I have been trying to model a storm drain system with SSA 2014 that contains a Retention (not Detention) basin. I think I'm entering everything okay, but it continues to ask me for an outfall. If I add an outlet it seems to work depending on the pipe size what elevation I use for the outfall. I have seen models that other people have done without an outfall and they work fine, but if I do it it tells me that no outfall has been designated for the system and it won't run.
What am I doing wrong?
I tried attaching my file, but he system said it does not accept the .spf extension. How can I attach the file?
Thank you in advance.
Miguel
Solved! Go to Solution.
Solved by fcernst. Go to Solution.
Rename the to suffix to something like .txt.
Surely you have an overflow in this basin, use that as the outfall.
Bill
Bill,
I have attached the spf file. Like you suggested I changed the extension to .txt.
The retention basin has no outfall. Here in bakersfiled we have basins that are supposed to hold the 100 year storm and percolate in 7 days. There is no overflow. They are designed with a watersurface that is 1-foot below the lowest catchbasin inlet elevation, so you have at least a 1-foot buffer.
I have seen more complex systems modeled with this program that have basins with no outfall and work fine. Those were provided to us by the public agancy for coordination, so I can not share those files.
I think I must be doing somthing wrong here.
Thank you,
Miguel
Miguel:
I am about the last person to try to help you on this. I keep hoping that Fred would enter this discussion.
I ran your file and it ran just fine. Unfortunately, I have no idea how your Retention basin should be set up. Your program setup has a one hour 10 year storm that raised the basin up four feet. Most of your pipes are surcharged but did not over top their inlets so I guess that is OK.
What kind of duration storm do your agencies require?
Bill
Bill,
The local agancy only requires a 10 year storm. Things on the file seem to function because it has an outfall, but I would like to run it without the outfall. In real life the sump has no outlet. It is sized to hold a 100 year storm and percolate in 7 days. I also tried it with a wier at the water surface elevation and it seems to work, but as I said this is not the true condition.
I can see if it was a detention basin, then this would work just fine with an outfall.
I can get the model to work with no sump and just an outfall. This is what I did. I will keep reviewing other files where they have managed to get the sump condition to work with no outfall.
Thank you,
Migul
.. I will keep reviewing other files where they have managed to get the sump condition to work with no outfall...
They are probably running the models with Kinematic Wave flow routing.
Fred,
Your are right. That is what they did.
As far as you know is that the only way to do it if you don't want an outfall?
Thank you,
Miguel
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