I am doing a floodplain study in which I have a proposed arch culvert with two different wing wall angles (45-degrees and 90-degrees...to direction of channel flow). FWHA Chart and Scale Number options provided in the program only allow for a 0-degree, 45-degree and 90-degree wing wall angle...
I need to calculate the 100-year floodplain for a project I am working on. The stream flows into a long culvert (500 LF +/-) which is undersized. The overflow from the stream/culvert continues overland to a detention pond where it is detained (along with additional runoff from overland flow)...