Dissertations / Theses on the topic 'Water sensitive urban design WSUD'

“Global floods and extreme rainfall events have surged by more than 50% in the past decade and recent studies show that they are occurring four times higher than in 1980” (Neslen, 2018). At the same time, the urban population is rising. Today, 55% of the world’s population lives in urban areas and it is estimated to increase to 70% by 2050 (United Nations, 2018). This expansion of urbanized areas is correlated with the increase of impermeable surfaces that, in case of extreme weather events, are not able to drain the water efficiently. The rainfall-runoff is channelled from roads, parking lots, buildings, and other impervious surfaces to storm drains and sewers that cannot handle the volume. The high ratio of impermeable surfaces and the increased extreme rainfall events cause severe environmental, social, economical problems in urban areas. Merely technical and engineering solutions are no sufficient, therefore a new approach that can maintain and adapt the natural water cycle inside the urban areas is needed. Ecosystem services and resilience thinking have become key principles in adaptation strategies at different levels, from international policies (e.g. Sustainable Development Goals) to local actions (e.g. Copenhagen adaptation plan 2015) and design (e.g. climate resilient San Kjeld in Copenhagen). In this scenario, the design approach of Water Sensitive Urban Design (WSUD) aims to promote resilience at the local level by managing stormwater, encouraging the defence of the aesthetic value of green and blue areas. WSUD is a multidisciplinary approach that involves water management, urban planning, architecture, and landscape design. The main idea of WSUD is that sustainable stormwater systems should be beautiful, meaningful, and educational (Echols, 2007). This master thesis explores the concept of Water Sensitive Urban Design and its application in the cities of Copenhagen, Malmö and Rotterdam. The case study of PHVision in Heidelberg, Germany, is analysed from the concept of WSUD. Design improvements are suggested stemming from the analysed European examples and the theoretical background.

With an ever-increasing population and global warming, fresh water resources are nearing depletion resulting in a global water crisis. As a consequence, cases of drought have been reported worldwide especially in sub-Saharan Africa. In addition to climate change, urbanisation adds strain to infrastructure as well as water supply and the management of water resources. As a result, most developing countries are faced with a water management challenge. There is thus a need for a paradigm shift towards an Integrated Water Management (IWM) approach. Worldwide, countries have responded to the Integrated Urban Water Management (IUWM) concept through the implementation of various management strategies; with Water Sensitive Urban Design (WSUD) emerging from Australia. Some closely allied management strategies in response to IUWM emerged in the USA as Low-Impact Development (LID), in the UK as Sustainable Drainage Systems (SuDS), and in New Zealand as Low-Impact Urban Design and Development (LIUDD). Namibia is situated along the south-west coast of Africa and is considered the driest country in sub-Saharan Africa. It is characterised by a semi-arid environment, with more than 80% covered by desert or semi-desert. The country is regularly afflicted by drought and has fluctuating and unreliable rainfall patterns, often accompanied by high evaporation rates. The City of Windhoek, as the capital city, the biggest municipality and also the largest densely populated town in Namibia, is faced with an ever-increasing shortage of water for its inhabitants. For close to 50 years, the water scarcity situation has led to direct waste water reclamation for potable re-use in Windhoek. Other measures implemented by the City of Windhoek (CoW) towards IUWM include Water Demand Management (WDM), Managed Aquifer Recharge (MAR) and Water Conservation (WC). In order for Windhoek to transform into a Water Sensitive City, the implementation of WSUD is imperative. Although the CoW has implemented measures towards IUWM, more options still need to be explored in order to contribute to IUWM processes and to ultimately become a Water Sensitive City. This research was aimed at conducting a comprehensive review of existing WSUD practices within the CoW and identifying gaps pertaining to WSUD implementation. The research confirmed, via a review of relevant literature, that the implementation of WSUD mainly flourishes when documented policies and regulations drive implementation. To review WSUD implementation in the CoW, this study followed a qualitative research approach by gathering data via online questionnaires using the SurveyMonkey platform. To validate the survey outcomes, structured interviews were conducted with selected survey participants to gain more insight into the outcomes. For the data collection, the study targeted a sample of managers and specialists from the three departments within the CoW that deal with urban infrastructure design and planning. A 72% response rate was achieved. The study revealed that there was a general understanding and knowledge of WSUD concepts among all the CoW stakeholders involved in water management, planning and design. This was mostly due to their academic knowledge and sometimes via exposure to existing WSUD practices within the city. Water Demand Management, Water Recycling, and Voluntary Green Roofs and Rainwater Harvesting were identified as existing WSUD options currently practised within the CoW. The study identified lack of capacity, lack of knowledge, lack of management support, a fragmented approach, the absence of policies and legislation, and no perceived financial benefits as barriers to WSUD implementation within the CoW. Based on the above findings, the study recommended that the City of Windhoek address existing barriers to WSUD implementation, increase awareness of WSUD within the city, secure government funding and apply for carbon credits to upscale the implementation of WSUD.

