Super-pipe storage slope 2

[19680316]

I am going to control the run off using two orifices( lower and upper) with super pipe storage. I would like to keep the super pipe slope to a minimum. What is the commonly use minimum slope?
I use 1200mm dia CSP.
Thanks!

 

[cvg]

what is a "super" pipe?

 

[19680316]

Super pipe is , an over sized pipe to detain storm water

 

[cvg]

If you plan to store water in a closed pipe, than I'm not sure why slope would be important. Make it flat. If you plan to run low flows through the pipe, than make sure you have 3 fps through the super pipe to flush sediment out. Otherwise, how will you remove sediment?

 

[hydroponder]

The last two "super" pipe I designed I laid them flat. They were 48" and 96" CMP. If you are detaining water in the pipe with orifices, you will not be able to keep the pipe clean from sediment, so you really don't need any slope on it. I just put access manholes on it for cleaning. Depending on the soil conditions, you might think about perforating the pipe to allow for infiltration/groundwater recharge..

 

[hydroponder]

cvg, looks like we were on the same page. Didn't mean to reiterate your post, we must have posted at the same time..

 

[vie]

most municipalities in Georgia require them to be placed on 0.5 percent slope, but I agree flat is best and will yield more storage volume.

For systems like the chambers and perforated pipe that store water in the #57 or #4 stone voids I always lay the pipes and chambers flat. There's a 6 inch bed of underdrain rock that I slope 0.5 percent and use an underdrain to collect the water at the low point. Those designs have 2 pipes entering the OCS (the underdrain and the overflow pipe). You will save lots of money typically going with the rock void storage, even when stone is expensive. Smaller system all together.

1200 mm?? - I'd go with chambers - look up StormTech

David