Our local agency is requesting a composite q for runoff instead of a composite CN. Do Bentley products have this capability?
Hi Brian,
Is this "composite q" based on runoffs from different sub-areas of a catchment? However, it is not possible to get individual runoffs from sub-areas, unless you model each sub-area as an independent catchment with its own CN value.
Is this what you are looking for?
Regards,
Yashodhan Joshi
Just wondering if stormcad/sewer gems can do a weighted q yet? As previously posted our agency requires separate runoffs for each curve number to be added together in a catchment. We are no to use a composite curve number for a catchment.
We use weighted q method with rational and SCS TR-20
Thanks for the details, Brian. I am consulting with my colleagues and will get back to you soon.
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.
Brian, our product managers will look into this and prioritize for a potential future release - this is recorded with reference # 538362 which I have attached to a new Service Request opened on your behalf, so that you will receive an email alert if this is implemented in a future release.
In the meantime, the solution you can use is to model each land type as a separate catchment area, with its "Outflow Element" set to a single common discharge point (the same that you would have chosen for the single catchment). This will also enable you to align your model more closely to the real system (by drawing the catchment polygons for each type of land).
I have documented this in the following article in our Wiki: Using the Weighted Q method for catchment runoff