Possible land drain in corner of trench fill foundation pit

[GoodDIYjob]

What is the best approach for something like this?

There is no water running in it presently and it appears dry. It is dry weather here today though.

It is cutting diagonally across our rear garden, I pushed a rod up stream and got to 10M which is just over the neighbours rear garden boundary and it was still going. If it continues out the back boundary of the neighbours yards it would eventually reach an old school building and school yard c1920s.

I went over there, as it has been unused for 5 years or more and their sewer lines run to the front where their road is as you would expect. Can't tell rainwater arrangements as they just go into ground.

We are 30m + from those school buildings, so it is a long way away, but that is the trajectory.

Down stream I only got 2.5M before it stopped and I got clay and sand on the end of the rod. It heads straight into the middle of the neighbours extension that direction, and the distance corresponds, so I expect has possibly been severed when that extension was done. Either that, or the pipe takes a sharp turn and is damaged.

It is in a tricky spot right at the corner of the foundations to be poured and near the bottom about 900mm depth. Strip foundations are to be poured and my understanding is, even if I was to get the builder to repair the pipe there, the pipe shouldn't be left in the strip concrete foundation anyway - supposed to be in blockwork due to the loadings....

So best option?

• Repair - doesn't work as can't leave in strip depth
• Block up both ends?
• Follow path back up stream in our garden a few metres, and cut into it and divert into our new soakaway? Block up downstream and redundant section entries.
• Something else?

Based on the position of it being in the foundation strip, I am leaning towards cutting into it upstream a few metres and diverting to our soakaway.....and sealing the downstream section...

 

[oldbutnotdead]

Divert to soakaway will be the best option, you might want to consider connecting the downstream leg to the soakaway as well. If the land drains are the old clay flatbottomed type then they probably date back to when all this was fields and it would be unwise to ignore them

 

[Ian H]

Do the joints on the pipe have collars or are they just butted together?

I'd repair it, plus 100mm either side out of the trench, then pour your concrete. In the unlikely event it ever needed digging up you would have enough each end to connect to.

Is that your new gully above it?

 

[GoodDIYjob]

Thanks for comments.

Kind of wish I had of just told builder to cut in the upstream and divert into the soakaway and then crack on.. but I could not 100% say what drainage it actually is!

He spoke with Building Regs and BR wanted it repaired and lintel and padstone over which has meant more excavation around corner area, lifting out the soakaway 100mm run that was backfilled, again and some more costs for something, I feel pretty confident is blocked 2.5M further downstream. Again though, not 100% certain without surveys, borescopes etc etc.

Time was/ is the issue as well as they want to pour strips tomorrow.

The other thing is, the school which this heads towards has not been occupied for the 5 years we are here so another unknown.... But it is also 30M away so none of it makes a lot of sense...

Yes, it has collars and all looks in surprisingly good condition but doesn't appear to be presently carrying anything.

Yes, that is the gulley for the extrension roof running down into a new soakaway 5M away in our rear garden.