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Stormwater management is a topic of growing complexity. It includes all measures in mitigating stormwater runoff. Various studies have identified stormwater as a major carrier of various pollutants and other contaminants. The utmost motive behind the implementation of stormwater management strategies is to use a suite of Best Management Practices to reduce sediment load, nutrients and chemical pollutant loads in stormwater before they reach natural watercourses downstream. Mitigation of the flood threat is another objective. Mitigation measures have been implemented in many countries with the same objectives. The relevant factors to be considered when adopting stormwater management measures are the geophysical aspects such as the climate, hydrology, land, soil and topography, law and social factors as well as the technical and economic issues. The world is moving more towards green concepts in mitigating stormwater runoff. Some of these measures are Low Impact Designs, Sustainable Urban Drainage System (SUDS) and Water Sensitive Urban Design. SUDS are more attuned to the green concept. The primary goal of SUDS is to switch from pipe-engineered system to practices and systems that use and enhance natural processes, i.e. infiltration, evapotranspiration, filtration and re-use. While conventional drainage systems focus only on the stormwater quantity, SUDS pay attention to all three aspects of quantity, quality and amenity/biodiversity. These measures have their own advantages and shortcomings. This review targets the present the state of the art of SUDS and its importance in stormwater management.
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*Corresponding author. Tel.: +6140 6468212
Email address: upakasanjeewa@gmail.com
doi: 10.14456/easr.2017.36
Engineering and Applied Science Research October December 2017;44(4):235-241 Review Article
Engineering and Applied Science Research
https://www.tci-thaijo.org/index.php/easr/index
Published by the Faculty of Engineering, Khon Kaen University, Thailand
Sustainable urban drainage systems (SUDS) what it is and where do we stand today?
Uvini Srishantha and Upaka Rathnayake*
Department of Civil Engineering, Faculty of Engineering, Sri Lanka Institute of Information Technology, Malabe 10115,
Sri Lanka.
Received February 2017
Accepted March 2017
Abstract
Stormwater management is a topic of growing complexity. It includes all measures in mitigating stormwater runoff. Various
studies have identified stormwater as a major carrier of various pollutants and other contaminants. The utmost motive behind
the implementation of stormwater management strategies is to use a suite of Best Management Practices to reduce sediment
load, nutrients and chemical pollutant loads in stormwater before they reach natural watercourses downstream. Mitigation of
the flood threat is another objective. Mitigation measures have been implemented in many countries with the same objectives.
The relevant factors to be considered when adopting stormwater management measures are the geophysical aspects such as
the climate, hydrology, land, soil and topography, law and social factors as well as the technical and economic issues. The
world is moving more towards green concepts in mitigating stormwater runoff. Some of these measures are Low Impact
Designs, Sustainable Urban Drainage System (SUDS) and Water Sensitive Urban Design. SUDS are more attuned to the green
concept. The primary goal of SUDS is to switch from pipe-engineered system to practices and systems that use and enhance
natural processes, i.e. infiltration, evapotranspiration, filtration and re-use. While conventional drainage systems focus only
on the stormwater quantity, SUDS pay attention to all three aspects of quantity, quality and amenity/biodiversity. These
measures have their own advantages and shortcomings. This review targets the present the state of the art of SUDS and its
importance in stormwater management.
Keywords: Best management practices, Green infrastructure, Green roofs, Stormwater management, Sustainable urban
drainage systems, Urbanization
1. Introduction
Stormwater originates from precipitation and melting
ice. A significant portion of stormwater infiltrates into the
soil. The other portion flows on the surface and is known
as surface runoff. Stormwater, when it is in a controllable
state, is not a serious issue. However, it becomes one of the
most critical issues when there is excessive stormwater
runoff and it cannot be controlled. Unlike sewage,
stormwater is not treated before it reaches the receiving
water in most countries. Therefore, it carries various
pollutants including suspended solids, heavy metals,
biodegradable organic matter, organic micro-pollutants,
pathogenic microorganisms and nutrients [1]. Stormwater
washes these pollutants into nearby bodies of water. The
impact is much higher in the first flush [2-4]. It has been
identified that the largest mass of pollutants are often
transported during the initial period/volume of stormwater
runoff. This is commonly known as the “first flush” or the
“first foul flush” [1]. Phosphorus and nitrogen are two of the
most important components in fertilizers. They are very
prominent in stormwater runoff. Therefore, many urban
streams suffer from increased phosphorous concentrations
due to the ubiquitous application of lawn and garden
fertilizers. However, urban areas also contribute nitrogen to
waterways. This comes from industries. Additionally, metals
including lead, zinc, chromium, copper, manganese, nickel
and cadmium are common in urban runoff [5-6].
