499 BASINS OF RECEPTION. 
erection of barriers or dams across their channels, at points 
convenient for forming reservoirs large enough to retain the 
superfluous waters of great rains and thaws.* Besides the 
utility of such basins in preventing floods, the construction of 
them is recommended by very strong considerations, such as the 
furnishing of a constant supply of water for agricultural and 
mechanical purposes, and, also, their value as ponds for 
breeding and rearing fish, and, perhaps, for cultivating aquatic 
vegetables. + 3 
The objections to the general adoption of the system of 
reservoirs are these: the expense of their construction and 
maintenance; the reduction of cultivable area by the amount 
of surface they must cover; the interruption they would 
occasion to free communication; the probability that they 
would soon be filled up with sediment, and the obvious fact 
that when full of earth, or even water, they would no longer 
serve their principal purpose; the great danger to which they 
would expose the country below them in case of the bursting 
of their barriers; { the evil consequences they would occasion 
by prolonging the flow of inundations in proportion as they 
diminished their height; the injurious effects it is supposed 
they would produce upon the salubrity of the neighboring 
districts ; and, lastly, the alleged impossibility of constructing 
artificial basins sufficient in capacity to prevent, or in any con- 
* On the construction of temporary and more permanent barriers to the 
currents of torrents and rivulets, see MARCHAND, Les Torrents des Alpes, in 
Revue des Haux et Foréts for October and November, 1871. 
+In reference to the utilization of artificial as well as natural reservoirs, 
see ACKERHOF, Die Nutruny der Teiche und Gewisser, Quadlinburg, 1869. 
{ For accounts of damage from the bursting of reservoirs, see VALLEE, 
Mémoire sur les Reservoirs @ Alimentation des Canauz, Annales des Ponts et 
Chaussées, 18338, ler sémestre, p. 261. 
The dam of the reservoir of Puentes in Spain, which was one hundred 
and sixty feet high, after having discharged its functions for eleven years, 
burst, in 1802, in consequence of a defect in its foundations, and the eruption 
of the water destroyed or seriously injured eight hundred houses, and pro- 
duced damage to the amount of more than a million dollars.—AYMARD, 
Irrigations du Midi de? Europe, pp. 257-259. 
