Active measures such as anchored netting should only be used on coherent rock or soil slopes, but not over rock debris slopes. I have seen it many times, it has never worked, especially with those big rock blocks. Along the rockfaces, I assume some nets or other active measures such as rock bolting are required. As you know, rockfall barriers only go up to 10.000 kJ, but for me it looks like, there is bigger blocks in there, which must be stabilised or blasted before they fall. No barrier can stop them.