Furthermore, the quantity of stormwater is also a
problem [1, 7-8]. The discharge of stormwater into water
bodies causes impact depending on the characteristics of the
discharge (quality and flow velocity) and the volume and
quality of the receiving water [1]. More importantly, the
quantity of stormwater matters when it falls on hard or
impervious surfaces such as paved roads, roofs, driveways
and parking lots [1]. Impervious layers restrict the infiltration
and increase surface runoff. Figure 1 clearly shows the
accumulation of stormwater due to limited infiltration.
Urbanization increases the impervious area. It is well
understood that urbanization increases surface water runoff
[9]. Human activities including removal of vegetative
surfaces, conversion of raw land into impervious pavement,
Engineering and Applied Science Research October December 2017;44(4) 236
Figure 1 Accumulated stormwater at the Sri Lanka Institute of Information Technology (SLIIT) (Photo curiosity: Mr.
Babishya Khaniya, undergraduate student, Faculty of Engineering, SLIIT, Sri Lanka)
and filling in of natural ponds and streams. These directly
increase the impervious area. Some studies show that
impervious area increased by about 255% over a 34 year
period. This research work was carried in the Snohomish
water resources area of western Washington. It clearly shows
the adverse impact to surface water runoff [10]. The situation
is much worse in China. The amount of urbanized land
increased by 43.46% in the years 2000 to 2008 in China.
However, the impervious area increased by 53.30% in the
same period [11]. This is a good example showing the
relationship between urbanization and increased impervious
area. Figure 2 further illustrates the temporal variation of
impervious area in Urumqi, China from 1990 to 2010 [12].
Impervious area increased from 25% to 63% over 20 years.
Greater impervious area increases surface runoff and can
cause local flooding. Additionally, high volume flows can
cause other impacts to nature. River banks can be eroded due
to higher flow rates and wildlife habitats can be destroyed.
Uncontrolled stormwater runoff is one of the main causes of
stream impairment in urban areas [13-14]. Therefore,
stormwater planning and management are very important.
Thus, this review paper presents the state of the art of
sustainable urban drainage systems (SUDS) and its
importance in stormwater management all over the world.
2. Stormwater management
Stormwater management is the management of the
quantity and quality of stormwater. The general advantages
of stormwater management include mitigation the damage to
the property, protection of the natural water bodies from
pollution, to provide the economic benefits, and to promote
public health. However, unplanned stormwater runoffs have
to be treated in an engineered system. Over the past couple
of decades, many countries have implemented new policies
to address stormwater runoff. Unplanned stormwater runoff
(or excessive stormwater runoff) can be triggered due to
reduced infiltration, altered riparian ecology and frequent
peak stream flows [15]. It has a direct impact upon the
livelihoods of people, irrespective of geographic or climatic
regions [16]. Stormwater management frequently follows
Best Management Practices (BMPs). BMPs are techniques
or structural measures that can be used to better control
stormwater flow and its quality. They are used to maintain
an acceptable level of quality, including reducing sediment,
nutrients and other contaminants before the stormwater
reaches natural water bodies.
3. Sustainable urban drainage system (SUDS)
Structural and non-structural measures are quite
common in stormwater management. Both developing and
developed countries follow structural measures. However,
several countries now use non-structural ways to control
stormwater. The world has moved mostly towards green
measures in mitigating stormwater runoff [17-19]. Under
these measures, municipalities try to reduce stormwater
runoff at its origin [20-21]. One of these emerging practices
is "Sustainable Urban Drainage Systems”, commonly called
SUDS.
In an organically rich environment (humus soil), a
significant volume of rainfall soaks into the ground through
infiltration [22]. However, this is reduced in urban areas
where the land is paved by various impervious materials.
Conventional drainage networks are designed to transport
stormwater to natural water bodies or wastewater treatment
plants. These can either be stormwater networks (where
only stormwater is transported) or combined sewers (where
stormwater it’s transported with wastewater) [23-24].
