Tarmac footpath drainage design - Tarmac footpath drainage design

[life_can_be_draining]

Good afternoon
I am an engineer for a civil engineering contractor and have been tasked with designing a walkway diversion route for a level crossing. I am starting to now focus on drainage and would like some help on where I can find the relevant information with regards to assessing whether any drainage is needed? I need to be able to justify any decision made, so if anyone knows of the best/relevant standards/guidance documents that would be greatly appreciated.
Thanks in advance

[seanandruby]

Builing regs' part h. Also sewers for adoption.
There is a lot of information on the index page under drainage on this forum. Good luck.

[life_can_be_draining]

Cheers, i'll let you know how I get on.

[life_can_be_draining]

I suppose from reading through the guidance you mention, I would need to undertake a percolation test to assess whether the run-off soaks into the ground adequately? I only have a small catchment of about 350m2. The only issue is that the path is adjacent to a row of houses (back gardens) so I would have to be mindful of this. Do you believe a percolation test would give me the answer I need? Historic boreholes suggest clay material so not good!