On the screens in Ismail Aydin's Istanbul water management control room a worrying number flashes up: 29.7 percent. That is the capacity level to which Istanbul's reservoirs have fallen after another baking summer, leaving Turkey's largest city facing a potential catastrophe. "This time last year, the same figure was close to 60 percent" says Aydin, who asserts that, despite the low water levels "there is no alarming situation at the moment". Turkey's rainy season is coming and the reservoirs should recover over the next few months, but global heating is changing weather patterns. Istanbul has had barely any precipitation at all this summer and water usage has soared due to the heat. "Bad days await if it goes on like this" warns Nejat Karakas, a resident of a village near the Terkos dam. IMAGES AND SOUNDBITES