Flooding of the Copenhagen Metro, Denmark

The first phase of the Copenhagen Metro, a fully automated driverless underground metro system, was put into service in October 2002 and a second phase is being added in two steps during 2003. When completed the system will comprise 21 km of alignment, whereof 10 km, servicing 9 stations, will be underground. The underground stations are box structures with a length of 61 m, a width of 20 m to 22 m and a depth of 20 m to 22 m. The stations are connected by two single track tunnels with an internal diameter of 4,9 m. Evacuation shafts have been constructed between the stations to keep the length of escape way below 300 m. As the underground part of the metro system is generally located 20 m to 30 m below mean sea level, the safeguarding against flooding from the sea or flooding from extreme rainfall is crucial. Due to the topography and the climate of the region of Copenhagen both types of natural hazards present real threats to the metro. Therefore very comprehensive and sophisticated research and planning activities were carried out to establish a rational and practical design basis to ensure safety against flooding.