Developers don't give a fuck. They built a small estate near me on the slope of a small hill, that is thick clay about 1 foot down. (Where there used to be a clay works).
There protection, they dug a load of holes in the clay. What happened, they all flooded and overflowed mucky clay water, it's run everywhere even down to the main road.
I worry the whole lots gonna suddenly slide down the hill one day haha.