Water Sensitive Urban Design Techniques - Report Example

Water Sensitive Urban Design Techniques Name: Student ID: Course: Instructor: Date: Water Sensitive Urban Design Techniques Water is a basic need for man, and thus requires that he maintains a close relationship with water sources for survival. This need has over time forced human beings to be located in areas that are close to water sources for the continuous flow of clean water for survival and to also ensure that their daily activities run as expected such as farming and transport services. Water has provided lots of positive impacts to the society including beautifying a community that identifies itself with a specific water body, and also creates locations for recreation facilities. This then ensures that the location with these water sources benefits from the income caused by the water course such as tourism both on a domestic note as well as internationally. Although water is so critical to man, various challenges have arisen over time that have led to its scarcity, flooding as well as its pollution (Ashley, Lundy, Ward, Shaffer, Walker, Morgan & Moore 2013). These problems have all been caused by the main reason of people not acknowledging the need to design and plan on the locations in the water sources vicinity. The development of our environments then gets overwhelmed by the water cycle that takes place naturally since human beings do not strategies of overcoming this challenge, thus leading to flooding, pollution and water shortage in the long run. Storm water runoff is therefore caused by the landscape development that is ill managed, hence causing nuisance to the people in the specific locality. Management strategies have been put up to try and overcome these challenges over the years and include, the use of infiltration systems, incorporation of permeable and porous pavements, the construction of wetlands, use of green roofs, vegetated filter strips and rainwater tanks. (Hess 2014). Bioretention is being used as a technique to deal with storm water runoff in major urban developments currently and has turned out as a success for many. The technique involves the use of vegetations to filter out contaminants such as solids by using specific media. Water is also treated in the same system through the biological process of respiration, where there is the uptake of gases such as nitrogen and phosphorous from the water. Bioretention is also commonly known as the rain garden since the storm water is collected in the system for treatment which is composed of plants, soil, mulch, a sand bed and a grass shield strip (Hickman 2011). The storm water then flows through the sand bed where its speed is reduced, since it fairly distributes the water to the pond which is graded and its centre is depressed and is also graded. The pond area also houses an organic layer and planting soil, where water is retained for a while in the underlying soils before its release. This then helps overcome major challenges caused by excess water in the landscapes. Bioretention helps in the filtration of water from a storm off since all the segments in the system are designed to operate their functions in independently. This then helps in ensuring that the process is efficient and works as required. In this case, the grass planted is meant to reduce the speed in which the storm water s flowing and at the same time also filter out any contaminants present in the flowing water. The sand bed that is put in place has the main purpose of also reducing the runoffs speed, filtering out solids as well as distribute the water flow to the bioretention system for treatment to take place. Treatment here involves the use of soil to provide aeration and drain the water, this takes place in the sand bed (Hussey & Kay 2015). The sand bed also also filters out particulates from the running water thus removing any pollutants. The pond area acts as the temporary store for the filtered water for a short period of time before it evaporates or is infiltrated. The main purpose of the mulch is to filter out all contaminants and providing a favorable environment for the growth of microorganisms that will break down products that are composed of petroleum as well as organic matter. Mulch also helps in preventing soil erosion and also prevents the drying of core soils. The planting soils play a key role in providing the adsorption of contaminants and other solids such as heavy metals, hydrocarbons and nutrients present in water (Lundholm 2015).These filtrates as well as the stored water are beneficial to the growth of the plants in the bioretention system after uptake. The location of these systems depends on various reasons based on the soils present in the area, the vegetation present, the presence of utilities and the drainage system in the current vicinity. The preferred soils that are best suited for bioretention systems are sand soils which provide easier water retention and filtration techniques. Run off water contains different types of contaminants since they collect all types of matter on the sidewalks and roads. Some of the contaminants may include heavy metals such as zinc and lead which may cause major health defects in human beings when they get into contact with such contaminated water (Kazemi, Beecham & Myers 2011). The rain garden can in this place be used to eliminate such metals from water since the dissolved forms of the metals are adsorbed to the soil particles. The metals can also be eliminated by binding to the sediment particles. Water