The 21st century is known as the century of urbanization. Numerous debates are currently taking place to define cities and what they should aspire to be. A number of terms have appeared in this arena,such as sustainable city, eco-city and green city to name a few. However, the main question remains how to measure the performance of a city in regards to these aims. In addition, it is vital to note that major urbanization activities take part in cities of the developing world, where informalization is synonym to urbanization, thus necessitating a profound study of informal areas and their potential role in achieving sustainable cities. This paper studies how a city performs in terms of consuming and producing resources and how they flow through its various systems, described as urban metabolism. The paper particularly discusses how informal areas perform regarding their metabolism, focusing on water flow through these areas as a priority identified by the residents. Imbaba district, one of the largest informal areas in Cairo, is investigated as a case study to determine the actual quality of life of local residents and their ecological footprint and to provide practical insights. The whole process depends on a multidisciplinary participatory research where the citizens and local community based organization are the focal point. In addition, the process depends on open source data and data sharing as a way to empower local communities to identify their needs and issues and hence their appropriate interventions. This is conducted through questionnaires and interviews to identify what the current conditions and processes in informal areas provide for the residents. The paper concludes with identifying points of leakages in the resources flows and the possible interventions to improve the quality of life in the area while maintaining an efficient use of local resources and minimizing the impact of urbanization of the ecological footprint of cities. This will assist cities to become more resilient in the face of water scarcity, and provide a more vibrant life for its residents.