Water Sensitive Urban Design (WSUD) systems have the potential mitigate the hydrologic disturbance and water quality concerns associated with stormwater runoff from urban development. In the last few years WSUD has been strongly promoted in South East Queensland (SEQ) and new developments are now required to use WSUD systems to manage stormwater runoff. However, there has been limited field evaluation of WSUD systems in SEQ and consequently knowledge of their effectiveness in the field, under storm events, is limited. The objective of this research project was to assess the effectiveness of WSUD systems installed in a residential development, under real storm events. To achieve this objective, a constructed wetland, bioretention swale and a bioretention basin were evaluated for their ability to improve the hydrologic and water quality characteristics of stormwater runoff from urban development. The monitoring focused on storm events, with sophisticated event monitoring stations measuring the inflow and outflow from WSUD systems. Data analysis undertaken confirmed that the constructed wetland, bioretention basin and bioretention swale improved the hydrologic characteristics by reducing peak flow. The bioretention systems, particularly the bioretention basin also reduced the runoff volume and frequency of flow, meeting key objectives of current urban stormwater management. The pollutant loads were reduced by the WSUD systems to above or just below the regional guidelines, showing significant reductions to TSS (70-85%), TN (40-50%) and TP (50%). The load reduction of NOx and PO4 3- by the bioretention basin was poor (<20%), whilst the constructed wetland effectively reduced the load of these pollutants in the outflow by approximately 90%. The primary reason for the load reduction in the wetland was due to a reduction in concentration in the outflow, showing efficient treatment of stormwater by the system. In contrast, the concentration of key pollutants exiting the bioretention basin were higher than the inflow. However, as the volume of stormwater exiting the bioretention basin was significantly lower than the inflow, a load reduction was still achieved. Calibrated MUSIC modelling showed that the bioretention basin, and in particular, the constructed wetland were undersized, with 34% and 62% of stormwater bypassing the treatment zones in the devices. Over the long term, a large proportion of runoff would not receive treatment, considerably reducing the effectiveness of the WSUD systems.

This research project contributed to the in-depth understanding of the influence of hydrologic and hydraulic factors on the stormwater treatment performance of constructed wetlands and bioretention basins in the "real world". The project was based on the comprehensive monitoring of a Water Sensitive Urban Design treatment train in the field and underpinned by complex multivariate statistical analysis. The project outcomes revealed that the reduction in pollutant concentrations were consistent in the constructed wetland, but was highly variable in the bioretention basin to a range of influential factors. However, due to the significant amount retention within the filter media, all pollutant loadings were reduced in the bioretention basin.

The overarching goal of this research is to establish a successful forum for a transition from the existing paradigm of managing wastewater infrastructure to a more sustainable paradigm that achieves a more efficient utilisation of wastewater assets. A transitioning approach to support a more efficient utilisation of surface water and wastewater assets and infrastructure is proposed and developed. The determined transitioning approach possesses key stages namely developing the arena, developing the agenda, case study, and monitoring. The case study stage investigates a drainage utility identifying their improvement drivers, the removal of surface water through detailed drainage modelling and the financial examination of the costs incurred under the various scenarios conducted. Understanding the implications of removing/attenuating surface water from the network is improved through obtaining data by detailed drainage modelling. Infoworks software is used to investigate and assess the current and future operational scenarios of a wastewater system operating over one calendar year. Modelling scenarios were conducted removing surface water from selected areas focusing on the volumes requiring pumping and durations of pumping station(s) operation prior to treatment during storm conditions. The financial implication of removing surface water in combined sewer systems is examined in three main components. Firstly the costs of electricity incurred at the single sewage pumping station (SPS) investigated during the various scenarios modelled require to be addressed. Secondly the costs to retrofit sustainable urban drainage system (SUDS) solutions needs to be identified. Thirdly the implications of removing surface water for the drainage utility at the national level and the potential saving for householder’s committing to a surface water disconnection rebate scheme. When addressed at the macro level i.e., with over 2,100 pumping stations, some operating in sequence and contained within one drainage utility annually treating 315,360 megalitres the significance of the same multiple quantifiable and intangible benefits becomes amplified. The research aims, objectives and findings are presented to the identified and convened stakeholders. The transitioning approach developed encourages positive discourse between stakeholders. The level of success of the transitioning approach determined is then tested using a quantitative methodology through the completion of questionnaires. From the questionnaires completed the respondents unanimously agreed that surface water flows should be removed as well as reduced from the combined sewer system. The respondents agreed that the removal of surface water from a typical combined sewer system is justified by applying a transitioning approach focusing on the energy consumption required to pump increased volumes during storm events. This response is significant based upon the economic evidence and is contrary to the respondents previous position that finance was their most influencing factor. When provided with other potentially available benefits the respondents were even more supportive of the justification to remove surface water from the combined sewer system. The combined findings of the work presented in this thesis provide further justification that the transitioning approach applied to the removal of surface water from a typical combined sewer system, as determined in this research has been successful.

This research developed mathematical models to generate reliable future rainfall data in small spatial and temporal scales, and used them to estimate future floods and water quality scenarios. Outcomes of the study suggested a substantial increase in the occurrences and the extent of future floods and the amount of pollutant that they carry. Outcomes will be highly valued in future-proofing urban flood mitigation measures and water sensitive urban design infrastructure.

