New paradigms in urban water management for conservation and sustainability Andrea G. Capodaglio a, *, Paolo Ghilardi a and Joanna Boguniewicz-Zablocka b a Department of Civil Engineering & Architecture, University of Pavia, 27100 Pavia, Italy b Department of Thermal & Industrial Engineering, Opole University of Technology, Opole, Poland * Corresponding author. E-mail: capo@unipv.it Abstract In order to achieve a sustainable degree of water resources usage, new paradigms in urbanized basins planning must be adopted. Worldwide urbanized areas total population has overcome in 2010, its rural counterpart. While urbanization can be a powerful driver of sustainable development, as the higher population density enables gov- ernments to more easily deliver essential infrastructure and services in urban areas at relatively low cost per capita, these benefits do not materialize automatically and inevitably. Water bodies are usually severely hit and impaired by poorly planned urbanization. Old water resources planning paradigms must be abandoned and new ones, which include the connection of ‘green cities’ and their infrastructure with new modes of drainage and landscape planning and improved consideration of receiving waters, ought to be adopted. These must not only be environmentally and ecologically sound, but also functionally and aesthetically attractive to the public. New eco-cities shall no longer rely on excessive water volumes withdrawn from often distant surface and groundwater sources, with a once-only use of the resource, and large water losses due to leaks and evapotran- spiration. Long-distance transfer of wastewater and high energy usage and emissions for its treatment should be avoided by distributed and decentralized integrated water/wastewater management. Effluent-domination shall no longer be a characteristic of urbanized river basins. The paper examines some of the paradigms that have been proposed for improving integrated water resources management in urban basins and illustrates some recent examples whether already implemented or still at the proposal stage. Key words: urban water planning, water resources, urban watershed protection, sewerage, conservation, water reuse and recovery INTRODUCTION Worldwide urbanized areas total population has overcome, in 2010, its rural counterpart (WHO 2009); it is expected that, by 2030, urban dwellers will constitute 60–70% of the world’s total population. Many cities in the world (in the USA as well as China and elsewhere) are subject to droughts and water scar- city of severe proportions; however, not all of these are located in naturally arid areas: Beijing, for example, has reached a 3.6 billion cubic meters water consumption (BWA 2013), far more than the 2.1 billion cubic meters locally available (Gangsheng & Jun 2005). This is not surprising, in the general consideration that China has about 20% of the world’s population but just 7% of the world’s freshwater resources. The lack of available freshwater water will in many case not only hamper development of a city, but can in the long run result in true ‘human disaster’ conditions. In the past, Beijing had an abundant supply of water from the five rivers that flow through the city. Yongding River, one of the main tributaries in the Hai River system and best known as the largest river to flow through Beijing Municipality, has now almost dried up, a clear example of hydrological © IWA Publishing 2016 Water Practice & Technology Vol 11 No 1 176 doi: 10.2166/wpt.2016.022 Downloaded from https://iwaponline.com/wpt/article-pdf/11/1/176/381531/wpt0110176.pdf by guest on 30 May 2020