Separate drainage systems to collect stormwater and
wastewater can be seen in Australia. However, combined
systems are common in other places. During stormy
periods, downstream floods are frequent due to this
stormwater.
However, SUDS offers a sustainable solution to
flooding. SUDS switches from piped engineered system to
practices and systems that use and enhance natural processes
(i.e., infiltration, evapotranspiration, filtration, retention and
reuse). It provides drainage solutions by introducing
alternatives to the direct channeling of stormwater runoff
through pipes and sewers to nearby water resources [25].
SUDS uses a set of techniques that is collectively referred as
the “Management Train”. This includes four key steps:
source control, pre-treatment, retention and infiltration. The
other objectives of implementing SUDS are reducing surface
water flooding, improving water quality and enhancing the
amenity and biodiversity of the environment. In achieving
the above objectives, SUDS reduces flow rates, the transport
of pollution to the environment and increases the water
storage capacity.
237 Engineering and Applied Science Research October December 2017;44(4)
Figure 2 Land cover change over the years [12]
(a) (b)
Figure 3 a: An ecological swale with river gravel making up a flow flow channel [26]; b: SUDS at the Royal North Shore
Hospital, Sydney, Australia (Photo curiosity: Ms. Uvini Sirishantha, Instructor, Faculty of Engineering, SLIIT, Sri Lanka)
Figure 3a shows an ecological swale [26] developed by
the University of Sains in Malaysia to simultaneously reduce
surface runoff velocity and increase infiltration. River gravel
was used to enhance the porosity of the contact ground to
increase the infiltration.
Figure 3b shows the application of SUDS at the Royal
North Shore Hospital, Sydney, Australia. There is clear
space for SUDS between the roads and the footpath. A green
area with a highly porous soil allows infiltration of much
stormwater and the nearby screen shown in the figure allows
excessive stormwater to run into a drain.
While the conventional piped system mainly addresses
the stormwater quantity control, SUDS pays attention to all
three aspects of stormwater, i.e., its quantity, quality and
amenity/biodiversity [27-28]. Figure 4 shows couple of
plants (Schoenoplectus tabernaemontani and Juncus
edgariae) [29] after being submerged for one year in a
synthetic stormwater to experiment the capture of various
pollutants in stormwater. The experiments were done in New
Zealand yielding sound results.
Additionally, climate change [30-31] and urbanization
[29, 32] are believed to be two of the main reasons for urban
flooding. Many researchers have found that the frequency
and magnitude of flooding are increasing as a result of
climate change. Concurrently, urbanization plays an
important role in degrading the quality of stormwater.
Therefore, SUDS can be an effective solution to
aforementioned issues of stormwater runoff.
Figure 4 Plants from vegetated floating mats [29]
4. SUDS renamed?
SUDS have been implemented in many countries under
different names. In Europe, SUDS are being implemented
with the goals of maintaining public health, protecting
valuable water resources from pollution and preserving
biological diversity and natural resources for future needs. In
Australia, a similar catchment-wide approach is being
practiced under the name, Water Sensitive Urban Design
(WSUD), where SUDS is a part of the design. It sustainably
integrates urban water management into city landscapes to
minimize environmental degradation. In the United States
and Canada, Low Impact Development (LID) measures
are practiced. These acts as an approach promoting the
Engineering and Applied Science Research October December 2017;44(4) 238
Figure 5 Comparison of conventional and renewed urban drainage system [33]
interaction of natural processes with urban environments to
conserves and uses natural features to mitigate the adverse
impacts of urbanization [1]. However, the main role of any
system is to reduce the adverse impacts of increasing
volumes of polluted stormwater runoff.
5. SUDS vs conventional drainage systems
Conventional drainage systems were designed and
implemented with the main goal of managing stormwater
volumes to avoid or reduce urban flooding. Conventional
drainage systems are comprised of many structural
components, e.g., concrete pipes, manholes and storage
facilities. Therefore, the construction and installation costs of
conventional drainage systems are high. Additionally, the
burden on the existing drainage systems is high because of
increased stormwater flows resulting from climate change
and urbanization. Therefore, new construction is necessary if
the authorities are to rely on conventional drainage systems.
