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and subsidence, soil erosion and high tide are only some of the problems northern Jakarta is facing.

The partial collapse of coastline embankments in Pantai Mutiara and Muara Angke, both in North Jakarta, over the weekend has raised alarm about the extend of those problems.

The incidents inundated hundreds of houses in both areas on Friday night and Saturday night respectively.

As of Sunday, floods in both areas have receded after the city administration installed water pumps and deployed workers from various institutions to tackle the breaches in the two embankments with sandbags.

Jakarta authorities blamed the incidents on the high tide and land erosion by seawater.

Jakarta Disaster Mitigation Agency (BPBD) spokesman Bambang Surya Putra said the high tide would likely last until Thursday.

He added that as long as phase A of the giant seawall project, also known as the National Capital Integrated Coastal Development (NCICD), to extend and repair the existing 90-kilometer seawall on the shores of the Jakarta Bay were not completed, northern parts of the city would remain under threat of inundation due to high tide.

Initiated in 2012, the NCICD aims to protect sinking Jakarta against flooding from the sea.

Under the NCICD master plan published in December 2014, the giant project requires two presidential regulations, one for the approval of the master plan and another for the formation of the development authority. Neither has been issued yet.

Commenting on the incident, Jakarta Governor Basuki “Ahok” Tjahaja Purnama said none of the embankments in northern Jakarta were sufficient to hold back seawater due to the rising sea level caused by global warming.

“Therefore, we need to build 3.8 meter-high embankments,” he said in an interview aired by a TV station on Saturday. He was referring to Phase A of the NCICD projects.

However, Bosman Batubara, a scholar on water science and governance who is pursuing his doctoral degree at the UNESCO-IHE institute for water education in Delft and the University of Amsterdam in the Netherlands, questioned Ahok’s statements on the rising sea level as the main cause behind the breach of the embankments and hence his suggestion to build higher embankments as a simple way out.

“The fact is that the extent of land subsidence in Jakarta is greater than the rise of the sea level,” he told The Jakarta Post on Sunday.

He added that the rising sea level caused by global warming in Jakarta was less than 1 centimeter a year, while land subsidence amounted to 10 cm per year.

Currently about 40 percent of the Jakarta area is below sea level; land subsidence is mainly caused by the heavy load of buildings on the land.

Research by the Jakarta Mining Agency from 2007 showed that 80 percent of the city’s land subsidence was caused by building constructions, 17 percent by groundwater exploitation and 3 percent by natural causes.

A 2008-2009 seismic study by three geophysics experts, Suhayat Minardi (Mataram University, West Nusa Tenggara), Darharta Dahrin (Bandung Institute of Technology, West Java) and Mahmud Yusuf (Meteorology, Climatology and Geophysics Agency) from showed that land subsidence in the city amounted to about 15 cm per year.

“Therefore, Ahok’s solution to build a giant seawall as an answer to protect North Jakarta against floods caused by high tide is irrelevant. The construction of such a seawall, on the contrary, will accelerate land subsidence, hence increasing the risk of floods,” Bosman claimed.