Ground water pump

[JimG]

Our garden is near the base of an incline where the subsoil is clay. When t here is heavy rain, the lawn becomes sodden and often there is surface wate r. Currently considering putting in perforated pipe land drains and collect ing the water in a large underground tank.

The plan then is to automatically pump out the tank when it is full and her e is where I would appreciate some advice.

Should I go for a submersible pump or an above ground pump that will work w ith a negative head ie a lift of about 4 feet? Alternatively should I put a pump in the pit alongside the tank?

Any advice would be appreciated. Thanks.

[Andrew Mawson]

Whatever you choose make sure that it is 'solids capable' - you'll be amazed what will end up in it :) However if you have somewhere lower to pump it why don't you lead your underground drain there and avoid the tank and pump altogether. (I'm sure that you're not considering dumping it into the public sewer !!)

Andrew

[Gazz]

are you planning to feed the collected water to your bogs, washing machine or similar? as that may affect the type of pump you choose,

or were you just hoping to pump it out on a dry day onto next doors lawn :)

Do you know the depth of the clay layer in your garden? my garden has about a foot of soil over about a 4 foot layer of clay, so is a bog a lot of the time, with the exception of the area near my neighbors conservatory, and that is because when he had it put in, they had to dig down 6 feet to get the footings through the clay, and as a result that corner of both our gardens drains nicely.

I keep thinking about renting one of those engines with a big drill bit on them about a foot wide, and drilling a few 6 foot holes in the lawn, then either some of that perforated pipe and gravel fill back in the holes, hoping the rain water would be able drain away down the pipes through the clay that is stopping it draining in a reasonable time,

But it'd be just my luck i drill into the coal mines that are below us, or my idea would not work at all.

[JimG]

There were old land drains there before which drained in to the foul water drain but these got silted up and broken up when a patio was constructed.

Have things changed so that it is against the regs to let your run-off go into the drains?

[Andrew Mawson]

Not up to current regs as we have our own private sewage system, but certainly surface water never used to be permitted into foul drains without a license having paid an annual fee. Surface water is supposed to go into soakaways.

Andrew

[JimG]

We are in South London where the clay is many metres deep.

[damduck-egg]

Have you seen this ?

G.Harman

[Andrew Gabriel]

You need the permission of whoever handles the sewer waste in your area. It will depend on the local load on the system if they give this or not. It needs to be in writing and a copy lodged with LA building control records. They can charge you based on the surface area being drained.