Nature Based Solutions for Sustainable Urban Storm Water Management in Global South: A Short Review

Rapid urbanization in the Global South exacerbates urban water management challenges such as urban flooding and water pollution, rendering many areas water-insecure. Our reliance on grey infrastructures to combat these water management challenges is not sustainable in the long run, due to which a better alternative must be sought. Nature-based Solution (NBS) promote ecosystem services and enhance climate resiliency along with flood control and improvement of water quality by utilizing natural elements including green spaces and water bodies within the urban environment. In the past few decades, NBS have been adapted for urban drainage in Global North and evolved by means of various terms based on geographic location, practices and applications. Some of these well-known terms include Low Impact Development (LIDs), Sustainable Urban Drainage Systems (SUDS), Water Sensitive Urban Design (WSUD) and Best Management Practices (BMPs). The transition towards a resilient and sustainable environment has been made possible through the application of NBS. Recently, countries in the Global South such as Singapore, Malaysia, Vietnam, and Thailand are trying to alter urban storm water management strategies through conversion of grey infrastructure to green infrastructure by employing various NBS techniques. The findings of this study show how NBS has influenced the Global South’s urban water management.

Green infrastructure-based hydrological modelling, a comparison between different urban districts, through the case of Szeged, Hungary

Because of the climate uncertainties caused by climate change and the growing urban areas, today’s cities face new environmental challenges. The impervious artificial elements change the urban water cycle. Urban districts with inadequate water infrastructure and treatment can be a major source of environmental risks, like urban flash floods. Modern cities need to be prepared for the changing environment in a sustainable way, which can be realised with the help of green infrastructure. The primary role of the green infrastructure is mitigation, such as surface runoff reduction and retainment. The aim of our research is to examine urban district scale data about the role of green infrastructure in urban water management. Hydrological models can provide adequate data about the surface runoff, infiltration and the mitigating effect of vegetation (interception and evaporation). We compared two significantly different urban districts (downtown and housing estate area), based on land cover and vegetation data. The analysis of the districts of Szeged (Hungary) suggests that the vegetation can significantly contribute to the reduction of surface runoff. Differences between these urban districts can be quantified, thus, these data can serve as a basis for urban water management planning processes.

Tacit knowledge in water management: a case study of Sponge City

Sustainable, resilient urban water management is fundamental to good environmental and public health. As an interdisciplinary task, it faces enormous challenges from project complexity, network dynamics, and the tacit nature of knowledge being communicated between actors involved in design, decisions and delivery. Among others, some critical and persistent challenges to the implementation of sustainable urban water management include the lack of knowledge and expertise, lack of effective communication and collaboration, and lack of shared understanding and context. Using the Chinese Sponge City programme as a case study, this paper draws on the perspectives of Polanyi and Collins to investigate the extent to which knowledge can be used and exchanged between actors. Using Collins’ conceptualisation of the terrain of tacit knowledge, the study identifies the use of relational, somatic, and collective tacit knowledge in the Sponge City pilot project. Structured interviews with 38 people working on a Sponge City pilot project provided data that was rigorously analysed using qualitative thematic analysis. The paper is original in using theories of tacit knowledge to explain barriers and pathways for information and messages being communicated between actors in urban water management. The methods and results provide the groundwork for analysing the access and mobilisation of tacit knowledge in the Sponge City pilot project, with relevance for other complex, interdisciplinary environmental projects and programmes.

Management of Urban Waters with Nature-Based Solutions in Circular Cities—Exemplified through Seven Urban Circularity Challenges

Nature-Based Solutions (NBS) have been proven to effectively mitigate and solve resource depletion and climate-related challenges in urban areas. The COST (Cooperation in Science and Technology) Action CA17133 entitled “Implementing nature-based solutions (NBS) for building a resourceful circular city” has established seven urban circularity challenges (UCC) that can be addressed effectively with NBS. This paper presents the outcomes of five elucidation workshops with more than 20 European experts from different backgrounds. These international workshops were used to examine the effectiveness of NBS to address UCC and foster NBS implementation towards circular urban water management. A major outcome was the identification of the two most relevant challenges for water resources in urban areas: ‘Restoring and maintaining the water cycle’ (UCC1) and ‘Water and waste treatment, recovery, and reuse’ (UCC2). s Moreover, significant synergies with ‘Nutrient recovery and reuse’, ‘Material recovery and reuse’, ‘Food and biomass production’, ‘Energy efficiency and recovery’, and ‘Building system recovery’ were identified. Additionally, the paper presents real-life case studies to demonstrate how different NBS and supporting units can contribute to the UCC. Finally, a case-based semi-quantitative assessment of the presented NBS was performed. Most notably, this paper identifies the most typically employed NBS that enable processes for UCC1 and UCC2. While current consensus is well established by experts in individual NBS, we presently highlight the potential to address UCC by combining different NBS and synergize enabling processes. This study presents a new paradigm and aims to enhance awareness on the ability of NBS to solve multiple urban circularity issues.

