Alternative Water Supply Systems

Owing to climate change related uncertainties and anticipated population growth, different parts of the developing and the developed world (particularly urban areas) are experiencing water shortages or flooding and security of fit-for-purpose supplies is becoming a major issue. The emphasis on decentralized alternative water supply systems has increased considerably. Most of the information on such systems is either scattered or focuses on large scale reuse with little consideration given to decentralized small to medium scale systems. Alternative Water Supply Systems brings together recent research into the available and innovative options and additionally shares experiences from a wide range of contexts from both developed and developing countries. Alternative Water Supply Systems covers technical, social, financial and institutional aspects associated with decentralized alternative water supply systems. These include systems for greywater recycling, rainwater harvesting, recovery of water through condensation and sewer mining. A number of case studies from the UK, the USA, Australia and the developing world are presented to discuss associated environmental and health implications. The book provides insights into a range of aspects associated with alternative water supply systems and an evidence base (through case studies) on potential water savings and trade-offs. The information organized in the book is aimed at facilitating wider uptake of context specific alternatives at a decentralized scale mainly in urban areas. This book is a key reference for postgraduate level students and researchers interested in environmental engineering, water resources management, urban planning and resource efficiency, water demand management, building service engineering and sustainable architecture. It provides practical insights for water professionals such as systems designers, operators, and decision makers responsible for planning and delivering sustainable water management in urban areas through the implementation of decentralized water recycling. Authors: Fayyaz Ali Memon, Centre for Water Systems, University of Exeter, UK and Sarah Ward, Centre for Water Systems, University of Exeter, UK

During the third decade of the 21st century, communities across the world are being challenged with water scarcity both in rural and urban areas. Another significant problem is the energy demand for producing potable water. Our recent book “Resilient Water Management Strategies in Urban Settings: Innovations in Decentralized Water Infrastructure Systems” (Springer; 2022) introduced various facets of decentralized water infrastructure and the significant need for a shift toward using locally available alternative water sources. The proposed volume will expand on the concept and use of alternative water sources; rainwater, stormwater, wastewater/greywater, saline waters, and atmospheric water. Use of alternative water sources for potable purposes is a critical emerging research and technology area. In our knowledge such a book does not exist at this time. This volume will be a significant resource for researchers and graduate level teaching, and serve as a roadmap for water resource engineers and planners tackling water scarcity and diverse water resources portfolios.

This book is based on a screening of 113 worldwide experiences in alternative urban water management. A range of alternative water management strategies have been reviewed and 15 cases from around the world were studied in detail. These are presented as examples of possible water management strategies that have reduced the cities’ dependency on water imports. The strategies include implementation of potable and non-potable wastewater reuse, rainwater collection and desalination. Alternative Water Management and Self-Sufficient Water Supplies provides inspiration for water planners in cities with restrained water resources by highlighting actual technical opportunities and challenges. It represents a unique collection of state-of-the-art water management practices and the opportunities and challenges presented are from real-life case studies. The book is primarily aimed at urban water management professionals working across different technical and management disciplines. These include water supply engineers and environmental planners that can use it for professional reference. It will also be a useful introductory text for under-graduate level courses on water supply.

This detailed study of the use of water at different price levels by residential consumers in the Toronto-centred region from Hamilton to Oshawa challenges the basis of our present urban water supply policy. Adoption of the recommendations presented would mean higher prices to householders, but a considerable saving of hundreds of millions of tax dollars over the next three decades. The present policy uses a 'requirement approach' in which future water needs are calculated by extrapolation of past trends and an assumption that demand is inelastic. This leads to excessive levels of water use and over-investment in water supply, sewage collection, and treatment systems. The resultant misallocation of resources can be corrected by adoption of a demand/management approach in which investment policy is guided by consumer demand and alternative pricing arrangements are used as a management tool. Dr. Grima examines several alternative choices for management, such as metering, increasing marginal prices, sewerage charges, seasonal charges, and an increasing price block schedule, and describes the results of each. Water managers in Canada are strongly challenged to begin a fundamental rethinking of their basic policies. (Department of Geography Research Publication 7)

Rainwater tank systems have been widely adopted across the world to provide a safe local source of water in underdeveloped rural areas, a substitution for mains water for non potable end uses in water stressed urban areas, as well as providing flooding control in monsoonal climates such as Korea, or combined sewer systems such as Germany. The importance of these systems in cities has grown, as water managers seek to provide a range of decentralised solutions to supply constraints of current water supply systems, whilst reducing the impact of urban development on the natural environment, and increasing resilience to the impacts of climate change. Rainwater tank systems are now often implemented under integrated urban water management (IUWM) and water sensitive urban design (WSUD) philosophies, which take a holistic view of the urban water cycle. Rainwater Tank Systems for Urban Water Supply is based on a comprehensive, multi-million dollar research program that was undertaken in South East Queensland (SEQ) Australia in response to the Millennium drought when the water supply level in the regions drinking water dams dropped to 17% in July 2007 and the area came close to running out of water. In particular, the book provides insights and detailed analysis of design, modelling, implementation, operation, energy usage, economics, management, health risk, social perceptions and implications for water quality/quantity of roof water runoff. The approaches and methodologies included in Rainwater Tank Systems for Urban Water Supply inform and validate research programs, and provide insights on the expected performance and potential pitfalls of the adoption of rainwater tanks systems including: actual harvested yield and resulting mains water savings, optimal sizing for rainwater storages and roof collection systems, expected water quality and implications for managing public health risks, modelling tools available for decision support, operation and management approaches of a decentralised asset at the household scale and community acceptance. The book is suitable for use at undergraduate and post graduate levels and is of particular interest to water professionals across the globe, who are involved in the strategic water planning for a town, city or a region. It is a valuable resource for developers, civil designers, water planners, architects and plumbers seeking to implement sustainable water servicing approaches for residential, industrial and commercial developments.