62 Kansas Academy of Science. 



they do on the uplands. Anything whatever which retards to any 

 degree the flow of water after it once enters a stream becomes di- 

 rectly a flood producer. There can be no question but that when 

 the water has once overrun the flood-plains every tree, every bush, 

 every blade of grass retards its movements. To whatever extent 

 this is done they are positively objectionable. It is passing strange 

 that so much importance should be placed on this subject at a time 

 so little removed from the days when practically all of the river 

 valleys in America were forested, in view of the fact that all of our 

 history and legends coincide with geological evidence showing 

 conclusively that our rivers overflowed their banks in those days 

 as frequently and to as great an extent as they do now. ' 



LEVEES. # 



Certain prominent citizens and engineers are enthusiastic over 

 the beneficial effects that may be obtained by the building of 

 levees along river banks in order to prevent flood destruction. It 

 seem to the writer that this method of improvement in general 

 should be handled with great care. In effect, it is virtually the 

 the same as deepening the channel. All rivers while meandering 

 through their flood-plains naturally build levees. Invariably such 

 streams through the greater part of their course have built up the 

 levees from five to ten feet and even twenty feet above the flood- 

 plain farther back from the river. At Lawrence during the flood 

 of 1903 there was one little spot of dry ground on the north side of 

 the river immediately at the river bank. Between this and the 

 bluff to the north in some places the water was as much as ten feet 

 deep, while here the surface was from one to three feet above the 

 water level, showing that the natural river levee was ten or twelve 

 feet higher than the main flood-plain farther towards the bluffs. 

 But with all this natural levee building streams overflow their 

 banks and change their channels. The influence of artificial 

 levees is similar to that of the natural levee. They are first-class 

 for mild floods, but when excessive floods come they must be en- 

 tirely inadequate, and after the flood-waters break through them 

 they become positively harmful, in that they interfere seriously 

 with the free flow of the water. 



One phase of this subject apparently has been overlooked, and 

 it is the most important one, namely, the filling up of the bed of 

 the stream, which in itself is immensely objectionable. Could the 

 Kansas river be leveed five feet in height' from Junction City to 

 its mouth, it is practically certain that such a process would in- 

 crease the tendency of the stream to silt up from the bottom. 



