LOTS learnt.

I heard, years ago, that to avoid grass drying in a drought, don't water it.
The theory - If you water, the roots stay near the surface; then you get a hose-pipe ban and all the roots die. Don't water and the roots follow the falling water table down.
At 1st glance this seemed to give the lie. There's always a HOWEVER.
This however  - Closer inspection shows that all/most of the dry "Hay" is actually moss. I've often wondered whether to kill the grass & have a Moss lawn or Vice versa.
I think this answers the question.