PUNCH Consulting Engineers were appointed by TJ O’Connor & Associates Consulting Engineers to develop a hydraulic model to assess the flood risk at a proposed development in Dundrum, Co. Dublin.  The study consisted of a desktop study of the flooding events, a site walkover, a hydraulic model of the Dundrum Slang and analysis of LIDAR data of the surrounding area.

Given how complex the hydrology of the area is with numerous out of channel flow paths a 1D-2D linked hydraulic model was required to assess the flood risk.  The 1D Flood Modeller model represented the in channel flows of the River Slang while the linked 2D TUFLOW model assessed the out of channel flow paths. LiDAR data in combination with topographical survey data of buildings was used to generate the 3D ground model used in TuFLOW.  Simulations suggested that extensive flooding would occur during extreme events, similar to that experienced in October 2011.