Located in a semi-arid region in the south and east of the country, the Moroccan oases are characterized by severe aridity and scarcity of water resources. However, the ancestral populations have shown a major form of adaptation to aridity constraints through the development of knowledge and heuristic expertise on a traditional water supply system called ‘Khettara’. Currently, the effects of climate change on the one hand and the deep social, cultural and economic transformations on the other, have caused the productivity of traditional agriculture to no longer match population needs with progressive vanishing of Khettara as its consequence. A diagnostic study of the situation of oases conducted in the south of Morocco makes it possible to address the socio-economic, environmental and cultural aspects by developing and using a specific methodology to assess fragile ecosystems (DPSIR: Driving Force-Pressure-State-Impact-Response). The main aim of the present work is to provide a methodology allowing the formulation of the required knowledge for the mobilization of traditional water resources techniques such as Khettaras, in order to maintain the national heritage of oases. The modeling formalism of UML (Unified Modeling Language) is borrowed from information technology for the purpose of standardization. The developed methodology enhances these traditional water supply systems by combining traditional and modern techniques to increase their performance in terms of reduced maintenance costs and increased productivity. The developed methodology has been applied to a real case characterized by extreme aridity.