Reference tables for drainage design
The coefficient and ordinate tables behind Delta Hydro Studio's calculators, with the formulas they belong to, worked examples and their sources. Each page reads the same data file the calculator uses.
Manning's n table
Roughness coefficients for excavated, lined and natural channels and for pipes: minimum, typical and maximum values.
Used by: Channel Analysis, GVF Profiles, Channel Lining, Culvert Designer
Runoff coefficient (C) table
Rational method runoff coefficients by land use, slope and soil permeability, with the range and the typical value.
Used by: Rational Method Calculator, Tc Calculator
SCS curve number table
NRCS runoff curve numbers for urban, cultivated and other agricultural land by hydrologic soil group A to D.
Used by: TR-55 Peak Discharge Calculator, Hydrograph Generator, Tc Calculator
SCS 24-hour rainfall distributions
Cumulative ordinates of the NRCS Type I, IA, II and III 24-hour design storms, hour by hour.
Used by: Design Storm Generator, TR-55 Peak Discharge Calculator