Neighbour's run-off

[Big G]

Hi, great site by the way will spread the word )

My problem is this.

I live in a smallish semi with a small (10m long x 7m wide) garden. At the end of the garden there is a 400mm high two brick retaining wall that separates my garden from the property at the rear. On the wall is a panel fence that has two gravel boards at the base.

The neighbours at the rear have a flower bed up to the wall and partially up the gravel boards.
Weep holes are visible in the wall that used to allow some water through from their garden during heavy rain.

Although their garden being at a greater height, caused my garden to be more moist than I would have preferred (clay soil doesn’t help), it was never really a big problem.

Then recently after heavy rain and wind, two of the three conifers planted at the end of my garden for screening, started to lean towards the house.
Reluctantly I had to cut all three down yesterday after closer examination revealed that the soil was water logged around them and the roots had given way.

I awoke this morning after further heavy rain in the night and my garden is like a swamp!

This got me curious and my first thought was collapsed drains etc, but after peering through the fence I could see they'd had the entire garden block paved.
Although I cannot be sure how recent this has been done, I know it wasn’t there a couple of years ago as I remember being woke very early each Sunday morning by the sound of a lawn mower - something which now I think of it, haven’t heard for so time.

Clearly the problem has arisen due to the run-off from my neighbours 'new' patio (I imagine previously, the grass soaked up the majority of the water).


So (deep breath :p ) having read your land drain section, it appears to be the most feasible solution, but will it be sufficient to run a drain the width of the garden i.e. parallel to the wall (the garden slopes down towards the house), or do you have to use the herringbone layout shown in your diagram?

Also, if I did the above, would it still be safe to plant conifers near to the drain for screening purposed, so long as I use a geoliner (or whatever it was called), without danger of damaging the drain?

Thanks for any help in advance

[Tony McC]

If your elevated neighbour is draining their paving into your garden, they can be compelled to install intercepting drainage. However, the paving would need to come right up to the boundary fence - if there was so much as a 300mm wide 'bed' between the end of the paving and the fence, you would still have a case but it would be much less cut-n-dried.

If you house is mortgaged, it could well be worth having a word with your mortgage provider as this situation may be compromising the integrity of your (their) property.

However, if it's going to be down to you to install an interceptor drain on your side of the fence, then a single line parallel to the fence would/should be adequate - but do you have somewhere for it to drain to??

A geo-membrane/root barrier would be a wise precaution if you decide to re-plant conifers (or any other trees/shrubs) and, whether you re-plant or not, I would definityely advocate that any interceptor drain is protected by a geo-membrane envelope, if only to keep it free from silt.