364 THE IRRIGATION AGE. 



on the lower part of the Mississippi in an effort to confine the stream 

 and to prevent overflow of the adjoining land. Another character of 

 improvement is the dredging of the rivers for the purpose of meeting 

 the period of drought in the summer when th rivers are low and 

 when bars and shallows obstruct navigation. The flow of the lower 

 Mississippi is increased by the flow of the rivers tributary to it. Some 

 of them, like the Ohio, taking their source in the humid regions, and 

 others, like the Missouri, the Arkansas, and the Platte, taking their 

 source in the arid regions from the snows of the mountains, and it is 

 contended that by storing the flood waters in the mountain regions, 

 caused by the rapid melting of the snows in the Spring, a large pro- 

 portion of the flood in the Missouri and the Mississippi rivers can be 

 prevented and a more equal and sustained flow of the rivers thus 

 promoted. 



It should be remembered that the waters stored in these reservoirs 

 are not the only waters which will be held back during the flood sea- 

 sons* The character of all the mountain streams in the arid region is 

 that they are torrential during April, May and June aad that they are 

 reduced to almost nothing in the following months. Large areas of 

 arid lands lie within reach of these streams, but the condition of the 

 flow during the hot months of July, August, and September limits the 

 area of reclamation; for whilst the waters of the early spring and 

 summer months is sufficient for the requirements of vast areas of land, 

 yet if the waters were diverted over them and crops were planted, 

 they would lack water at the period of greatest want when the crops 

 were ripening for harvest. 



The storage of water above enables a larger utilization of the flood 

 waters which are unstored, and storage insures a supply during the 

 period of greatest drought. The result would be that for every acre- 

 foot of flood water stored there would be four or five acre-feet of flood 

 water taken out over the arid lands, thus diminishing the flow of the 

 streams tributary to the Missouri and Mississippi during the torren- 

 tial period, and these great plains, now arid, would themselves be 

 made the storage reservoirs of vast quantities of flood waters which 

 would otherwise rush down to the Mississippi, so that effectual stor- 

 age will not be confined simply to the artificial reservoirs, but will be 

 extended to these large areas of land which will be reclaimed and 

 which will absorb annually a volume of water at least two feet deep 

 over the entire surface. The diversion and overflow of flood waters 

 over the arid lands above would diminish the overflow in the Lower 

 Mississippi and would diminish the cost of the levees intended for 

 protection of the adjoining lands. The water carried over the arid 

 lands above would penetrate the soil and would seep gradually back 

 to the rivers and keep the streams below fuller during the hot month 



