modelling culvert network in hec-ras 1

[bertieboo]

Hi,

I am carrying out a flood risk assessment on a small stream but the engineers have provided me with a design layout for the proposed culverting of the watercourse (see attachment for plan).

Now I know how to model one single culvert, same gradient etc but how do you model a culvert system with different gradient etc throughout its length.

I have treid this previously by trying to join different cross sections with associated culverts together but for some reason hec-ras thinks theres a break in between the portions of culvert. Is there anyway to join the small seperate portions of culvert together to create the complete culvert network? Or is there a better way to model a culvert network?

Thanks

 

[Ryb01]

bertieboo,

You can't model a storm sewer network like this within HEC-RAS. I would be inclined to model the storm sewer network using a program like SWMM. You can also code in sections of channel at the downstream limits if needed. The visual HGL within SWMM would be a good idication of how the network is functioning.