Burradoo BU2 Catchment Floodplain Risk Management Study and Plan

Brief description

Cardno was commissioned by Wingecarribee Shire Council to undertake a Floodplain Risk Management
Study and Plan (FRMSP) for the Burradoo BU2 Catchment. This FRMSP has been prepared to define the
existing, future and continuing flood behaviour and associated hazards, and to investigate possible
management options to reduce flood damage and risk. It has been prepared in accordance with the NSW
Government Floodplain Development Manual (2005).

Burradoo BU2 Catchment is a sub-catchment of Mittagong Creek which is a tributary of the Wingecarribee
River. The total catchment area is approximately 244 hectares within the suburb of Burradoo with land use
being predominantly rural-residential. Figure 1-1 shows the general location of the Catchment.

The Burradoo BU2 Catchment Assessment Study – Stage 1 Flood Study Report was prepared by Cardno in
2010. The Flood Study defined flood behaviour in the Catchment under existing and future climate change
conditions for the 20% AEP, 5% AEP, 2% AEP, and 1% AEP events and the Probable Maximum
Flood (PMF).

#Study Objectives
The overall objective of this study was to assess flooding risk, investigate floodplain risk management
options and develop a management plan that addresses the existing and future flood risk and minimises the
continuing flood risk in the Burradoo BU2 Catchment. This was undertaken in accordance with the NSW
Government's Flood Prone Land Policy as detailed in the Floodplain Development Manual (2005).
Objectives of the Burradoo BU2 Floodplain Risk Management Study and Plan were to:

* Ensure that the most up-to-date flood-related information is available within the study area to
investigate existing, future and continuing flood behaviour including consideration of potential
catchment and climate change conditions as well as hydraulic and true hazard categories and the
continuing risk for the community.
* Review Council’s existing environmental planning policies and instruments, including Council’s long
term planning strategies for the study area.
* Identify works, measures and restrictions aimed at reducing the social, environmental and economic
impacts of flooding and the losses caused by flooding on development and the community, both existing
and future, over the full range of potential flood events. Innovative solutions to the management of the
flood hazards within the study area were being sought, along with effective community consultation and
participation throughout the Study.
* Evaluate the effectiveness of these works and measures for reducing the effects of flooding on the
community and development, both existing and future. It also considered the social, environmental and
economic impact of these measures.
* Examine and recommend measures to improve community flood awareness and emergency response
measures in the context of the NSW State Emergency Service's developments and disaster planning
requirements.
* Undertake risk category mapping based on four zones (High, Medium, Fringe Low and Low) in line
with Bowral Floodplain Risk Management Study and Plan (Bewsher Consulting, 2004).

#Report Outline
In order to achieve the objectives above, the report is outlined as follows:

* Community consultation (Section 3);
* Environmental and social characteristics of the catchment (Section 4);
* Defining the existing flood behaviour, including flood levels, depths, velocities, hazard zones and
hydraulic categories (Section 5);
* Assessment of economic impact of flooding (Section 6);
* Review of current emergency response arrangements (Section 7);
* Review of development controls (Section 8);
* Assessment of floodplain risk management options (Section 9);
* Economic assessment of flood management options (Section 10);
* Multi-criteria assessment of flood management options (Section 11); and
* Floodplain risk management plan (Section 12).