Drains in back yard

Iamnotarobot_2

Hello. I live in a terraced property (approx 1920s) with small back yard.

There is a soil pipe that comes out the toilet and into the ground. About a meter or two away from that is the open drain, which has pipes going into it from the gutter, the sinks and the bath.

Does anyone know if these 2 join together and then go out of the yard into the back alley main sewer through one pipe or are there likely 2 pipes going under the yard?

If joined is one more likely to feed into the other ie go across laterally and then out the yard?

I know an option is to get drain mapping but wondered if anyone here would have an idea, thanks.

FreeBear

There will probably be a manhole cover within a metre or two of the drain pipe. Possibly in the communal alleyway. Lift the cover, run the tap over the sink or bath, and watch for a flow of water. Then flush the loo and see if there is a wave of water hurtling through. That will tell you if the two are connected (they probably are).

Davesnave

You need to run water through both seperately, then observe at the inspection chamber whether the water arrives via one pipe or also seperately. This will show whether there is a join before the chamber, or not.

TELLIT01

The likelihood on a property of that age is that it is a common sewer for all waste.

Iamnotarobot_2

Thanks for your responses. I’m hoping to be able to make a bit of a soil bed and have a little herbaceous border so I’m trying to gauge where it is safe to dig and where any (small) roots won’t be a risk to the pipes.