In many coastal and delta cities land subsidence exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Increased flooding and other widespread impacts of land subsidence result in damage totaling billions of dollars per year. A major cause of severe land subsidence is excessive groundwater extraction due to rapid urbanization and population growth. A major rethink is needed to deal with the ‘hidden’ but urgent threat of subsidence. Deltares presents a comprehensive approach to address land subsidence from the perspective of more sustainable and resilient urban development.