However, such construction disrupts the general public. So,
this solution is not sustainable. Conventional drainage
systems are more challenging. SUDS can overcome these
issues. The early objectives of SUDS were to provide a
convenient cleaning mechanism to promote public hygiene
and to provide flood protection [9]. Nevertheless, SUDS
today have enhanced capabilities by adding recreational
value, ecological protection to aquatic environments and
pollutant control along with the provision doe other water
uses.
Figure 5 shows another example of a practical
application of SUDS [33]. This shows a comparison of a
conventional approach to a SUDS upgraded drainage system
in Colarado, in the USA. Stormwater runoff from impervious
surfaces drains into a micro-flow system, where a filtration
process takes place. Porous pavers, grass swales and
bio-retention basins can be fitted into this micro-flow
system. The overflow from this layer is directed to drains
along the streets. However, conventional systems only
collect stormwater through the roadside drains.
6. SUDS in action
SUDS gives equal importance to stormwater quantity,
quality and biodiversity/amenity. It considers the technical,
environmental, social and economic impacts of stormwater
runoff [28]. Various techniques have been adopted to satisfy
the three goals of SUDS, runoff attenuation and mitigation,
pollutant reduction and amenity construction. The filters and
infiltration trenches, permeable surfaces, water storage areas,
swales, water harvesting, detention basins, wetlands and
ponds are major devices that have been used. From a
hydrological point of view based on the impacts on water
runoff and routing processes, SUDS act as a source control
measure, an on-site control measure and a downstream
measure [34]. It is expected to keep the excess stormwater
runoff upstream to delay the downstream flow. Next on-site
control is necessary to prevent flooding and to minimize
flood damage. Finally, downstream measures are required to
efficiently control the upstream flow to reduce the runoff and
increase the infiltration.
SUDS have many advantages. They reduces the peak
flow in the hydrograph. It helps to improve the water quality
and naturally mitigate waterborne deceases. Additionally,
SUDS provide a temporary storage in the event of extreme
rainfall to keep downstream areas safe from flooding while
recharging the ground water table. SUDS have some
disadvantages too. The stormwater infiltration trenches can
become clogged by sediment over time and their life span
reduced [35]. This is costly. Therefore, sediment traps are
necessary in the upstream infiltration trenches [36].
7. Implementing Green Infrastructure (GI) in
stormwater runoff mitigation
Green infrastructure (GI) is an intergral component of
SUDS approaches [37]. GI can be defined as any green
spaces that are interconnected to protect nature and benefit
mankind, flora and fauna [38-39]. It is a way of managing
stormwater runoff by infiltration into the soil or reducing
runoff through reuse [40]. The utmost motive behind
implementation of GI is to improve the quality of prevailing
surface conditions while managing stormwater in a
sustainable manner.
GI can be implemented through structural and
non-structural measures such as green roofs, rainwater tanks,
wetlands. Pervious pavements, bio-swales, planter boxes,
cisterns and rain barrels are examples of structural GIs [39].
Non-structural measures include policy decisions to design
buildings and roads to minimize impervious area, improve
the infiltration capacity of soils and increase vegetation cover
[41].
Computer models play an important role in
implementing GIs. They can make highly accurate
predictions. Therefore, their use in GIs is becoming popular.
RECARGA [42], P8 Urban Catchment Model [43], SWMM
5.0 [44-45], MUSIC [46], SUSTAIN [47] and WinSLAMM
[48] are few computer models used by researchers and
industrial designers. Computer models of green architecture
239 Engineering and Applied Science Research October December 2017;44(4)
enhance the accuracy of simulation results. SWMM by
United States Environmental Protection Agency (US EPA)
provides for more benefits than other models as it can be used
in more complex, large-scale projects. It is one of the most
sophisticated tools in modeling stormwater quality, quantity
and GI performance [39, 44].
Green infrastructure has growing public interest in recent
years due to its provision for eco-system services. Energy
savings, air quality improvement, mitigation of climate
change impacts can be achieved by reducing greenhouse
gases, and increasing the green cover. These are a few of the
ecosystem services of GI [39].
8. Source control as an approach
As was previously discussed, the increase of impervious
surfaces associated with urban development is partially
responsible for the current stormwater management issues.
Structural infrastructure has been introduced to address these
management issues. However, they provide temporary and
short term solutions in storing excess water. Source control
is a good solution due to the area limitations in urban zones.
It has many benefits over traditional approaches [49-51].
