This document discusses the value of using urban stormwater to help cool cities and improve liveability. It provides evidence that stormwater reuse strategies like street tree irrigation, rain gardens, and wetland systems can significantly reduce pavement and air temperatures. Capturing stormwater in these nature-based ways also helps offset rising temperatures due to climate change. The document outlines many successful stormwater harvesting projects in Australia that provide irrigation for parks, sports fields, and even drinking water. It argues that cities should view streets as catchments for trees and rooftops as catchments for drinking water to make better use of this valuable cooling resource.

1. Use it or lose it
The value of urban stormwater in cooling our cities

2. Feeling the
heat:
Climate
and
liveability
2

3. 3
3:25pm 6th January 2018
PENRITH - the hottest place on the planet

4. C. Munck et al. / Urban Climate 23 (2018) 260–286 26
5. 2-m mean nighttime air temperature profiles during the six days of the heat wave for the west-to-east cross section identified on the map of temper
presented for the REF simulation, estimated across three hourly terms - 2, 3 and 4 UTC. The profile for the baseline simulation (REF) shows a heat islan
The urban heat island effect
4
5 degrees higher
City temperatures

5. Human thermal comfort
5

6. 6
Urban stormwater should be one of the answers
to cooling the city

7. 7
Yet we still seem to design systems to flush it down the drain
... albeit a little cleaner

8. 8
With increasing housing density
we are generating more stormwater than older suburbs

9. 9
By 2036 development within the South Creek Valley
will generate streamflows greater than the Desal plant

10. SouthCreek•641ML/day
Desalplant•500ML/day
$530K per day for 50 years
10

11. 11
Use it or lose it.

12. How can
stormwater
help?
12

13. The evidence base - shade trees
13

14. New
York
City
https://www.milliontreesnyc.org/html/urban_forest/urban_forest_benefits.shtml
Climate change benefits - Co2 capture $24.9M
Increased property values $52M
Stormwater interception 5772litres/tree/PA - $35M
Energy savings through local cooling $27M
Air quality improvements $10M / PA
Improved health and wellbeing $100M or $172/tree net benefit
14

15. Shade trees - Pavement temperature reductions of up to 35 degrees
MELBOURNE
January 2017
KNUCKEY STREET CROSSING THERMAL VIDEOS
DARWIN
38
60
34
61
15

16. The evidence base - ground moisture
Rosehill Racecourse - Parramatta
16

17. 44-5326-31 32-37 35-40
8th February 2013
Irrigated lawn Asphalt pavement
Bare groundUnirrigated lawn 17

18. There is no real incentive to do so
Cost of implementing
Reluctance to take on maintenance of the system
Low cost of water
Legislation and regulations
Ownership of water all play a part
Barriers to stormwater reuse and irrigation
18

19. Two Big
Ideas
19

20. 20
Water sensitive cities

21. Liveability and the
Water Sensitive City
Science-Policy Partnership for Water Sensitive Cities
Phillip Johnstone, Rachelle Adamowicz, Fjalar J. de Haan, Briony Ferguson and Tony Wong
Monash University Water for Liveability &
Victorian Government Department of Sustainability and Environment
Focus on Liveability
Cooperative Research Centre
for Water Sensitive Cities
21

22. 22
Sponge cities

23. Chinese Landscape Architect Kongjian Yu
Retain • Adapt • slow down • re-use
23

24. stormwater
re-use
examples
24

25. Domestic rainwater tanks
1
2
3
4
1. Rainwater tank collection
2. + Garden irrigation - shade tree growth
3. + Household re-use - potable water
reduction
4. - Geometric limitations on amount of
roof that can be harvested
5. - Size limitations of domestic tanks
6. - Lack of understanding on operation
25

26. Passive street tree irrigation
1. Stormwater captured
by streets
2. Watering via side entry
pit
3. Tree pit in permeable
paving
4. Geotextile layer
5. City Green“stratavault”
structural soil system
6. Sandy loam topsoil
with high air filled
porosity
7. Subsoil drainage
8. Street high flow
drainage
1
2
3
4
5
6
7 8
makes use of otherwise lost street catchment
26

27. Passive street tree irrigation
1
2
1. Tree watering side entry pit -
for each tree
2. High flow regular stormwater
side entry pit pit every 10
trees, or as required
2
27

28. Keeping water there for the long haul
Wet sump raingardens
28

29. Green and functional
longer detention of water
29

30. The Coal Loader platform
Sustainability at its core
30

31. 1. Storm water captured off building
roof, footpaths, lawns and gardens
2. Flows use old coal loader chutes
3. Some act as rain gardens
4. Flows diverted to storage tunnel
into 25 domestic scale 5,000 litre
tanks. [250,000 litre total]
5. UV filtration and booster pump
pressurises water for irrigation.
6. Water returned for irrigation
Community garden.
7. Water returned for irrigation in
lawns and gardens
8. Excess irrigation water returned to
storage tanks
1
2
3
4 5
6
7
8
31

32. 32
Riparian sponges - The Ponds
Mimicking natural systems

33. A highly desirable liveable community
1. Storm water captured off residential
catchment - Flows out 2x 1700mm diameter
pipes.
2. Pool riffle system graded at 1:100 with stone
drop structures.
3. Riparian vegetation.
4. 3Ha lake provides storage and captures water
to replace evaporateive losses.
5. Non irrigated native woodlands.
6. Parkland lawns irrigated with Recycled water
from Rouse Hill.
7. Sand filter for direct treatment of runoff into
lake.
8. Natural wetland system and habitat.
9. Economic uplift to residential values.
1
2
3
4
5
6
7
8
9
33

