Delta Works was completed by the Europoortkering which required the construction of the Maeslantkering in the Nieuwe Waterweg between Maassluis and Hoek van Holland and the Hartelkering in the Hartel Canal near Spijkenisse. The works were declared finished after almost forty years in 1997. In reality the works were finished on 24 August 2010 with the official opening of the last strengthened and raised retaining wall near the city of Harlingen, Netherlands. Due to climate change and relative sea-level rise, the dikes will eventually have to be made higher and wider. This is a long term uphill battle against the sea. The
Motorways of the Sea land. The routes selected to be Motorways of the Sea should be able to maintain a series of quality criteria; these pertain to frequency, port to port costs, simplicity of administrative tasks. Future routes should compensate for congestion experienced, for example when crossing the Channel (as the similar road networks should do for routes crossing the Alps or the Pyrenees). One envisaged impact of the Motorways of the Sea is energy savings, pollution reductions and more capacity on current overland European transport networks. The adoption of Article 12a of the TEN-T by Council and European Parliament gave a legal framework