To cope with flood problems, it is necessary to use a number of technical procedures and models to define the physical nature of flooding in terms of flood frequency, flowrates, depths and widths.  This information is combined with social and economic analyses within a governmental, administrative framework to set up procedures and plans for coping with flood problems.

The technical procedures involve:

      (a) data collection - assembly of existing data such as maps and records of previous floods, and surveys to collect specific information such as stream cross-sections and floor levels of buildings,

      (b) hydrological analysis - flood frequency estimates based on available flood information,

      (c) hydrological rainfall-runoff modeling - using a simulation model to define flooding due to actual storms and statistical design storms, interpolating and extrapolating from the available information,

      (d) hydraulic modelling, using flowrates developed from the hydrological models and the physical characteristics of channels (topography and roughness) to define the dimensions of flows and

      (e) data storage and visualisation using databases, GIS and other software.

With the addition of storage routing models, DRAINS can perform runoff-routing calculations in the same manner as the programs RORB, RAFTS and WBNM, which are used throughout Australia. The unsteady flow hydraulic models available in DRAINS can carry out 1-dimensionsl modelling in open channels and flow paths in urban areas.