Thesis (MA)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: This study investigated the extent of Water Sensitive Urban Design activities in the George municipality in the Western Cape Province, in South Africa. Water resource management in urban areas worldwide had become unsustainable with the widespread implementation of outsized infrastructure, environmental degradation and overuse of natural resources. The result was a concept called Integrated Urban Water Management (IUWM). IUWM encapsulates the entire water cycle from rainwater to surface water, groundwater and wastewater, as part of urban water management, and not as separate entities. There was worldwide response to IUWM, with the USA formulating Low-Impact Development (LID), the UK designing their Sustainable Urban Drainage System (SUDS), and New Zealand articulating Low Impact Urban Design and Development (LIUDD), all to improve urban water resource management. Australia responded with Water Sensitive Urban Design (WSUD). WSUD explores the design and planning of water infrastructural development in an urban setting, vital in Australian cities which experience continuous severe water shortage conditions. The WSUD approach aims to influence design and planning from the moment rainwater is captured in dams, treated, and reticulated to consumers, to the point of wastewater re-use, as well as stormwater use. Various techniques are specified as part of the WSUD approach namely: the installation of greenroofs, demand reduction techniques, stormwater management and the re-use of treated wastewater for irrigation and fire-fighting. These WSUD activities can be implemented from large-scale efforts with whole suburbs working together to manage stormwater by construction of wetlands, as well as small-scale change in design and planning, e.g., with household rainwater tank installation for irrigation and toilet flushing. With South Africa’s progressive legislation at a national, provincial and local municipal level, various WSUD activities can be implemented to aid and guide municipalities. The study aimed to investigate what type of WSUD activities the George municipality has implemented, and to what extent the activities had an impact on water consumption, since the drought in 2009. The reasons behind any lack of implementation were also explored. Proof of only eight WSUD activities implementation could be found. Water debtors’ data and bulk water data was sourced in order to determine the effect of the eight WSUD activities on water consumption. Bulk meter data could however not be used to correlate with the debtors’ data since readings from many bulk meters had not been recorded. Debtors’ data did prove however that the WSUD activities had a short-term impact on water consumption in the suburbs where it was implemented. The reasons given for non-implementation were not satisfactory. Recommendations are that the municipality should focus on better planning and implementation of diverse activities and that keeping records and data should be made a priority to determine any progress made.
AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die omvang van die Water Sensitiewe Stedelike Ontwerp (WSUD) aktiwiteite in die George munisipaliteit in die Wes-Kaap, in Suid-Afrika. Waterhulpbronbestuur in stedelike gebiede in die wêreld het nie-volhoubaar geword met die grootskaalse implementering van buitenmaatse infrastruktuur, agteruitgang van die omgewing en die oorbenutting van natuurlike waterhulpbronne. Die gevolg was 'n konsep wat Geïntegreerde Stedelike Water Bestuur (IUWM) genoem is. IUWM omvat die hele watersiklus vanaf reënval, tot oppervlakwater, grondwater en afvalwater, as deel van die stedelike waterbestuur, en nie as aparte entiteite nie. Daar was 'n wêreldwye reaksie te IUWM, met die VSA se Lae-impak-Ontwikkeling (LID), die Verenigde Koninkryk se ontwerp van hul volhoubare stedelike dreineringstelsel (SUDS), en Nieu-Seeland se formulering van Lae-impak Stedelike Ontwerp en Ontwikkeling (LIUDD), om stedelike water hulpbronne beter te bestuur. Australië het reageer met Water Sensitiewe Stedelike Ontwerp (WSUD). WSUD verken die ontwerp en beplanning van waterbestuur infrastruktuur ontwikkeling, in 'n stedelike omgewing, waar dit noodsaaklik was in die Australiese stede wat deurlopende tekort aan water ervaar. Die WSUD benadering het ten doel om die ontwerp en beplanning te beïnvloed vanaf die oomblik reënwater in damme opgevang is, behandel, en aan verbruikers versprei word, tot by die punt van afvalwater hergebruik, sowel as stormwater gebruik. Verskeie tegnieke word verskaf as deel van die WSUD benadering, naamlik: die installering van “greenroofs”, wateraanvraagbestuur tegnieke, en stormwater gebruik en hergebruik van behandelde afvalwater vir besproeiing en brandbestryding. Hierdie WSUD aktiwiteite kan implementeer word vanaf grootskaalse pogings met die samewerking van hele voorstede met stormwater bestuur deur die konstruksie van die vleilande, sowel as kleinskaalse verandering in die ontwerp en beplanning by huishoudings, byvoorbeeld met reënwatertenk installasie vir besproeiing en toilet spoel. Met Suid-Afrika se progressiewe wetgewing op 'n nasionale, provinsiale en plaaslike munisipale vlak wat munisipaliteite steun en lei, kan die verskeie WSUD aktiwiteite ïmplementeer word. Die studie is gemik om ondersoek in te stel na watter tipe WSUD aktiwiteite deur die George-munisipaliteit implementeer word, en tot watter mate die aktiwiteite 'n impak gehad het op die water verbruik sedert die droogte in 2009. Die redes agter 'n gebrek aan implementering is ook ondersoek. Bewyse van implementering van net agt WSUD aktiwiteite kon gevind word. Data van die water debiteure en grootmaat water meters is verkry ten einde die effek van die agt WSUD aktiwiteite op die water verbruik te bepaal. Grootmaat water meter data kan egter nie gebruik word om te korreleer met die data van die debiteure aangesien die lesings van baie grootmaat water meters nie aangeteken is nie. Debiteure se data het egter bewys dat die WSUD aktiwiteite 'n korttermyn-impak op die waterverbruik in die voorstede waar dit geïmplementeer is gemaak het. Die redes gegee vir nieuitvoering is nie bevredigend nie. Aanbevelings is dat die munisipaliteit moet fokus op beter beplanning en implementering van diverse aktiwiteite en dat die hou van rekords en data prioriteit gemaak moet word om vas te stel of enige vordering gemaak is.

Climate change presents us with greater and greater challenges and stormwater is an important part of our future water problems. In some parts of the world the increase and intensification in precipitation causes strain on existing infrastructure while, in others, draughts are becoming more and more severe. Handling stormwater sustainably does not only gain the environment by controlling pollutant spreading, helping with flooding control and water reuse but can also have added values in urban areas if included in urban planning. Implementing green infrastructure and sustainable stormwater solutions creates jobs and are in many countries seen as the future way of handling stormwater. There are many different techniques and ways of adopting sustainable stormwater handling depending on the local problem and physical as well as economic conditions. Together they all have in common of creating added values when implemented. Increased biodiversity, improved air quality, reduced noise, improved growing conditions for urban trees and aesthetical values that have a positive effect on human health are just some of the positive added values of sustainable stormwater handling. The case study in this report concerns a new development on a peninsula in the municipality on Nacka, Stockholm. The recommendation is to adopt the approach of many small solutions that combines to a sustainable way of handling stormwater that not only solves the problem but creates added values in the living and working area. Stormwater is a resource that should be used as one in order to have sustainable urban planning.

