Land drainage advice

[Skier]

Hi

I am currently in the process of doing the garden which is a sloping surface(towards the house) at the moment.

I am going to be leveling and building a wall to make 2 level surfaces. At the moment the ground is clay and water does not drain through. Obviously I have to include some kind of drainage into the design. My initial thoughts were to create some kind of french drains angled toward the house so that the water ends up where it ends up at the moment. I have had a quick look at what is there and it looks like a load of gravel near the foundation and if I dump water into it then it dissapears after a few seconds. Does anyone know if it is regulation (house was built about 4 years ago) to include some drainage around the house. If that is the case I think I will be ok doing what this. any thoughts?

The other option I have is the rainwater downpipes ar in the same location. Can I "T" into this and connect my land drain? Though about a sediment trap before the T.

Cheers

[Chris Bacon]

How does a "sediment trap" work?

[Kevin]

This sounds very similar to my garden. I've mulled over various ideas, including making a soakway at the furthest point from the house. This is difficult because I would be attempting to run the water against the natural slope of the garden. I don't really feel too comfortable about having the soakaway close to the house as you have suggested but cannot give any firm reasons why this is a bad idea. My latest idea is to put something like a drive drain running parallel to the rear of the house and about two or three feet from the house. I should then be able to run this into one of the rainwater gulleys. The only part I haven't yet worked out is how to get the water from the land drains into the drive drain, or even if I can make some kind of arrangement using just land drains which would remove the need for the expensive drive drain altogether. I'm also thinking that I could hide the outflow from the land drains underneath some decking which I'm thinking of putting along the back of the house, but again I would be hoping to eventually route the water into one of the rainwater gulleys rather than just let it soak away.

[Kevin]

This sounds very similar to my garden. I've mulled over various ideas, including making a soakway at the furthest point from the house. This is difficult because I would be attempting to run the water against the natural slope of the garden. I don't really feel too comfortable about having the soakaway close to the house as you have suggested but cannot give any firm reasons why this is a bad idea. My latest idea is to put something like a drive drain running parallel to the rear of the house and about two or three feet from the house. I should then be able to run this into one of the rainwater gulleys. The only part I haven't yet worked out is how to get the water from the land drains into the drive drain, or even if I can make some kind of arrangement using just land drains which would remove the need for the expensive drive drain altogether. I'm also thinking that I could hide the outflow from the land drains underneath some decking which I'm thinking of putting along the back of the house, but again I would be hoping to eventually route the water into one of the rainwater gulleys rather than just let it soak away.

[Skier]

it is basically a 'bin' that is sunk into the ground and then the inlet and outlel pipes enter into it at the top at opposite ends. as the water flows through it the heavier sediment drops to the bottom and does not enter the the other part of the drain. After a few years you would need to empty the trap.

[Skier]

same here and the soak away would never drain in my case leaving me with a large underground pool that would eventually overflow

This is my question too, I think the builders should have included some kind of soakaway into the building already and I want to 'tap' into it - or rather continue using it because that where the water ends up anyhow.

thats pretty much my plan, have a look on a search for french drains, would be alot cheaper than a drive drain.

[Chris Bacon]

What is a "drive drain"? One of the Accodrain type things?

I

You could have a gravel square with a trapped gulley/grille to underground drain.

[Weatherlawyer]

Your best option is a manhole into the surface water drain. It is very silly to have loose water slopping around a house and especially dangerous in clay soil where it might lift and drop the foundation seasonally.

You can get some pastic ring inspection worreverey-callems that fit on onto the other. You might want to brick up around them if you are going deep but they are OK for 3 or 4 layers:

you make a brick manhole then you can make it large enough to have a weir to collect debris in one chamber and drain out the other. That might be cheaper than the road drain thingie you seem to be discussing elswhere on this thread.

[The Natural Philosopher]

A French drain is just a ditch filled with gravel, so you can walk on it.

It has itself to be drained somewhere else...I take it your house is not at the bottom of a dip, but on a slope?

Somewhere you have to find a point lower than the house to drain to.

And it would be wise, if dumping water from upper terraces, to increase flow to it from the house French drains.

I have the reverse situation - ground slopes from the road to the house, then down the garden. The house is surrounded by a moat, filled with gravel and a perforated pipe. This French drain itself is drained by a pipe to a pond..I have terraced a small section of lawn around the house and the brick wall is rubble loaded behind as backfill, and has a few pipes running through it to keep the wall dry. It works well, but dumps water to the lower lawn.

You have to be aware of where the water is going before you dumpy more into the French drain...maybe there is a soakaway somewhere?

[Andy]

IIRC newish regs say a soakaway has to be 5m or more from the house. I learned this when I looked into getting rid of my rainwater into a soakaway to save on the water rates. I'm still mulling over the pros and cons.

Andy