How to build a haha?

[Me!]

We have a largish ditch between us and a neighbour and are considering building a haha in it. The ditch has standing water in it for much of the year, and the haha wall will have earth piled against one side of it and nothing against the other. So, does anybody have any suggestions please as to the size and type of foundations that will be required, and also the type of construction to use for the wall? For example, should the wall actually be vertical, or should it lean towards the earth side to help resist the weight on that side? Are some form of buttresses required? Do we need to somehow tie the wall back into the earth behind it to keep it upright?

The wall will need to be about 4 feet tall, and doesn't actually matter too much what it looks like from my side (the ditch side) as that will be hidden behind trees and undergrowth. We have considered steel sheet piling, but it looks like the size of machinery required to put it in could be a problem.

I have tried to Google for info on this, and also searching on this forum, but unfortunately the word haha brings back far more dodgy humour than sunken walls!

Thank you.

 

[LadyArowana]

Mr Google will be happier if you look for ha-ha or "building a ha-ha" this seemed to have promise http://faculty.bsc.edu/jtatter/haha.html but I didn't read the whole thing.

 

[Me!]

Thank you, I've found a couple of articles like that about restoring an old haha, but none of them have needed to replace any foundations so no mention has been given to that part of the problem. Also, a lot of old hahas tend to be fairly posh ones in the grounds of old estates, where the ditches seem to be fairly dry most of the time. What we are hoping to build is something that is functional to allow to neighbour to make full use of his garden right up to a firm edge, and that can cope with standing in a wet ditch for much of the year.
Maybe I'm just being overcautious, but it seems to me to be a lot of force on one side of a straight wall, that is built on something that is often waterlogged. Which all sounds to me like it isn't going to be easy

 

[malcolm]

The ha-ha is a retaining wall (much easier to search for). All it really needs to do is hold up a triangle of gravel behind it so sheet piling seems a little excessive. I imagine the difficulty will be how to build foundations in the bottom of a soggy ditch.

 

[Moo]

Doesn't Joce have a ha-ha?

 

[LadyArowana]

Doesn't Joce have a ha-ha?

Yes she does, brick and in a sort of herringbone construction IIRC, however I don't know if it is near water or not. Their area is generally quite dry although I think there are some springs.

 

[Moo]

I've found the thread but don't know how to post the link on my iPad, so all I can suggest is putting Haha Progresses into the Search box.

 

[Flyfisher]

My understanding is that a haha was developed as a form of invisible stock-proof 'fencing'. A near vertical ditch would be dug out and lined with brick to avoid erosion and the other side would slope gently back up to the ground level. When viewed from the 'wall side' (i.e. out of the windows of the estate mansion), the whole construction would be completely invisible but any livestock outside of the haha would only be able to walk down into the ditch but not climb up the wall.

What is being described sounds more like an existing drainage ditch and for a wall to be built on the visible side "to allow to neighbour to make full use of his garden right up to a firm edge". If the existing ditch is marking the boundary of the two properties then the actual boundary might be the centre of the ditch, in which case the proposed wall would actually be built on the neighbour's land. Presumably the neighbour is fully involved in these plans?

 

[jocelyn plummer]

I am sure Joce will be along soon----kimono and all!!!

 

[Moo]

Hmm. I think Joce finds Facebook much more fun than PPUK these days.

 

[CliffordPope]

My understanding is that a haha was developed as a form of invisible stock-proof 'fencing'.

Exactly. It's not a ha-ha, it's a ditch. Just dig it out and pile some rocks up the slope on your side.

The point about a ha-ha is that it is invisible from your side - it just looks as if your open parkland rolls on for miles with no obstructions or intrusions, but your livestock can't stray onto your lawns.

 

[Lime]

My understanding is that a haha was developed as a form of invisible stock-proof 'fencing'.

Exactly. It's not a ha-ha, it's a ditch. Just dig it out and pile some rocks up the slope on your side.

The point about a ha-ha is that it is invisible from your side - it just looks as if your open parkland rolls on for miles with no obstructions or intrusions, but your livestock can't stray onto your lawns.

Yes I agree.
Its not impossible to do but I'd consult with the neighbour beforehand to avoid any problems.
They would be looking at a new wall and may throw up objections re. boundary, drainage, visual impact etc.
In order to build an effective ha-ha, the land would have to be raised on your side to obtain the invisible effect unless the topography is already in your favour.

 

[Me!]

Yes, it is basically just a ditch with a wall in it. The reason I described it as a haha is that it is a very wide ditch, and the neighbour hopes that by building a wall in it he will be able to extend the usable flat area of his garden. I believe that the entire ditch is actually on my side of the boundary, however we have a large garden and the neighbour has a very small garden, so I'm not going to quibble over him trying to get an extra couple of feet of usable space. I've now looked up retaining wall designs as suggested, and that all makes much more sense. I guess that some form of cantilever design is probably the best option given the soft base it will be sitting on for much of the year, but I will consult a civil engineer to be sure.

Thank you everyone for pointing me in the right direction with this.

 

[Lime]

Do you have a drainage board in your area?
I ask because I recall a relatively recent episode where a land owner had put up a wall in the centre of a ditch to gain more garden.
However they flouted the drainage regulation/bylaw concerning capacity of the ditch and eventually it was forcible removed at their expense.
The owner of a drainage ditch doesn't have an absolute right to alter its capacity to drain or hold water.

 

[CliffordPope]

Have a look on the gardenlaw forum for lots of warning stories about people losing bits of their garden.
If the boundary is on the far side of the ditch you can do what you like with the slope on your side - maintain it or let it slide (unless a watercourse).
But if you concede the whole ditch to your neighbour and build a retaining wall, one day that will become the new boundary, and you will become responsible for maintaining that wall and stopping soil slide into your neighbour's garden.

 

[Keith Bowman]

Have a look on the gardenlaw forum for lots of warning stories about people losing bits of their garden.
If the boundary is on the far side of the ditch you can do what you like with the slope on your side - maintain it or let it slide (unless a watercourse).
But if you concede the whole ditch to your neighbour and build a retaining wall, one day that will become the new boundary, and you will become responsible for maintaining that wall and stopping soil slide into your neighbour's garden.

Surely it's the neighbour who wants to build the wall and who will, presumably, become responsible for maintaining it (although it might be best to get that in writing!).