Istanbul's dam occupancy rate rose by 7.16% in a single day to 45.22% following heavy rainfall, according to data from the Istanbul Water and Sewerage Administration (ISKI).
Rain that began Tuesday evening and intensified Wednesday raised water levels in reservoirs supplying Türkiye's largest city, ISKI data shows.
Elmalı Dam reaches full capacity at 100%, while Istrancalar stands at 84.2%, Alibey at 68.13%, Darlık at 67.74% and Ömerli at 62.17%.
Terkos Dam recorded a fill rate of 34.64%, Büyükçekmece 29.02% and Sazlıdere 27.47%. Meanwhile, Pabuçdere remains at 3.41% and Kazandere at 8.28%.
The city's dams and reservoirs have a combined storage capacity of 868.68 million cubic meters, with the total water volume reaching 392.45 million cubic meters as of Thursday.
Istanbul has received 837.7 kilograms of rainfall per square meter across its dams this year, according to ISKI. The city has also received a combined 567.87 million cubic meters of water from the Melen and Yeşilçay systems.
Drinking water treatment plants supplied 908.006 million cubic meters of water to the city this year, while daily consumption stands at 2.093 million cubic meters on Wednesday.
ISKI data shows Istanbul's dam occupancy rate on Oct. 15 stood at 24.96% in 2025, 34.74% in 2024 and 21.69% in 2023.
The current rate of 45.22% also exceeds the 44.56% recorded in 2022 and the 41.88% recorded in 2016 on the same date.
However, the level remains below the 53.95% recorded in 2018 and the 53.17% seen in 2017.