An overview of the problems associated with worldwide water shortage problem and of the increasing public participation and awareness to this problem is presented in this work. The existing water treatment processes and their importance in terms of amount, quality and cost of water produced as well as their environmental impact are illustrated. That includes a survey of the current desalination techniques in use and an overview of possible future technologies, aiming at solving different water issues. The technological developments and challenges together with new possible production modes for the future urban water planning are also presented. Finally, routes towards a modern and advanced city planning in a cheaper and more sustainable way based on a more rational use of water, by supplying water of different quality to the final users according to their requirements, as well as the employment of process intensification principles are discussed. (C) 2011 Elsevier B.V. All rights reserved.