Jakarta. State-owned construction firm Hutama Karya and South Korean major builder Daewoo E&C recently inked a memorandum of understanding (MoU) on an immersed tunnel project in Indonesia’s upcoming new capital Nusantara.

The signing ceremony took place at the Korea-Indonesia Economic Cooperation Forum in Jakarta on Thursday. Hutama Karya is carrying out a study on a 2-kilometer underwater tunnel that is expected to lessen the ecological impact of infrastructure projects on Nusantara’s mangrove forests. 

“By building an immersed tunnel, we want to make sure we have as little ecological impact as possible, be it during the tunnel construction or once it operates,” Hutama Karya’s operations director Agung Fajarwanto told reporters after the MoU signing ceremony.

Hutama Karya is seeking Daewoo’s expertise who has experience in building the 8.2-kilometer Geoga bridge that links the South Korean city of Busan and the Geoje Island. The Geoga Bridge -- also known as the Busan-Geoje Fixed Link -- includes a 3.7-kilometer immersed tunnel. The underwater tunnel goes 48 meters underwater, making it the world’s deepest tunnel. 

The study is still ongoing. The construction costs for the immersed tunnel will roughly start from Rp 8 trillion ($515.6 million) to Rp 10 trillion. The funding scheme remains undecided as it is still waiting for the final results of the study, although a public-private partnership has become an option. 

“We expect to finish the study in the coming two to three months. We have collected the primary data, among others, on the waves, and geotechnics, among others. … Now our engineers are discussing with our partner Daewoo. … But of course, it is important to include the regulators, namely the Public Works Ministry, in these discussions,” Agung said.

Hutama Karya data shows that Nusantara has “relatively good conditions” for the underwater tunnels. The area has a water depth of around 10-20 meters and no high waves.

The Nusantara Capital Authority so far has received 323 letters of intent (LOIs) from companies wishing to take part in the capital relocation project, according to data shown at the same forum. About 45 percent of the LOIs came from foreign investors. South Korean firms submitted 10 of those letters.