Soakaway - overflow advice

[DaveSpud47]

Hi ,

I have installed a soakway but due to heavy clay, it drains extremely slowly. Building control advised to install overflow just to the ditch at the side of the road for any excess to drain into. (as it is only rainwater)

The land drains (old porus red pipes )that run across our land from the fields behind all seem to drain into this ditch.

Falls: Distance from ground surface to entry in our soak away crate side below soil is approx 1m.

I understand I need approx 20cm of shingle below all pipeworks, so need to dig trench at 1.20m at the soakaway end.

Im using 110mm pipe

The opposite end is 16.3 meters away, and needs to have a 1:40 fall. from my calcs just over 40cm deeper at the far end. 1.6 meters deep at the ditch end. :/

The ditch at the side of the road is overgrown from what I can tell its approx 50 cm deep, so my outlet I suspect is going to be underground.

Do I just dig this section of ditch out deeper?

I suspect this : Do i dig around the outlet in the ditch, line with membrane and fill with shingle to bring the level back to existing ditch bottom height?

We get a shedload of rain in winter and I suspect the overflow will be heavily used.

Any advice would be great thanks!

 

[Nige F]

Hi ,

I have installed a soakway but due to heavy clay, it drains extremely slowly. Building control advised to install overflow just to the ditch at the side of the road for any excess to drain into. (as it is only rainwater)

The land drains (old porus red pipes )that run across our land from the fields behind all seem to drain into this ditch.

Falls: Distance from ground surface to entry in our soak away crate side below soil is approx 1m.

I understand I need approx 20cm of shingle below all pipeworks, so need to dig trench at 1.20m at the soakaway end.

Im using 110mm pipe

The opposite end is 16.3 meters away, and needs to have a 1:40 fall. from my calcs just over 40cm deeper at the far end. 1.6 meters deep at the ditch end. :/

The ditch at the side of the road is overgrown from what I can tell its approx 50 cm deep, so my outlet I suspect is going to be underground.

Do I just dig this section of ditch out deeper?

I suspect this : Do i dig around the outlet in the ditch, line with membrane and fill with shingle to bring the level back to existing ditch bottom height?

We get a shedload of rain in winter and I suspect the overflow will be heavily used.

Any advice would be great thanks!

Why do you need to go into soakaway sdie ? why not top . 200mm of shingle below pipe ? seems a lot to me. 1:40 fall is self cleaning velocity for sewage pipe, not needed for rainwater. I'm sure you can arrange things so you end up just above the ditch bottom . Are Build Control going to inspect the soakaway ? Connecting a pipe to a ditch needs to be discreet ( in my opinion) you might get nosy dogwalkers assuming it's a cess pool overflow and moaning to authorities.