Underground Detention to Gravel Perc Bed

[ksmcclung]

I am trying to model a 72" diameter underground detention system with orifices that discharge to an underground gravel percolation bed. I have to discharge the first 1.2" first flush by infiltration only.

Having trouble know if I have modeled this correctly in Hydraflow-Hyrdrographs.

Any help would ge great!

 

[bbengineering]

Enter the entire system as an above ground basin with a void percentage. Then add in the exfiltration value located in the pond inputs. You should either do a field percolation test or get a lab to test for the permeability.

 

[beej67]

Depending on where you're at, you'll need to show the system recovers in a given time period.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com