I've just started to analyze hydrology data in OpenRoads Designer, and I'm wondering if there is a way to compute a composite runoff coefficient in a catchment I drew by hand rather than one auto-delineated by an inlet node. I know this is relatively new functionality but I'm looking for an OpenRoads replacement for the composite rational method C values I would previously find in Geopak Drainage.
The guidance in Bentley's documentation all seems to depend on a context-sensitive option which only appears if the catchment was itself automatically delineated. I'm currently unable to follow that procedure because of issues auto-delineating catchments with the existing terrain file (it only produces very small, irregularly shaped drainage areas due to LIDAR anomalies). So, having drawn the catchments myself using 2d topography, is it still possible to generate composite C values using ORD? I have already drawn and defined the land use area drainage elements.
Also, can the automatic TR-55 time of concentration calculation tool be used in a manually drawn catchment. perhaps by manually inputting a flow path?
Any help or advice is appreciated
https://youtu.be/aLTlHxke3hQ?list=PLnJUnxLwu_N67mfsglQQ-Zllajd8MZjHc
Bentley just sent me this video through a support ticket, and this is exactly what I was looking for. If anyone else is trying to do this, update to ORD 10.12!
You can also do this in 10.11 by making sure your surface polygon land use shapes are set to use the catalog runoff C adjustment method after assigning C values to your land uses in your engineering library, but it's a little harder to work with than 10.12
Answer Verified By: Parker Welch