Outside Stop Valve?

i am currently working at someones home and the owner wants to renew his kitchen sink but the stop tap inside their home doesnt fully turn off the water just lowers the pressure... that'll probably be a washer problem we eventually found the water main access panel (in the back garden) gas and water mains seem to run through the back gardens this panel im almost certain is for the water main to the house as it says WATER on it, it is a black plastic circle about 8 inches in diameter, levered it open and found some sort of valve, not the usual brass stop tap, seems like a modern installation, but i cant figure out how to turn it off, there is a something in brown plastic at the bottom of the hole then a plastic t shaped stem but this doesnt turn, or does the water board need to turn it off with a specialist tool..... any ideas?

i am currently working at someones home and the owner wants to renew his kitchen sink but the stop tap inside their home doesnt fully turn off the water just lowers the pressure... that'll probably be a washer problem we eventually found the water main access panel (in the back garden) gas and water mains seem to run through the back gardens this panel im almost certain is for the water main to the house as it says WATER on it, it is a black plastic circle about 8 inches in diameter, levered it open and found some sort of valve, not the usual brass stop tap, seems like a modern installation, but i cant figure out how to turn it off, there is a something in brown plastic at the bottom of the hole then a plastic t shaped stem but this doesnt turn, or does the water board need to turn it off with a specialist tool..... any ideas?

oops! posted it three times... sorry!

Mine tap is like this. In mine the plastic T piece is a separate item and it should engage in a slot across the top of the tap. the tap is tucked away at the bottom of the hole, partly hidden by the meter so it's not easy to get them engaged. It takes a half turn to go between open and closed (not a quarter turn like a gas tap.

Robert

On the occasions I have had to deal with one of these, I feel like the plastic stem will break before the valve turns. I suspect the idea is that the valve can't be harmed by over tightening. If the stem breaks though...

The *idea* is that you have to get the water board out each time you need the water turning off, at a premium of course, whereas before, everyone and his uncle had a stoptap key, even though we aren't allowed to use them - yeah right!