The Dutch city of the Hague has an extensive sewer system that ensures healthy living in the city. The system that collects and removes sewage and rainwater encompasses about 1,400 kilometres of underground pipes and features 30,000 inspection shafts under the city’s streets. Some of the sewer pipes date from 1880 and are still working. The “Municipal Sewer Plan The Hague” was developed to monitor the system and replace infrastructure were required. The plan outlines the strategy dealing with various sewer and urban water problems and, most importantly, provides the (financial) justification and means to ensure the performance of the system.