Istanbul reservoirs surge above 50% after record-breaking rains

Intense precipitation that started on the evening of Oct 13 and intensified on Oct 14 pushed Istanbul's average reservoir fill to 52.43% by Oct 18, the highest level recorded since 2018, according to data from the Istanbul Water and Sewerage Administration (İSKİ). The rain, described as the strongest in 84 years, produced floodwaters that killed at least five people in Istanbul, left several missing, and caused one death in the adjacent province of Kocaeli.

Rainfall totals were especially high in the northern districts, with Beykoz recording 277.1 kilograms per square meter, a figure not seen since 1942. Reservoir levels rose unevenly: Elmalı (77.48%), Darlık (75.75%), Alibey (75.03%) and Istrancalar (70.48%) topped the chart, while Terkos (36.67%) and Sazlıdere (30.95%) lagged behind. The city has drawn water from external sources this year, including significant volumes from the Melen and Yeşilçay projects, and its treatment plants have supplied nearly a billion cubic meters of water so far.