An overview of on-site retention and detention policies for urban stormwater management in the Greater Western Sydney Region in Australia

Stormwater has been recognised as one of the main culprits of aquatic ecosystem pollution and as a significant threat to the goal of ecological sustainable development. Water sensitive urban design is one of the key responses to the need to better manage urban stormwater runoff, the objectives of which go beyond rapid and efficient conveyance. Underpinned by the concepts of sustainable urban development, water sensitive urban design has proven to be an efficient and environmentally-friendly approach to urban stormwater management, with the necessary technical know-how and skills already available. However, large-scale implementation of water sensitive urban design is still lacking in Australia due to significant impediments and negative perceptions. Identification of the issues, barriers and drivers that affect sustainability outcomes of urban stormwater management is one of the first steps towards encouraging the wide-scale uptake of water sensitive urban design features which integrate sustainable urban stormwater management. This chapter investigates key water sensitive urban design perceptions, drivers and barriers in order to improve sustainable urban stormwater management efforts.

Typically, best management practices (BMPs) are implemented to help sustainable stormwater management in urban areas. Over recent decades the selection of urban stormwater management measures for a site has been a challenge among urban planners where thecriterion based on flood volume no longer suffices for selecting urban drainage solutions. Therefore there is a need to consider a set of holistic criteria beyond runoff and inundation objectives by which it would be possible to evaluate sustainability of urban drainage projects. Frequent urban flooding events have justified the use of ‘resilience’ concept and pertaining criteria. This paper proposes a methodology to verify the sustainability of BMPs projects alongside their resilience. The multi criteria decision making (MCDM) technique has been applied for BMPs ranking based on proposed criteria. The methodology has been applied to urban drainage system of a municipal district of Tehran (Iran). Results indicate the effects of manager’s preferences on selecting BMPs. The proposed methodology provides an effective tool for urban managers to adopt more resilient-sustainable decisions in urban areas.

The purpose of this paper is to outline strategies of sustainable stormwater management design and innovation for private developments and public infrastructure projects in urban areas. This paper will focus on urban stormwater management, with several examples of private and public projects recently completed that implement sustainable stormwater management design. Through examination of specific projects this paper will assist the audience in understanding current local trends for sustainable stormwater management, provide information on local agency requirements for their implementation, and foster a discussion of techniques to change the current way of thinking in their application in public and private infrastructure projects. This paper is based on the authors’ experience as an engineer and designer of sustainable stormwater management systems as well as review of current literature addressing sustainable stormwater management. I. Introduction Managing stormwater has been part of human’s interaction with their environment for millennia. Humans have used numerous methods to prevent damage from flooding and erosion caused by stormwater during rainfall events. Typical stormwater management controls consist of structural and non-structural elements that contain and convey stormwater during a rain event. These typical stormwater management controls can consist of wet and dry detention basins, large pipes, and concrete structures. Recently, new practices of managing stormwater have begun to develop that place the focus on preserving and maintaining the natural hydrology within a watershed. Maintaining and replicating natural hydrology provides sustainable benefits that include reductions in pollutant and nutrient loading to existing watersheds, groundwater recharge, decreasing erosion, and lowering the burden on existing sewer and stormwater management infrastructure. The new practice and understanding of stormwater management can be seen in large metropolitan areas in the United States such as Chicago, Los Angeles, and Seattle, as well as smaller municipalities and local communities (Newell, et al. 2012). In particular, the City of Chicago and surrounding area have recently developed codes and requirements that promote sustainable stormwater management for new developments within their jurisdiction. Examining the current trend in Chicago will

Stormwater has been recognised as one of the main culprits of aquatic ecosystem pollution and as a significant threat to the goal of ecological sustainable development. Water sensitive urban design is one of the key responses to the need to better manage urban stormwater runoff, the objectives of which go beyond rapid and efficient conveyance. Underpinned by the concepts of sustainable urban development, water sensitive urban design has proven to be an efficient and environmentally-friendly approach to urban stormwater management, with the necessary technical know-how and skills already available. However, large-scale implementation of water sensitive urban design is still lacking in Australia due to significant impediments and negative perceptions. Identification of the issues, barriers and drivers that affect sustainability outcomes of urban stormwater management is one of the first steps towards encouraging the wide-scale uptake of water sensitive urban design features which integrate sustainable urban stormwater management. This chapter investigates key water sensitive urban design perceptions, drivers and barriers in order to improve sustainable urban stormwater management efforts.

