FAA METHOD FOR SMALL DET. PONDS

[johnhan76]

Has anyone used the FAA mass diagram method for designing detention ponds on small sites. I have seen it referenced before but am unable to find it in print. The SCS method doesnt seem to work well on small sites. Any suggestions?

 

[jjn]

the faa mass balance technique is described in maidment's "handbook of hydrology" (mcgraw-hill) pg28.27/28.28 - along with a sample problem. it works well for situations where i-d-f based (rational method) procedures are appropriate - don't push your luck beyond that. set up a spreadsheet to calculate cumulative inflow and cumulative outflow over time - detention volume is the maximum difference between these two volumes. acceptance by governing bodies depends on the governing body and your ability to make a case for its validity. hope this helps