In message , BigWallop
writes

Is this a communal drainage system? Then get together with the other user
and have the whole thing cleaned properly and inspected fully, of course, by
a reputable company. Communal drainage costs can be shared between everyone
that is on the system, and this helps in keeping the price down for each
individual user.

The other user is my sister so any costs are likely to be mine.

Tackling a communal system may leave you in the proverbial that normally
goes down the drain, and others may say that you caused the problem if there
part starts to give problems in the future. So this is the time to make
contact with them all, and get your heads together on this one. Everyone
must be affected by the blockages, so everyone needs to share in its repair.

I have plenty of drain rods and I could pi*s faster than the last
commercial jetting system here. Each time it happens I put the gear away
thinking I have fixed it:-(

The leak I will fix next time the yard is dry and I feel like lying face
down in an inspection pit. Sorting the narrowing is long term and may
never happen. If there is debris in the system it is now below my
sister's garden where there is a run of some 50m and no inspection
access.

regards



--
Tim Lamb