Question wheter to show natural drainage courses on a PM or not...

[liftmys10]

I know we need to show Flood Hazard zones, but how about a fairly large "natural drainage course" on a Parcel map i am creating? Would it be to the best interest of my client to show it? I found a previous Tract Map that shows the natural drainage course which we have also identified by field topo, so i'm curious if i should show it on my Parcel Map and make a note that says "Portions of lots 1 adjacent to natural drainage courses are subject to flood hazard"

thanks,