Terminologies

Discuss About The Engineering Procedures Stormwater Melbourne.

This research paper is about the water sensitive urban design while focusing on the modern urban stormwater management approaches. Water sensitive urban design is an engineering design and land planning approach which integrates the water cycle in the urban areas, including water supply, wastewater, groundwater, and stormwater management, into the urban design to improve recreational an aesthetic appeal and reduce environmental degradation. Urban planning is greatly advocated as a significant way of encouraging the more sustainable of stormwater in urban areas through application of alternatives to piped systems. Water bodies in the entire country are facing issues as a result of runoff stormwater and also urbanization.

Huge quantities of impervious constructions and surfaces have resulted to rise of the quantity of runoff and consequently promote pollution. Pollution during storms can be as a result of the combined overflow of sewers that carry bother stormwater and raw sewage, permitting sewage that is untreated together with stormwater to flow into the water bodies. With the pollution triggered by combined overflows of sewage and the state of the water bodies in major urban centers, there is need to assess to stormwater runoff in every element of the urban fabric through environmental and creative design (Arnold, 2010).

Some of the terms used to refer to the water sensitive urban design which is a term used in Australia and the Middle East include Sustainable Drainage System and Low impact development. Sustainable Drainage System is a term used in the UK and it is designed to minimize the potential effects of existing and new developments relative to the discharges of surface water drainage. The term urban was removed so as to accommodate sustainable management of water in rural areas. Low impact development is a term used in Canada and also in the United States to describe an engineering and land planning design approach of managing runoff of stormwater as part of the green infrastructure. It stresses the use of natural features on-site and conservation to protect the quality of water (Authority, 2008).

The modern drainage system evolved from the combined sewer system which was introduced in the 1850s so as to enable urban areas to do away with traditional ditches that were being used. These sewer systems were used to assist in drying the streets and keeping both sewage and runoff stormwater underground in a pipe network. However, there have been drastic improvements in this system since, during large storms, the sewer systems would be filled with both runoffs of stormwater and sewage and then would spill over into numerous sections of the local water bodies and streets. The modern drainage system has been improvements to replace the traditional sewage system (Booth, 2012).

Evolution of Modern Drainage System

These improvements have been put in place to minimize the runoff of stormwater that reaches the combines systems through eliminating the section of the load that the system has to convey. Through suitable practices of stormwater management and design, the public reams are normally used to relieve the drainage systems and assist to minimize the frequency and likelihood of the mixture of stormwater runoff, commercial and industrial waste, and domestic sewage in the urban environment (Borah, 2009).

The old and new public places tackle the questions concerning the environmental accountability and sustainability. Public space or public realms is composed of two sections, these include the components of the public of the physical space and the way in which the society decisions are made for the public space. Urban design is involved in both sections of the public realm. The physical components used for public spaces are the urban design products, however, the objective of the development of the space affects the urban design process directly. The public realm includes those regions in which the public has access to, even though that permission may be sometimes restricted. It consists of both outdoor and indoor spaces such as parks, plazas, squares, streets, arcade, and public buildings (Bozeman, 2010).

Hardscape is a space that uses a type of solid material or pavement for its foundation and does not possess numerous green spaces. These public spaces also include natural attributes natural features like small green space components and vegetation, they are also characterized by variations of the natural state and the application of pavements. Public spaces design may be lacking relative to the integration of permeable pavements and stormwater management. There is need of developing a public space that has the ability to deal with stormwater in an environmentally sensitive and efficient manner without forgetting the appeal of the space itself. It is initially significant to plan and design public hardscapes for the public who will be using the spaces (Clarke, 2015).

During planning new designs of public hardscape, it is critical that the needs of the public take first significance since cities are filled with public spaces and majority of them have been designed for social interaction while other have become public space as a result of interactions that takes places in those areas. Some of the features that the local populations desire from the public space include comfort, relaxation, and engagement. The idea of comfort incorporates safety from traffic and crime, natural features, and sunlight. There is also need for relaxation for the population after busy life within the urban environment, this may include water and natural features, retreats, and seating (Committee, 2009).

