SSA - Sizing an Infiltration Facility

[nmartinQY8ZA]

I am coming up with a standard procedure for modeling an underground infiltration gallery in SSA and I couldn't find many resources which talk about modeling this. I have attached an example SSA model which includes some basic features to show this. In terms of procedure, this is what I have gathered: 

• Under Project Options, set the storage node exfiltration method to constant rate, wetted area.
• The ponded area defines the surface area occupied by ponded water atop the storage node once the water depth exceeds the maximum depth of the structure. An infiltration facility should be designed to fully infiltrate all of the tributary stormwater runoff. Therefore, disable the ENABLE OVERFLOW PONDING AT NODES analysis option in the Project Options.
• Select the “Add Storage Node” icon:and click within the plan view window to add. Add an outfall node and use a link to connect the storage node and outfall node. The inlet invert of the link should be equal to the maximum elevation of the storage facility to show if there is any stormwater runoff that exceeds the maximum depth of the facility.
• Double click on the storage node to open the popup window. Specify the invert elevation, the maximum elevation, the initial water surface elevation (bottom of facility), assume 0.005 (0.5%) for evaporation loss if infiltration pond is above ground and 0% if underground.  Keep ponded area at 0 sq ft. Exfiltration type is typically at all elevations. Set the exfiltration rate.
• Set storage shape to storage curve, set inputs by clicking on the ellipses. Unless you use a storage chamber type specified in the drop down list, use the storage curve data table by inputting a depth and area at different heights within the infiltration facility. Start at the bottom (depth = 0) and end at the top (maximum elevation – initial WSEL). For an infiltration facility without side slopes, no other depths and areas area required. For infiltration facilities with side slopes, input the depth and associated area at 0.5-foot or 1-foot increments. Increase the depth and/or area of the facility until the pipe exiting the storage node has a peak flow during analysis equal to 0 cfs, or until the max water elevation of the storage node is less than the maximum.

Please let me know if there is anything incorrect in this procedure/model.

[MattAndersonGauge]

I think SSA is missing the fixes to the green-ampt pond infiltration routines added in 2009, but have been fixed in later EPA-SWMM 5.1 releases