Can I ask my neighbours to reroute their rainwater drain that runs through my garden?

Section62

MikeJXE said:

If you have not seen a drainage plan how can you be sure where it runs ?

OP has had a drainage survey done.

Where the neighbour's pipe goes to is unclear.  This needs to be worked out to know whether the pipe is a public sewer (/lateral drain) or not.

susi_oh_susi

Thames Water said that it is a private matter between me and the neighbour and it has nothing to do with them. I was thinking of asking the council if they have plans of the drain runs, but I have to pay a fee for a search although it is not certain that they hold any plans The council said that if they do find plans I will have to pay more money to see them.

Section62

susi_oh_susi said:

Thames Water said that it is a private matter between me and the neighbour and it has nothing to do with them.

Thames will say that until there is evidence the pipe is a public sewer.  When that happens they will flip their position and tell you that neither you nor the neighbour can do any work on it without consent and/or a build-over agreement.

That you are connected to the public sewer, and your neighbour's pipe crosses into your land before (presumably) joining the public sewer ought to be enough that Thames Water take responsibility to investigate - the alternative that the neighbour's drainage goes to a soakaway on your land is a possibility, but less likely that the pipe goes to the public sewer.

Why couldn't the CCTV survey continue down the neighbour's pipe towards the sewer? Was there a blockage or something?

susi_oh_susi said:

I was thinking of asking the council if they have plans of the drain runs, but I have to pay a fee for a search although it is not certain that they hold any plans The council said that if they do find plans I will have to pay more money to see them.

How old is your property?  Was the neighbour's built at the same time?

Access arrangements to building control plans is generally really poor these days.  And in some cases you need to obtain the consent of the original architect to be able to get a copy of the plan.  It may be cheaper/easier to get someone to overcome whatever issue that stopped the survey being completed, rather than trying to get a copy of a plan which may not exist and/or not show the as-built drainage.

casper_gutman

It seems very unlikely that a previous owner of the OP's house would have allowed a neighbour to build a soakaway in their garden when their own surface water goes to a perfectly good public sewer in the street.

The only scenario I can immediately think of where this could have happened would be if the soakaway predates the OP's house and was built when the OP's garden was part of the neighbouring property, before the land their house sits on was split off and sold.

susi_oh_susi

There are 4 Victorian terraced houses all build at the same time and we are the middle ones. We are not sure why the drain survey does not show where it leads to. We've seen the neighbour's report and it states that it becomes a shared run after it crosses into our boundary and therefore is Thames Water's responsibility.

Section62

susi_oh_susi said:

There are 4 Victorian terraced houses all build at the same time and we are the middle ones. We are not sure why the drain survey does not show where it leads to. We've seen the neighbour's report and it states that it becomes a shared run after it crosses into our boundary and therefore is Thames Water's responsibility.

Did they use those exact words - if so, why do they think it is 'shared' if your drainage doesn't go into it?  If your drainage is separate then the pipe would be Thames Water's responsibility because it is a lateral drain, not because it is shared.

Being Victorian, Thames should be alert to the possibility the drains are what is known as a Section 24 sewer - therefore been willing to investigate the issue themselves rather than passing the buck to you.

I think you may be justified to use the survey report saying it is the responsibility of Thames to make a complaint to them that they have said otherwise without doing their own investigations.  A complaint should lead to them investigating properly, rather than someone in a call centre fobbing you off.

susi_oh_susi

The drain company that carried out the neighbour's drain survey stated in their report: Shared Run: NO and under Comments: Run becomes shared at 0.5m after crossing the boundary. The drain survey that we had carried out on our drains showed no connecting drains. And our rainwater drain runs straight out into the main drain in the road and our manhole only shows our foul run.

susi_oh_susi

We don't quite understand why our rainwater drain runs straight out into the sewer and you would have thought that our neighbour's drain would run parallel as the rain water gullies are right next to each other.

GDB2222

Are you having a problem with subsidence ?

MikeJXE

susi_oh_susi said:

We don't quite understand why our rainwater drain runs straight out into the sewer and you would have thought that our neighbour's drain would run parallel as the rain water gullies are right next to each other.

Rain water gullies sounds like a combined sewer to me, have you done a drain tracing dye on both rainwater systems ?