Use of Digital Elevation Model to compute Storm Water Drainage Network

Often planners and engineers are faced with various options and questions in storm drainage network design e.g. topography, flow pattern, direction and therefore size of drain or scenario after a road, airfield or building has been constructed. In most instances planning without drainage in mind has caused failure or extensive damage to property including the storm water drains which channel the water away. With the advent of GIS tools this problem can be averted. The Bhimrad area of surat city (Gujrat, India) had no storm drainage network for persistent flooding. This paper describes a method of assessing the effectiveness of storm drainage networks by a Digital Elevation Model (DEM). The DEM was generated from .dwg contour map and the data imported into ArcGIS, The 141.91hactor basin was then delineated into sub-catchments using ArcGIS Hydro extension tools. Also to derive impervious land cover, arial image of study area (Bhimrad) was accessed through ArcMap’s built-in base map function. The roads, buildings, canal, creek, water body existing land use were obtained by digitizing arial image. By overlaying the natural flow lines derived from the DEM with the reconstructed physical drains a comparison of the flow direction and the orientation of the drains was achieved. It is particularly useful for new areas where development is being contemplated.