Narellan Creek Overland Flood Study (Vol 1) - Flipbook - Page 83
7
FLOOD PLANNING INFORMATION
7.1
Overview
Appropriate land use planning is one of the most effective measures available to manage
the flood risk (particularly to control future risk but also to reduce existing flood risks as
redevelopment occurs). A full review of land use planning including appropriate zoning,
policies and planning/building controls is typically undertaken as part of the floodplain risk
management study.
Nevertheless, 8Australian Disaster Resilience Handbook 7 Managing the Floodplain: A Guide
to Best Practice in Flood Risk Management in Australia9 (ADR Handbook 7) (AIDR, 2017)
recommends using the best available information to manage the flood risk at all times.
Therefore, if a flood study is available that contains relevant information (such as this one),
there is no need to wait for the floodplain risk management study before this flood
information is used to inform land-use planning. Accordingly, the following chapter outlines
the process that was employed to develop flood planning category constraint mapping to
assist in informing future land-use planning decisions.
In addition, the results of the flood study can be used to determine the flood planning area
and floodplain risk precincts. This information can be used to understand areas with a
higher flood risk and, should new development or re-development be suitable for those
areas, what controls are applied to ensure the flood exposure/risk is appropriately
managed.
7.2
Flood Planning Area
Flood Planning Levels (FPLs) are an important tool in the management of flood risk and are
derived by adding a freeboard to the Defined Flood Event (most commonly the 1% AEP
flood). The FPLs can then be combined with topographic information to establish the Flood
Planning Area (FPA). The FPL and FPA can then be used to assist in managing the existing
and future flood risk by:
Setting design levels for mitigation works (e.g., levees).
Identifying land where flood-related development controls apply to ensure that new
development is undertaken in such a way as to minimise the potential for flood impacts
on people and property.
The
