The overall aim of this project consists in the development, planning and implementation of concepts to improve water supply and sanitation situation in large conurbations, taking into account technological, environmental and socio-economic considerations, whilst ensuring appropriate public participation and the consideration of all stakeholders’ interests. As a case study, the Metropolitan area of Lima is chosen, since it is characterised by a number of features typical of emerging megacities and since good cooperation with the relevant Peruvian agencies could be established. Also a guideline document will be developed during the project, summarising the experiences gained in this project and giving recommendations for improvement of water supply and sanitation also for megacities located in other regions of the world. The preparatory phase of the project (Years 1 and 2) will establish the necessary transdisciplinary cooperation and will result in a project work plan and proposal for the subsequent phases of the project (Years 3 to 11). During the preparatory phase, also a prototype application will be set up (to be refined in later stages of the project), in order to illustrate the ideas to be further developed in Years 3 to 11 and to demonstrate their feasibility.