Istanbul’s Dam Levels Continue to Decline Amid Dry Summer: Current Average at 66.62%

Water levels in Istanbul’s dams are steadily dropping as the city grapples with hot, dry summer conditions and reduced rainfall. According to the latest data from the Istanbul Water and Sewerage Administration (İSKİ), the average dam occupancy rate across the city stood at 66.62% as of June 29, 2025, down from 66.96% just one day earlier.

Over 16-Point Drop Since April

The ongoing decrease is particularly notable when compared to previous months. On April 22, the average occupancy rate was 82.93%, indicating a sharp 16.3-point drop in just over two months.

Officials warn that continued high temperatures, increased water consumption, and limited rainfall are putting strain on Istanbul’s water supply infrastructure, making careful monitoring essential throughout the summer.

Current Water Levels by Dam – Lowest in Istrancalar

As of June 29, İSKİ data reports the following individual dam occupancy rates in Istanbul:

• Elmalı Dam: 81.5% (highest)

• Ömerli Dam: 73.3%

• Darlık Dam: 72.15%

• Terkos Dam: 69.49%

• Pabuçdere Dam: 65.7%

• Kazandere Dam: 64.95%

• Büyükçekmece Dam: 61.58%

• Sazlıdere Dam: 51.52%

• Alibey Dam: 49.81%

• Istrancalar Dam: 23.46% (lowest)

The Istrancalar Dam, typically more reliant on rainfall, now holds less than a quarter of its capacity, highlighting the uneven impact of seasonal drought across the city’s reservoirs.

Water Usage Expected to Rise Further in Summer Months

The combination of heat-driven demand and falling precipitation is expected to accelerate water consumption, potentially pushing dam levels lower in the coming weeks.

With Istanbul’s population exceeding 16 million, officials emphasize the importance of public awareness and water conservation efforts to prevent future shortages.