Public manhole in my Existing garage

Hi, all manholes except for inline inspection junctions connected to your drains only are public in the sense that they are all connected and if youre mid terraced and downhill every house probably would have on their side of the property line simply because its more cost effective for the original builders to run it in the shortest route possible with the least abounr of bends as possible. You can alter the cover to suit its location. Private land double sealed and load bearing to something around 1.5 tonns. Public land single or no seal at all. The water board is responsible for everything not on private land except in your case as its a junction of multiple properties. They couldn't go past that point, upstream, to anyones drains. Only u0 the the shared junction. Hope that helps.