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research, $ vs performance
financial sustainability“are all assets made equal?”
urbanisation trends
WSUD in Geelong
4https://www.polleverywhere.com/multiple_choice_polls/DaepgoW6mvz1cid
6https://www.polleverywhere.com/clickable_images/kkio3665vcuqx3X
8https://www.polleverywhere.com/free_text_polls/is150EwaoYofHKv
“by 2051 the total area of
impervious surfaces in
Melbourne will increase by
around 43%”
DELWP, 2018
in rural environments
85% of precipitation is
evaporated or
transpired, while in an
urban environment this
figure is reduced to
around 15%
The runoff from urban
areas has been identified
as the largest non-point
source of pollutants within
stormwater
Source:EPA
pollutants in stormwater
Source: NSW Government
identified as the highest
priority threat to:
environmental assets
social cultural and
economic benefit
35
WSU
D in
Geelo
ng are the assets that are being installed, the most
sustainable for the ultimate asset managers?
“concerns over cost and
maintenance of WSUD
systems are the most
vocalised barriers to
its implementation”
Building Capacity with regional
and rural Councils.
Clearwater, 2012
rese
arc
h
39
studies show the economic, environmental and
social benefits of these spaces
also that the increase in property prices can
offset the capital and maintenance costs of
these assets
rese
arc
h
42
Comparing Financial Efficiency
Wetlands
Bioretention Basins
How about the size
of the asset?
$ per kg?
rese
arc
h
57
wetland
bioretention
more cost effective
less cost effective
small assetlarge asset
x2
comparing financial efficiency of
wetlands and bioretention
rese
arc
h
58
wetland
bioretention
more cost effective
less cost effective
small assetlarge asset
x2
comparing financial efficiency of
different size assets
rese
arc
h
59
limitations on current study:
wetland
bioretention
more cost effective
less cost effective
small assetlarge asset
rese
arc
h
60
- climatic conditions
- only one location (data)more cost effective
less cost effective
limitations on current study:
small assetlarge asset
rese
arc
h
61
- sensitivity to renewal costs
more cost effective
less cost effective
limitations on current study:
small assetlarge asset
rese
arc
h
62
more cost effective
less cost effective
- sensitivity to renewal costs
limitations on current study
small assetlarge asset
RCC: Reference Construction Cost
rese
arc
h
63
Financial Efficiency - learnings
bioretention systems were able to
provide higher TN removal, per $
spend by Council over the asset life
larger systems are more efficient
(no surprises here)
64
financial efficiency is however just one
criteria in appropriate asset selection!
rese
arc
h
$ per kg
site layout,
topography
environmental
values
catchment
characteristics
local amenity expertise
rese
arc
h
69
Calibrating Asset Flow
ModelsTest Pollutant
Concentrations
Calibrate First-Order
Decay Models
WSUD asset testing
is the asset working as designed?
financial sustainability
both asset type and asset scale can have an
impact on required dollar spend per kg of
pollutant removed over the asset life
Urbanisation trends
(aus) 89% current population in urban areas.
population and urban coverage will continue
to grow
WSUD in Geelong
predicted to reach >$60m of WSUD assets by
2020, mainly through new growth areas