Improving Storm Water Quality through Water Sensitive Urban Design

Running head: WATER SENSITIVE URBAN DESIGN
1
Improving Storm Water Quality through Water Sensitive Urban Design
Student’s name
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WATER SENSITIVE URBAN DESIGN 2
Improving Storm Water Quality through Water Sensitive Urban Design
Abstract
For more than 100 years, there has been an implementation of centralized water that is in
large scale, waste waters as well as systems of storm water. The systems have been of great
importance because they have provided a supply of safe water for drinking, a very efficient and
effective collection as well as disposal of waste water which helps in protecting the health of
human beings. It also helps in mitigating risks of flooding in urban areas. The systems of current
urban water sustainability are facing a lot of pressure due to various challenges. These challenges
include the impact of climate change; very rapid growth of population which leads to
urbanization, as well as ageing infrastructure and that has reached capacity constraints. So as to
address all these issues, there is implementation of services of urban water with IUWM
(Integrated Urban Water Management) as well as WSUD (Water Sensitive Urban Designing)
methods. The systems of WSUD have a role of delivering multiple benefits which include
conservation of water, improving the quality of storm water, controlling flooding, landscape
amenities as well as living environments that are healthy. The systems can either be provided as
a combination in systems that are centralized or as systems that are standing alone. These
systems are facing a lot of knowledge gaps that impede the mainstream uptake. These knowledge
gaps are covering various aspects in implementing them. The gaps include economic, technical,
and social as well as aspects of institution.
Keywords: Water Sensitive Urban Design, storm water, waterways, pavements, bio-retention,
run off, and quality.

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Content
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Introduction.................................................................................................................................................4
Background information..........................................................................................................................6
Policy, Planning and Legislation.............................................................................................................8
Principles.................................................................................................................................................9
Objectives for WSUD............................................................................................................................10
Techniques under WSUD......................................................................................................................10
Elements of WSUD...............................................................................................................................11
Bio-retention systems........................................................................................................................12
Bio-retention basins...........................................................................................................................13
Infiltration systems and trenches.......................................................................................................14
Sand filters.........................................................................................................................................14
Rainwater tanks.................................................................................................................................15
Porous paving....................................................................................................................................16
Effectiveness of WSUD elements..........................................................................................................17
Benefits of WSUD.................................................................................................................................18
WSUD benefits to environment.........................................................................................................18
WSUD benefits to the urban areas.....................................................................................................18
Conclusion.................................................................................................................................................19
References.................................................................................................................................................20
Appendices................................................................................................................................................26

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Introduction
The WSUD (water sensitive urban design) involves a method of planning cities in ways
that help in minimizing water runoff to ensure that the storm water causes the minimum amount
of damage. It also involves application of best strategies to utilize the water leading to an
improved urban environment (1). The urban areas have been known to alter the manner in which
water flows through natural environments. Roads, buildings and all the impervious surfaces
within urban areas prevent the soaking into the soil of rainwater, and force it into watercourses
such as storm water drains. In Australia storm water is channeled into storm water drains made
of concrete and other channels that feed into the waterways of urban cities. The result is
increased flash flooding that sometimes leads to erosion of water courses and damages
vegetation that is along waterways (2). This storm water passes into rivers and lakes taking in
sediments, nutrients, hydrocarbons and other gross pollutants that include litter. WSUD is the
methodology for having the urban water cycle integrated in city areas into the urban design and
planning towards mitigating the negative impact of storm water in waterways and making the
best use of this water by mimicking the cycle processes of natural water.
Storm or runoff water contains various types of pollutants including heavy metal such as
copper (Cu), cadmium (Cd), chromium (Cr), zinc (Zn), lead (Pb), and nickel (Ni) (3, 6,7). Heavy
metal in storm water comes from tires, road asphalt, parking dust, automobile exhausts, and fuel
combustion. It gets washed by water runoff and their discharge into streams create environmental
and health hazards. Other pollutants include total nitrogen (TN) and total phosphorus (TP) that
gets washed from farms due to continued use of fertilizers (3). Water runoff also carries with it

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organic compounds that include insecticides, pharmaceuticals, synthetic fibers, plastics, synthetic
detergents, food additives, synthetic pesticides and VOCs (volatile organic compounds) that
come from man-made activities such as spillage. WSUD helps remove these substances before
their discharge into water bodies.
WSUD has the support of the value of water in urban areas and water provision services
in ways that factor in specific opportunities as well as limitations evident in site developments
towards the provision of water services to protect as well as enhancing the ecological and
hydrological integrity of the local areas. WSUD takes into account all the aspects related to
water cycle in urban areas as resources of high value. Thus the implementation of WSUD in the
city development improves the challenge of low yields from the conventional catchments of
supply of water caused by potential impact of changes in climate. This is a critical element of the
IUWM (integrated urban-water management) (3) which promotes the planning methods that are
coordinated concerning drinking water, storm water and waste water services, taking into
account the wider implications of sustained development that includes greenhouse gas emissions,
energy demand, nutrient losses, solid waste generation, community acceptability and life cycle
costs. In the United Kingdom WSUD is known simply as SUDS or sustainable urban drainage
systems (4). In America, it is known as low impact development or the LID and storm water
BMPs or best management practices. It is broadly structured within the green infrastructure term.
The history and description of these terms have been well presented including the
definition of systems that are decentralized and developed concerning the current recognition of
the need for decentralized water, storm water and waste water systems towards the mitigation of
the urban development environmental impact. These definitions also highlights the drivers for
decentralized system implementation including; to overcome the limits in the capacity of waste

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water and local water management service, protection of the environment that is sensitive,
showcase the examples involving sustainable development landscape amenity, water
conservation and innovation and technology promotion (5). These definitions are in line with the
WSUD philosophy. The various impediments that affect a greater uptake of WSUD include the
fragmentation and inadequacy of current governance, lack of knowledge and skills, guidelines
and regulations for WSUD, public health risk potential increase, and poor incentives of finance.
There is also a gap in the knowledge for centralized alternative and conventional systems
interactions. Studies indicate that institutional and socio-technical factors need to be considered
on the development of enabling environments in the case of systems applied alternatively. The
systems involve the potential of reducing the workload on the environment as well as resources.
Background information
Traditional industrial and urban development changes the landscapes that have penetrable
vegetated sides to impermeable interconnected sides that result in large quantities of runoff or
storm water which needs to be managed. In the past Australia, similar to other many
industrialized nations like United Kingdom and United States has managed storm water runoff as
a nuisance and hindrance which endangers property and human health (6). This emanated in a
well-built focus on the outline of the storm water administration systems that swiftly carry storm
water runoff straight to streams that have small or insignificant focus on conserving the
ecosystem. This strategy of management leads to the aspect of urban stream syndrome. Increased
amounts of flows from rainfall, rush quickly into the water ways conveying sediments and
pollutants carried off from impermeable areas. This process leads to waterways to convey aerial
concentrated nutrients, suspended solids and other pollutants. Enlarged peak flows, additionally