their navigable rivers, has embraced reforestation as an 

 essential part, or even any part at all. 



Doctor Swain quotes in extenso from the papers read before the Milan con- 

 gress, but a careful reading of these papers will show that the arguments in 

 favor of forests are based, in great part, upon the question of erosion and the 

 torrential flow of mountain streams. They do not touch the question of control 

 of our great rivers. Doctor Swain's reference to M. Lauda's report upon this 

 subject is certainly not indicative of that author's views, as your committee 

 can readily see from reading the inclosed translation of his report upon*the 

 great flood of the Danube in 1899. M. Lauda makes it very clear that forests 

 on that watershed had no appreciable influence in diminishing the flood ; in fact, 

 the largest run-off came from those very portions which were most heavily 

 wooded. 



Summing up this particular matter, it is my opinion that the views of river 

 engineers may be correctly expressed as follows : That they are heartily in 

 favor of the creation of forests for the preservation of our timber supply and, 

 possibly, also in the prevention of erosion in particular stiuations, but they 

 have no faith whatever in the efficacy of forests to simplify the problems of 

 river control. 



I now take up the point of which considerable is made by the forestry advo- 

 cates, and that is that it is not the extreme floods and low waters that are of 

 so much importance as the frequency of moderate floods. Doctor Swain calls 

 these extreme conditions " freaks." I am quite unable to appreciate the force 

 of this argument in even the smallest degree and I will try to make my reasons 

 therefor clear to you. It must necessarily be the extreme conditions which engi- 

 neers have to consider in the control of our rivers. Take the city of Pittsburg, 

 for example. That city could not be satisfied with any measure of flood control 

 which does not take into account the great floods. The forestry advocates 

 might say to that city, if you will give us an appropriation to reforest the 

 Monongahela watershed, we can assure you that the average moderate floods 

 of that river will be diminished in height and in frequency by 10 or 15 per cent 

 of what they are at the present time, and you can then get along by constructing 

 protection works that will meet this new condition, letting the " freaks " when 

 they come alojig, take care of themselves. Now, any such proposition as this is 

 manifestly absurd, and the city would at once reply that the great damage 

 which has been done in its past history, the great inconvenience suffered, have 

 come from these particular extreme floods, which are denominated " freaks." 

 The city would say that its people would not be satisfied with any scheme of 

 protection that did not provide for these conditions. Inquiring of the forestry 

 advocates as to whether they could have any assurance that these " freaks " 

 could be eliminated by reforestation, the reply must inevitably be that they 

 could not. The city would then probably say, " It seems to us that it would be 

 better to take this extra money for reforestation and add it to our protection 

 works and make these strong enough and high enough to keep the ' freaks ' out. 

 If we can be assured of local protection against the extreme floods, we shall 

 not worry very much about those that are smaller; they may cause some 

 inconvenience, but we will worry along with them very well." 



In like manner exactly the same reply must be given to any attempt to apply 

 this agreement to the levees of the Mississippi River and also to low-water 

 navigation of our streams. The reply of the boatmen must inevitably be that 

 any scheme of river control must include the "freak" years; that they do not 

 want their boats laid up every now and then, simply because an exceptional 

 year comes along which pulls the water down lower than the " mean " of a 

 certain number of years. They say that if provision is made for these extreme 

 low years all the others will take care of themselves. 



I think that any practical man must take this view of the case, that in our 

 problems of river control it is the extremes that must govern; and it is now 

 admitted, particularly since my paper appeared, that forestry has no power to 

 mitigate these extremes in the slightet degree; that they were just as great 

 before the forests were cut off as they are to-day, and there is some evidence 

 that they were greater. 



But the very argument itself that deforestation has made moderate floods 

 more frequent than they used to be stands without proof. Mr. Leighton's re- 



72538 AGE 09 8 