Sustainable urban stormwater management (SUSM) is essential to urban sustainability. However, barriers to adopting it are observed even in places where SUSM is more widespread. Recent studies have evaluated strategies for overcoming some barriers. However, no study has systematically analyzed the strategies available for overcoming the most common barriers in developing countries. Thus, this article aimed to provide a literature review on these strategies. Ninety-two documents were evaluated, resulting in eight solution strategies, detailed by 80 implementation measures. The interrelationships among the solution strategies and their applicability to overcome the SUSM-related barriers were evaluated. This analysis showed that the solution strategies are interdependent, so it would be inefficient to adopt them in isolation. On the other hand, adopting a strategy can help overcome several barriers, also enhancing other strategies and urban issues. The availability of this systematized information can help to break through common barriers, optimizing efforts to adopt SUSM.

In recent years, considerable advances have been made in techniques and legislation for decentralized stormwater management worldwide. However, decentralized stormwater management systems are still underutilized and acceptance among citizens and professionals is still lacking. Indeed, decentralized stormwater management will be essential for the sustainable development of cities in the future. The main question that needs to be answered is: How can sustainable stormwater management be integrated with urban planning in order to create liveable, sustainable, and attractive cities? The approach of Water Sensitive Urban Design (WSUD) proposes a solution. This manual, developed by the Hafen City University of Hamburg, in the ambit of the European research project SWITCH (Managing water for the city of the future, under the sixth research framework programme of the European Union). The book was published by Jovis Verlag GmbH in March 2011. It is organised into four chapters plus an introduction and the conclusions. - The first chapter provides an overview of the WSUD approach, underlining the differences between conventional stormwater management in cities, the problems with conventional stormwater management and the variations in stormwater in different climate zones around the world. - The second chapter, the ideas of WSUD and sustainable stormwater management, is organised in three parts: definitions, technical elements, solutions and drivers. The first defines the WSUD as an interdisciplinary cooperation of water management, urban design and landscape planning and clarifies that the primary objective is to combine the demands of sustainable stormwater management with the demands of urban planning. The second lists the technical elements and solutions grouped according to their primary function: water use, treatment, detention and infiltration, conveyance and evapotranspiration. The third gives an overview of international and national regulations, engineering standards and guidelines primarily focused on Europe, Australia and USA. - The third chapter identifies principles for a successful WSUD, focusing on six issues: water sensitivity, aesthetics, functionality, usability, public perception and acceptance, as well as integrative planning. - The fourth chapter presents an international selection of case studies ranging from small scale (site level) up to large scale (city level), demonstrating WSUD principles in the context of temperate climates. All the projects come complete with a fact sheet, several images and construction details, and were assessed against the following principles of WSUD: water sensitivity, aesthetic benefit, integration in the surrounding area, appropriate design, appropriate maintenance, adaptability, appropriate usability, public involvement, acceptable costs, integration of demand, interdisciplinary planning, impact on public perception. WSUD strives to harmonise the urban built environment and the urban water cycle, combining the functionality of water management with principles of urban design and planning. The approach embraces interdisciplinary cooperation of water management, urban design, architecture and landscape planning in order to achieve WSUD goals as well as integrating water management concerns into overall concepts and development plans. The application perspectives of the WSUD method, supported by the implementation of new quantitative techniques, pave the way for interesting types of interventions in the urban environment that could be included in the implementation tools of the plans and could turn policies in the Environmental Strategic Assessment of plans and the Environmental Impact Assessment of designs into technical choices. Salvatore Losco

In urban and suburban areas, stormwater runoff is a primary stressor on surface waters. Conventional urban stormwater drainage systems often route runoff directly to streams and rivers, thus exacerbating pollutant inputs and hydrologic disturbance, and resulting in the degradation of ecosystem structure and function. Decentralized stormwater management tools, such as low impact development (LID) or water sensitive urban design (WSUD), may offer a more sustainable solution to stormwater management if implemented at a watershed scale. These tools are designed to pond, infiltrate, and harvest water at the source, encouraging evaporation, evapotranspiration, groundwater recharge, and re-use of stormwater. While there are numerous demonstrations of WSUD practices, there are few examples of widespread implementation at a watershed scale with the explicit objective of protecting or restoring a receiving stream. This article identifies seven major impediments to sustainable urban stormwater management: (1) uncertainties in performance and cost, (2) insufficient engineering standards and guidelines, (3) fragmented responsibilities, (4) lack of institutional capacity, (5) lack of legislative mandate, (6) lack of funding and effective market incentives, and (7) resistance to change. By comparing experiences from Australia and the United States, two developed countries with existing conventional stormwater infrastructure and escalating stream ecosystem degradation, we highlight challenges facing sustainable urban stormwater management and offer several examples of successful, regional WSUD implementation. We conclude by identifying solutions to each of the seven impediments that, when employed separately or in combination, should encourage widespread implementation of WSUD with watershed-based goals to protect human health and safety, and stream ecosystems.