Hardscape Design

The culture and location of these public spaces will normally define the character of the place. Urban design should be keen so as not to ignore the locality when designing the public hardscapes. There is the need for incorporating porous pavements on the public hardscapes as a step towards stormwater management practices. The structural stormwater management practices include the engineered and constructed systems that are designed to provide water quality control and water quality of stormwater runoff. The public space’s design focuses the requirement of physical features which will efficiently deal with stormwater such as structural stormwater management practices as discussed below (Council, 2011).

When raining, water falls onto a surface that is impermeable before flowing to the nearest local water body or storm drain. This can also come in form of street wash water or snowmelt, all of which describe stormwater. The major concern regarding runoff stormwater is the safety which focuses on draining and directing water from the hardscape surfaces as efficiently and quickly as possible. Stormwater runoff is normally not considered after it is out of the vicinity, however, the results associated remain after moving off from the impermeable hardscape surface. This section illustrates the stormwater management practices that have been implemented in numerous states and can be considered as standard approaches for management of stormwater (Fletcher, 2009).

As discussed above, porous pavements are one of the recognized stormwater management practices recognized by numerous states. This section discusses the structural stormwater management practices by considering the constructed and engineered systems that are designed to give control of water quality of the stormwater runoff. The structural stormwater management practices can be narrowed into wet ponds and vegetative system and structural management practices based on the public space design as discussed above. The stormwater management practices can be defined as the structural control, measure, or technique that is used for a certain condition to improve the quality and manage the quality of stormwater runoff in a manner that is cost-effective (Gaffield, 2013).

These measures are the method of monitoring the water that moves through the stormwater management practices and also the capability of reducing the pollutants conveyed by the stormwater. Urban areas are defined by a huge percentage of impermeable surfaces which generates difficulties when dealing with stormwater because the natural hydrology of the area is disseminated as a result of urban growths. The changes in the pathways of water from the urban developments have resulted in issues concerning stormwater along with implementation and creation of the stormwater management practices (Hoyer, 2011).

Stormwater Management

The stormwater is conveyed within urban regions where pollutants like synthetic organics, metals, hydrocarbons, pathogens, phosphorous and nitrogen, oxygen-demanding substances, and solids are moved into storm drains and then disposed of in water bodies. These pollutants result in environmental degradation to the urban water bodies which receive them and also to the ecosystem surrounding which depend on the water adjacent. Research shows that 32% of estuaries impaired, 18% of lakes impaired, and 13% of rivers impaired in the majority of urban areas are affected by the suburban/urban stormwater runoff. There are a lot of damages caused by runoff that takes place as a result of that takes place as a result of the increased quantity of water that is conveyed during periods of peak flows (Lloyd, 2010).

Peak flows is promoted in numerous urban centers due to compact developments and in the majority of instances results in new events of runoff. The high level of frequency of events of peak flow and quantity of runoff results in a greater contaminated volume of stormwater to be discharged into the water bodies receiving. The discharge of stormwater can result in the displacement of natural habitats and also contamination of drinking water for the users living downstream. The rowing urban centers also call for the growth of the need to tackle the issues of stormwater to make sure that the unnatural pollutants do not pollute the receiving water bodies (Pitt, 2009). 

There is need of the urban authorities to set limits on industrial waste and also establish the standards for control of quality water. This will prevent pollutant discharge from a point source unless a permit is acquired to allow such discharge. In the US, a body known as the National Urban Runoff Program was established to assess the stormwater runoff quality in urban residential and commercial areas. Their findings show that the suspended solid discharge in drainage systems was near the magnitude of solids suspended that were discharged the plant of sewage treatment of the municipal. There is need of reducing the pollutants of discharge at higher density positions not only to the point source runoff but also to non-point source runoff. The stormwater management approaches should be applied in phase one of the stormwater programs such as vegetative practices, public education, and the use of alternative materials for paving (Ruth, 2009).

