...but my Tailwater is not fixed
...but my Tailwater is not fixed
(OP)
My pond riser outfalls into a stream channel. I'd like to create a rating curve for the outfall channel because it influences the riser. Adding a reach like in TR-20 doesn't seem appropriate because there's no attenuation, but this seems to be the only way. With the old HY-8 it was pretty easy to input an irregular channel shape, slope, and manning's roughness. Any suggestions?
THANKS !!!
THANKS !!!





RE: ...but my Tailwater is not fixed
A custom tailwater table might be a nice wishlist item.
RE: ...but my Tailwater is not fixed
Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve
RE: ...but my Tailwater is not fixed
Sometimes a project does not warrant determining data for the entire contributing watershed to the stream reach at the outfall. If one is familiar with the reach and can approximate wse for specific events.
Another option that came to mind is the "below headwater" option on the tailwater tab of the pond editor dialog.
I believe all these methods could be suitable depending on the project and engineering judgement.
RE: ...but my Tailwater is not fixed
But if the tailwater is a function of the pond outflow into a channel, then using a reach is the best solution, as suggested above. If you set a very short length (10') you'll get the desired rating curves without any significant routing effects.