Rainfall Record for the Last 84 Years in İstanbul: 277.1 Kilograms of Rainfall per Square Meter Recorded in Beykoz

The intense downpour that affected İstanbul caused one of the highest rainfall amounts to be recorded in the last 84 years. While 277.1 kilograms of rainfall per square meter fell in Beykoz, the rainfall amounts measured in some parts of the city exceeded four times the long-term October average. The İstanbul Metropolitan Municipality (İBB) continued its fieldwork with 8,564 personnel and 2,325 vehicles and work machines under AKOM coordination.

HIGHEST RAINFALL AMOUNT IN 84 YEARS RECORDED IN BEYKOZ

İstanbul, which came under the influence of a cold air wave coming over the Balkans and rain systems originating from the Central Mediterranean, experienced strong downpours that started Tuesday morning and affected the entire city. In some districts around the Bosphorus and in the northern and central parts of the European Side, total rainfall of between 130 and 277 kilograms per square meter was measured.

According to AKOM meteorological data, the 277.1-kilogram rainfall recorded in Beykoz went down as the highest value measured at the stations since 1942. While İstanbul's long-term average total rainfall for October is 66.3 millimeters, the rainfall measured in Beykoz reached approximately 4.1 times this average.

RAINFALL AMOUNTS BY DISTRICT

Rainfall amounts rose to high levels especially around the Bosphorus and in the northern and central parts of the European Side. In other districts, the rainfall per square meter varied between 35 and 120 kilograms.

The rainfall amounts measured at the stations were listed as follows:

- Beykoz: 277.1 kg/m²

- Sarıyer: 211.8 kg/m²

- Eyüpsultan: 203.9 kg/m²

- Sarıyer İTÜ Maslak Campus: 191.8 kg/m²

- Beykoz Anadolu Feneri: 166.5 kg/m²

- Yavuz Sultan Selim Bridge: 158.3 kg/m²

- Şişli: 147.4 kg/m²

- Arnavutköy: 146.1 kg/m²

- Olimpiyat (Başakşehir): 142.0 kg/m²

- Büyükçekmece: 137.1 kg/m²

- AKOM (Kağıthane): 135.5 kg/m²

- Şile Darlık Village: 135.4 kg/m²

- Çekmeköy Ömerli: 131.2 kg/m²

- Kartal Aydos Mountain: 119.8 kg/m²

- Sancaktepe: 115.5 kg/m²

- Üsküdar: 113.2 kg/m²

Lighter downpours ranging between 5 and 45 kilograms were seen around the Bosphorus on the Anatolian Side throughout the night. It was reported that the rains had largely lost their effect, while light rain passages could continue on the Anatolian Side until noon.

İBB TEAMS RESPONDED TO 9,755 NOTIFICATIONS

İBB set up a crisis desk under the management of AKOM, affiliated with the Department of Disaster Affairs and Risk Management, in order to reduce the effects of the adverse weather conditions and coordinate intervention efforts across the city. A total of 8,564 personnel and 2,325 vehicles and work machines from the Fire Department, İSKİ, Road Maintenance, İSTAÇ, Municipal Police, Parks and Gardens, İBB Traffic, İGDAŞ and other relevant units took part in the operations.

A total of 9,755 notifications were received regarding incidents such as water accumulation, manhole overflow, road collapse, people being trapped, and fallen trees. Of the notifications, 7,131 were received by İSKİ, 1,460 by the Fire Department, 815 by the Solution Center, and 349 by the Road Maintenance units.

Citizens who were trapped due to flooding and stream overflows were rescued by İBB teams and evacuated to safe areas. Rescue operations were carried out in Göktürk, Kemerburgaz and Ayazağa for citizens, students and employees trapped in schools, housing complexes and workplaces.

PREVENTIVE WORK CARRIED OUT ON RAIL SYSTEMS

In order to reduce the possible effects of the rainfall on transportation, Metro İstanbul extended services on main metro and tram lines until 02:00 at night. Technical teams also focused on maintenance, cleaning and water drainage work to support the safe and uninterrupted operation of the rail systems.

Drain and rail groove cleaning was carried out on the T5 Eminönü–Alibeyköy and T1 Kabataş–Bağcılar tram lines. Water drainage and hygiene work was carried out at stations on the M1A, M3, M4 and M5 lines.

Routine vehicle washing operations on the M2, M6 and M7 lines were temporarily suspended, and personnel were directed to risky areas with insulation and water leakage issues. On the M7 Alibeyköy line, mud cleaning and washing work following the flooding was completed in coordination with İSTAÇ.

SHELTER AND REFRESHMENT SUPPORT PROVIDED TO CITIZENS

İBB Social Facilities and BELTUR points were kept open until morning for citizens who had to spend the night outside or needed shelter. Hot tea and water were offered to citizens at these points.

Monitoring and assessments carried out in the Cendere Basin determined that the stream water level had dropped by approximately 1.5 meters compared to its highest level. It was reported that the flood risk had decreased to the lowest level in line with current hydrological conditions.

Measures were taken by the İstanbul Governorship to close schools and grant leave to employees on October 15 and 16 due to adverse weather conditions. İBB teams' cleaning, maintenance, evacuation and intervention work across the city continued.

FILL RATE IN İSTANBUL'S DAMS ROSE TO 45.22 PERCENT

The intense downpours also caused an increase in İstanbul's water resources. While the overall fill rate of the dams stood at 38 percent on October 14, it rose to 45.22 percent as of October 15 following the heavy rainfall.

While the effect of the rainfall on dam fill rates drew attention in terms of the city's water resources, İBB teams continued their work to eliminate the effects that occurred after the adverse weather conditions.