Each case is different, at you're right to point out that there's a cliff.
At that location, the sand depth is approximately eight metres. Depending on the water level, it can be as deep as 10 metres.
The soil along the coast is not the same everywhere. To the east, the soil is less sandy and more like clay. To the centre and west of the village, the coast is indeed much more sandy, and hence very friable.
I know that some people obtained information about how much the work would cost, and it was extremely expensive. Talking about cost is one thing, but having to obtain all the required authorizations before beginning the work is an issue that needs attention.