French drains into regular drain/sewer?

Pete123456

Will shortly be moving into a new build and the ground in the back garden is quite wet. I know we’re only coming out of winter but it’s a common complaint in the estate - it will also be a north facing garden so most of the lawn will be in shadow I assume most of the year. It’ll be approx 60sq m rectangular.

I am assuming the ground will only be seeded for grass so I was going to take the opportunity to dig some french drains to try and dry up the garden a bit. Down the road my plan is to have the garden redone and landscaped which will probably mean getting rid of the grass altogether.

I’ve seen people digging large sump holes and having the French drains lead into those but I was wondering if there would be benefit in having the French drains lead into the mains sewerage/drains? Can this be done and can anyone advise who I would need to help me get this done or whether it’s advised/allowed?

The Continental Op

afaik your not supposed to do it? But I don't have any links to prove that. Maybe a better question for the Construction & Planning forum.

Pete123456

The Continental Op wrote: »

afaik your not supposed to do it? But I don't have any links to prove that. Maybe a better question for the Construction forum.

Thanks! Maybe a mod would be able to move it if they think it would be better in construction please?

delly

Moving thread from DIY at OP's request.

Speaking of French Drains, here is my creation from many years ago.
https://www.boards.ie/vbulletin//showthread.php?t=2054939061

Calahonda52

Pete123456 wrote: »

Will shortly be moving into a new build and the ground in the back garden is quite wet. I know we’re only coming out of winter but it’s a common complaint in the estate - it will also be a north facing garden so most of the lawn will be in shadow I assume most of the year. It’ll be approx 60sq m rectangular.

I am assuming the ground will only be seeded for grass so I was going to take the opportunity to dig some french drains to try and dry up the garden a bit. Down the road my plan is to have the garden redone and landscaped which will probably mean getting rid of the grass altogether.

I’ve seen people digging large sump holes and having the French drains lead into those but I was wondering if there would be benefit in having the French drains lead into the mains sewerage/drains? Can this be done and can anyone advise who I would need to help me get this done or whether it’s advised/allowed?

Not permitted under SUDs regulations.
Where does the rainwater from the roof go?

Pete123456

Calahonda52 wrote: »

Not permitted under SUDs regulations.
Where does the rainwater from the roof go?

Thanks. They drain into little gullies which I assumed were just connected into the sewer system or is this not common?

Is the alternative then to do as Delly did and dig a very deep hole and fill with gravel?

Calahonda52

Pete123456 wrote: »

Thanks. They drain into little gullies which I assumed were just connected into the sewer system or is this not common?

Is the alternative then to do as Delly did and dig a very deep hole and fill with gravel?

Not up to speed with current suds, used to be in my last house two separate sewer systems.
The whole focus is to reduce the load on the sewage plant with water that does nt need treating.
I would dig the hole to start with and see will it drain without the full Delly monty.

Renault 5

Am I allowed put a french drain run off into the drain from the kitchen or do I need to go to the gutter drain?

Pete123456

Renault 5 wrote: »

Am I allowed put a french drain run off into the drain from the kitchen or do I need to go to the gutter drain?

My original question was whether a french drain could be connect to either but it seems not?

blackbox

Pete123456 wrote: »

My original question was whether a french drain could be connect to either but it seems not?

It definitely should not go to the kitchen drain for reasons stated above by Calahonda52.

Personally I can't understand why it shouldn't go to the stormwater (gutter) drain as long as you have a trap to prevent silt from going down.

BryanF

blackbox wrote: »

It definitely should not go to the kitchen drain for reasons stated above by Calahonda52.

Personally I can't understand why it shouldn't go to the stormwater (gutter) drain as long as you have a trap to prevent silt from going down.

Because that’s not what the housing estates design was and not what they got planning for. The fact the developer doesn’t seem to have complied with/dealt with the garden drainage is a separate issue, probably to late to resolve now. OP soak away would be the best option open to you.

Fine Cheers

As a new build, foul and surface water drainage must be separate at least within the housing estate and around each property. Absolutely do not connect to foul but I wouldn't rule out connecting to surface water system if absolutely necessary. Its disappointing to have such issues in a new build but not uncommon. Developers tend not to worry about what's underneath, just get enough topsoil in so grass will grow.
Are you digging by hand ?
French drains typically have stone up to surface level and not always piped. Land drains include perforated piping surrounded in stone and layer of topsoil over. Have you considered spiking or an aerator ? Maybe material has been compacted by machinery which happens alot.
As already suggested, soakaway would be first option but could you locate it to allow like an overflow connection to surface water system via a silt trap ?

Calahonda52

DIY KING wrote: »

As a new build, foul and surface water drainage must be separate at least within the housing estate and around each property. Absolutely do not connect to foul but I wouldn't rule out connecting to surface water system if absolutely necessary. Its disappointing to have such issues in a new build but not uncommon. Developers tend not to worry about what's underneath, just get enough topsoil in so grass will grow.
Are you digging by hand ?
French drains typically have stone up to surface level and not always piped. Land drains include perforated piping surrounded in stone and layer of topsoil over. Have you considered spiking or an aerator ? Maybe material has been compacted by machinery which happens alot.
As already suggested, soakaway would be first option but could you locate it to allow like an overflow connection to surface water system via a silt trap ?

Some of the above may breach the SUDS regs

Fine Cheers

Certainly not an expert on SUDS but my understanding that in the main it deals with surface water from hard surfaces ie roof, roads, driveway, footpaths etc.
Grassed surfaces in theory are self draining (but not in this instance perhaps)
if it was me, I would go the way as I have suggested.
If there was ponding on your driveway, would you not provide a gully or 2 and connect to surface water ?
If selling on, would an engineer have a problem with it or even pick it up ?
Once a silt trap provided, I personally don't see a small domestic garden causing an issue.

Calahonda52

Calahonda52 wrote: »

Some of the above may breach the SUDS regs

What are the SUDS regs?

If me, I'd tap into the surface drain via filter.
Its going where its meant to go eventually!
Once the grass is established there shouldn't be a whole lot anyway.

Have something similar (prior to my purchase) in a 1960s house, only its to a combined sewer.