Mr. Harts, 
360 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
might provide against a flood occurring under definite conditions, 
would be totally inadequate to cope with all the various combinations 
of distribution of rainfall and floods of tributaries, by which floods 
are produced in the main river.” 
In a “Discussion on the Conservancy of Rivers,”* Mr. L. F Vernon- 
Harcourt is reported as saying that flood storage reservoirs had been 
proposed for torrential rivers, and might possibly be adopted with 
advantage where deep valleys, with narrow gorges, would admit of a 
large volume of water being retained by a short high dam. 
“This system had, indeed, been partially adopted on the Loire; 
but the extension of this system on that river, and its adoption on 
the Yonne, had been rejected on economical grounds. The valleys 
of gently-flowing rivers were not suited for storage reservoirs. The 
lands bordering on these rivers were too valuable to be devoted to 
such a purpose; and the long duration of winter floods would render 
such reservoirs of little avail. It must suffice, in most cases, to provide 
against summer inundations; and high winter floods must be allowed 
to flow over the land, except where towns were liable to be flooded.” 
Further on (p. 291) Mr. R. Rawlinson remarked that rivers in a 
eivilized country had two purposes to serve, which were in some degree 
antagonistic. 
“Those who used them for navigation wished to put them in an 
effective state to accomplish that purpose; those who wished to prevent 
land flooding would act in a different way; they would not care much 
about the navigation if floods could be kept from their lands.* But 
there, again, the question was complicated. There were riparian 
owners who would be glad to have floods kept off their land if they 
had not much to pay for it, while others would say that if the floods 
were kept off their lands they would be seriously injured. The proposi- 
tion had been to prevent floods by making reservoirs, and it had been 
stated that in some continental countries that system had been tried. 
He could only say that any engineer who made himself acquainted- 
with meteorology, and with the volume of water that came down in 
excessive floods, would soon abandon the idea of forming impounding 
reservoirs to prevent flooding.” 
Referring to the same subject, M. de Lagréné stated (p. 309) that 
the authors [of the two papers under discussion] were right to reject 
large impounding reservoirs, as, in order to be of use, they would have 
to be placed low down in the valleys, where the land was generally most 
valuable, and their construction would be costly. 
“Also, their functions would be exercised at times irregular and far 
apart, and they would induce serious opposition from the neighboring 
inhabitants. 
“Longitudinal banks, notwithstanding their occasional failure, 
offered the best preservation against floods, but certain considerations 
*Minutes of Proceedings, Inst. C. E., Vol. LXVII, p. 287. 
