National Capital Integrated Coastal Development (NCICD) – Phase 2 ContextThe coastal zone of Jakarta has been sinking for many decades. Land subsidence rates are between an few centimetres per year up to 15 centimetres per year. Coastal areas which were still above sea level one hundred years ago have sunk to 3 meters below sea level. More and more land is situated below sea level and existing sea walls need to be upgraded every five to ten years to stop sea water entering the city. Groundwater extraction for water supply is an important factor in the sinking and the city administration is working hard to replace groundwater extraction with other forms of water of water supply. Nevertheless, the city will continue to sink, albeit at a slower pace.The existing sea wall is around 120 kilometers long and is integrated in the residential, commercial and industrial areas. This creates a difficult urban setting for upgrading the sea defenses as houses, factories and other infrastructure are to be removed from the sites. Upgrading will become more and more difficult over time and the need for a new protection strategy is becoming clear. In the coming 10 years the existing long, complicated urban sea wall could be replaced by a shorter (25 to 30 kilometers) offshore sea wall, which would simplify the sea defense. This concept is similar to the Dutch "Afsluitdijk" or "Deltawerken", which are based on the same concept. The Jakarta Coastal Defence Strategy (JCDS 2008-2011) and the National Capital Integrated Coastal Development (NCICD I 2012-2015 and NCICD II 2016-2020) projects aimed to provide a short, medium and long term strategy. Both JCDS and NCICD stressed the importance of managing the land subsidence, improving the water quality in the rivers and canals and a revitalization of the coastal communities (thus the words 'Integrated' and 'Development' in NCICD) as important contributing factors.ApproachSummarized, the protection strategy would consist of three phases: upgrading the existing sea wall would buy some time and this upgrade should be completed in the short term. At