Manhole in Lawn

[ChrisinShropshire]

We have a manhole in the middle of our back lawn. It is about 10m from the house. In the summer when it is dry, you can see down the 15" dia pipe about 6 feet. At the bottom, there are gullies coming in a different angles, but we suspect that all but one of these are closed/blocked. In the winter, the manhole fills with water, but is usually 2-3' below ground level. In really bad rain (late 2013), that corner of the garden flooded. The water in the hole is slightly brown coloured.

As far as we can tell, nothing drains from the house into this hole. So, is it likely to be part of a soak away system? Does the hole fulfil any purpose? To me, it is just a useful hole into which I can drop a submersible pump when the garden floods in heavy rain.

 

[r896neo]

I assume you are on mains drainage and its definately nothing to do with a septic tank or effluent field etc?

If your on the mains sewer system ok then its almost certainly something to do with a soakaway or perhaps a land-drain system?

The '15'' diameter pipe' is probably inspection chamber risers and the multiple gullies sounds like a chamber base.

Is this stuff all modern plastic? and does it look like this inside?

http://mybuilder-uploads.s3.amazonaws.com/2_thumb/420976_1c627c2a82.jpg

Where do you propose pumping it too?

Also how old is your house

 

[ChrisinShropshire]

The house is 10 years old. It is on the mains sewer.

Ithe inspection chamber is black plastic. And the bottom looks just like your photo.

I have a long hose and would pump the water into the drain in the street

 

[r896neo]

In that case it must be some part of a land drain or soakaway system.

Your plan sounds fine but is technically illegal.

Do your gulleys that serve the downpipes from the gutters discharge into the mains sewer? Its unlikely unless your garden is very small.

 

[WalksWithTurkeys]

Check your property documents, such as deeds and water company plans, which you would have been given when you bought your house. I have a pipe coming off the street and down the side of my garden, carrying grey water from the road. It drains into a main sewer which crosses my garden. All are marked on the plans.

 

[ChrisinShropshire]

It is not marked on the deeds. I have spoken the the house builders who say that, after 10 years, they don't have records covering the development.

I think that the soak-away system is the most likely, but I still do not know why it has an inspection chamber/manhole.

Thanks for your help.