Question re drainage from a field.

[Dr Wu]

Hi there

Our house is basically on a hill with a big field (usually hay) running parallel to our side garden.

We've been here 9 years and every year when it rains heavily there's a mini stream appears in the ploughed field carrying all the water down the hill and more importantly away from us!

This year however, after heavy rain the usual stream has not appeared in the field and instead water is pooling at the back of our house (obviously coming off the field) eventaully draining away round either side of our house down to the street but is also pooling in the crawlspace underneath the house.

This doesn't cause any problems and the crawlspace obviously means the house itself is never going to flood but I wondered if anyone had any ideas why a field should suddenly stop chanelling the rainwater away and perhaps more importantly what we can do about it?

I'm guessing we're just going to have to sink some drainage pipes to carry the water away?

Cheers

Steve

[MustafaTickl]

Land is not a fixed substance and often changes both its levels and characteristics. There are many reasons why the water flow has diverted - too many to list here.

Along the boundaries where the water is entering your property you should dig a trench commencing at about 12-18 inches deep and finshing at about 24-36 inches at the point where the water leaves your property. The trench should be about 18 inches wide. In the bottom should be placed a 4 inch diameter crush resistant moulded plastic pipe covered in fabric. These can be bought in 50 feet lengths. The trench should then be filled with (say 2 inch) stones - not ballast. If the water leaving your property can be channelled into ditch then continue the trench to achieve this. If not you will have to dig a soakaway on your property. This should be at least six feet wide and about the same diameter. The cheapest way is to fill this with bricks, very large stones etc but if you can run to two or three six foot diameter concrete manhole rings plus a concrete top then so much the better as the completely open space provides much more storage.

[Dr Wu]

Thanks so much for that answer, really helpful.

Confirms what I thought I might have to do but the specifics are particularly useful.

Thanks again

Steve

[MustafaTickl]

Couple of amendments:

(1) ....... crush resistant moulded perforated plastic pipe....

(2) ........at least six feet wide should be ...at least six feet deep ....

It is rather important that you stop the water from flowing around and under your house as soon as possible. There are obvious major health risks, but on top it could cause serious structural damage. The water scours earth away underground and could cause settlement and cracking. Also, sometimes when it is very wet the ground "heaves" upwards with the same structural damage. You refer to a "crawling space" under the floor so presumably there are sleeper walls supporting the floor. These may not have the same depth of foundation as the external walls, so there is a real risk of of floor collapse and structural damage if you do not stop the water asap.

[Dr Wu]

Thanks again

I knew what you meant

There's only a very small amount of water settling in the crawl space under the house, about 2 or 2 inches deep, and only in one patch, the crawl space is about 3 and a half feet high so any water is well away from the underside of the floor. But you're dead right, any water getting in and around the founds and the walls is going to be trouble, ..........ASAP if not a bit sooner then!

Cheers again!

ps: does anyone want to buy some rather soggy 2000AD comics!

[Dr Wu]

Latest advice from a helpful chap who came round from the council today is that the field next to our house has probably got a broken tile drain which is causing the water to divert via our garden.

I'm going to speak to the farmer!