How do I go about doing this? I'm putting a new bathroom in, and the
soil pipe is too far from the old one to redirect - I know there is a
sewer running just below the garden (it's on the council charts) and
my guttering drain already flows to this. Can I route my guttering
elsewhere, hook into that drain (with some kind of seal around it) and
forget the issue, or do I need to dig down to the sewer and install
some kind of conenction there? The house/sewers are old - early
victorian. Or, is there a fixed charge for water companies to carry
out this work for me?

Any ideas?