Culvert replacement-tidal region
Culvert replacement-tidal region
(OP)
What can anyone tell me about design criteria for culvert replacement when the flow is tidal? The PM says we don't need a HEC RAS run for water surface elevations, but I need velocities to give to another department for scour calculations. Also, I need to reset/resize these culverts to aleviate flooding over a roadway. I am not sure what I'm governed by. Can anyone help?





RE: Culvert replacement-tidal region
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Culvert replacement-tidal region
RE: Culvert replacement-tidal region
The PM may be right that you don't need a HEC-RAS, but you will need some kind of modeling. Ask your PM what he/she suggests. If they say you can do these calculations in your head, use whatever software you're most comfortable with.
You should be able to account for the tides with tailwater elevation set to the high/low tide mark. I'm not sure how this would affect your flow rate/velocity upstream of the culvert, however, and you may indeed want to use HEC-RAS with ineffective flow areas specified below the high/low water elevation.