A key challenge facing developing countries is the rapid increases in urbanisation and the effect this has on their water systems. Water sensitive urban design (WSUD) is a process that considers the entire water system with the aim of achieving a water sensitive city (WSC). However, little is known about how value can be created through WSUD in terms of the sustainability of urban precincts in South Africa. The researcher therefore considered the well-established literature highlighting the relationship between WSUD and sustainable urban development. To understand the value derived from these concepts, two case studies were assessed, namely the Victoria & Alfred Waterfront (V&A Waterfront) and Century City. However, it should be highlighted that due to the uniqueness of these cases, no generalisations from the findings can be generated. The methodology implemented for the case studies was social constructivist in nature and to satisfy the research objectives, semi-structured interviews were conducted, documentary material was gathered, and photographic evidence was collected. Moreover, a diverse collection of data was assessed, which was extracted through various methods of data collection, thereby resulting in an in-depth understanding of the case studies. This research concludes there is a relationship between WSUD, sustainable urban development and value. It further argues that the underlying principles of facilities management (FM) and more specifically urban FM provide a managerial framework that can connect these concepts to achieve sustainability for urban precincts. Furthermore, the study uncovered the need for value capture mechanisms as a form of infrastructure financing and value creation for urban precincts. However, it was established that neither case study make use of such mechanisms, so future research is required in this regard.

Magister Scientiae - MSc (Environ & Water Science)
Urban hydrogeology can be used to facilitate a decision-making process regarding the implementation of water sensitive urban design (WSUD) to manage water systems of periurban cities. This thesis was aimed at providing explanation of how that approach can be applied in Cape Town using Cape Flats Aquifer as a case study. To achieve this main objective, three specific objectives were set, namely, objective 1 which focused on estimating aquifer parameters using Theis analytical flow solution, in order to identify areas for implementation of managed aquifer recharge (MAR) suggested by WSUD principles; Objective 2 focused on conceptualizing groundwater flow system of Cape Flats Aquifer using the Finite Difference Method (FDM), in order to predict aquifer behaviour under stresses caused by the implementation of WSUD; Objective 3 focused on assessing gw-sw interaction using Principal Aquifer Setting, environmental isotope, and hydrochemical analysis, in-order to identify where and when groundwater surface water interaction is occurring, and thus informing the prevention strategies of the negative effluence of such exchanges on WSUD. The analysis of data collected through pumping test approach which were conducted in March, October 2015 and June 2016, showed that average transmissivity ranged from 15.08m2/d to 2525.59m2/d, with Phillipi Borehole (BG00153) having the highest and Westridge borehole 1 (G32961) having the lowest transmissivity values based on Theis solution by Aqua test analysis. Theis solution by excel spreadsheet analysis showed that average transmissivity ranged from 11.30m2/d to 387.10m2/d with Phill (BG00153) having the highest transmissivity and Bellville 2 (BG46052) having the lowest transmissivity. Storativity values ranged from 10-3 to 10-1 with Phillipi borehole (BG00153) having the highest storativity and Lenteguer borehole 1(BG00139) having the lowest values from both analysis. Average transmissivity visual maps showed that highest transmissivity values within the Cape Flats Aquifer can be obtained around the Phillipi area towards the southern part of the aquifer. Storativity maps also showed that the greatest storativity values can be obtained around Phillipi and Lenteguer area. These findings reveal that MAR would be feasible to implement around the Phillipi and Lenteguer area, where aquifer storage and discharge rates are higher.

The author examines effective urban water management as a means to promote sustainable development and achieve water sensitive cities. A qualitative method is utilised in the collection of data through document studies, desktop analysis and a literature review. A review of the current national and local water policies and approaches within South Africa, and more specifically Cape Town, indicated the need for a coordinated, systems based and holistic approach to urban water management. Water Sensitive Urban Design (WSUD) is considered as an alternative approach to urban water management in Cape Town to build resilience among local communities against the threat of drought and flood events, and promote sustainable development in moving toward a water sensitive city. A model for implementing WSUD in the context of limited resources and capacity within local municipal departments is considered. Incorporating the principles of WSUD within spatial planning initiatives to implement this approach and catalyse a systemic transition in urban water management is considered and assessed in a case study of the proposed development of the River Club. The case study considers a bottom-up approach to transforming urban water management and the capacity of WSUD, when implemented through spatial planning, to simultaneously address multiple objectives including those of sustainable development and those contained within national and local policies. The benefits of a WSUD approach for all are considered. Many if these benefits are as a result of reduced pressures on municipal infrastructure and increased water resources accrued as a product of the proposed implementation model. The implementation model proposed creates conditions in which municipal resources and investment can be redirected to promote equitable water resource and service provision distribution throughout the city. The model is proposed to effect a transformation in water policy, institutional structures and water resource management to reflect the principles of WSUD in a manner which is cognisant of the various limitations inherent to the City.

The provision of water, wastewater and stormwater infrastructure is an essential ingredient of cities. However, questions are being raised about the type and form of urban infrastructure, for economic and environmental reasons. Traditionally these techologies have offered linear solutions, drawing increasing volumes of water into cities and discharging waste at ever increasing levels, causing escalating stress on the environment. In addition the costs of water infrastructure provision and replacement, both in the developing and developed world, is becoming prohibitive. In response, a new paradigm has been called for and new solutions are emerging that have been labelled as Integrated Urban Water Management (IUWM). This concept can be considered to consist of both technical and philosophical dimensions, and represents a new form of professional praxis. However, the adoption of these techniques and concepts is constrained by the inertia of the existing urban water systems. It is therefore argued that the introduction of any change must occur across a number of dimensions of the technoeconomic system of the city. These dimensions-artefacts and technical systems (i.e. the technology and knowledge systems), professional praxis and socio-political context (i.e. institutions, culture and politics) and biophysical realities and world views (i.e. the environment and underlying values) - provide a framework for analysis of the change process - both how it is occurring and how it needs to occur. This framework is used to illustrate the link between environment values and the process of technological innovation, and points to the need for the emerging values and innovations to be institutionalised into the professional praxis and socio-political context of society. Specifically, it is argued that a new form of transdisciplinary professional praxis is emerging and needs to be cultivated. A broad review of the literature, an evaluation of selected emerging technologies and three case studies are used to illustrate and argue this position. These examples show the potential economic, social and environmental benefits of IUWM and provide some insight into the potential which this approach has to influence the form and structure of the city and at the same time highlighting the institutional arrangements required to manage urban water systems.

