sewer map on property

[kevinga]

Hi,
Im about to purchase a property as a first time buyer. I have question to all the experienced guys out there.

I read through the water drainage search of the property. Im not sure how to make of the map.It shows a point for sewerage and also another point with blue marks which Im assuming surface water point.Property is mark as x in the image. Please see the image.



Does this mean I have a sewer main point at my backyard because as far as I can tell I dont see any manhole cover at the garden.
Would this also mean I cant extend the rear property up to 3 metres.

Thanks for your views and suggestion.http://h.imagehost.org/download/0217/sewer_map

 

[kevindgas]

can't help with your question as don't understand the drawing enough.
but one of my old houses had the main sewer for the street running right underneath the middle of it from front to back it was so far down that an extension could have been added without a problem.

 

[kevinga]

Hi thanks for reply.
this is thames water map.
the red is pretty sure sewerage but im not sure whats the blue sticks.are.
the black dot might be manhole but theres non that i can see in the middle of the garden.2 of the 3 pipes converging on the black dot is 220mm and another going out 900 mm.

 

[^woody^]

The map should state if these are public or private sewers. If public, you will need the water authorities' permission to build over or near, and if they will give it, depends on several factors.

The map should have a key.

I would suspect red to be foul, and the blue to be storm.

Also, the authority should be able to state whether the map is accurate or not. Unless the drains have been surveyed, or other such details exist, then in many cases, drains are not where they think they are, and neither are manholes

 

[kevinga]

It's public sewer.
Here's the key.
http://img80.imageshack.us/i/watersearch18.pdf/

But I could not clearly confirm on the blue thing compared to the key.
So keep fingers cross the actual is a bit off from the map or else hope permission given for an extension.

Thanks[/url]

 

[Steve]

perhaps the blue thing indicates this is YOUR manhole, where your drains connect - since your drains are not indicated on the map.

Dig a little. You should find a manhole. Unless the black dot is just a change of direction (i take it your house is #19)

 

[stellaman]

Water and Sewer maps usually only indicate public sewer details. The black dots are maholes so you should have one in your back garden somewhere. These maps are not 100% acurate but quite close, bit odd that it goes under your house but not impossible. You need to find it and check the depth and size, this will determine how close you can build to it, with it going under your house it will a bit deeper than normal.