34. 34
Peel Reserve - The Ponds
Recovering every drop

35. 1. Stor mwater captured off oval,
footpaths building roof and
carpark.
2. Overland flows captured by kerb
and gutter around oval.
3. Flows diverted to 500,000 litre
underground tank.
4. UV filtration and booster pump
pressurises water for irrigation.
5. Water returned for irrigation.
6. Excess seepage collected through
sub soil drainage network and
returned to tank.
1
2
3
4
5
6
35

36. 36
Blacktown International Sports Park
Capturing high flows

37. acktown Stormwater Harvesting and Reuse scheme – Final Report Page 7
ing weir that can be adjusted to allow flows above 10 litres per second into the pool. This ensures
at Council will only be harvesting stormwater during rainfall events and that environmental flows
e not taken. The weir can also be used to prevent any flows into the offtake pool in case there is
emical spill or similar in the catchment. Council has also installed a flow monitor in the creek that
l turn the Offtake Pool pumps on when flow in the creek is measured above 10 litres per second.
is is a secondary measure to ensure there is ample flow in the creek when harvesting is to occur.
oto 3: The flow control structure Photo 4: The tilting weir with pollution
deflector
e way in which water enters the offtake pool is shown in Figure 2 below.
1. High flows diverted off 665 Ha Angus Creek
catchment with simple weir.
2. Off take dam.
3. Pumping station.
4. 8ML harvest storage ponds with floating wetlands.
5. Treatment wetlands.
6. Chlorine dosing , UV filtration and booster pump
pressurises water for irrigation.
7. +Fields irrigated with water.
1 2
3
4
5
200ML per year 75% of park irrigation needs
$325,000 cost saving per annum
6
7
37

38. 38
Cintra Parklands - Five Dock
Recovering leaking pipe flows

39. 1. High quality low flows diverted off 172 Ha highly
urbanised catchment through simple trash rack /
intake drop structure in concrete lined canal.
2. Glass filter, sand filter and UV treatment.
3. 4.5ML storage tanks.
4. Booster pump pressurises water for irrigation.
5. +15 playing fields irrigated with sub surface
irrigation.
6. +Two golf courses irrigated.
1
2
3
4
250ML per year from 116ML PA projection
75-84% reduction in potable water
6
5
6
http://www.canadabay.nsw.gov.au/green-infrastructure-projects.html#acctab1
5
39

40. 40
Sydney Park wetlands
Stormwater for industrial use

41. 1. Urban stormwater flows off highly urban catchment
through Munni channel below the level of the lakes
2. Channel collection / offtake point
3. Water pumped at up to 1000 litres per sec up to ponds
4. Gross pollutant trap and into upper pond
5. Low flow and park collection / bioretention system
6. Barwon Road collection
7. Cascades / aeration
8. Wetland treatment ponds / wetlands
9. Water reticulated through Sculptural artworks
10. Offtake for commercial re-use and parkland irrigation
11. Reticulation back to top pond.
14
planned up to 850ML per year
5
9
7
6
8
11
10
artwork expresses water
3
2
41

42. 42
Warrnambool Victoria
Roof to tap - rain water for drinking

43. 12ML per year - 84 houses
125ML per year - 850 houses
1. Small buffer tank to throttle larger
rainfall events
2. Clean roof water piped
uncontaminated to storage dam
in small diameter pipes
3. Passes through trash rack
4. Chlorine dosing
5. Delivered back to the house for
drinking water
6. +Smaller stormwater network
pipes
7. +Separates contaminants at the
source
8. +Less flooding / reduces
stormwater management costs
9. +Local collection and use means
less transportation / pipe costs
1
4
6
32
7
8
5
43

44. Conclusions /
What can you
do?
44

45. Ask yourself - what can we do with this water?
Legislative targets • incentives for re-use
Make liveability the core driver of your water projects
45

46. Think of streets as water supply catchments for trees
Excess flows go to type 2 raingardens
46

47. Think of rooftops as water supply catchments for drinking
47

48. Locally treated sewerage flows go to irrigate parklands
48

49. With irrigated sports fields
49

50. With cool green parklands
Riparian corridors mimmick natural systems
as a pool / riffle chain of ponds
50

51. Use it or lose itThe value of urban stormwater in cooling our cities
and are corridors for people
and fauna
51

52. Lakes and wetlands to slow down water
52

53. For a cool and green livable city
53

54. Martin O’Dea
Associate Director
CLOUSTON Associates
65-69 Kent Street, Millers Point, NSW
+612 8272 4999
Thank you • Questions
54

55. BIBLIOGRAPHY/ SOURCES
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BIBLIOGRAPHY/ SOURCES
PAGE
IMAGES CREDITS:
City Green: Page 26 (edited by CLOUSTON Associates) see also refrences for page 26
CLOUSTON Associates: Pages 2, 7, 12, 18, 20, 25, 27, 28, 29, 30 34, 35, 38, 40, , 44, 45, 49, 51, 53
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ISSUE B FINAL 26/10/2018
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