How Engineers Built a 275-Meter Dam Where a Mountain River Refused to Be Controlled

High in the narrow valleys of northeastern Turkey, engineers faced one of the most unforgiving construction environments in modern dam engineering: a steep mountain river that cut violently through unstable rock and left almost no flat land for construction. To control this unpredictable flow, they built the 275-meter-tall Yusufeli Dam—the tallest dam in Turkey—by carving an underground powerhouse deep inside solid bedrock and installing three massive steel-lined pressure tunnels to drive 558 megawatts of hydroelectric power. Every stage of construction had to adapt to landslide-prone slopes, limited access roads, and extreme terrain that made conventional dam building nearly impossible