The Green Square Floodplain Risk Management Plan has been prepared in accordance with
the NSW Floodplain Development Manual (April 2005) and:
Is based on a comprehensive and detailed evaluation of all factors that affect and are
affected by the use of flood prone land;
Represents the considered opinion of the local community on how to best manage its
flood risk and its flood prone land;
Provides a long-term path for the future development of the community.
All possible management measures were evaluated in the Floodplain Risk Management Study
(Reference 5) taking into account a range of parameters. This process eliminated a number of
measures including:
- Flood mitigation dams (no available space in catchment). Note that these options are
distinct from detention basins which are proposed as part of the plan,
- Levees, flood gates and pumps,
- Flood warning (available warning time too short),
- House raising (no suitable buildings), and
*Voluntary purchase.
The evaluation process for assessing each measure involved interaction with the Floodplain
Management Committee technical committee, the Floodplain Management Committee itself and
meetings with Council officers. The proposed measures identified as part of the present study
are described in Sections 0 to 5.5. Note that the various measures are presented in no
particular order within each priority group.
Catchment Description
Historically, the land use within the study area has been predominantly industrial and low density
commercial, with a pocket of residential area (mainly terraces) around Elizabeth Street
between Bourke Street and Joynton Avenue. In the last ten to fifteen years, a large proportion
of the catchment has been redeveloped into high density residential and mixed-use
development. The ACI glass factory site north of Lachlan Street and Victoria Park precinct have
been almost completely redeveloped, and similar re-development is planned for the Midblock,
GSTC precincts and the area south of Victoria Park between Joynton Avenue and Link Road.
The upper reaches of the catchment are flanked by open space areas within the Moore Park
and The Australian golf courses, and medium-density residential development east of South
Dowling Street within the Randwick LGA. There are also a number of smaller parks and private
open space areas throughout the catchment.
Drainage throughout much of the catchment is characterised by underground pipe systems and
overland flow conveyed along the roads, which are nearly entirely formed with kerbs and
gutters. Much of the Green Square catchment was developed between 1912-1920 and was
fully developed by the 1940s, with most of the subsurface drainage system in the Green Square
area estimated to have been constructed prior to the 1930s (Reference 4). Major changes since
1980 have included the re-development of industrial premises at Raleigh Park into medium
density residential estate and drainage works associated with the Eastern Distributor.