Laksam Municipality in Bangladesh, a floodplain area, is vulnerable to the effects of climate change, including seasonal floods due to excessive rainfall and rising water levels. A Sustainable Urban Stormwater Management (SUSM) planning framework is crucial for climate change adaptation in municipalities, focusing on environmental and social benefits alongside traditional drainage concerns, ensuring inclusive urban stormwater management. The study aims to create a comprehensive, practical framework for sustainable stormwater solutions in the municipality to mitigate climate change risks and improve urban resilience. The author used a three-step process to write this paper: identifying the watershed characteristics and assessing the existing storm drainage system, rainfall patterns analysis, and drainage priority setting based on multiple factors for the city’s drainage network and flood-prone area management. Factors like physical feature surveys, GIS data, land use and structural density, drainage basins and sub-basins, drainage outfalls, potential flood-prone areas, and stakeholder consultation are considered for community participation. However, the implementation of sustainable stormwater management approach in third-world urban context is challenging due to socio-cultural dynamics and slow development. Understanding the capabilities, trade-offs, and synergies of the existing storm drainage system is essential to overcoming these challenges. Non-regulatory interventions like education and participatory planning can help raise awareness about SUSM’s benefits. The research concludes by emphasizing the necessity of implementing a thorough approach to the SUSM framework in order to improve water quality, build a sustainable urban environment, and increase Laksam Municipality’s resistance to floods.

Barriers to sustainable urban stormwater management in developing countries: The case of Brazil

Performance, environmental and cost comparisons of onsite detention (OSD) and onsite retention (OSR) in re-developed residential catchments

On-site detention (OSD) of storm runoff decreases catchment peak flows through the routing effect of temporary storage; on-site retention (OSR) achieves the same objective by abstracting part of the urban flood wave and passing the retained water to disposal on site. The investigation explored both strategies applied to a set of hypothetical present/re-developed urban catchments ranging in size from 14 ha to 210 ha. Comparisons were made on the basis of site storage required (SSR) to achieve the same global peak flow reductions, environmental aspects and cost. OSR practice was shown to out-perform OSD generally in medium-large catchments with respect to SSR and, hence, cost. The retention option also has clear environmental benefits that fall beyond the scope normally ascribed to OSD practice. The paper cautions against use of OSR in unsuitable circumstances.

The rise in urbanisation has led to increased stormwater runoff due to the proliferation of impervious surfaces, vegetation loss, and decreased drainage efficiency. To manage urban stormwater, water sensitive urban design (WSUD) has been proposed in Australia, which reduces urban flooding and protects our natural waterways. Stormwater quality improvement devices (SQIDs) are elements of WSUD that can remove pollutants from urban stormwater. This paper reviews key SQIDs, which are widely adopted globally. A bibliometric analysis is conducted based on relevant publications from 2000 to 2024, which reveals that the USA, China, and Australia are the leading countries in sustainable stormwater management research. A significant international collaboration between USA and Australia is found. Also, research on bioretention and other nature-based solutions has been increasing in recent years, highlighting the need for sustainable urban stormwater management. It is expected that WSUD will be up-taken by developing countries following its success in developed countries. This paper also presents learning aspects of stormwater engineering by the first author.

Single lot on site detention requirements in New South Wales Australia and its relation to holistic storm water management

Challenges to implementing urban sustainable stormwater management from a governance perspective: A literature review

Climate change is impacting urban areas, especially through extreme rainfall that stresses conventional water management systems. Rainwater resulting from impervious runoffs, stormwater leads to an increase in the amount of wastewater that requires treatment and an overflow of the combined sewer system. Therefore, untreated wastewater is released into the surroundings or, in some cases, causes damage to urban systems. Nevertheless, many cities in the world are in the process of establishing a sustainable approach to urban water management. Sustainable stormwater management practices are essential for overcoming various environmental challenges and promoting community sustainability and resilience. The purpose of this paper is to communicate Oslo’s success in implementing sustainable stormwater management in urban areas. By analyzing successful cases, researchers may be able to record patterns that offer potential answers to the stormwater management challenge. The present case study presents an approach that can enlighten urban planners and policymakers about the potential outcomes of sustainable stormwater management under the conditions presented.