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Policies and initiatives
> Direction 7. A greener city >
Policy 7.4
Policy 7.4 – Reduce the impact of stormwater
on bays and catchments
The quantity and quality of stormwater entering
our waterways and bays is an important issue for Melbourne 2030.
Impervious surfaces in built-up urban areas result in less water
being absorbed into the ground and can exaggerate peak flows into
a stormwater system. These surfaces affect the quality and quantity
of stormwater, often generating significant pollutant loads that
are readily washed off and conveyed into the stormwater system.
Further, urban development and activity occurring
within the catchment, such as the construction of roads and buildings,
affects the quality of stormwater, as sediments and pollutants from
urban areas are transported to our creeks, rivers, bays and oceans.
Measures to manage urban stormwater quality will be critical in
maintaining the ecological health of Port Phillip Bay and Western
Port, as well as improving the health of our waterways.
The BPEM Guidelines for Urban Stormwater suggest
that urban stormwater management should achieve a 45 per cent reduction
in nitrogen load, 45 per cent reduction in phosphorus load and an
80 per cent reduction in suspended solids load.
The Government will work with Melbourne Water,
local government and other key stakeholders to develop programs
to ensure the achievement of best practice performance objectives
for stormwater (see ‘Water-sensitive urban design’). EPA
Victoria runs the Victorian Stormwater Action Program which provides
grants to local governments throughout Victoria for the development
and implementation of stormwater management plans. Melbourne Water
and local government fund the development and implementation of
these plans for the metropolitan area. All stormwater management
plans developed will be consistent with the BPEM guidelines.
In addressing stormwater impacts on urban waterways
and their inputs to the bays, it is recognised that the performance
objectives in the BPEM guidelines may best be pursued by incorporating
measures at various scales:
- water-sensitive urban design techniques such as domestic rainwater
collection and increased land permeability may be used on-site
for small developments
- these techniques can be incorporated into streetscapes or open
space planned at local precinct scale for larger developments,
or for retrofitting within local catchments
- larger (catchment) scale measures include constructed wetlands
and retrofitting drainage systems.
An integrated approach to the planning of measures
at all scales, involving all relevant agencies to ensure sustainable
outcomes will be pursued.
Initiatives
| 7.4.1 |
Develop measures to achieve best
practice performance objectives as outlined in the BPEM Guidelines
for Urban Stormwater (prepared for the Victorian Stormwater
Committee), in order to ensure water quality objectives are
met |
| 7.4.2 |
Support integrated planning of
stormwater quality at all scales, through a mix of on-site measures
and developer contributions |
| 7.4.3 |
Promote measures to achieve more
effective mitigation of stormwater pollution from construction
sites in line with the EPA Victoria’s Environmental Guidelines
for Major Construction Sites |
| 7.4.4 |
Work with local government to develop
and implement stormwater management plans that incorporate integrated
drainage management principles consistent with the BPEM, and
include measures for annual monitoring and reporting |
| 7.4.5 |
Introduce appropriate controls
in the Werribee and Cranbourne- Pakenham growth areas to ensure
that stormwater (and ground water) does not have a detrimental
effect on the Ramsar wetlands |
| 7.4.6 |
Include water-sensitive design
criteria in an amended Clause 56 (Residential Subdivision Provisions)
of the Victoria Planning Provisions |
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Water-sensitive
urban design
Water-sensitive urban design integrates urban planning and
development with management, protection and conservation through
the whole water cycle. It is about a balanced approach –
the right applications in the right locations to achieve sustainability.
Planned and implemented correctly, its concepts and technologies
allow new developments and the water cycle to complement each
other.
Its key principles are:
- protect and enhance natural water systems
- integrate stormwater treatment into the landscape
- protect quality of water
- reduce run-off and peak flows
- add value while minimising drainage and infrastructure
costs.
Techniques available include:
- grass or vegetated swales
- infiltration trenches
- bio-retention systems
- wetlands
- rainwater tanks
- greywater reuse
- rain gardens, rooftop greening, urban forests
- any combination of these and other techniques for the
best possible outcome.
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