So having fired off rockets complaining of lack of progress on the leak restitution in our front garden I thought that I might as well have a go at them for this one that's remained unrepaired for about six weeks.
Amazingly we had a SE Water chappie round that morning who tried to trace where the pipe was where the leak was but there was nothing on his plan! Using his CAT tool there certainly WAS something there so he got a digging crew out this morning with quite dramatic results.
There appears to be a 3" branch main off the 10" pipe that I knew about. Goodness knows what this 3" once fed but other than the leak there was no flow so presumably an abandoned branch main.
Once the digger exposed the pipe we had quite a dramatic fountain - loads of water underground as this has been flowing at least 6 weeks!
It has now been bandaged with a clamp on Band Aid and we are awaiting back filling with something solid - I refused to let them back fill with the wet clay they had dug out as vehicles park on this spot.