Tahtalı Reservoir

Tahtalı Reservoir, formed behind a dam south of İzmir, is the single largest surface-water source feeding the city's drinking and utility supply, holding a reserve capacity of roughly 305 million cubic meters. On its own it covers close to half of İzmir's water needs, drawn down each year by tens of millions of cubic meters to serve the metropolitan area. Because of its outsized role in the city's supply, the reservoir's fill level is tracked closely by the public and local water authorities, and years of low rainfall have at times pushed its reserves to historic lows, prompting conservation warnings from officials. In wetter years the reservoir has filled to three-quarters of capacity or more, underscoring how directly the fortunes of İzmir's water security rise and fall with the basin's seasonal rains. Beyond its utilitarian role, the lake and its forested catchment have also become a point of reference in discussions about the region's long-term climate and water resilience.