Identifying stormwater problems and implementing
necessary solutions at the origin is the basis of the source
control [52]. Green roofs and pervious pavements are widely
used source control structures.
9. Green roof - an emerging trend
Green roofs reduce stormwater runoff volume by
retaining a portion of the precipitation. They use the existing
roofs and space limitations are not an issue in urban areas.
Many researchers have shown that the there is a significant
reduction in stormwater runoff from green roofs [53-54].
Additionally, green roofs keep buildings cooler during the
summer months [55]. Furthermore, green roofs can return
water to the atmosphere by evapotranspiration [56]. Land use
information, basin information, precipitation and the
potential for evapotranspiration are important input variables
when designing green roofs [52]. Researchers found that the
total the area coverages is more important than the thickness
of the green roof. The initial costs for construction of these
green roofs is high. However, over a longer term, green roofs
are economical [56].
Figure 6 [57] shows green roofs that were tested by the
United States Environmental Protection Agency (US EPA).
Successful application of green roofs can be clearly seen by
the growth of the plants in green roof after a six month and
one year timeframe.
10. SUDS in various climatic regions
SUDS have been successfully applied in many climatic
regions. However, there are some differences from region to
region. Scandinavian countries have a six month winter
season. Therefore, countries like Norway, Sweden and
Finland have to implement their SUDS during the non-winter
seasons. They also have to maintain their systems properly.
However, these countries use country specific guidelines for
stormwater control [58].
However, there is a slight advantage in stormwater control in
cold climates in winter. Snow takes a time to melt and there
is no sudden stormwater flow during the winter. Instead, the
snow can infiltrate into the soil later. Nevertheless, there can
be problems in the spring. There may be sudden snow
melting due to the rising temperatures. Additionally, frozen
soil and dormant biological functions lead for poor
stormwater management during the winter months [59].
However, the findings of Roseen et al., [59] showed that
LIDs were not affected by seasonal effects whereas
hydrodynamic separators and swales exhibited large
seasonal variations. Therefore, these structures have to be
oversized.
Stormwater management in dry or desert areas is
interesting and has not been given enough attention. Many
people believe there are no significant issues in stormwater
management in arid regions as they receive little
precipitation on an annual basis [60]. There are some arid
regions with significant amounts of precipitation, but with
lower event frequencies. The characteristics of the
precipitation in areas with large inter-storm durations should
be considered in stormwater management for arid areas. This
is similar the case of humid and trophic environments [61].
Consideration of the climatic region is an important factor in
selecting the correct SUDS approach in stormwater
management.
11. Final remarks and conclusions
Stormwater runoff has recently been a topic under
discussion. This is largely due to the immeasurable damage
it causes socially, environmentally and economically.
Therefore, measures addressing this issue should be
implemented. Recent research has shown green adoption
measures to be more sustainable and eco-friendly than most
(a) (b)
Figure 6 An example of a green roof in a SUDS: (a) in November 2003 and (b) in June 2005 [57]
Engineering and Applied Science Research October December 2017;44(4) 240
of the structural mitigation measures. Thus, green
approaches have gained popularity. One such emerging
green trend is Sustainable Urban Drainage Systems (SUDS).
This review touches the state-of the-art of SUDS as practiced
in today’s world.
SUDS have augmented conventional drainage pipe
networks with their economic and environmentally friendly
benefits. They have proven to be a good solution for
stormwater management. These systems avoid floods by
providing temporary water storage during extreme rainfall
events. They adds aesthetical value to the areas in which they
are located. Furthermore, the can attract wildlife thus
creating new habitats promoting bio-diversity. In this way,
SUDS increase the amenity of the environment.
SUDS also have some barriers to their application.
Expert knowledge is required when implementing and
maintaining them. Additionally, the cost to convert from
conventional drainage systems to SUDS is high.
Furthermore, their infiltration trenches can become clogged
over time providing hindering the performance of such
systems. Every system has its benefits and its shortcomings.
Efficient performance can be expected when the necessary
modifications are made before adopting the measures. This
review examines green measures that have been
implemented so far, the reasons for using them and their
shortcomings. It is important to note that different measures
can be adopted considering the various characteristics that
change from region to region. Appropriate modifications
should be made to design the best systems possible.
