The Istanbul Metropolitan Municipality said the city has experienced some of the highest precipitation amounts of recent years. In certain localities the rain fell at a rate of up to 240 kilograms per square meter, a figure the municipality described as notable for the season. This intense rainfall set the stage for a rapid change in the city’s water storage situation.
Among the districts measured, Beykoz recorded the greatest amount of rain. The municipality’s statement noted that Beykoz received 242 kilograms of water per square meter, exceeding the 240‑kilogram threshold cited for the city’s wettest spots. This localized deluge contributed directly to the surge in reservoir inflows.
Torrential rain has triggered flash floods across Istanbul, sweeping cars through neighbourhoods, stranding people, triggering landslides and bringing traffic to a standstill, with more rain expected. https://t.co/jL6XcIHII2
Other districts showed substantial but slightly lower totals. Eyüpsultan registered 190.5 kilograms per square meter, while Sarıyer logged 187.9 kilograms per square meter. The municipality also observed that many points across Istanbul saw around 100 kilograms per square meter of rainfall, illustrating a broad but uneven distribution of the storm.
The agency’s numbers corroborated the municipality’s report of a rapid rise in stored water.
Before the rain, the combined occupancy rate of Istanbul’s supplying dams stood at 38.06 percent. After the intermittent rainfall, the same measure climbed to 45.22 percent. The increase amounted to 7.16 percentage points in a single day, a jump the municipality highlighted as significant for the region’s water reserves.
One reservoir responded especially strongly to the inflow. Elmalı Dam was measured at 100 percent capacity following the rain event, meaning its storage was completely filled. This milestone was cited in the municipal update as a clear indicator of the storm’s impact on the system.
The Istanbul Water and Sewerage Administration (ISKI) released data that mirrored the municipal figures. According to ISKI, the average water occupancy rate across the city’s supplying dams increased by 7.16 percent in one day, reaching 45.22 percent. The agency’s numbers corroborated the municipality’s report of a rapid rise in stored water.
BREAKING: At least 2 dead as torrential rain floods Istanbul; a 14-year-old is electrocuted in a puddle and schools shut citywide Torrential rain has killed at least two people in Istanbul and shut much of Turkey’s largest city. Al Jazeera and the Associated Press report a 14-year-old boy was electrocuted after stepping into a puddle in the Fatih district, and a 34-year-old died after slipping and hitting their head in Sariyer. Authorities recorded 1,277 floods and 15 landslides, suspended classes Thursday, banned motorcycles, and urged residents to stay home. Some areas saw the heaviest rain since 1985. #Istanbul #Turkey #Flooding #BreakingNews Follow @BreakingWire_HQ for verified updates.
Beyond the immediate change, ISKI also provided a broader accounting of water delivered to Istanbul. From the start of the year through the date of the statement, treatment plants supplied a total of 908,006,000 cubic meters of water to the city. This cumulative figure offers a baseline for understanding the scale of the city’s annual water provision.
ISKI’s data also included a measure of everyday use. The administration reported that Istanbul’s daily water consumption amounts to 2,093,000 cubic meters. This number reflects the volume of water drawn from the system each day to meet residential, commercial and municipal needs.
On 2026-10-15, the Istanbul Metropolitan Municipality issued a formal announcement detailing the rainfall measurements and the resulting changes in dam occupancy. The statement combined the precipitation figures for Beykoz, Eyüpsultan, Sarıyer and other areas with the updated reservoir levels, presenting a snapshot of the weather‑driven shift in water resources.
The same date, 2026-10-15, is recorded as the day when the rainfall occurred across Istanbul. The municipal announcement and the ISKI data both refer to this single day of precipitation, linking the observed weather event directly to the reported rise in dam levels and the full‑capacity reading at Elmalı Dam.