Surface Water Drainage

[Chrisgr31]

I have wondered for some time where the surface water from my house, water off the roof etc goes.

It comes off the roof into pipes to go where? I know from when the sewer was blocked a few years ago it doesn’t go in to the sewer.

Last weekend I was in my immediate neighbours garden as I was replacing some fence panels. There was a manhole which I lifted to ensure I wasn’t going to put my posts through any pipes. I discovered it contained a lot of mud, so I cleared it out which revealed inflow pipes which appear to come from the neighbours and my house and an outflow pipe which goes out under my garden. However all the pipes are blocked with mud and tree roots.

How though to I discover where it goes? I know there’s no manhole in my garden, pretty certain there isn’t one in the garden of the neighbour the other side of me.

So how do I find where it all goes and who is responsible for clearing it all out?

[bigpriest]

I think you need a drain survey company who will probably do the jetting and clearing as well. In older properties the rainwater isn't contained, it flows onto the pavement in some cases, and then into the drains in the road. The surface water from your house may be collected in smaller drains directly from your downpipes but if there was a blockage the water would back-up and overflow (often the cause of damp interior walls). You can tap the downpipes to see if they feel empty. Depending on age these smaller drains join up with the larger sewage pipes under the road.

[The Three D Mucketeer]

Most of mine just go under my garden and into the verge of the country road which is 10' below my garden .... Same for the old septic tank outlet , which is now obsolete since the house is now on main drainage .

[bigpriest]

The Three D Mucketeer said:

Most of mine just go under my garden and into the verge of the country road which is 10' below my garden .... Same for the old septic tank outlet , which is now obsolete since the house is now on main drainage .

I bet there's a stream / river nearby with fish that glow in the dark

[Chrisgr31]

I am guessing mine either
-end up in a soak away (probably clogged up) in either my or my neighbours garden
- or end in a ditch which has been filled in.

The land the direction the pipe rises the other side of my neighbour

[The Three D Mucketeer]

bigpriest said:

The Three D Mucketeer said:

Most of mine just go under my garden and into the verge of the country road which is 10' below my garden .... Same for the old septic tank outlet , which is now obsolete since the house is now on main drainage .

I bet there's a stream / river nearby with fish that glow in the dark

With a Nuclear Fuel Factory in the village , we ALL glow in the dark

[gmaz]

My neighbour's patio runs to the side of the house which is next to my garage and about 20cm higher. Over time it has leaked through the mortar and now floods the garage during heavy rain, but she won't take responsibility.

[Chrisgr31]

My neighbours path is only just under my DPC at its highest point. As it slopes down I am not too concerned.

[RATATTAK]

bigpriest said:

I think you need a drain survey company who will probably do the jetting and clearing as well. In older properties the rainwater isn't contained, it flows onto the pavement in some cases, and then into the drains in the road. The surface water from your house may be collected in smaller drains directly from your downpipes but if there was a blockage the water would back-up and overflow (often the cause of damp interior walls). You can tap the downpipes to see if they feel empty. Depending on age these smaller drains join up with the larger sewage pipes under the road.

You can also tap the fall pipes on your property and listen at the (assumed) soakaway. If the drain is not too blocked with tree roots and silt, you should be able to hear the tapping.
As a point of interest, your water company is probably charging you to dispose of your surface water ... if you can prove it doesn't empty into the foul sewer, they should discount the bill accordingly.

[Sheepshanks]

Chrisgr31 said:

I have wondered for some time where the surface water from my house, water off the roof etc goes.

It comes off the roof into pipes to go where? I know from when the sewer was blocked a few years ago it doesn’t go in to the sewer.

Last weekend I was in my immediate neighbours garden as I was replacing some fence panels. There was a manhole which I lifted to ensure I wasn’t going to put my posts through any pipes. I discovered it contained a lot of mud, so I cleared it out which revealed inflow pipes which appear to come from the neighbours and my house and an outflow pipe which goes out under my garden. However all the pipes are blocked with mud and tree roots.

How though to I discover where it goes? I know there’s no manhole in my garden, pretty certain there isn’t one in the garden of the neighbour the other side of me.

So how do I find where it all goes and who is responsible for clearing it all out?

Do your surface water gulleys overflow in heavy rain? If they don’t, the water must be going somewhere.

[silentbrown]

If you're on mains drainage it most likely does end up in the sewer.

If you have a septic tank it *should* go to a separate soakaway on your land (but it's not uncommon to find it's also going to the septic tank which is far from ideal)

[guitarcarfanatic]

silentbrown said:

If you're on mains drainage it most likely does end up in the sewer.

If you have a septic tank it *should* go to a separate soakaway on your land (but it's not uncommon to find it's also going to the septic tank which is far from ideal)

It's more than "far from ideal" - it's a ticking timebomb as to when either the soakaway/drainage field chokes, or the EA come knocking with fines for pollution

Rainwater plumbed into a septic tank flushes all the bad stuff and solids straight through and stops it doing it's job. So hopefully, it surface water goes to it's own soakaway or it connects to a sewer (less likely).