There is growing concern that South Africa's urban centres are becoming increasingly vulnerable to water scarcity due to stressed surface water resources, rapid urbanisation, climate change and increasing demand for water. Furthermore, South Africa is a water-stressed country with much of its surface water resources already allocated to meet current demands. Therefore, in order to meet the future urban water supply requirements, countries like South Africa will need to consider alternative forms of water management that focus on moving towards sustainability in urban water management. WSUD is one such approach that aims to prioritise the value of all urban water resources through reuse and conservation strategies, and the diversification of supply sources. This study investigates the capacity of the Cape Flats Aquifer (CFA), assessing the feasibility of implementing Managed Aquifer Recharge (MAR) as a strategy for flood prevention and supplementing urban water supply. The implementation of MAR on the CFA aims to facilitate the transition towards sustainable urban water management through the application Water Sensitive Urban Design (WSUD) principles. The fully-integrated MIKE SHE model was used to simulated the hydrological and hydrogeological processes of the CFA in Cape Town at a regional-scale. Using the results of the regional-scale model, four sites were selected for more detailed scenario modelling at a local-scale. Several MAR scenarios were simulated to evaluate the aquifer's response to artificial recharge and abstraction under MAR conditions. The first objective was to evaluate the feasibility of summer abstractions as a flood mitigation strategy at two sites on the Cape Flats prone to winter groundwater flooding, viz. Sweet Home and Graveyard Pond informal settlements. The second objective of the study was to assess the storage potential and feasibility of MAR at two sites in the south of the Cape Flats, at Philippi and Mitchells Plain. In addition, the migration of solute pollutants from the injected or infiltrated stormwater was simulated and climate change simulations were also undertaken to account for potential fluctuations in rainfall and temperature under climate change conditions. The results indicated that flood mitigation on the Cape Flats was possible and was likely to be most feasible at the Graveyard Pond site. The flood mitigation scenarios did indicate a potential risk to local groundwater dependent ecosystems, particularly at the Sweet Home site. Yet, it was shown that a reduction in local groundwater levels may have ecological benefits as many of the naturally occurring wetlands on the Cape Flats are seasonal, where distinct saturated and unsaturated conditions are required. Furthermore, MAR was shown to improve the yield of wellfields at Philippi and Mitchells Plain through the artificial recharge of stormwater while also reducing the risk of seawater intrusion. MAR was shown to provide a valuable means of increasing groundwater storage, improving the supply potential of the CFA for water supply while aiding the prevention or mitigation of the seasonal flooding that occurs on the Cape Flats. Furthermore, the case was made that MAR is an important strategy to assist the City of Cape Town in achieving its WSUD objectives. MAR and groundwater considerations, in general, are essential for the successful implementation of WSUD, without which, there is an increased risk of overlooking or degrading urban groundwater resources. The findings of this study resulted in a number of recommendation to urban water resources managers, planners and policy makers. First, MAR is an important means for Cape Town to move towards becoming a truly water sensitive city. This study indicated that the CFA should be incorporated as an additional source of water supply for Cape Town especially considering the recent drought conditions and due to its ability for the seasonal storage of water, this would improve the city's resilience to climate change. Furthermore, it was recommended that the application of MAR on the CFA could also be used to reduce groundwater related flooding on the Cape Flats. Second, it was emphasised that urban planning, using WSUD principles is essential for the protection of the resource potential of the CFA. Finally, for the implementation of WSUD and MAR to be successful, there needs to be appropriate policy development alongside the implementation of these strategies to ensure they are achieving their initial objectives and are not causing detriment to the aquifer.

Nothing can exist, live, survive or thrive without water. Water is the basis of life for all living organisms and the centre of life for all societies. The global attitude around water has become territorial as it encompasses an intricate link to the development of nations. Centralising main water supplies beyond urban boundaries may have improved the utilisation of water but has also resulted in the separation of society and water. Water is what gave rise to the city of Cape Town, as there was an abundance of rivers and springs located on and around Table Mountain. This water was first used by the Khoi people and became the reason for colonial settlers residing in the Cape. The City is currently experiencing the worst water crisis in over a century due to increased temperatures and decreased rainfall. Amid the water crisis there appears to be underused, freshwater below Cape Town's CBD, flowing to the Atlantic Ocean via the stormwater reticulation system. This water originates from Table Mountain's rivers, streams and, to an extent, springs. Naturally, the drought has sparked widespread concern for, and attention given to, water and its sustainable usage. This dissertation explores the ways in which the City's water, environmental and spatial planning policies could spark a new and improved water-culture within Cape Town to ensure sustainable, long-term water availability. This is done through investigating the potential of Oranjezicht in becoming a catalytic area for water sustainability due to the locations of the Field of Springs and the Platteklip Stream. This dissertation proposes using water sensitive urban design as well as integrated, collaborative partnerships and management mechanisms to encourage an improved urban water culture.

