420 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
Mr. Leighton. adjusted to hold the entire mean run-off, has been overtaxed, dry 
seasons would intervene, during which the reservoirs would be needed to 
supplement the low-water discharge. But, supposing this were not 
always true; admitting for purposes of argument that there would be 
times, at rare intervals, when the reservoirs were overtaxed and a 
flood would descend on the valley below, does this make the proposition 
valueless? Is there not virtue in a project that will render floods ex- 
tremely infrequent, instead of extremely common, as they are at 
present? The speaker believes that the proposed reservoir .system 
could be operated always to control floods, but he contends that, even 
if now and then a portion of a flood should get past the reservoir 
system, there would still be ample benefits accruing from that system. 
Colonel Chittenden surely will not contend that because benefits are 
not 100% it is not well to secure 90 or even 80 per cent. 
The same observation holds good for the low-water conditions. A 
storage of 100% begets confidence, and properly so; but, supposing there 
would be times when the reservoirs would be “too empty” to afford full 
supplementary flow during dry seasons, would there not still be a large 
measure of benefit for water-power purposes in a partial flow, and 
would not the condition be infinitely better than that which prevails 
to-day? Let us not be petulant. If we cannot secure a whole loaf, 
let us take three-quarters or even a half, remembering that the half 
is sometimes the sole arbiter between a dead man and a live one. 
The observation that the proposed reservoir system would not, in 
the case of the flood of 1907, have helped the situation at Cincinnati 
indicates that Colonel Chittenden has fallen into the same error that 
Major Newcomer did in assuming that it was expected that the Upper 
Ohio reservoirs were to control the situation all the way from Pitts- 
burg to Cairo. If, as stated, the maximum at Cincinnati and that at 
Pittsburg occurred about the same time, it ought to be plain that the 
flood-waters which furnished the maximum at Cincinnati did not come 
from the Pittsburg district. They came from lower tributaries, and 
the proposed system of reservoirs covers these lower tributaries.* 
The author’s river hydraulics become somewhat involved when he 
undertakes to discuss flood-wave propagation. The effect of flood-wave 
prolongation that he describes would be favorable, rather than detri- 
mental, to reservoir control. In fact, the whole paragraph presents a 
symmetrical contradiction, and the speaker will endeavor to analyze 
the conditions. 
There is established, in the Ohio River, a certain flood regimen 
in which are comprehended all the flood phenomena, including progress 
of crest, prolongation of wave, etc. When, in his original report, the 
speaker discussed the effect of reservoirs, he did not start at Pittsburg 
with a certain crest and volume, and compute what the effect would 
yoo, Lara’ eoneene of this point may be found in Engineering News, November 5th, 
