groundwater recession problem

[shane369]

I am having a problem with model calibration relating to groundwater recession. The site I am working is composed mainly of sandy soils with high infiltration potential. thus I believe that the water response I see in the stream draining the site is mainly groundwater discharge.

The problem is that the observed recesion is on the order of 12 to 24 hours but Mike SWWM is trying to force a recession of up to 100 hours. Does anyone have a recommendation of how to adjust this or advice on which parameters to focus on in the groundwater input lines?

Thanks,
Evan Williams