Backdrop _ Sewage network design

[mohsen alshamali]

I have a project where the project outlet will be connected to an Exist Manhole. the flow of the sewage flow of the project 1.8 L/s (relatively low).
Another facts about the project:-
1- the inspection chamber will be connected to existing manhole via 200 mm pipe line.
2- the horizontal distance between I.C and Ex. MH is 5.5 m. and the difference in elevation level between I.C and EX. MH is 11 m.
(I will post a croky drawing for illustration)

the only way is to connect to Ex.MH is going to be through BackDrop (according to the code the maximum elevation for the backdrop is 4.5 m, in order to avoid scouring in the inner pipe surface), in this case the elevation is over 4.5m.
the question:-
Is it possible to possible construct a backdrop to the existing manhole, since the flow is too low (1.8 L/s) or is there another solution?

 

[bimr]

Not really clear as to what you are asking, but maybe you are looking for something like this, an inside drop manhole:

Link