The Botany Area Plan project aims to provide an integrated
strategy for managing water, wastewater, recycled water and
stormwater infrastructure in order to provide safe, reliable and
sustainable water services. These services will meet the needs of
urban growth in the Botany area, while complying with the
requirements of Sydney Water Corporation’s (SWC) operating and
Environmental Projection Licences (EPLs).
The Botany area is close to Sydney's CBD.
Redevelopment plans for the area are underway and some development
has already started. The Botany area includes the infill growth
areas of Redfern/Waterloo, Green Square, Wolli Creek, Cooks
Cove and Sydney Airport. This project also takes these areas into
account. In addition, the plan boundary incorporates the areas of
Alexandria/Mascot, Botany Banksmeadow and North Arncliffe as they
include minor growth pockets that needed to be considered.
The outcomes of the servicing strategy were
discussed in terms of SWC’s own corporate sustainability goals.
These provided the framework to fully address the economic, social
and environmental aspect of SWC’s sustainability performance. These
goals were:
- To provide clean safe drinking water
- To contribute to clean beaches, oceans, rivers
and harbours
- To help develop a water efficient city
- To provide effective customer service
- To optimise resource use
- To deliver an economically efficient and
viable business
The first step in the process was to agree upon
a set of objectives for the strategy, requiring input from a
number of key high-level stakeholders. This enabled derivation 15
criteria against which potential servicing initiatives could be
qualitatively and quantitatively measured.
Demands in each of the growth areas were
calculated by performing research into the future populations
(residential and commercial) and the volume of water that was
likely to be used for each end-use (and that could be potentially
replaced by non-potable water). These non-potable water demand
figures then allowed the determination of a broad set of
non-potable water servicing initiatives to meet these demands.
From the set of non-potable water servicing
initiatives, options were devised, each consisting of a water type,
a water source and a treatment /distribution scale and method.
A detailed assessment was then performed on
each short-listed option. This involved investigation into
potential social, environmental, planning, technical demands, water
balance using GHD's Toolkit (see figure below for example of
output, hydraulics, required infrastructure amplification and/or
upgrading), and financial constraints and risks.
These qualitative and quantitative inputs were
then used to perform a multi-criteria analysis to determine
the preferred option. Weighting of the criteria was first performed
to determine their relative importance against the other criteria
and then scoring of qualitative criteria was performed. This
process was performed both internally (within SWC) and externally
(with a range of key stakeholders). The Liverpool-Ashfield pipeline
(LAP) network was the preferred option for both groups.
The LAP network option involved the transfer of
secondary treated effluent from the LAP to a recycled water
treatment plant (to be potentially located at Potts Hill). The
tertiary treated water will be stored in a buffer tank and then
distributed to all future growth via new recycled water trunk mains
or reusable disused gas mains to meet the non-potable demands.
A further detailed investigation was performed
on the LAP network to determine specific risks, costs and
requirements (planning and infrastructure and/or upgrade) and to
develop a preliminary investment and implementation plan.