I can tell you it may start a civil war.
I have designed and built roads. I have experience
with private roads.
who use the shortest length of the road will complain about sharing full length cost
- some will speed and wreck road and argue its not them
- some will be eyeing any water for themselves.
I would start by talking with the neighbours and suggesting removing the water will reduce erosion damage
- I would deal only with the water in the gutter on your side only and see what happens
- I would not put lines across the road
- depending on how long the frontage is I would take water from the start and the end of your frontage
Without seeing photos I would not be able to see if my points are worthy and perhaps you can help with that.
What is happening to the water at the moment?