Alexandros Petropoulos pauses as he surveys the miles of pipeline arrayed in front of him, reflecting on what it took to get here. It's late 2020, and the Greek island of Aegina has exhausted its once-bountiful water. Thousands of second homes have sprung up along its shores since the 1980s. Hundreds of thousands more tourists from nearby Athens pour in every year to see its ancient temple. Amid ever-growing demand and continuing loss of supply, Aegina effectively ran dry by the end of the millennium.

The pipeline would be the solution, steadily flushing in water from the mainland. Because residents currently rely on bottled water for drinking, an added benefit would be alleviating Aegina’s expensive addiction to plastic. When construction finally began in 2018 after decades of bureaucratic stalling, residents and municipal officials were buoyant. “This is by far the longest, deepest and most ambitious pipeline project ever undertaken in Greece,” says Petropoulos, a civil engineer and the project manager in charge of laying the line across a 15-mile (24 kilometer) stretch of the Aegean. “What you see here is as perfect a solution to Aegina’s problems as one could possibly devise.”