Modeling Culverts

[gdreighton]

Is there an issue with using HEC-RAS to model long culverts?
(about 1300' long)

Thanks

[Chris Maeder]

Note that HEC-RAS uses the Federal Highway Administration (FHWA) culvert nomographs for computing flow through a culvert. Therefore, modeling flow through a 1300 ft long culvert would stretching the model limits by quite a bit.

I would recommend analyzing the culvert with something like SWMM.

Sincerely,

Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com

I have tried that in RAS 3 with a 300 m culvert. it worked fine, I even
could reproduce a hydraulic jump withhin the culvert, which we could
really see in nature. if your discharge is not enough to fill the
culvert, you could also model the culvert as open channel. this would
have the advantage that you could model changes inthe geometry of the
culvert and add inflows.

office@ib-humer.at