[Closed] 700mm surface water sewer under house - liability ?

You can build over a sewer, you need a build over agreement from SWW. They are quite hard to get but not impossible.

Nothing to do with building control IIRC

You need a "building over agreement" with SWW. 700mm is fairly big how modern is it, what is its construction, what's the catchment?

Also look to the planning comments on the LA planning portal from SWW. They should have flagged the existence of the sewer then. That may help in the discussion.

Yeah 700mm dia (non standard size for adoption btw, should be 675 or 750) is pretty big for a build over agreement although not imossible but you would need to bridge over the pipe and show structural calculations, which won't be cheap.

With it being surface water, ownership could be a bit murky! it might not necessarly be owned by the local water authority, could be private or part of a highway or land drain system. I would try to get hold of the sewer records to see if it's shown on them. If it is, it is owned by the water authority.

Also try to establish what it is draining. If it's residential it should be owned by WA and therfore should be their responsibilty and will have an easement on it, (easement size is based on pipe size and depth), if it's private.....can of worms.....

When you say inherited, are you owners outright, or does the property still vest with the deceased's estate? I only ask as if the deceased bought it from the developer, there may be a slim chance you could bring a claim against them in the event the property does suffer a diminution in value; but if ownership has transferred to you both, I suspect that ship may have sailed.

SWW have already stated no you cant build over it is its a major surface water sewer

They have said they own the sewer and will maintain it

But so far they have not said what would happen if sewer collapsed along with part of house..

looks like at time of build an actual stream got diverted and whoever was inspecting the build ticked off the requirement to actually move the surface water sewer before the house could be built.. - thats not possible now as house are built where the pipe would have been diverted to

Looks like i'll have to wait for answer from sww legal - and then re-market giving all the information about pipe to any buyers and see what affect it has on price..

I work for a water company - it’s sort of good news that SWW say they are responsible as if anything did happen to the pipe I would guess they probably would be responsible for any damage caused. It would probably be decided by how it collapsed, was it due to poor maintanance or design? Their fault. If something outside their control eg some sort of network abuse or building work that might be a different story.
Whenever we do work on someone’s property we do have a legal right to access the property to do the work needed (which for a 700mm sewer would be a lot of machinery and equipment - that’s a huge sewer) and we always have to ensure whatever is above the sewer is put back afterwards.
This probably won’t help you but if it’s built right there’s almost no chance you’ll get a collapse from a sewer that big, they are big engineered things a lot of the time have been in place hundreds of years sometimes. The more pressing issue would be flooding if it was blocked or not big enough for extreme flows.

Talk to your solicitor about a sewer indemnity policy. They're usually pretty cheap (a few hunderd pounds) and will give the buyer some peace of mind.

SWW might be aware of the sewer, but who does own it?
If it is surface water / storm drain it might not have transfered ownership in 2010/2011 Private Sewer Transfer/ Adoption of Private Sewers Regulations 2011.

This partly explains what happened in 2010/2011, after the house was built.
https://www.severntrentsearches.com/private-sewer-transfer-introduction/

The OP has said SWW have already confirmed they own it and maintain it. He just wants to know if they are liable for any damage from collapse.

Does the sewer actually go under the house?

United utilities searches show a surface water drain under our house. But someone lazy just drew a straight line on the map from source to outlet. There is a note on the bottom of the map saying it might not be accurate.

The drain actually runs 2/3rds down the garden, there's an inspection chamber there.

Our buyers still want a £265 indemnity policy in place.

No need for an indemnity if SWW claim it. I'd say no impact on value really.

I've been digging through old papers  and I've found that back in 2001 there was a cockup with building inspectorx confusing a surface water conduit with a surface water drain , from what I can see that was diveted but the sewer pipe that is 2.5m down was not noticed even though original planning said it should be diveted before houses were occupied.

Survey was done In 2008 and pipe does go under house, which probably has no special foundations

Someone else has suggested  that we should get company that specialising in diveting drains like this to quote for doing the divett as per original plans but can neighbour whose  house was built at same time be made to allow dirty great holes to be built at end of garden and then down thier drive, their house is also less than 3 m from pipe, I know id have to pay but could we force through diversion to meet original plans which said before both houses could be occupied drain haD to be moved

SWW have the powers to divert but they would probably want to charge and it won't be cheap and there needs to be a logical route. They may be cheaper than getting your own contractors as they have rights of access and hopefully will charge their actual rates rather than an elevated figure.

