On 31st July 1990, a low pressure system developed off the Queensland Coast. This system moved slowly south over the next few days directing easterly winds into most of the NSW Coast.

The result of these weather conditions was heavy rainfall over the Shoalhaven River catchment, causing moderate flooding to the Nowra and Shoalhaven Heads areas over the period from 1st to 3rd August 1990.

In line with the Department's responsibilities to collect flood data, the South Coast Regional Office proceeded to carry out observations of flooding together with stream gauging operations on the downstream side of the Old Nowra Bridge.

Recording of stage heights by the Department's CSR at Nowra Bridge showed the river peaked at a gauge height of 4.92 (Standard Datum) metres at 0800 hours on 2nd August 1990. From the stage height-frequency curve for Nowra Bridge, the average recurrence interval of the flood event is determined to be 1: 15 years.

This report summarises the data collected for the storm event and resulting flooding.