DO FOREST LANDS FOE THE PROTECTION OF WATERSHEDS. 



justify giving it much weight." In discussing the paper above referred to, the 

 author stated that, while he had never visited the sites in question, it was his 

 opinion that, as to most of them, it would not be possible to realize over one- 

 fourth to one-third of the benefits claimed, and he based his opinion on the 

 published records of the flood of 1907, which was the greatest in the history 

 of the river. George L. Dillman, member American Society of Civil Engineers, 

 in discussing the paper, flatly pronounced the whole scheme impracticable, and 

 gave his reasons in detail for this conclusion. 21 Among thenx, he cited in one case 

 the great value of the lands to be flooded by the reservoirs, which he claimed 

 were altogether more important for agriculture than for any diminution of flood- 

 ing which the storage might cause in the valley below. In another case he cited 

 the difficulty, which always suggests itself to an engineer in considering the sub- 

 ject, of timing the operations of the reservoirs so as to combine their effects to 

 the best advantage, and particularly in keeping them empty in periods of pro- 

 longed precipitation, so that their capacity may be available at the critical mo- 

 ment. Other obstacles were pointed out, and the whole discussion presents 

 ^another instance of the practical difficulties that stand in the way of any com- 

 prehensive reservoir scheme for controlling floods. 



In 1903 the great flood of the Kaw River brought up the reservoir question 

 again. Ex-Senator Burton, of Kansas, advocated the plan very urgently, 

 stating in a speech at Kansas City that he " would have tens of thousands of 

 reservoirs, beginning at the headwaters of the stream and coming right down." 

 A board of engineer officers was appointed to investigate the practicability of 

 providing against future disasters such as this flood had caused. The reservoir 

 idea had made so deep an impression upon the public mind that a specific con- 

 sideration of that feature of the problem was requested. In its report c the 

 board found adversely to the scheme, on the ground that its great cost, con- 

 servatively estimated at $11,000,000, and the annual loss from the withdrawal 

 of the necessary lands from occupancy, conservatively estimated at nearly 

 $600,000, would not be justified on the ground of flood protection alone. Owing 

 to the character of the country, this last consideration was particularly strong. 

 The only real justification of so extensive a system in a country so largely 

 devoted to agriculture would be its use in irrigation and power, and, if it be- 

 came necessary for these purposes, doubtless a portion of it would be built. 



The most elaborate study of this subject ever undertaken until very recently 

 was made by the French Government, to determine whether reservoirs could 

 be utilized to prevent the recurrence of such great disasters as the floods of 

 1856 in the valleys of the Rhone and other streams. A full resume of these 

 studies is given in the author's report, already referred to, on " Reservoir Sites in 

 the Arid Regions." The conclusion was the same that has been 'reached in every 

 similar investigation. An interesting feature of the system then considered 

 was that the reservoirs were to have sluices permanently open, so that it would 

 not be possible to close them entirely. They would operate, it was expected, to 

 hold back a definite percentage of flood discharge enough to keep the floods 

 below the dams within safe limits. They would thus act automatically, just as 

 forests are supposed to do. This was all right so far as the individual tributaries 

 were concerned, but it was found, when the possible effect upon tributary com- 

 bination in the main stream was considered, that by holding back earlier por- 

 tions of freshets and prolonging their run-off, they might actually swell the 

 combination in the lower courses of the main stream. 



Similar studies have frequently been made in all the principal countries of 

 Europe, and in none of them, so far as the author is aware, has such a project 

 on a large scale ever been undertaken or even favorably considered. 



Coming now to the Ohio River, the immense importance of that stream as a 

 factor in the floods of the Mississippi makes the regulation of its flow a matter 

 of greater moment than that of any other stream. The project of controlling 

 the run-off of its watershed by means of reservoirs was urged very forcibly 

 more than sixty years ago by Col. Charles Ellet. The subject has often been 

 considered since, both in private and official investigations. The conclusion has 

 invariably been that, great as the benefits of such a system would be if in exist- 

 ence, the cost of bringing it into existence would be out of all proportion to 

 such benefits. 



"Report Commissioner of Public Works, State of California, for 1905. 



& Proceedings American Society Civil Engineers, May, 1908, p. 464. 



c Senate Document 160, Fifty-eighth Congress, second session, pp. 14-17. 



