202 



AMERICAN FORESTRY 



TORRENT OF LES GORGETTES 



The upper basin, showing a series o{ barrages and some of the boulders which 

 the stream carries down with it; also showing steep, almost bare slopes. 'The 

 patches of vegetation seen are rapidly slipping down into the stream bed 



encountered will be roughly divided 

 into three broad classes and an example 

 given under each class. The classes 

 are : 



1 . Prevention of straight cutting 

 down. This is generally on very steep 

 slopes of a more or less loose and 

 gravelly nature. 



2. Bodily slipping of large masses, 

 often man}' acres in extent, to be pre- 

 vented. 



3. Combination of straight 

 cutting down and bodily 

 slipping. 



i. Prevention of straight 

 cutting down. A typical ex- 

 ample'of this is the torrent 

 of Les Gorgettes near Gre- 

 noble. This torrent, though 

 small, is extremely steep 

 and was very destructive 

 before being taken in hand. 

 It repeatedly cut an impor- 

 tant highway and ruined 

 considerable areas of valu- 

 able agricultural land by its 

 deposits of large boulders 

 and sand. 



The work, which was 

 begun years ago, consists 

 chiefly in the building of a 

 series of stone "barrages" 

 in the tributaries on the 

 steep slope forming the 

 catchment area of the 

 stream and in the main 

 channel of the stream itself. 

 These are designed chiefly 

 to prevent further cutting 

 down because the deepen- 

 ing of its bed by the stream 

 naturally involves further 

 crumbling of the already 

 too steep slopes on either 

 side. These barrages are 

 placed at such frequent in- 

 tervals in the upper and 

 steeper parts of the stream 

 bed that, as one looks up 

 stream, they give the im- 

 pression of a channel of 

 solid stone. Along the 

 base of some slopes, walls 

 have been constructed to 

 prevent the slipping down of large 

 masses of soil ; in other parts of 

 the torrent stone wings may be seen 

 extending out into the stream to 

 turn the force of the current away 

 from precariously loose banks. As one 

 walks along the rugged path up toward 

 the catchment area at the head of the 

 stream, he will notice clearly marked 

 lines on the rocky almost perpendicular 

 slopes above him. These are made 



