Georges River Flood Data April 28th - May 1st, 1988

This report details the flood gauging operation undertaken on 30th April, 1988 and\r\npresents the data collected for the Georges River catchment, Sydney.\r\n\r\nThe Georges River catchment area is approximately 960 square kilometres and is\r\nshown in Figure 1.1. The main arm of the river begins its course near the Cataract\r\nDam, and exits into Botany Bay. The main channel is joined throughout its course\r\nby minor streams and creeks. The Woronora River catchment also drains into the\r\nGeorges River.\r\n\r\nThe catchment area comprises a large part of the south western urban area of the\r\ncity of Sydney, and the floods that have occurred in the catchment have at times\r\ncaused significant damage to property.\r\n\r\nTo rationalise future development of the area in the face of potential flood threats,\r\nvarious numerical and physical models have been developed by both the University\r\nof N.S.W. Water Research Laboratory, and the Public Works Department's Manly\r\nHydraulics Laboratory. The success of the models in predicting the flooding\r\ncharacteristics of various flood events depend upon collecting specific flood data\r\nover a series of floods for model calibration and verification. To this end, all known\r\ninformation regarding previous floods has been documented (Ref. 1 and 4), but\r\nthere is a need for more comprehensive flood data, especially for major floods.\r\n\r\nManly Hydraulics Laboratory (M.H.L.) was requested by the Department's Coast\r\nand Rivers (C&R) Branch to co-ordinate and undertake flood monitoring at various\r\nsites over the area which is being modelled. These monitoring sites appear in Figure\r\n1.2. Previous reports (Ref. 1 and 4) detail the results of gauging of earlier floods\r\nundertaken in 1978, 1983 and 1986.\r\n\r\nFlood gauging on the 30th April, 1988 was carried out by personnel from the\r\nDepartment's M.H.L. and C&R.\r\n\r\nThe general extent of the flooding 12 hours after the peak can be seen in Plates 1 4.\r\n\r\nThe current metering lines, flood gauge locations and automatic recorder locations\r\nfrom which data was collected are as follows:\r\ni) Current metering/gauge observations at:\r\n\r\n1. East Hills Footbridge\r\n2. Mountbatten Bridge\r\n3. Lansdowne Bridge\r\n\r\nii) Automatic recorders located at:\r\n\r\n1. Milperra Bridge\r\n2. Cutler Road, Lansvale\r\n3. Scrivener Street, Warwick Farm (* This recorder malfunctioned during the flood event.)\r\n4. Liverpool Weir\r\n5. Prospect Creek, Lansdowne