HECRAS simulation with ocean l as DS boundary condition

[jeffc]

I am trying to figure out the best approach to model flood flows through bridges where the downstream boundary is going to be sea level. I know HECRAS is not the best tool for this, but I using it as a first approximation to determine the sites where I will be using multi-d unsteady models. I am assuming a fixed (no tide) elevation for the DS boundary. Looking for some suggestions on boundary conditions and geometry (infinite width cross section at DS?)

 

[SMIAH]

Do you think that there is a water level gauging station located on the lake?

Are you modeling steady flow using a particular peak flow rate?

If both answers are yes, then you could perform a statistical analysis with the water level recorded to find the WSEL for a particular return period (i.e. same as in the reach).

Some thoughts...