One option is to get it CCTV surveyed, that will establish condition. But ultimately it will need to be maintained/ diverted at some point. Indemnity policy may cover that risk.

It would cost a mind bending amount to have that sort of sewer diverted. In my job I assess civil works and authorise funding for them and that sort of diversion would be many many tens of thousands of pounds, I wouldn’t be surprised if it could run to a hundred thousand plus.

Don’t forget you have to fill in the old line when you divert it, that would be expensive as it is. And if you didn’t do that why are you diverting it in the first place?

Easier to keep it where it is.

I’m having a think on how hard it would be to divert a 700mm sewer. The first thing will be to set up over pumping. A line that size will be carrying flow all the time, even in dry periods, but you’d have to set up pumping that would cope with any rainfall that might occur. Diverting a sewer that big is going to take a couple of weeks minimum so anything could happen weather wise. Our biggest mobile trucks couldn’t pump a 700mm sewer even at half flow so you’d have to set up some fairly hefty standalone pumps and the appropriate pipe work (basically a 700mm above ground sewer). Even if you managed to dig the new sewer before you did the over pumping it’d take days to connect the new line up from the old.
Next issue is the 2.5m depth. Even if that’s to the bottom of the pipe you’re going to need to get a structural engineer to design a shoring plan to dig down to make the new sewer. If that’s needed over tens of metres you’re looking at tens of thousands of £ just for the shoring design and implementation.
Then you’ve got to pay site supervisors, dig supervisors, plant hire, drivers, plant operators, general workers etc. And of course the cost of the new line itself, the backfill, the reinstatement, the connections. Oh and the planning, the legal side of things, the insurance, health and safety provision.
And because you’ll have big machinery everywhere you’ll need somewhere to park it, as you’ll have spoil/equipment /supplies to store and welfare arrangements you’ll probably have to have that on the road so will quite likely need traffic management there too. Which needs people to set it up......

Then you have to figure a plan to fill the old one in. Properly so it’s structurally the same as if there was never a sewer there in the first place - or what’s the point in the diversion?

Can you see how this sort of thing can get a bit spendy??

I got a quote recently for relaying 40m of 150mm surface water sewer in a pavement which was less than 1m down from the surface and that was £55k all in. Might have come in a bit cheaper in the end but not miles cheaper.

I suppose the question is what needs to be done to make the house saleable.
Once you have sold it it's not your problem anymore

Yours won't be the only property with this issue, so there will be some precedent.

Otherwise rent it out

looks like at time of build an actual stream got diverted and whoever was inspecting the build ticked off the requirement to actually move the surface water sewer

I don't understand this. Is the 700mm pipe a diverted stream (technically a culverted watercourse), or a surface water sewer?

I’ve been digging through old papers and I’ve found that back in 2001 there was a cockup with building inspectorx confusing a surface water conduit with a surface water drain , from what I can see that was diveted but the sewer pipe that is 2.5m down was not noticed even though original planning said it should be diveted before houses were occupied.

It sounds as if there was some negligence when the house was built, but establishing by whom and who is now liable could be a way to spend a lot on money on lawyers.

Survey was done In 2008 and pipe does go under house

Assume that was by SWW, so they've known about the problem and not (apparently) done anything so if they're not worried it's probably a low risk. If you can get an insurance policy against future issues that would be a good way forward.

I don’t understand this. Is the 700mm pipe a diverted stream (technically a culverted watercourse), or a surface water sewer?

That's what I was thinking.

It could easily be a combination of the two now. If it's a culverted watercorse that is now taking SW runoff from recent development it'll now be classed as a SW drain.....probably...

I certainly wouldn't be wanting to divert it now Unless the house is worth millions!

If it was a culvert it would be unlikely SWW would have any interest or responsibility for it.

