The water begins its 400-mile journey gushing from a spring tucked in a rocky Anatolian slope. Following the narrow channel, it rushes past grazing lands and olive groves, and then through a steep, half-moon canyon carved by the currents before it. The water then enters a flat valley that stretches to the Aegean Sea. Across this wide plain, it curves and curls like a dark snake. Along the way, smaller tributaries feed the flow. Other things enter the river: sediment, agricultural runoff, and chemicals from tanneries and other industries, all…