I have a riser with a weir that discharges to a triple box culvert. Do I put all three at elements in one outlet control structure? I put the downstsream id for the riser and the weir as the culvert. Then I put "free outfall" as the downstream id for the culvert. But then you have to do a tailwater condition for the entire structure, so I generated an elevation-flow curve for the culvert in a separate program (HY-8) and then I put that in as the tailwater condition for the entire structure. Is that right? Something is wrong b/c my estimate peak flows are ridiculous compared to my 100-year inflow that I entered in for the catchment area (100,000 cfs vs. 1,000 cfs). Any thoughts on what I did wrong?