Ground water drain construction?

[rogerdygas]

Iam doing some digging in my garden (going to be turfed and no vehicle access) and have noticed that the underground pipes for both my downspouts are in 68mm downspout pipe, there is no inspection points etc just an elbow on the end of each downspout and a clay and concrete formation where both downspouts meet at a Y and go out under the pavement to the road to drain.

Should all these pipes be replaced in 110mm with gullys at each downspout and a proper inspection chamber to join the two before going out to road drain? The outlet to the road drain is clay and about the same size as the 68mm pipe.

The only problem I could see with having an inspection chamber is the highest point of the outlet (top of the pipe to road) is about 150mm below the finished level, and to get the falls on the pipes from the downspouts they would have to be lower than the outlet.

 

[Hugh Jaleak]

If it works, dont fix it..... Altering things, and especially if there is a backfall, is just asking for problems....

 

[rogerdygas]

Thanks Hugh Jaleak,

After further inspection the drain to the road is totally blocked and all the buried pipes, so my water has been draining to next doors down pipe.

Do you think this could be a common occurrence with such small pipes?

Also ive smashed the concrete Y piece once I found all the pipes were blocked how do I go about joining it up again (a 68mm pushfit branch might not have the correct angle nor is it a leak proof)

 

[Hugh Jaleak]

Often common, I had similar problems in a house once when the council resurfaced the road and didnt realign the rainwater pipes under the pavement, so the road surface covered bottom half of the pipe....

Worst case scenario, relay the pipes on your property in 68mm downpipe, and realign to suit. May be able to get a leak proof joint by solvent welding the pipework together, but do not glue until happy with position, it wont come apart again and anything wrongly glued is scrap..... Alternatvely, look at the 'Flexseal' type couplings, will llow a bit of movement and should be watertight, but are expensive in comparison to plastic fittings.