Pavement surface flow.

[Bhotar3]

I'm designing the drainage for an industrial facility. There's about 190'x 55' paved area(+ roof) that will accumulate storm water.
I was designing a subsurface drainage system. Three inlets spaced 80' apart, with an outfall pipe running to a nearby ditch. My team lead says, if possible, he wants to avoid sub surface drainage for cost reasons. I guess my question is.. This paved area will be poured adjacent to a building and it's slab. To runoff water on concrete (assuming 1% slope) about 220' to the ditch, that's 27.5" of fall from the Hydraulic Length. Seems to me subsurface is the way to go. Advice?

 

[pinkpig]

as a minimum, you need to check the maximum allowable flow depth on your parking lot and make sure yours is below this max number.
You may also consider to design some types of vegetation swales to direct runoff to the ditch if possible, or other LIDs.

 

[beej67]

What's the SWPPP say?

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com