Flood Resistant Design
Flood Resistant Design
(OP)
Has anyone been required to certify that the construction of a building is in accordance with ASCE 24? I am wondering if there is anything noteworthy or what sort of undertaking this is. We were asked to evaluate a residential addition which is in a flood plane. There is a crawl space which follows the detail that allows water in/out and there are deck piers. I'm assuming we will need to check piers and house foundations for the flow of water. Are there prescriptive requirements for residential projects?
I'm just trying to get an idea if it is worth it for us to do it and what sort of fee we will need to propose.
Thanks!
I'm just trying to get an idea if it is worth it for us to do it and what sort of fee we will need to propose.
Thanks!






RE: Flood Resistant Design
Anytime you need to train yourself and might get corrected by the building official, don't be shy with you fee. See Link
RE: Flood Resistant Design
I'm not entirely sure when you do and don't need to look at breaking wave loads, but from ASCE 24 section 4.1.1 the definition of "Coastal A Zone" seems to be any area with a stillwater depth above ground surface of 1.9 ft or more.
RE: Flood Resistant Design
area, landward of a V-Zone or landward of an open coast without
mapped V-Zones. To be classified as a Coastal A-Zone, the
principal source of flooding must be astronomical tides, storm
surges, seiches, or tsunamis, not riverine flooding, and the potential
for breaking wave heights greater than or equal to 1.5 ft (0.46
m) must exist during the base flood.
So for "riverine flooding" you don't need to design for wave loads, but you do need to design for hydrodynamic, debris loads, and hydrostatic load of 1'.
RE: Flood Resistant Design
EIT
www.HowToEngineer.com
RE: Flood Resistant Design
Any suggestions for Debris Loads?Sorry, as you said, "see commentary". Good info there, got it. Thanks.
EIT
www.HowToEngineer.com
RE: Flood Resistant Design
RE: Flood Resistant Design
RE: Flood Resistant Design
I found the section that defines to what extent you cannot worsen flooding.
ASCE24 section 2.2 Development in Floodways
Structures and fill shall not be constructed or placed in floodway areas unless it is demonstrated that those structures and fill will not, during the design flood (1) increase flood level, and (2) reduce the conveyance of the floodway.
If the design flood elevation has been determined and a floodway has not been designated, structures and fill shall not be constructed or placed unless it has been demonstrated that the cumulative effect of proposed structures and fill, combined with all other existing and anticipated development will not increase the base flood elevation more than 1 ft.
Doesn't that basically mean you can't build new structures in designated floodways, because it would increase the flood level? Or everything needs to be on stilts? We are replacing an existing structure, so we should be able to work something out with the building department.
RE: Flood Resistant Design
Robert Hale, PE
RE: Flood Resistant Design