Rational Method Calculation Question for PondPack V8i

Question

My model includes Scenarios for 2, 10 & 100 yr. reoccurrence intervals, utilizing the Modified Rational Method. Rational Method calculations in Virginia (and probably many other locals) require the use of a C f (saturation coefficient) multiplier for reoccurrence intervals above the 10 yr. (C f 25 = 1.10, C f 50=1.20, and C f 100=1.25). So for those large storms beyond the 10 yr., the Rational Method Equation becomes Q = C f CiA. 
 
 Is there a way to account for this multiplier in the program calculations for the selected reoccurrence intervals (25, 50 & 100 yr.) as needed? 
 
 Any help would be greatly appreciated. 
 
 Thanks, 
 
 Tom

Jesse Dringoli · Accepted Answer

Hello Tom, 
 Yes, you can use the "C Adjustment" option in the modified rational catchment properties to apply your adjustment factor. Make sure to set up each return event's scenario with a different Hydrology alternative, to keep the settings separate. See below support solution for more information: 
 communities.bentley.com/.../15965.applying-a-c-adjustment-factor-to-different-return-events.aspx 
 Let us know if this helps.