ii6 THE IMPROVEMENT OF RIVERS. 



"The flood conditions, therefore, prevailing from Xevers for a long distance down 

 are those of extreme height but short duration. Were it possible to cut off the upj*T 

 part of this curve and retain the water which it represents, thus reducing the flood 

 curve to the normal form of the other principal tributaries, the floods would be brought 

 within limits which would keep them between the dikes proposed to be constructed 

 along the river. 



"An examination of the valleys of the upper Loire and the Allier disclosed the 

 following possibilities as to the storage of water: 



"In the valley of the upper Loire twenty-two reservoirs would store about 

 8,250,000,000 cubic feet of water, and would reduce to 111,653 cubic feet per second 

 the flood-flow, which, without these reservoirs, would be 153,555 cubic feet per second 

 at Bee d'Allier. In the valley of the Allier sixty-three reservoirs, storing about 

 10,000,000,000 cubic feet, would reduce to 104,664 cubic feet per second the flood-flow 

 which, without the reservoirs, would be 167,675 cubic feet per second. The total 

 reduction would therefore be about 95,000 cubic feet per second from a total flood-flow 

 of 320,000 cubic feet per second, or a reduction of about 30 per cent. This would 

 deprive floods of their destructive character as far down as to the mouth of the Cher, 

 a distance of about 180 miles below the junction of the two streams. 



" It is thus seen that the peculiarly favorable conditions existing on the upper 

 Loire make possible an important reduction of flood-height for a certain length of the 

 river below Nevers. In the upper valleys, near the reservoirs, their effect would, of 

 course, be far greater, and would effectually remove the possibility of flood. 



"These proposed works, however, were of great magnitude, estimated to cost over 

 $13,000,000, and they have never been carried out. 



"A very interesting and exhaustive investigation, similar to those just described, 

 has been conducted by German authorities in the valley of the river Alb. The study 

 goes into too much detail to be given here, but its general conclusions are so in line with 

 those of the French engineers that they cannot fail to be of interest. The report says : 



" ' It cannot be denied that for the head waters of rivers, and also for the territory 

 of small streams, the question might be solved. The Government of Wiirtemberg 

 investigated the matter and found that high, floods could be prevented by means of 

 reservoirs, but that the benefit would not be commensurate with the cost. . . . This 

 investigation [the prevention of floods on the Alb] has proved that the construction 

 of reservoirs for the purpose of keeping back the high water of the Alb, although possi- 

 ble, and with no doubt of their effectiveness, is still unjustifiable on account of the 

 enormous cost.' 



"And again: 



" ' There seems to be no doubt that the construction of a system of reservoirs on a 

 large scale in the valley of the Alb is inexpedient, on account of the great cost.' 



"Particular emphasis is placed upon these studies, because they disclose the true 

 obstacle to the use of reservoirs for the sole purpose of flood prevention. It is the cost, 