Cities globally are progressively becoming hotspots for water related risk and disaster mainly as a result of the cumulative effects of rapid urbanisation, population growth and the impacts of climate change. South African cities in particular are faced with the dual challenges of meeting demand for scarce water resources, as well as mitigating urban flooding. A shift towards adaptive and sustainable approaches has been proposed in order to address these complexities whilst ensuring the satisfactory delivery of water services to citizens. To support this change, local authorities are tasked with restructuring policy to include climate change adaptation strategies in order to adapt more adequately and proactively. In this regard, Water Sensitive Urban Design (WSUD) has gained importance in terms of guiding cities around the world in transitioning towards becoming water sensitive. WSUD aims to ensure that urban planning and design is undertaken in an interdisciplinary way and minimises the hydrological impacts of development on the surrounding environment. Sustainability transitions literature recognises that infrastructure and technologies are highly intertwined with institutional structures, regulations and social practices. For this reason, transitions towards sustainability-oriented technologies typically involve significant changes along assorted dimensions of the socio-technical system. Accordingly, this project aims to understand and identify the fundamental institutional conditions necessary to support a transition towards WSUD, using the City of Cape Town (CoCT) as a case study site. In order to achieve this aim, the City Blueprint Approach (CBA) was applied to the CoCT based on in-depth interviews and publicly available data. The CBA was developed by the KWR Watercycle Research Institute in cooperation with Utrecht University, The Netherlands and has been tested on various cities globally. It is a set of diagnostic indicator tools comprising the Trends and Pressures Framework, the City Blueprint Framework and the Governance Capacity Framework. The CBA assessment was followed by a thematic analysis to understand the context of transitions to a WSUD approach in Cape Town. The results of the research indicate that the CoCT has had some success in its efforts related to the sustainable management of water resources through the implementation of policy, action plans and a range of learning opportunities for city officials and local stakeholders. Despite these efforts however, issues of financial viability, implementing capacity and political will have hindered progression towards WSUD in the City. In conclusion, the research has emphasised that sustainable water management and a transition towards a WSUD approach requires more than just redesigned infrastructure; it has also highlighted the different institutional aspects that make transitioning towards WSUD possible both in Cape Town, as well as for other cities in developing countries with similar socio-economic contexts to South Africa.

Pervious pavements in car parks and driveways reduce peak discharge and the volume of runoff flowing in to urban drains and improve the water quality by trapping the sediments in the infiltrated water. This reduces the risk of pollutants such as suspended solids and particle bound chemicals such as phosphorous, nitrogen, heavy metals and oils and hydrocarbons entering receiving waters. The key objectives of the study are to establish relationships between rainfall and pervious pavement runoff and quantify improvements to infiltrated stormwater quality through the pervious pavement. The field experimental results were used to calibrate the PCSWMMPP model and to develop water flow and quality improvement transfer functions of the MUSIC model for concrete block and turf cell pavements. The research reported herein has demonstrated that pervious pavements can be introduced as a sustainable stormwater management initiative and as a key Water Sensitive Urban Design feature to deliver numerous benefits to the environment. The outcomes from the study will be useful in designing environmentally friendly car parks, pedestrian paths, light traffic drive ways, sporting grounds and public areas in the future. Land developers and local government authorities will be major beneficiaries of the study which has increased the understanding of the use of pervious pavements and explored a number of issues that previously inhibited the wider use of pervious pavements in practice.

Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Urbanismo apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.
De um crescimento acelerado e projectado, na sua generalidade, para apresentar soluções que respondam às questões que o tempo foi levantando, nasceu uma cidade fragmentada, funcionalmente desequilibrada e com estruturas urbanas desconectadas entre si. Edifícios que, cruzando vários períodos históricos e com o que deles advém, foram perdendo as suas características mais especificas e deixados à mercê do tempo e da natureza; grandes espaços vagos foram surgindo no tecido urbano, apropriados pela pessoas das mais variadas formas; e estruturas mais pequenas que, uma vez desagregadas daquilo que é a cidade como mega estrutura, surgiram deste desacerto na história, no tempo e no correcto planeamento da cidade. A água apresenta-se no espaço público, na sua grande maioria e muitas vezes por autoria de quem o planeou, como um elemento tranquilizante e harmónico. No entanto, a presença da água em meio urbano não podia ser mais complexa. Desde a rede de águas pluviais, à rede doméstica, são números os processos pelos quais esta passa. Num clima seco como aquele que caracteriza Portimão, são cada vez mais frequentes os episódios de chuva intensa e, por consequência, os danos que esta provoca na cidade. Este documento, apresenta assim no contexto da cidade de Portimão, soluções que, através do espaço público como elemento de articulação, integrem estas dispersas estruturas na cidade como elementos potenciados e qualificadores desta. Assim, numa perspectiva de consolidar o território e adaptá-lo como forma de o preparar para estes cenários que se revelam cada vez mais frequentes, o desenho do espaço público surge como palco de múltiplas intervenções na lógica da adaptação e como estrutura agregadora dos vários componentes que formam a cidade.
To present solutions that answer the questions that time has been raising, from an accelerated and projected growth, a fragmented city was born and functionally disconnected. Buildings that withstood countless historical periods started losing their most specific characteristics and left at the mercy of time and nature; substantial vacant land was emerging in the urban tissue, appropriated by people in uncountable ways; and smaller structures that once were disaggregated from what the city is as a megastructure, arose from this mismatch in history, time and proper planning of the city. Water presents itself in the public space, mostly and often by the authorship of the urban planner, as a soothing and harmonic element. However, the presence of water in urban areas could not be more complex, since the rainwater and domestic network, there are many processes that the water travels through. In a dry climate like the one that characterizes Portimão, episodes of heavy rain are becoming more frequent and, thus causing damages in the city. Therefore, this document presents in the context of Portimão, solutions that, by making public space an articulation element, that incorporates these dispersed structures and transforming them into empowered and qualifying elements of the city. Lastly, in a perspective of consolidating the territory by adapting it as a way of preparing for these increasingly frequent scenarios, the design of public space emerges as the stage of multiple interventions in the logic of adaptation and as an improved structure that adapts several components that constitute the city.
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This research study comprehensively analyses the dynamics of nitrogen and suspended solids removal in stormwater biofilters. The study focuses on pollutant removal during an event with time, rather than the conventional event-mean analysis. Antecedent dry days (number of days in between rainfall) during which biofilters remain dry and the inflow concentration of pollutants were two other important variables analysed in this study. The research outcome highlights the significance of dry-phase processes and the process of stabilization on filter performance and sets a paradigm shift from the current approach towards an innovative way of performance analysis of biofilters.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Civil Engineering, 2020
Rapidly urbanizing areas present unique opportunities to implement alternative approaches to conventional water management as the Republic of South Africa (RSA) is a water-stressed country. An integrated systems approach that takes into account the different water users, sanitation and drainage have the potential to make urban areas more ‘water-sensitive’. Some of the challenges facing RSA include inadequate supply, lack of accountability by those put in charge, failing of existing infrastructure, unsynchronized planning and environmental challenges brought about by climate change (e.g. drought). The main objective of‘ water-sensitive’ design is to decelerate runoff as well as reduce the quantity of surface water runoff. This is to allow for the effective management of downstream flooding, pollution risk, and potable water demand reduction. These objectives are achievable by harvesting, infiltrating, decelerating, storing, conveying, and treating runoff on site and, where possible, on the surface rather than underground. In this research, the conventional design of storm water and potable water systems is compared to Water Sensitive Urban Design (WSUD) systems within a greenfield township development in South Africa. The key goal of this study is to determine if the benefits of applying WSUD methods to a greenfield urban development in South Africa is likely to outweigh the benefits of conventional design methods. Prior to the detail design, an overview to the many conventional and WSUD interventions are provided. The study then focuses on the design of the water systems using the two approaches. Following the design of both systems, the cost of implementation is determined by measuring the quantities of the different elements of the solutions and applying the applicable market related costs. The runoff generated in the post-development WSUD scenario is 30% less than the value of the post-development no control scenario. The cost benefit ratio is used to determine if the WSUD is economical as compared to the conventional design. A benefit cost ratio of 1.07 is calculated. As such the WSUD is considered better than the conventional design alternative. The study concludes that the implementation of WSUD within new developments is a starting point in achieving water sensitivity in greenfield developments in RSA
CK2021

