Share Email Facebook Twitter LinkedIn Background (Reference/Theory) The background theory for InfoDrainage™ includes a range of procedures and formulas that can be used in concert to simulate the effects of site runoff, pollutant generation, hydrology routing and hydraulic attenuation. Topics in this section Manning Formula Colebrook-White Formula Rainfall Map RED (Rainfall) File Format Volumetric Runoff Coefficient Unit Hydrograph Index Flood and Adjustment for Return Period Runoff Generation MicroDrainage File Support Analysis Units Translation Guidance on Conductivity Rates Hydraulic and Energy Grade Lines Land Use and Soil Type Calculations