EXECUTIVE SUMMARY

Overview

This report presents outcomes of a Flood Risk Management Study (FRMS) and Plan (FRMP) for the Gurungaty Waterway catchment (the study area is shown in Figure 1). The catchment is generally encompasses the suburb of Wollongong south of Crown St, as well as parts of Coniston, Mangerton and Mt Saint Thomas, but is referred to as the Gurungaty Waterway catchment to make a distinction from the broader Wollongong City government area.

The overarching objectives of the FRMS&P are to identify and compare various flood risk management options, including an assessment of their social, economic and environmental impacts. These management options have the primary aim to reduce the flood hazard and risk to people and property in the existing community and to ensure future development is controlled in a manner consistent with the flood hazard and risk.

The main body of the report is the FRMS (Sections 1 to 11), which includes documentation of;

• A historical overview of catchment development and flood behaviour (Section 2);
• community consultation (Section 2.6);
• model verification (against observed flooding in February 2012 and March 2014) – see Section 3 ;
• identification of “hot spots,” areas of higher flood risk to people and/or property (Section 4),
• collection of floor level survey and estimation of flood damages and flood affectation of properties (Section 5);
• review of planning controls (Section 6);
• discussion of potential climate change impacts; and
• assessment of potential flood risk mitigation measures including (Sections 8 to 11):
• flood modification measures;
• planning controls and property modification measures; and
• flood preparedness and response measures.

Key Areas of Flood Risk The area north of JJ Kelly Park, where Swan Street intersects the southern parts of Church Street, Evans Street, Kembla Street and Corrimal Street, was identified as the primary priority area for the FRMS. This is due to frequent above floor flooding of residential property that has occurred in recent years, as well as closure of Swan Street and other major roads. Above floor level flooding has been recently experienced in this area as a result of storm events in February. Other key priority areas identified include;

• Springhill Road, which is a major arterial road and has several low-lying sections subject to relatively frequent inundation. This road potentially poses a significant risk to life from people driving through floodwaters.
• Low lying areas upstream of the railway line, where there is a concentration of risk for above floor inundation, and a risk of flooding being exacerbated by blockage.