The basic purpose of vegetative systems in the urban centers are to relax the population and also provide a sense of natural amenity. The function of vegetative systems in the stormwater management practices of more than for natural appeal or aesthetic, but to minimize the runoff of stormwater and also treat water before the process of soil infiltration. As rainfalls begin accumulating on the surface, it is directed to the area of bio-retention where there is infiltration of stormwater into the soil. This biofiltration and bio-retention processes removes pollutants from numerous processes such as decomposition, ion change, volatilization, filtration, and adsorption. The application of the vegetative system in the stormwater management practice provides stormwater with the chance to be cleaned and filtered and can be an excellent source of recharge of groundwater (Ruth, 2009).

The public space should not be identically designed while incorporating the climate, culture, and location of the local community. The same applied to the vegetative management practices. There should be numerous vegetative components that should be used based on the requirements of a given location. These components include plants, sand beds, planting soil bed, organic mulch layer, ponding area, vegetative swales, grass filter strip, and grass buffer strip. Numerous components create many implementation options and also a combination of numerous components. The climate and location of the urban area normally determine the plant species that can be utilized by the by the vegetative system, hence developing a landscape design that is unique for every location and their application in this structural management practice (Shaver, 2014).

This is the second type of structural management stormwater practice. Wet ponds are one of the categories of the system retention that can be defined by the capability of capturing stormwater runoff and retaining it until the future runoff substitutes it. The water remains in the wet pond unlike dry ponds and services as a place for huge runoff quantity and also treats the water quality during retention. Water storage and treatment are designed objective for wet ponds, however, it may also give terrestrial and aquatic habitat for numerous animals and plant, and also provides aesthetic value (Water, 2013).

Pollution conveyed by runoff gets in the wet pond through design such as settling process, then the runoff is cleaned to replenish and infiltrate supplies of the groundwater in case the wet pond does not possess a bottom liner. Wet ponds are one of the most effective retention systems of pollutant removal because of shallow depths and consistent water pool. The wet ponds applications for the environment of the urban areas may satisfy both the aesthetic value of the public space and also the stormwater management function (William, 2011).

The approach to public hardscape sustainability in regards to the management of stormwater should address the real materials used in hardscape. There has been broad use of impermeable materials on the surface in the past for the public hardscape, sidewalks, and systems of national highways. Currently, a lot of progress has been made in the development of paving materials that minimize the adverse impacts on the environment. These porous pavement treats and infiltrates rainwater as it falls, this instance rainwater infiltration minimizes the volume of runoff that is generated and the capability of capturing and heating stormwater on a wide surface and enable the land to function at its full potential in the management of stormwater (Wong, 2012).

These porous pavements can save the urban developers the cost of having to purchase an extra piece of land for the purposes of stormwater management. The effects caused by runoff of stormwater on the urban areas are substantial, however, the application of porous pavements may minimize some impacts related with paved sections. With intentions of creating public hardscape which imitates the features of natural land such as hydrology, the porous pavements are the alternative design on such spaces. Some of the types of porous pavements that can be used to minimize the impacts of stormwater runoff in the urban areas include porous asphalt, porous concrete, and permeable interlocking concrete pavement (Booth, 2012). These porous materials are discussed below:

Porous Asphalt: This material has fine particles of stone to enable screening and reduce to permit the flow of water through. The actual asphalt layer is produced to enable water to pass through it so as to reach the following level of loosely compacted particles or stone aggregate. This material is the most affordable option for porous pavements as determined in its life cycle cost analysis. Some of the factors that should be considered during the implementation of these porous pavements include depth of water table, depth of bedrock, infiltration rate, and the type of soil (Bozeman, 2010).

Pervious Concrete: Materials such as pervious concrete enables percolation of water into the soil and not halting the process of infiltration. This process can take place through pervious concrete since there is no sand that can fill the aggregates spaces. The strength of this type of pavement is one of its advantages since it can withstand a strength of approximately 3000 psi. This material can also develop a detention section for stormwater and hence can assist as an alternative to other stormwater management practices. This can minimize the cost of materials, construction, and labour for a given site. This pavement option is an effective tool of stormwater runoff management in the urban areas since it reduces the effect on natural surrounding by minimizing the total quantity of runoff that is produced by capturing initial precipitation (Clarke, 2015).

