1:100 FLOODLINE .How far from the study area must you start your cross sections in HEC RAS

[munya48]

I am using hec-ras to do a 1:100 flode line. where are the cross sections suppose to start,. Do you have to do them on the whole stream or you can just take on your study area.

 

[LincolnPE]

You need to prove where your project ties into the existing condition model both upstream and downstream.

 

[gbam]

To start off there is no set distance. The beginning and ending of your study reach should be far enough downstream and upstream to be outside of your proposed improvement's influence. Hope this makes sense; it is not just a set number.