How Does Digitization Succeed in the Municipal Water Sector? The WaterExe4.0 Meta-Study Identifies Barriers as well as Success Factors, and Reveals Expectations for the Future

Water is increasingly taking center stage when it comes to coping with climate change. Especially in urban areas, negative consequences from heavy rainfall events and prolonged dry periods are rising worldwide. In the past, the various tasks of urban water management were performed by different departments that often did not cooperate with each other (water supply, wastewater disposal, green space irrigation, etc.), as the required water supply was not a question of available water volumes. This is already changing with climate change, in some cases even dramatically. More and more, it is necessary to consider how to distribute available water resources in urban areas, especially during dry periods, since wastewater treatment is also becoming more complex and costly. In the future, urban water management will examine water use in terms of its various objectives, and will need to provide alternative water resources for these different purposes (groundwater, river water, storm water, treated wastewater, etc.). The necessary technological interconnection requires intelligent digital systems. Furthermore, the water industry must also play its role in global CO2 reduction and make its procedural treatment processes more efficient; this will also only succeed with adequate digital systems. Although digitization has experienced an enormous surge in development over the last five years and numerous solutions are available to address the challenges described previously, there is still a large gap between the scope of offerings and their implementation. Researchers at Hof University of Applied Sciences have investigated the reasons for this imbalance as part of WaterExe4.0, the first meta-study on digitization in the German-speaking water industry, funded by the German Federal Ministry of Education and Research. Only 11% of roughly 700 identified products, projects and studies relate to real applications. For example, the surveyed experts of the water sector stated that everyday problems are considered too little or hardly at all in new solutions, which greatly overburdens users. Furthermore, they see no adequate possibility for a systematic analysis of new ideas to identify significant obstacles and to find the best way to start and implement a digitization project. The results from four methodologically different sub-surveys (literature and market research, survey, expert interviews and workshops) provide a reliable overview of the current situation in the German-speaking water industry and its expectations for the future. The results are also transferable to other countries.

Shaping More Sustainable Communities: a Case Study in Urban Water Management

<p>The motivation for this study was to consider how communities might take a more integrated and systematic approach to meeting the challenges of water management in New Zealand, and achieve more sustainable systems. The specific challenges facing a community pursuing sustainable urban water management objectives were examined and solutions sought and tested. Urban water systems, in particular, are under increasing pressure to meet the expectations of communities, with water managers required to articulate sensible management initiatives that secure water supplies and protect water for its intended use, now and in the future. Despite policy and regulation intended to advance outcomes and integrate efforts within the complex area of urban water management, fragmented approaches persist, while a pattern of decline in the quality of New Zealand's water resources remains a cause for concern. Nearly half of urban rates collected in New Zealand apply to water and wastewater management. Thus, this study is concerned with understanding the critical constraints to achieving healthier, more sustainable urban water systems that are affordable for New Zealand communities. The thesis demonstrates the methodology by focusing on Kapiti, a settlement north of Wellington, which has been debating and responding to water quality and security issues for more than a decade. Subsequent to a piloted investigation, a methodological framework was proposed, based on integrating three near complementary perspectives. The Theory of Constraints (TOC) was used with a Stakeholder Typology to identify system stakeholders, capturing and representing their perspectives with Intermediate Objective (IO), Current Reality Tree (CRT) and Prerequisite Trees (PRT), while Causal Loop Diagrams (CLDs) from Systems Dynamics were constructed with some participants to explore and circumvent potential negative outcomes. The combined framework provided a source of deep insights into the challenges, dilemmas, potential solutions and side effects facing resource managers and other stakeholders in an urban water system under pressure from population growth and climatic/topographical conditions. It is possible that the combined theoretical framework can be applied to other resource management cases. The use of the Stakeholder Typology to complement TOC provided a tactical element not routinely evident in systems studies, valuing the experiential and historical perspectives of those who might otherwise be treated as being outside the system, their perspectives marginalised or ignored. The TOC framework offered a logic-based means to identify and invalidate a critical assumption that peak demand would reduce to a level predicted by system managers. Further, the TOC tools were used to focus on and agree the set of conditions necessary to deal with the demand constraint and meet the system goal agreed by the stakeholder participants.</p>

Shaping More Sustainable Communities: a Case Study in Urban Water Management

<p>The motivation for this study was to consider how communities might take a more integrated and systematic approach to meeting the challenges of water management in New Zealand, and achieve more sustainable systems. The specific challenges facing a community pursuing sustainable urban water management objectives were examined and solutions sought and tested. Urban water systems, in particular, are under increasing pressure to meet the expectations of communities, with water managers required to articulate sensible management initiatives that secure water supplies and protect water for its intended use, now and in the future. Despite policy and regulation intended to advance outcomes and integrate efforts within the complex area of urban water management, fragmented approaches persist, while a pattern of decline in the quality of New Zealand's water resources remains a cause for concern. Nearly half of urban rates collected in New Zealand apply to water and wastewater management. Thus, this study is concerned with understanding the critical constraints to achieving healthier, more sustainable urban water systems that are affordable for New Zealand communities. The thesis demonstrates the methodology by focusing on Kapiti, a settlement north of Wellington, which has been debating and responding to water quality and security issues for more than a decade. Subsequent to a piloted investigation, a methodological framework was proposed, based on integrating three near complementary perspectives. The Theory of Constraints (TOC) was used with a Stakeholder Typology to identify system stakeholders, capturing and representing their perspectives with Intermediate Objective (IO), Current Reality Tree (CRT) and Prerequisite Trees (PRT), while Causal Loop Diagrams (CLDs) from Systems Dynamics were constructed with some participants to explore and circumvent potential negative outcomes. The combined framework provided a source of deep insights into the challenges, dilemmas, potential solutions and side effects facing resource managers and other stakeholders in an urban water system under pressure from population growth and climatic/topographical conditions. It is possible that the combined theoretical framework can be applied to other resource management cases. The use of the Stakeholder Typology to complement TOC provided a tactical element not routinely evident in systems studies, valuing the experiential and historical perspectives of those who might otherwise be treated as being outside the system, their perspectives marginalised or ignored. The TOC framework offered a logic-based means to identify and invalidate a critical assumption that peak demand would reduce to a level predicted by system managers. Further, the TOC tools were used to focus on and agree the set of conditions necessary to deal with the demand constraint and meet the system goal agreed by the stakeholder participants.</p>