The Ohio Naturalist. 
[Vol. XIII, No. 7 , 
“It is flying in the face of cold facts to contend any longer that reser¬ 
voirs to retain the flood waters can not be built, or not without danger to 
the entire valley below. The’Ohio floods of 1907, the most disastrous for 
more than two decades, were due to an excess of water estimated at 
23,000,000,000 cubic feet. To hold every drop of that excess discharge 
would have required a reservoir only a little more than half as big as the 
Pathfinder irrigation storage reservoir on the North Platte River in Wyom¬ 
ing, or one-third of the size of the reservoir in the Salt River project in 
Arizona. The Engle dam on the Rio Grande, a hundred miles north of 
El Paso, Texas, will impound about 120,000,000,000 cubic feet of water, 
equal to one-sixtiethMf the total annual discharge of the entire Mississippi 
system, or more than five times the quantity of water causing the most 
destructive Ohio flood in a score of years. These reservoirs are being built 
by the government at a cost of about .$4,000,000 for the Pathfinder dam, 
$5,300,000 for the Salt River project and $7,200,000 for the Rio Grande 
reservoir. Furthermore, it is expressly stated by the Reclamation Service 
that the Wyoming reservoir and the Engle dam will absolutley control the 
worst floods which the North Platte and the Rio Grande have ever known, 
the latter of these streams having been a notorious offender in flood dam¬ 
age. The mere fact of being able to retain the flood waters in impounding 
reservoirs can no longer be denied, nor can the claim of danger from break¬ 
ing dams be now advanced as a valid argument against this system. This 
government is most assuredly not spending millions in reclamation projects 
and encouraging thousands of people to take up irrigated lands if there is any 
remote likelihood of having homes, property and lives wiped out in floods 
from bursting reservoirs. 
Granting, then, that the reservoirs are feasible, there still remains the 
question of expense in constructing the number necessary to place one or 
more in each of the most important tributaries. Estimate the expense most 
generously, letting each one cost a third more than the Engle dam above 
El Paso, and the total figure then is less than what has already been spent 
on the Mississippi system. But there is another important factor to be 
considered—the tremendous possibilities which lie in the development of 
water power from each reservoir. The question of furtue motive power for 
industrial purposes, as the coal supply decreases, is a problem which must 
soon be met in this country, and probably will be solved by the use of water 
power either directly or through electricity. In fact, even now, water 
rights are being rapidly acquired and developed on every hand, as the 
advance guard of the change that is to come. A sample of what a storage 
reservoir will do can be seen in the case of comparatively small irrigation 
project at Minidoka, Idaho, which will develop about 30,000 horse power 
per year. Renting this power at the very low figure of $10 per horse power 
per year would pay for the entire Minidoka project, reservoir, irrigation- 
canals, gates and all, in six years. The amount of power generated by the 
Mississippi system is variously estimated high and low, with GO,000,000 
horse power per year as an intermediate figure. Much of this amount is 
not directly available, but granting on a conservative basis that a scries 
of impounding reservoirs would develop immediately 2 per cent of that 
amount, there would be 1,200,000 horse power to be turned into electricity 
and distributed to factories. A purely nominal rental would be ample 
enough to repay in two or three decades the entire original expense of the 
system, besides a good income on the investment. The reservoir system, 
however, must be intimately associated with forest conservation as a vital 
factor in regulating surface drainage and in checking the amount of soil 
erosion which supplies sediment to the river. 
The proper building of reservoirs in the headwaters, therefore, offers 
what no other plan can possibly offer: it promises effective regulation of 
river stages and water supply for all time to come, removing entirely the 