Short duration intense rainfall causes an increase in rainfall derived infiltration and inflow (RDII) in aging sewer networks, which leads to Sanitary Sewer Overflows (SSOs). This, in turn, causes various detrimental impacts, both on human health and the environment. This research aims to quantify the benefits of Water Sensitive Urban Design (WSUD) approaches to mitigate the negative impacts of rainfall induced SSOs. In this context, this research develops a generalised framework for assessing and mitigating the impacts of intense rainfall on the performance of the sanitary sewer network. The first part of the developed framework involves detailed hydraulic modelling to evaluate the performance of the sewer network. The second part deals with the development of SSO mitigation strategies based on popular WSUD approaches. This study also demonstrates the application of the developed framework for a case study catchment in Melbourne, Australia. A detailed hydraulic modelling to analyse the performance of the case study sewer network during a wet (2010) and a dry year (2008) has been presented. The hydraulic performance analysis found that the system experienced 23 ML of sewer overflow volume in 2010 as compared to 3.42 ML in 2008. Towards mitigating the negative impacts of SSOs, this study has implemented two commonly used WSUD approaches, namely rainwater tanks and rain gardens for the case study sewer network. A detailed hydraulic modelling has been undertaken with rainwater tanks and rain gardens (individually and in combination) for the wet year 2010. It was observed that rainwater tanks (individually) could lead to a maximum reduction in SSO volume by 33% when compared to the base case overflow volume of 23 ML. A higher reduction in SSO volume up to a maximum of 45% was observed when rain gardens were implemented in conjunction with rainwater tanks. Such an analysis will benefit the urban water authorities to develop sustainable WSUD based mitigation strategies for controlling SSOs in their sewer system. Thus, the study will be beneficial for the community and the environment.

Street trees provide cities with a range of social, economic and environmental benefits, with large, mature trees providing the maximum benefits. Street trees can be conceptualized as a form of ‘green infrastructure’, delivering a range of environmental and human services alongside the ‘grey infrastructure’ of conventional engineering services. However street trees face an extremely hostile environment in the city and may struggle to survive and grow. These challenges are exacerbated by ‘unsustainable’ streetscape design and tree planting practices, such as planting trees in undersized tree pits dug in compacted urban soils, and surrounding trees with hard impervious surroundings. These practices often result in declining tree health, reduced tree life spans, increased tree mortality and also conflicts between trees and surrounding infrastructure. This thesis aims to develop a more sustainable model for urban streetscape design and street tree planting practices in Australian cities, which better integrates the needs of street trees, based on the expert opinions of researchers and practitioners in the field. A mixed-method research strategy was adopted, using both quantitative and qualitative techniques. A detailed literature review of current tree planting practices was undertaken covering the following topics: providing space both above and below ground; providing trees with the resources for growth; and minimizing a range of infrastructure conflicts. The views of a variety of professionals across Australia were then collected using various techniques. These included an Australia-wide online survey of local government practitioners to address the wider picture, and in-depth interviews with practitioners in metropolitan Adelaide, to provide a detailed understanding of the issues. Detailed case studies were also conducted in four Australian capital cities, including interviews with local luminaries, to review current ‘best practice’ techniques and policies for street tree planting. The outcome of this research is presented as a new paradigm for the more sustainable urban tree planting and management practices, entitled ‘Tree Sensitive Urban Design’ (TSUD). A proposed “Model for TSUD” draws upon the practices identified in the thesis research, and recommends that the management of urban trees should move from an engineering-based approach to streetscape design, to considering street trees as an essential part of the city. The ‘Model for TSUD’ presented includes a set of objectives, planning and design principles, and a set of ‘structural’ and ‘nonstructural’ best practices to accommodate street trees.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences and School of Architecture, Landscape Architecture and Urban Design, 2010