management in urban developments can also be done by using green roofs on buildings in a locality prone to storm run offs. Water run offs tends to be collected on the roads, pavements and on the rooftops of most buildings. Green roofing has been incorporated as a technique to manage storm run offs in developing localities (Le Bel 2013). This roof plays the critical role of retaining a large portion of the storm water for a period of time hence decreasing the ultimate effects caused by storm runoff. The green roofing is composed of a drainage layer which is highly porous and directs water off the roof. Vegetation present is for the sole purpose of holding water and withholding it for a period of time while also providing means for drainage of the water (Williams, Lundholm & Scott 2014). Media present includes the growth media that provides growth of the vegetation and a lightweight medium that allows the installation of the retrofits on the existing buildings, hence reduce the need to construct new structures other than the buildings present. Plants present help in providing shade for the foliage as well as control the runoff from sloped roofs. This area also helps in the filtration of contaminants that cause pollution in water. The plants in this case depend on various conditions that may include, the climate of the locality and the depth of the roof. This then shows the need to use drought resistant, winter resilient, perennial plants such as the cactus plant. Another feature that is present in the green roof technique is the water proof membrane and the root barrier that is placed at the bottom of the system to prevent water surpassing the system and clogging on the rooftops then affecting the building structures from the top. Green roofs have been suggested in urban areas since they are cost effective and convenient depending on the development structures and buildings that have eventually limited space for use of other conventional methods of managing storm runoff. Green roofs are suitable for controlling water from roofs during storms since they are capable of absorbing most of the rainfall. Although this technique has been successful in most areas, it also encounters various challenges since the media used is sensitive to solids or particulates that may clog it. (Condon & Noyce 2011). This then reduces the capability of the system to work as expected. This then shows the need to use other pollutant traps in conjunction with the rain garden so as to reduce the potential risk of pollutants damaging the media and vegetation present. Other than this, studies have shown that the water quality of water gathered from the rain gardens is free of gases such as the atmospheric nitrate thus shows that the system is efficient in the removal of gases depending on the precipitation and rate of runoff. Water has been a challenge to various people during large or small storms, hence causing nuisance to many societies. These challenges are however reduced if people incorporate the water sensitive urban design techniques. These techniques are beneficial mostly to the communities in urban developments who have difficulties in using the conventional methods of controlling storm run offs. The techniques provide design approaches that help in controlling the natural water cycle in the urban design thus minimize the environmental degradation experienced. Awareness and education is therefore necessary and is being done throughout Australia and its environs, to help increase the use of the techniques that are necessary to ensure that storm runoff is managed to avoid possible challenges such as floods and drought. With the increased population, urban development and climate changes, prevention techniques have to be embraced to ensure that water is not perceived as a nuisance but as a resource in the near future. References Ashley, R., Lundy, L., Ward, S., Shaffer, P., Walker, A. L., Morgan C, & Moore, S. 2013. ‘Water-sensitive urban design: opportunities for the UK’. Proceedings of the Institution of Civil Engineers: Municipal Engineer Vol. 166, No. ME2, pp. 65-76. Condon, B., & Noyce, M. A. 2011. U.S. Patent Application vol.13,no.579, pp.213. Coutts, A. M., Tapper, N. J., Beringer, J., Loughnan, M., & Demuzere, M. 2012. ‘Watering our cities: The capacity for Water Sensitive Urban Design to support urban cooling and improve human thermal comfort in the Australian context’. Progress in Physical Geography. Hess, A. J. 2014. monitoring of evapotranspiration and infiltration in rain garden designs Hickman Jr, J. M. 2011. Evaluating the role of evapotranspiration in the hydrology of bioinfiltration and bioretention basins using weighing lysimeters Hussey, K., & Kay, E. 2015. ‘The opportunities and challenges of implementing ‘water sensitive urban design’: Lessons from storm water management in Victoria, Australia’. Understanding and Managing Urban Water in Transition pp. 593-614. Kazemi, F., Beecham, S., & Myers, B. 2011, June. ‘Water Quality Effects of a Water Sensitive Urban Design Retrofit in an Urban Streetscape in Adelaide, Australia’. III International Conference on Landscape and Urban Horticulture 999 pp. 321-327. Le Bel, P. D. 2013. Performance Evaluation of a Low Impact Development Retrofit for Urban Stormwater Treatment.pp.234-241. Lundholm, J. T. 2015. ‘Spontaneous dynamics and wild design in green roofs’. Williams, N. S., Lundholm, J., & Scott MacIvor, J., 2014. ‘Do green roofs help urban biodiversity conservation?’. Journal of Applied Ecology, vol.51, no.6, pp 1643-1649. Read More