Design Flood Hydrograph

CWC Synthetic Unit Hydrograph Method & Hydrograph Routing

Utmost care has been taken in the digitisation and extraction of factors and formulas from the CWC Flood Estimation Reports (FER); even so, errors may occur. Users are advised to cross-check the factors, formulas and assumptions against the source reports before use in design.

Catchment Characteristics

Enter the physical characteristics of the catchment. These parameters are used to derive the Synthetic Unit Hydrograph from the CWC sub-zonal regression equations.

Physical Parameters

Catchment Area ($A$) *

km²

Area must be a positive number.

Main Stream Length ($L$) *

Length must be a positive number.

Length to Centroid ($L_c$) *

Centroid length must be positive.

Equivalent Stream Slope ($S$) *

m/km

Slope must be positive.

CWC Sub-Zone Selection

CWC Sub-Zone *

Please select a CWC Sub-Zone.

OR Detect Zone from Coordinates

The Synthetic Unit Hydrograph is derived from these inputs alone. You will configure the design storm on the next step.

CWC Homogeneous Sub-Zones Map

Hydrometeorological homogeneous subzones as per CWC. Click on the map thumbnail below to open the interactive viewer where you can zoom in/out and drag to pan.

Click to Zoom & Pan

Source: MANUAL ON ESTIMATION OF DESIGN FLOOD, March 2001, by Hydrology Studies Organisation, Central Water Commision.