Relocation of public manhole for rear extension

[MattLowe]

Hi,

We are beginning the planning stage of an extension project. 1930's end of terrace house, rear extension to 4m.

Unfortunately a manhole is currently located at the rear of the property which services a drainage run picking up 2 other properties.

I don't want to build over the manhole, I want to move it. I believe this is possible.

1: Could somebody give me an outline of how one goes about this? Obtaining drawings, permission, approved contractor? etcs.

2: The same run then turns 90 degrees via a second manhole before running to the street past the side of the house. I would like to connect into the run passing the side of the house after the second manhole. (obviously this run is still serving some other houses. Is this possible? Would it mean putting in another manhole on the run down the side of the house to do so?

Just ask if any of the above is unclear. Hard to explain without drawings but I should imagine the issue has occured before?

Thanks in advance...

 

[dann09]

Approach your Utility co. that deals with your water/drainage.

 

[MattLowe]

Our local water co is Thames Water. Does anyone have experience with Thames related to moving public manholes/build over licenses and connection into a pubic sewer.

The costs on their website seem huge when you add them all up.

 

[^woody^]

They wont do the work, you need to submit an application, with plans etc detailing your proposal, and they either agree or not.

You pay their fee, and you need a drain survey either before the work or after or both

But first confirm if it is their pipework and chamber, or if it is yours

The work will also be part of your building regs application and the council inspector will also check the plans and the work

If you want a comment on the layout, post some photos and a sketch layout

 

[jeds]

Procedure depends on the category of drain. Minor drains (150mm or less) are usually straightforward. First of all download build-over or build-near application forms from Thames. That will outline the details you need to provide and the cost of the application and it should give you some guidance as to what they will accept. It would also be worth asking Thames if they have records of drain lines to the rear of your property just in case there are drains not visible. Unlikely but it does happen. You then basically need to provide a scaled drawing of the existing drains and manholes and another with your proposal. Note the size of the drain and direction and also note the depth of manholes. Show your foundation and note the proposed depth. If the drain is within 1m of your foundation the depth will need to be at least 150mm below the invert level of your drain. You don't normally need a cctv survey unless you are proposing to build over.