Istanbul Water and Sewage Administration’s estimations of decline of water supply is calculated as 24%, with a 2 °C increase in temperature by 2030 caused by increasing evaporation from reservoirs (van Leeuwen & Sjerps, 2016, 12). Considering the fact that 97% of water sources are these dams/reservoirs, it is obvious that İstanbul is vulnerable in terms of water supply without any alternative water supply. It can be indicated that the water that is supplied to the city is not being used efficiently. Even though the water comes from the taps are drinkable, according to a study made by Kanat (2017, 526-527) the use of tap water as potable water is 4% in the city. Furthermore, the treated wastewater is discharged to the Marmara Sea, and the Black Sea through Bosphorus Strait. Because of low water regeneration caused eutrophication of the Marmara Sea, higher effluent quality wastewater discharged in there, while the less advanced treated wastewaters are discharged to the Bosphorus Strait to reach the Black Sea by the currents (van Leeuwen & Sjerps, 2016, 7-8). It can be concluded that the current water management of Istanbul has many technical problems that affects and will be affecting the everyday life of its inhabitants. Examples can be given to these water related problems as drought due to lack of available water, or nuisance due to precipitation. If these current practices continue, with the effects of climate change and the fast, uncontrolled urban growth, problems affecting daily life will get worse in future. ‘Modern Water’ understanding of today sees water as a service to be provided and makes it invisible to users, thus, causes lack of awareness, responsibility and loss of a socio-cultural value which is the meaning of water. While these problems could be answered by spatial solutions, lack of integration between infrastructural and urban design only enlarges the deficiencies. This research aims to discover the relation between the modern water understanding and the unsustainable water practices that currently exist in İstanbul. This is aimed to be done through questioning ‘Modern/Rationalized Water’ and discussing how this caused the abstraction of the socio-cultural aspect of water. The thesis mainly studies the spatial manifestation of this rationalized water that is reduced to be only a natural element of H2O especially in public spaces. This is done by creating a new approach to water related problems in cities, which is inspired by the newly introduced fields of Hydro-sociology and Socio-hydrology. This new approach that aims to preserve the cultural and the social meanings of water while understanding the hydrological cycle of a city is later combined with Urban Water Mass Balance analysis that provides the quantitative examination of the water cycle. After concluding that the natural drainage network of İstanbul is damaged and is under the pressure of the fast urbanization of the city while the trends in the planning still using outdated methods and technologies to control the situation. The needed new approach is studied in the scale of the Kagithane Creek Basin of the Metropolitan Area of İstanbul. The study continues with a proposed design for a specific location near the Kagithane Creek to discuss how this new approach can lead to design activities and change locals everyday experience of water in the city.The thesis concludes that changing the perspective on the water management by including social and cultural aspect to it, changes the way of finding solutions to the technical water management problems by making more integrated management principles necessary.