Modeling a pipe with significant sediment build-up

Question

Is there a good way to model this in the GVF-Convex model? I am modeling a very old system and it is suspected there is sediment build-up in the header based on the observed system head and low flows (~800 gpm in a 20" pipe). There doesn't appear to be a way to input this directly to the model. If not, would the best option be changing the C factor dramatically? Any recommended rules of thumb for changing C values to account for this?

MPachlhofer · Answer

Allison, 
 If you know the flow through the pipe you can enter it as a known flow or additional subsurface flow . The difference between these flows is defined in the linked to wiki article. You could also enter a C factor that allows the model to convey that flow, but it may take some trial and error versus entering the flow itself.

Jesse Dringoli · Answer

See also for other options: 
 Modeling an obstruction, clog or excessive sediment in a conduit