We are working on a LEED for Schools 2009 project on a greenfield site and are targeting this SS 6.1. We are retaining 100% of stormwater on site through various methodologies including stormwater cisterns, vegetated swales and on site ponding. ZERO water will run off our site. Despite this fact, our civil engineer has told me that when he runs the Pre / Post Discharge Rate Calculations the Post is more than the Pre. I am not a civil engineer, but this does not make sense to me. We feel as though we've met the intent of the credit. Can someone explain if it is our strategy that is wrong or are we missing something in the calculations? Thanks!