12. References
[1] Barbosa AE, Fernandes JN, David LM. Key issues for
sustainable urban stormwater management. Water Res.
2012;46:6787-98.
[2] Hathaway JM, Tucker RS, Spooner JM, Hunt WF. A
traditional analysis of the first flush effect for nutrients
in stormwater runoff from two small urban catchments.
Water Air Soil Pollut. 2012;223(9):5903-15.
[3] Miguntanna NP, Liu A, Egodawatta P, Goonetileke A.
Characterising nutrients wash-off for effective urban
stormwater treatment design. J Environ Manag.
2013;120:61-7.
[4] Schiff KC, Tiefenthaler LL, Bay SM, Greenstein DJ.
Effects of rainfall intensity and duration on the first
flush from parking lots. Water. 2016;8:320-9.
[5] Reddy KR, Xie T, Dastgheibi S. Removal of heavy
metals from urban stormwater runoff using different
filter materials. J Environ Chem Eng. 2014;2(1):282-
92.
[6] Jang A, Seo Y, Bishop PL. The removal of heavy
metals in urban runoff by sorption on mulch. Environ
Pollut. 2005;133(1):117-27.
[7] Brattebo BO, Booth DB. Long-term stormwater
quantity and quality performance of permeable
pavement systems. Water Res. 2003;37(18):4369-76.
[8] Dotto CB, Mannina G, Kleidorfer M, Vessaro L,
Hentichs M, McCarthya DT, et al. Compassion of
different uncertainty techniques in urban stormwater
quality and quantity. Water Res. 2012;46(8):2545-58.
[9] Zhou Q. A review of sustainable urban drainage
systems considering the climate change and
urbanizatinon impacts. Water. 2014;6:976-99.
[10] Powell SL, Cohen WB, Yang Z, Pierce JD, Alberti M.
Quantification of impervious surface in the Snohomish
Water Resources Inventory Area of Western
Washington from 19722006. Rem Sens Environ.
2008;112(4):1895-908.
[11] Kuang W, Liu J, Zhang Z, Lu D, Xiang B.
Spatiotemporal dynamics of impervious surface areas
across China during the early 21st century. Chin Sci
Bull. 2012;58(14):1691-701.
[12] Yan Y, Kuang W, Zhang C, Chen C. Impacts of
impervious surface expansion on soil organic
carbon a spatially explicit study. Sci Rep. 2015;5:
1-9.
[13] Paul MJ, Judy LM. Streams in the urban landscape.
Annu Rev Ecol Systemat. 2001;32:333-65.
[14] Pitt R, Field R, Lalor M, Brown M. Urban stormwater
toxic pollutants: assessment, sources, and
treatability. Water Environ Res. 1995;67(3):260-75.
[15] Loperfido JV, Noe GB, Jarnagin ST, Hogan DM.
Effects of distributed and centralized stormwater best
management practices and land cover on urban stream
hydrology at the catchment scale. J Hydrol.
2014;519:2584-95.
[16] Gautam MR, Acharya K, Stone M. Best management
practices for stormwater management in the Desert
Southwest. J Contemp Water Res Educ. 2010;146:30-
49.
[17] Rushton B. Low-impact parking lot design reduces
runoff and pollutant loads. J Water Resour Plann
Manag. 2001;127(3):172-9.
[18] Bliss DJ, Neufeld RD, Ries RJ. Stormwater runoff
mitigation using a green roof. Environ Eng Sci.
2009;26(2):407-18.
[19] Stovin V. The potential of green roofs to manage urban
stormwater. Water Environ J. 2010;24(3):192-9.
[20] Sieker F. On-site stormwater management as an
alternative to conventional sewer systems: a new
concept spreading in Germany. Water Sci Tech.
1998;38(10):65-71.
[21] Van der Sterren M, Rahman A, Shrestha S, Barker G,
Ryan, G. An overview of on-site retention and
detention policies for urban stormwater management in
the Greater Western Sydney Region in Australia.
Water Int. 2009;34(3):362-72.
[22] Martens D, Frankenberger W, Modification of
infiltration rates in an organic-amended irrigated.
Agron J. 1992;84(4):707-17.
[23] Brombach H, Weiss G, Fuchs S. A new database on
urban runoff pollution: comparison of separate and
combined sewer systems. Water Sci Tech.
2005;51(2):119-28.
