Damaged around water meter inspection cover

Not really sure if this is the right forum - maybe should be in plumbing?
Anyway, at our tennis club there is a pressed steel inspection cover over the water meter. It straddles the boundary, as far as I can tell, the gate from the pavement to our property sits approximately half way across it.
The concrete(I would have expected engineering bricks or similar) seems to be crumbling away and the cover will now tip up if you walk on it. As a volunteer committee member, I am concerned that there could be some sort of accident, and I wondered:
a) If it it our responsibility or that of the water company
b) It it is our responsibility, what sort of tradesman do I try to engage to get it fixed.

Water Authority - possibly Thames Water as you are in Surrey?

Thanks. I rang Thames Water. At first they tried to shift the responsibility to the local council, but then they agreed to come and have a look. I had a better look this afternoon. It's a real bodge job. One side of the pressed steel hatch is sitting on half of the old cast iron cover.