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NSW Flood Data Portal

Post event data collection

August 1998 Wollongong Storms

During the evening of 17 August 1998 between 1700 and 2000 Eastern Standard Time (EST) extremely heavy rainfall near the Illawarra escarpment to the northwest of Wollongong caused flash flooding, extensive damage to property and one fatality. The rainfall during this three hour period was the most intense part of a 96 hour rainfall event extending from 1800 EST Saturday 15 August to 1800 EST Wednesday 19 August 1998. Prior to the heaviest rainfall, between 1700 and 2000 on 17 August, parts of the Wollongong catchment had already received up to 375 mm of rain during the previous 47 hours. This paper is a synopsis of a report currently being prepared by the Bureau of Meteorology. The highest rainfall total recorded over the entire 5-day period was 745 mm at Mt Ousley, while the highest 24 hour total to 9am on Tuesday 18 August, also at Mt Ousley, was 445 mm. Analysis of the rainfall intensity for durations from 5 minutes to 72 hours has revealed return periods over 1 in 100 years for durations between 30 minutes and 6 hours along the top of the escarpment near Mt Ousley, Rixons Pass, Bulli Pass, Balgownie Reservoir and Beth Salem.

Additional Information

Field Value
Title August 1998 Wollongong Storms
River Basin 214 - Wollongong
Publication Date 23 February 1999
Themes Land and Resource Management
Spatial Extent
© OpenStreetMap contributors
Council/LGA Wollongong City Council
Author/ Prepared by The Institution of Engineers, Australia: Sydney Division Water Engineering Panel
Publish date 27 May 2020
Update date 28 May 2020
Approval State Approved
Submitted for approval 28 May 2020
Submitted by Julia Muniz de Miranda Sa
Approved 28 May 2020
Approved by dstazic
Identifier 2d20f059-c6c8-43a9-bdae-7e3a4023ee22