[24] De Toffol S, Engelhard C, Rauch W. Combined sewer
system versus separate system - a comparison of
ecological and economical performance indicators.
Water Sci Tech. 2007;55(4):255-64.
[25] Mohammadhossein K, Zulkifli BY, Ali H. Advancing
stormwater management practice in Iran using water
sensitive urban design approach. Int J Water Resour
Environ Eng. 2013;5(9):515-20.
[26] Ghani AA, Zakaria NA, Chang CK, Ainan A.
Sustainable Urban Drainage System (SUDS) -
Malaysian experiences. 11th International Conference
on Urban Drainage; 2008 Aug 31 Sep 5; Edinburgh,
Scotland. 2008. p. 1-10.
[27] Apostolaki S, Jefferies C, Wild T. The social impacts
of stormwater management techniques. Water Pract
Tech. 2006;1(1):1-8.
[28] Perales-Momparler S, Andres-Domenech I, Joaquin A,
Escuder-Buenob I. A regenerative urban stormwater
management methodology: the journey of a
Mediterranean city. J Clean Prod. 2015;109:174-89.
241 Engineering and Applied Science Research October December 2017;44(4)
[29] Tanner CC, Headley TR. Components of floating
emergent macrophyte treatment wetland influencing
removal of stormwater pollutants. Ecol Eng.
2011;37:474-86.
[30] Brouwer R, Akter S, Brander L, Haque E.
Socioeconomic vulnerability and adaptation to
environmental risk: a case study of climate change and
flooding in Bangladesh. Risk Anal. 2007;27(2):313-
26.
[31] Botzen WJW, Van den Bergh WJCJM. Insurance
against climate change and flooding in the
Netherlands: present, future, and comparison with
other countries. Risk Anal. 2008;28(2):413-26.
[32] Suriya S, Mudgal BV. Impact of urbanization on
flooding: The Thirusoolam sub watershed - a case
study. J Hydrol. 2012;412-413:210-19.
[33] Guo CYJ. Green concept in stormwater management.
Irrigat Drain Syst Eng. 2013;2(3):1-8.
[34] Hoang L, Fenner RA. System interactions of
stormwater management using sustainable urban
drainage systems and green infrastructure. Urban
Water J. 2015;13(7):739-58.
[35] Heal KV, Hepbum DA, Lunn RI. Sedimentation and
sediment quality in sustainable urban drainage
systems. Proc. Second National Conference on
Sustainable Drainage Coventry University; 2003 Jun
23-24 June; Coventry, UK. 2003. p. 215-26.
[36] Revitt DM, Shutes RBE, Jones RH, Forshaw M,
Winter B. The performances of vegetative treatment
systems for highway runoff during dry and
wet conditions. Sci Total Environ. 2004;334-335:
261-70.
[37] Mguni P, Herslund L, Jensen M. Sustainable urban
drainage systems: examining the potential for green
infrastructure-based stormwater management for Sub-
Saharan cities. Nat Hazards. 2016;82(S2):241-57.
[38] Benedict MA, McMahon ET. Green infrastructure:
smart conservation for the 21st century. Washington:
Sprawl Watch Clearinghouse; 2005.
[39] Jayasooriya VM, Ng AWM. Tools for modeling of
stormwater management and economics of green
infrastructure practices: a review. Water Air Soil
Pollut. 2014;225(2055):1-20.
[40] Wise S. Green infrastructure rising. Planning. 2008;74:
149.
[41] Elliot AH, Trowsdale SA. A review of models for low
impact urban stormwater drainage. Environ Model
Software. 2007;22:394-405.
[42] Neilson I, Turney D. Green infrastructure optimization
analyses for combined sewer overflow (CSO) control.
Low Impact Development international conference
2010; 2010 Apr 11-14; California, United States.
Virginia: American Society of Civil Engineers; 2012.
p. 1533-41.
[43] Haris H, Chow MF, Usman F, Sidek LM, Roseli ZA,
Norlida MD. Urban stormwater management model
and tools for designing stormwater management of
green infrastructure practices. IOP Conf Ser: Earth
Environ Sci. 2016;32:1-18.
[44] Rathnayake US. Migrating storms and optimal control
of urban sewer networks. Hydrology. 2015;2(4):230-
41.
