Soldato
Yes, but specifically on that kerbstone bit around the gulley - what do I need to do there?
No expert here but it would involve removing the kerbstones and redoing that slabbed area so that it all runs towards the train.
TBH, the kerbstone may be thre to both protect the pipe from being struck with stuff being brought around and also to act as a reservoir in case of the drain not coping with heavy water flow so that it holds it until it can drain away down the drain