stage storage in pipes - how to calculate??

[zzmarkzz]

I'm working on a project where we will be providing storm water detention within a proposed storm sewer. Does anyone have any idea on how to calculate stage storage within a storm sewer pipe? The storm sewer will have different diameter pipe. Do you have to run a separate stage storage tabel for each size diameter pipe? I need to calc. the stage storage so that i could enter it into TR20. Any ideas would be greatly appreciated.

TIA,
Mark

 

[francesca]

This task is very difficult with a spreadsheet because your pipes are not flat so your volumes do not increase linearly with length of pipe as they would do with flat pipes, where the problem reduces to one of calculating the cross-sectional area of the partially-full pipe.

When I designed an underground detention system using pipes I used Hydraflow Hydrographs which has the capability. It eliminated the human error (which was bound to be vast) and was relatively simple. I just had to add in storage in my rather large junction boxes (we used 4' diameter pipe).

 

[zzmarkzz]

thanks for the response. I have Hydrafow Storm Sewers 2005, do you know if this program has hydrographs for calculating stage storage? I couldn't find "hydrographs" under any of the functions.

 

[francesca]

Hydraflow Hydrographs is another software package distributed by intellisolve. For just $400, it's probably worth buying.

http://www.intelisolve.com/products.html

 

[zzmarkzz]

Thanks francesca. One more ? for ya. Other than being able to calc. stage storage within a pipe, what else does the program do? I'm assuming you could use it to route/model a pond and if that's the case, i'm not sure if that program would be recognized/approved around here in IL - most municipalities 'round here recognize only TR20/TR55, etc. (I would need some good reasons for getting my co. to put up any $$)

TIA
mz

 

[francesca]

Yes, it does hydrograph creation and channel/pond routing. It utilizes the TR55 method, though it is also capable of using the Rational method (I don't think you can route the Rational method; that is, I think it's strictly a peak flow from the Rational method rather than an application of the Modified Rational method). Contact Intelisolve and your local authorities to have them answer your detailed questions regarding whether or not it'll be approved for use. In the mean time, see this:

http://www.intelisolve.com/hydrographs.html.