[45] Rathnayake US. Enhanced water quality modeling for
optimal control of drainage systems under SWMM
constraint handling approach. Asian J Water Environ
Pollut. 2015;12(2):81-5.
[46] Beck HJ, Birch GF. The magnitude of variability
produced by methods used to estimate annual
stormwater contaminant loads for highly urbanised
catchments. Environ Monit Assess. 2012;185(6):
5209-20.
[47] Zhen X, Yu S, Lin J. Optimal location and sizing of
stormwater basins at watershed scale. J Water Resour
Plann Manag. 2004;130(4):339-47.
[48] Pitt R, Clark S. Integrated storm-water management
for watershed sustainability. J Irrigat Drain Eng.
2008;134(5):548-55.
[49] Delleur J. The evolution of urban hydrology: past,
present, and future. J Hydraul Eng. 2003;129:563-73.
[50] Urbonas BR, Jones JE. Summary of emergent urban
stormwater themes. In: Urbonas BR, Editor.
Engineering Foundation Conference 2001: Linking
Stormwater BMP Designs and Performance to
Receiving Water Impact Mitigation; 2001 Aug 19-24;
Colorado, USA. Virginia: American Society of Civil
Engineers; 2012. p. 1-8.
[51] Petrucci G, Rioust E, Deroubaix JF, Tassin B. Do
stormwater source control policies deliver the right
hydrologic outcomes?. J Hydrol. 2013;485:188-200.
[52] Versini PA, Jouve P, Ramier D, Berthier E, Gouvello
B. Use of green roofs to solve stormwater issues at the
basin scale-Study in the Hauts-de-Seine County
(France). Urban Water J. 2016;13(4):1-11.
[53] Uhl M, Schiedt L. Green roof storm water retention-
monitoring results. 11th International Conference on
Urban Drainage; 2008 Aug 31 Sep 5; Edinburgh,
Scotland. 2008. p. 1-10.
[54] Gregoire BG, Clausen JC. Effect of a modular
extensive green roof on stormwater runoff and water
quality. Ecol Eng. 2011;37(6):963-9.
[55] Barrio EPD. Analysis of the green roofs cooling
potential in buildings. Energ Build. 1998;27(2):179-
93.
[56] Oberndorfer E, Lundholm J, Bass B, Coffman RR,
Doshi H, Dunnett N, et al. Green roofs as urban
ecosystems: ecological structures, functions and
services. BioScience. 2007;57(10):823-33.
[57] Berghage RD, Beattie D, Jarrett AR, Thuring C, Razaei
F, O’Connor TP. Green roofs for stormwater runoff
control. Cincinnati: US EPA; 2009.
[58] Nie LM, Lindholm OG, Thorolfsson S, Sægrov S,
Åstebøl SO. Integrated urban stormwater management
in Norway. 12th International Conference on Urban
Drainage; 2011 Sep 10-15; Porto Alegre, Brazil. 2011.
p. 1-9.
[59] Roseen RM, Ballestero TP, Houle JJ, Avellaneda P,
Brigg J, Fowler G, et al. Seasonal performance
variations for stormwater management systems in cold
climate conditions. J Environ Eng. 2009;135(3):128-
37.
[60] Gautam MR, Acharya K, Stone M. Best management
practices for stormwater management in the Desert
Southwest. J Contemp Water Res Educ.
2010;146(1):39-49.
[61] Rivard G, Rinfret L, Davidson S, Morin PL, Corrales
MV, Kompaniets S. Applying stormwater
management concepts in tropical countries. J Water
Manag Model. 2006;53-74.
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... One difference between the execution of the pre-flooding, post-flooding and design changes that were discussed in previous sections and SuDS adaptations is that the previous measures could be implemented by a single engineering or road construction agency, whereas the successful SuDS design and implementation requires liaising between multiple agencies like the local planning authority, the environmental regulator, planners, developers, the drainage and flooding authority, the local council, water and sewerage undertakers, open-space management, the municipal authority, etc., and inputs from drainage engineers, urban designers, highway engineers, architects, landscape architects, ecologists, local community representatives, resident organisations, etc., are required for its successful implementation [41]. ...
... SuDS provide urban cooling, shade and insulation to buildings and increase natural ventilation. A limitation of SuDS is that they are effective for short-and medium-duration, high-intensity events that cause local flood risks but have less impact on flood risks caused by longer-duration events [41]. ...
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