No atual contexto de alterações climáticas, a gestão da água necessita de responder a múltiplos desafios e pressões a que os recursos hídricos e as cidades estão expostos. A maior sensibilidade por parte da sociedade em relação a estas questões exige novas abordagens relativamente aos problemas existentes e impõe desafios aos utilizadores do território e do capital natural água. A tendência atual foca-se em modelos que promovam adaptação e resiliência do espaço urbano através de estratégias integradas e sustentáveis, para que o recurso água continue a satisfazer as necessidades humanas e a promover, além do equilíbrio ambiental, o bem-estar social. A abordagem Water Sensitive Urban Design (WSUD) define a cidade como uma bacia hidrográfica, integrando a gestão do Ciclo Urbano da Água (CUA) no processo de desenvolvimento urbano. As águas pluviais e residuais são elementos-chave na cidade, vistas como fonte de serviços de ecossistemas. Contudo, o desenvolvimento urbano e o próprio ordenamento do território exercem enormes pressões, podendo alterar de forma significativa o ciclo natural da água, o que, em conjunto com a existência de infraestruturas envelhecidas, aumenta manifestamente as ineficiências e vulnerabilidades dos sistemas. A introdução de técnicas WSUD na gestão do CUA pretende reduzir a quantidade de áreas urbanas impermeáveis, promover a retenção temporária de águas e o seu reaproveitamento, o mais próximo possível da sua origem, minimizando os impactos do desenvolvimento urbano sob o meio natural. O presente trabalho tem como principal objetivo desenvolver uma estratégia que promova a transição da cidade de Quarteira (concelho de Loulé) para uma Water Sensitive City (Cidade Sensível à Água), através da definição de um plano de intervenção assente nos princípios WSUD. O planeamento urbano sensível à água surge assim como alternativa à abordagem tradicional de gestão urbana da água, promovendo a gestão integrada e sustentável do CUA e, simultaneamente, a resiliência e adaptação da cidade às alterações climáticas, integrando a comunidade na tomada de decisões. O plano apresentado, suportado por melhores práticas de gestão estruturais no domínio de WSUD e cujo foco recai sobre as zonas críticas diagnosticadas na área de estudo, inclui medidas para controlo na origem, tratamento e promoção da infiltração, tais como, pavimentos permeáveis, coberturas verdes, recolha e armazenamento de águas pluviais, bacias de detenção e swales de biorretenção
The current climate change context poses multiple challenges and pressures to cities and water resources, to which water management needs to respond. A greater understanding of society regarding these issues requires new approaches to solve the existing problems, imposing challenges to current land and water resources users. The present trend directs the focus towards models that promote adaptation and resilience of the urban medium, through integrated and sustainable strategies, so that water resources, a cornerstone for societal development, continues to fulfil human needs and to promote, in addition to environmental balance, social well-being. The Water Sensitive Urban Design (WSUD) approach, defines the city as a catchment, incorporating the management of the urban water cycle (UWC) in the urban development process, in which stormwater and wastewater are key elements, considering the city as a source of ecosystems services. Urban development and land-use are acknowledged as a source of enormous pressures, which can significantly alter the natural water cycle, and that, together with existing old infrastructures, increase the inefficiencies and vulnerability of the urban system. The introduction of WSUD techniques in the management of the UWC aims to reduce impervious areas, promote the temporary retention of water and its reuse, as close as possible to its source, minimizing the impacts of urban development on the natural environment. The main objective of this work, is to develop a strategy that promotes the transition of the City of Quarteira (Loulé’s municipality) into a Water Sensitive City, through the development of an intervention plan based on WSUD principles, that is, on water sensitive urban planning, as an alternative to the traditional urban water management approach, which promotes the integrated and sustainable management of the UWC and, at the same time, the city’s resiliency and response to climate change, while engaging community’s participation in decision-making processes. The introduced plan, supported by structural best management practices (BMPs) in the WSUD domain, focuses on critical areas identified in the study area, which include source control, treatment and infiltration measures, for example, permeable pavements, green roofs, rainwater harvesting, detention basins and bio-retention swales.

Research Doctorate - Doctor of Philosophy (PhD)
This thesis is concerned with the problem of implementing new sustainable practices in urban environments through an analysis of the response to and reworking of a proposed urban design strategy over two decades in Australia, from the early 1990's until the mid 2000's. The analysis fits within a Science Technology and Society (STS) perspective but also draws on urban studies, theories of socio-technical change, and the exercise of agency by professional groups. The term Water Sensitive Urban Design (WSUD) originated in Perth in the later 1980's and has been rapidly adopted into environmental engineering and development planning. The meaning of the term is variable, but it typically implies the use of source control and natural surface strategies for the management of stormwater for both its resource value and to improve the environmental impacts on receiving waters. However, it can incorporate broader aims, integrating the management of water into a consideration of the urban water cycle and the whole urban landscape. Implementation depends on the technical credentials of the new methods, but also receptive governance, engineering and development communities. This thesis addresses the position of engineers, developers, and governance bodies within their political and social context to elucidate the effects of each group on shaping the eventual outcome; redefining and constraining the integrated intentions of WSUD to make it compatible with the commercial process of land development, the constraints of local and state government and the ecological modernisation perspectives of the federal government. The hosting of WSUD by the water engineering community is juxtaposed against the lack of intellectual debate amongst planners. The influence of different tiers of government is described in terms of the mechanisms used to express their power and direct changing priorities in light of political intentions and drought. While great progress has been made in mediating environmental impacts and capturing rainwater for useful outcomes, little progress has been made in integrating water management into a consideration of other aspects of a desirable urban form. The current political climate promotes strengthened accountability and project managed responses to resource and environmental problems. This is no conducive to nurturing the integrated planning aspects of WSUD or encouraging debate over the form of urban stormwater management that is desirable in the long term.