The northern part of Indonesia’s capital, Jakarta, contains all the city’s coastal area. North Jakarta is bounded by Java Sea to the north and this makes this low-lying area very prone to tidal floods. Out of the six districts of North Jakarta, Penjaringan has the most waterways. In the north part of Penjaringan Sub-district (Muara Angke), the coastal area experienced approximately 4.1 meters of subsidence between 1974 and 2010. At high tide, saltwater flooding in Muara Angke rises by between 20 and 50 centimeters.