Question

In order to prevent the possibility of the cross-flow towards the earthen embankments, it is necessary to provide _____________________

(a) counter berms

(b) sides walls of sufficient height and length

(c) spoil banks

(d) sufficient freeboard

I have been asked this question in final exam.

I'm obligated to ask this question of Failure of Earthen Dams topic in portion Earthen and Rock Fill Dams of Irrigation Engineering

Answer 1

Right answer is (b) sides walls of sufficient height and length

To elaborate: The cross-currents that may come from the spillway buckets is one of the reasons for the d/s toe erosion. To prevent the possibility of cross-flow towards the earthen embankment, sidewalls of the spillway also called diaphragm walls of sufficient height and length is provided.