Its not too big, I'd guess 100m2. It has a 3m2 fish pond in the middle
and about another 12m2 is flagged for a sunny area, plus a couple of
gravel paths running through it, so there isn't a huge amount.

I don't want to flag or gravel it though, I'm thinking of digging some
new french drains to my sump, however, If there was a more hardy type
of grass, I would try that first.

cheers

Andy