Interlocking Concrete: This pavement option is composed of two different options. Open-celled paving grids and open-jointed paving blacks. These features enable increased water infiltration of the surface since it enables the water to pass through the blocks and also infiltrating the joints. This pavement option decreases the quantity of runoff leading to reduced pollution inflowing the water bodies (Ruth, 2009).

There are two options of re-using the stormwater collected during rain before it could reach the surface, these include rainwater tanks and aquifer storage and recovery. The rainwater tanks are designed to collect water harvested from the stormwater o as to partially meet the domestic demand. These rainwater tanks minimize the volumes of stormwater runoff and also pollutants of stormwater from reaching the water bodies. Stormwater and rain from the rooftops of the structures can be accessed and collected precisely for the purposes of car washing, garden watering, laundry, and toilet flushing. Buffer tanks can also be implemented to enable stormwater collected from the pavement surfaces or drainage system to seep into the site and assist in maintaining the groundwater level and aquifer (Booth, 2012).

These tanks should be installed according to the drainage and plumbing standards of the particular state. Some of the issues that should be considered when using the stormwater tanks include material, shape, size, maintenance, available space, cost, stormwater benefits, water quality, and supply and demand. Aquifer recovery and storage involves enhanced recharge of water to aquifers underground through pumping or gravity feed. This system can also use treated wastewater or stormwater (Authority, 2008).

Water sensitive urban design stresses the benefits of waterways and water as assets and resources, and not as a nuisance as conventionally viewed. The WSUD ensures increased water conservation since a lot of water which could have gone into the water can be conserved through methods such as water tanks or wet ponds. This conserved water can be used in numerous ways that this conserved water can be put into use, these ways include car washing, garden watering, laundry, and toilet flushing. The WSUD also improves the quality of stormwater in the through filtration and water treatment before it can be channelled to the water sources. The quality of water is also improved through removal of pollutants by the porous pavements, these pollutants may be from processes such as decomposition, ion change, and volatilization, filtration, and adsorption processes (Water, 2013).

The WSUD also reduces the greenhouse gas emission through minimizing the consumption of water and improving the harvesting of rainwater as well as alternative natural treatments of water. Some of the natural ways of water treatment include passing of stormwater runoff through wet pons where the water can be treated by passing it through porous pavements used to secure the surrounding of the pond. The design also discourages excessive and irresponsible discharge of water from industrial sector into the drainage system without acquiring the permit from the urban authority. These regulations reduce the consumption of water by both the commercial and domestic sectors. The WSUD also provides an adoption measure to tackle the change in climate impacts such as heat island and flooding. This is made possible by legislation put in place by the urban authority such as encouraging the vegetative management practices (William, 2011).

Conclusion

Stormwater management can be defined as a structural control, measure, or technique that can be applied for a given set of conditions to improve quality and manage the quality of stormwater runoff in a way that is cost-effective. Some of the stormwater management practices that have been implemented in numerous states and can be considered as standard approaches for management of stormwater include hardscape design, legislation, vegetative management practices, wet ponds, and permeable materials. Some of the benefits of the water sensitive urban design include aesthetic purposes, filtering pollution out of stormwater, supporting aquatic life, protecting environmental values, reducing greenhouse gas emissions, improving biodiversity, improving the stormwater quality, and increasing water conservation.

There is the need for improving the integration of stormwater management practices in the design of the public landscape. From the literature above, there is the need for improving stormwater legislation and regulations in every state so all the stakeholders in the urban areas could be aware of the issues involving stormwater management. Through enforcement and passing of these regulations concerning the stormwater management, both nationally and locally, steps should be taken to promote the control of runoff. Education is also a direction that should be taken to ensure that integration is fully used and accepted in public hardscapes. The parties that should be involved in this integration education include public as a whole, neighborhood organizations, developer organization, and public officials (Booth, 2012).

References

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