Assessing the future water potential of Istanbul and the need for inter-basin water transfer and the trade-offs for water allocation
Nuray Akalın a,*, Bülent Mertoğlu b and Ali Ertürk
a Department of Environmental Engineering, Faculty of Engineering, Marmara University, 34854 Istanbul, Türkiye
b Department of Bioengineering, Faculty of Engineering, Marmara University, 34854 Istanbul, Türkiye
c Department of Freshwater Resources and Management, Faculty of Aquatic Sciences, Istanbul University, 34134 Istanbul, Türkiye *Corresponding author. E-mail: nurayakalin@marun.edu.tr NA,0000-0003-4252-4219
ABSTRACT
Istanbul faces significant water supply challenges due to limited resources and increasing demand. It has always been very challenging throughout history to supply water to the city and it is expected that the future demand will increase due to population growth, economic development, urbanization, and climate change. This study examines Istanbul’s current and projected water potential and demand, calculates the unmet water demand, and evaluates the potential countermeasures while considering possible trade-offs between sectoral water use. A hydrological system has been modelled to calculate water potential and develop scenarios to identify critical tipping points. Also, the unmet demand for different water potential scenarios has been calculated. By analysing these scenarios, it is revealed that the unmet demandwill intensify due to population growth and drought conditions. Inter-basin water and additional water resources will increase the resilience of the system but to address Istanbul’s water challenges, multiple factors must be optimized together as no single solution can satisfy all needs or eliminate all risks. As providing sufficient potable water is the first priority, the following key factors should be considered: expanding reservoir capacity, optimizing water transfer and reservoir management, minimizing water losses, implementing effective demand management, and prioritizing water allocation.
Key words: megacities, unmet demand, water availability, Water Evaluation and Planning (WEAP), water supply prioritization
. To read the full article, please click on
/wp-content/uploads/2026/07/istanbul%20water%20makalesi.pdf
^
Assessing the future water potential of Istanbul and the need for inter-basin water transfer and the trade-offs for water allocation
Nuray Akalın a,*, Bülent Mertoğlu b and Ali Ertürk
a Department of Environmental Engineering, Faculty of Engineering, Marmara University, 34854 Istanbul, Türkiye
b Department of Bioengineering, Faculty of Engineering, Marmara University, 34854 Istanbul, Türkiye
c Department of Freshwater Resources and Management, Faculty of Aquatic Sciences, Istanbul University, 34134 Istanbul, Türkiye *Corresponding author. E-mail: nurayakalin@marun.edu.tr NA,0000-0003-4252-4219
ABSTRACT
Istanbul faces significant water supply challenges due to limited resources and increasing demand. It has always been very challenging throughout history to supply water to the city and it is expected that the future demand will increase due to population growth, economic development, urbanization, and climate change. This study examines Istanbul’s current and projected water potential and demand, calculates the unmet water demand, and evaluates the potential countermeasures while considering possible trade-offs between sectoral water use. A hydrological system has been modelled to calculate water potential and develop scenarios to identify critical tipping points. Also, the unmet demand for different water potential scenarios has been calculated. By analysing these scenarios, it is revealed that the unmet demandwill intensify due to population growth and drought conditions. Inter-basin water and additional water resources will increase the resilience of the system but to address Istanbul’s water challenges, multiple factors must be optimized together as no single solution can satisfy all needs or eliminate all risks. As providing sufficient potable water is the first priority, the following key factors should be considered: expanding reservoir capacity, optimizing water transfer and reservoir management, minimizing water losses, implementing effective demand management, and prioritizing water allocation.
Key words: megacities, unmet demand, water availability, Water Evaluation and Planning (WEAP), water supply prioritization
. To read the full article, please click on
/wp-content/uploads/2026/07/istanbul%20water%20makalesi.pdf
^
