154 
IOWA ACADEMY OF SCIENCE 
to the flooding limit, this final disastrous flood, it is plain to be seen, 
could have been greatly reduced, if not entirely prevented. Then, again, 
had we been able to do this very thing, permitting the rapid escape of 
waters to the river, without any control, we might have produced floods 
of a no less serions nature, as will be observed from our former state- 
ment of how the final general rainfall brought flood. This sort of pro- 
vision for rapid escape of waters, without any control, is what is being 
sought by the engineer in the constrncton of miles of open ditches in 
one drainage district, and hundreds of these drainage systems as exten- 
sions of one river system. If yon are still with ns in the balloon, at that 
time, observing the whole face of the Des Moines River water-shed, yon 
would see that every lake and pond and depression was carrying its full 
capacity of waters ; that the grounds themselves, had you dug into these 
soils in this area, you would have found carrying their full load of ab- 
sorbed water. This suggests to us the necessity for the better control 
of these waters, than the mere construction of open ditches, to allow the 
escape of superfluous rainfall — some means by which the waters can be 
caught and held back and slowly fed to the river channels, enabling them 
to work continuously, with an even, regular flow of waters. Let us still 
consider that we are observing this area from a balloon. An engineer, 
at your side and mine, looking into the flooded channel of the Des Moines 
River, suggests, ^A¥e must straighten and deepen the channel of that 
river, enabling it to carry off these flood waters seven times faster than 
it now does. Then this flood would be prevented, these lands would be 
reclaimed and this loss would be stopped.” This is what is being tried 
in Harrison and Monona counties, in that big ditch. At our side in the 
car of the balloon speaks up the forester friend, saying : 
^^But you must reforest large sections of the water-shed in the head 
waters of these rivers. Forest retards the run-off until it soaks into the 
soil, is given off in springs, feeding continuously and steadily into 
small streams, these, in turn, furnishing even feed for the main river 
channels, of clear, non-sediment-bearing water, and your troubles will be 
over. ’ ’ 
The suggestions of our friend the forester are excellent, as viewed 
from directly above the lands, but when you stand on the ground, ob- 
• serving the value of each acre, its importance as a part of the food-bear- 
ing acreage of America, observing also that there is but little necessity, 
at any place, for trees to retard erosion of soils, the rare exception being 
the hill-sides and the gullies which are extended slightly out from the 
T)es Moines main river channel, and in but very few places ; the additional 
fact, growing out of this, that the slope of lands is insufficient to provide 
