Thankyou for the info. There are several larger brooks and wetlands throughout the property, but I don't believe that flood flows will be that significant even though the commercial portion of the site will add a significant amount of pavement. A 25y frequency was used in the design (noted on...
There are a number of open roadside swales throughout the site. I suspect that the municipal codes/erosion control requirements call for closed drainage though.
I know for sanitary sewer systems I was always required to add a riser pipe when the invert elevation difference was greater than 4'...
I'm performing a val/eng review of a road/drain design and have come accross numerous catch basins in a row that the invert out is substantially lower than the invert in (8'-10' drop). The road profiles are steep 7-12% and the design calls for the pipe(s) to step down at successive CB's as it...