A Mathematical Model for an Urban Drainage System

Abstract

Stormwater runoff from an area of approximately 2000 ha of the developed portion of Townsville drains to the tidal estuary of Ross Creek and thence to the sea. The connection of the catchment to Ross Creek is via a complex system of pipes, retention basins, lined and unlined open channels and culverts. At the outlet end the water flows through the Woolcock Canal which is a concrete channel of rectangular cross-section connected to Ross Creek by tide gates. As shown in Figure 1, the catchment is roughly bounded by Castle Hill at the north, Ross River at the east and south and by other natural drainage divides at the west and north west. A more detailed description of the physical system including an explanation of the difference between primary and secondary catchments will be given in section 2.