I’ve been digging through old papers and I’ve found that back in 2001 there was a cockup with building inspectorx confusing a surface water conduit with a surface water drain , from what I can see that was diveted but the sewer pipe that is 2.5m down was not noticed even though original planning said it should be diveted before houses were occupied.

Sounds like the developer knew they had to divert the sewer, but chose not to for whatever reason (I have my hunch it's to do with cost, complexity and not wanting to sterilise another housebuilding plot). Is the developer still around/trading? If I were looking at this from a SWW perspective, I'd suspect their legal advice would be "not our liability" as developer knew of problem but ignored it.

Sounds like a right awful situation for you though.

If the conditions of planning i.e. must divert the sewer - were not met then the builder was negligent?

Sounds like the building inspector was negligent in signing it off...?

The conveyancing solicitor when your relative bought the place was negligent too....?

Sounds like too many people had to be negligent for it to come off.

Just re-advertise and see if the next solicitor picks it up.......or send to auction. If no luck it might be best to just rent the place out as said as there would be no impact on rental income.

Theres no point in actually diverting it until if there is ever a problem. I doubt there ever will be, how many old terraces are there built over god know what?

Solicitors can easily put in place indemnity policies for this kind of thing. Sounds like this buyer was just a little nervous. Try again and ask your solicitor to find a policy.

If the conditions of planning i.e. must divert the sewer – were not met then the builder was negligent?

Sounds like the building inspector was negligent in signing it off…?

The conveyancing solicitor when your relative bought the place was negligent too….?

Sounds like too many people had to be negligent for it to come off.

Hence my question as to whether or not the property remained in the deceased's estate, or whether it been transferred to OP. If still in the estate, then any cause of action may still subsist (subject to limitation periods etc). However, if it's been transferred then the causes of action probably no longer exist.

Hi All

Found more paper work

builder submitted plans to build 2 houses on plot in 1996 - got refused because of the surface water sewer running through plot, he resubmitted again saying he was going to divert the pipe

houses were built in 2001 - but builder (Who is now dead) only diverted a surface water culvert - and manged to con the inspectors into thinking that was the surface water sewer...  to avoid the big costs of diverting the 700mm sewer

found more papers showing deceased did try to get his original solicitor to go after the builders, planners etc but that got no where, he then looked into suing his solicitor but got nowhere - then he gave up and stayed in house for another 20 yeasr

House is back on market now and i've told estate agents to tell everyone up front about the pipe and no extensions permitted - got 10 viewings before weekend - so will have to see how desperate people are to buy a house in current mental market...

Probably very until the mortgage survey

So was it a planning condition to move the sewer?  Or advice? If it's a condition that has not been discharged, the property may not have a right to even exist...

Or if the LPA discharged the condition incorrectly, it'll be a right mess to sort out.

Id be looking to rent it out in the interim while this gets bottomed out.  It could take years. Mostly because nothing is actually causing anyone any problems (other than you).

Sorry

20 years ago I bought a house, the sewer under the house next door collapsed and the house was compulsory purchased by the local council and subsequently removed with the gable wall rebuilt against my house

Lots of movement (needed underpinning again) in my property which I eventually had to get sorted on my house insurance

Long story short - cost me a fair bit in solicitors fees and insurance premiums - lost over a 3rd of the house in selling it cheap with known issues (although repaired)

never again

I don't go past the house often but I enjoy seeing the close to pisa amount of lean

Hi all

Thought I'd update , back  before stamp duty thing ended the housing market went mental in Devon

I was able to sell above market value  and that was even after I told all buyers about the surface water sewer running under the house and all the restrictions that came with it

Not sure if it would have been the same outcome now that stamp duty saving madness is ending

I really do miss being able to go down to the south west to ride now though

You can build over a sewer, you need a build over agreement from SWW. They are quite hard to get but not impossible.

This is exactly what happened to us when we built our extension. The main sewer runs at the back of our house so the extension went over it. Original plans diverted the sewer around which meant manhole covers at the corners and a couple of inspection points. The water company said they'd rather us just build over the sewer as builders disturbing them often causes problems. Its a relatively short run - 8m, and a straight run with no manhole covers so was about as simple as it gets. And these days if there is any issues with the sewers they can address the without having to dig things up - plastic linings can be used for example.