Site Design Drainage in a closed courtyard

[ClemsonVet]

what is your take on how to scope drainage within a closed courtyard? This is always a scoping challenge with the developer on who handles this. from a civil standpoint the risk involved is that you design the drainage space including the surface area and roof drainage that may collect there and then you have to rely on the plumbing designer to pass that flow through the building foundation. is the 100 year flow adequate? there's no overland relief so what can be done to ensure that there are no issues in the future? how does your firm handle this scope?

 

[dik]

Can you have detention/retention on site? How large an area is the courtyard?

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[CarlB]

Civil should be responsible for storm drain collection system, including site runoff and conveying roof runoff to site discharge point. A courtyard may be a bit of a gray area; if was above ground level might be considered similar to a roof and its drainage design is part of plumbing, but at ground level, part of civil site design.
Civil design could involve a drain pipe passing under the building, not involving plumbing piping. Or could be handled with infiltration/disposal, or a combination.
Design should include 100-yr event, since system should not allow ponding to building floor level, or other critical level.
If possible, coordinate with plumbing scope as part of proposal. If not, state assumptions in proposal.