CONSTRUCTION OF LEFT AFFLUX BUND AT JOSHIYARA BARRAGE

Uttarakhand Jal Vidyut Nigam Ltd. (UJVNL), Govt. of Uttarakhand, had decided to reconstruct the left afflux bund using prefilled / in-situ filled gabion / mattress. The main purpose was to provide a permanent and flexible solution which can easily withstand the rapid flow fluctuations and can counter the flooding of nearby areas in high flood conditions. For this the solution system provided was intended to: (a) Prevent the toe instability. (b) Prevent the bund from surficial erosion. (c) Prevent the scouring at toe. (d) Prevent the adjacent/nearby areas from flooding. (e) Prevent the country side slope of the bund from surficial erosion. The toe instability was prevented by providing a gabion wall over the already present RCC toe wall followed by a gabion mattress and a reno mattress as a revetment over the gabion wall for the surficial protection and a gabion mattress just below the gabion wall and in front of the RCC toe wall, for protection against scouring at toe for the river side. A similar pattern was adopted for the country side facing of the bund. The solution included a considerable increase in the height of the bund upto the required HFL with safe free board for prevention against flooding of the adjoining areas (country side).