Istanbul’s Reservoir Storage Levels Drop Below 50%
According to the latest report from the Istanbul Water and Sewerage Administration (İSKİ), water storage levels in the reservoirs supplying the city have decreased to 48.3% of total capacity. This figure shows a significant decline compared to two weeks ago, when it was recorded at 53.62%.
Spring rainfall had increased reservoir volumes to 82.22% by April 15. However, with the onset of summer and increased consumption, reservoir levels have trended downward. Storage levels vary across major reservoirs:
Ömerli Dam: 46.81%
Darlık Dam: 59.65%
Elmalı Dam: 66.10%
Terkos Dam: 53.01%
Alibey Dam: 31.53%
Büyükçekmece Dam: 47.76%
Sazlıdere Dam: 41.93%
Istrancalar Dam: 28.05%
Kazandere Dam: 34.07%
Pabuçdere Dam: 40.91%
Istanbul’s total reservoir capacity is 868,683,000 cubic meters, of which only 419.16 million cubic meters is currently stored. Since the beginning of the year, rainfall in reservoir basins has measured 334.78 kilograms per square meter.
Water transfers from sources outside the reservoir system – including the Melen River and Yeşilçay River – continue. To date, 403.72 million cubic meters have been supplied through these sources. The volume of water distributed throughout the city in the last 24 hours was reported as 3,489,000 cubic meters.
Analysis of İSKİ’s historical data shows fluctuations in reservoir storage levels on August 12 over the past decade:
2015: 74.42%
2020: 53.37%
2023: 34.27% (lowest level)
2024: 53.82%
2025: 48.3% (current level)
