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Finland's Hidden Artery: Water Flows Through 120km Rock Tunnel
22 Jul
Summary
- A 120.3-kilometer rock tunnel supplies Helsinki's water.
- The tunnel carries water from Lake Päijänne, taking nine days to reach homes.
- This gravity-fed system is one of the world's longest continuous rock tunnels.
Deep beneath Finland's landscape lies a vital artery for southern water supply: the Päijänne Water Tunnel. This 120.3-kilometer passage, completed in 1982, transports water from Lake Päijänne to the Helsinki metropolitan area, serving over a million residents. The tunnel's unique design utilizes gravity, allowing water to flow slowly and steadily for about nine days before reaching purification plants.
Engineered to ensure a reliable water source against pollution and seasonal variations, the tunnel was constructed by blasting through solid bedrock. Reaching depths of nearly 200 meters, it remains protected from external disruptions. Despite its scale and importance, the Päijänne Water Tunnel is a hidden marvel, rarely discussed but essential to daily life.
