Jakarta Governor Joko Widodo said that the tunnel will be built from Cawang in East Jakarta, along Jalan MT Haryono, up to Pluit in North Jakarta.
"This needs to be done because we have to race with the continuous development of residential areas and buildings. There should be balance," Joko said. "It is true that this is not in the blueprint, but we do not have to solely rely on that, there should also be a breakthrough. We have been inundated by floods for decades now."
He said that he had ordered all related city agencies and municipal leaders to conduct the necessary field checks for the project. He said that all institutions in the city should work together in developing the project.
"So far, there are only separate programs. The [Jakarta] Public Works [Agency] wants to do this in March, the state clean water company wants to do that in June, then there is also the telecommunication company Telkom which wants to do another thing in September. How can this happen? If everyone wants to work at the same time, then do the deep tunnel," he said.
He said that each institution so far was taking turns in digging up areas already dug up and filled again by others. The tunnel, he said, would be able to accommodate the needs of all those institutions.
Earlier on 26 Dec. 2012, Joko inspected the underground drainage network along Jalan Thamrin and found that the diameter of those drains was at 60 centimeters and that, he said, was not enough to accommodate the high volume of rain.
"It is also impossible to put every utility network into a drain of 60 centimeters. Rains in the old times were not as extreme as now and the volume of water could be absorbed but now everything is covered in concrete and therefore all waters are flowing into the drains," he said.
Jokowi said that he estimated that the deep tunnel project is estimated to need some Rp 16 trillion ($1.66 billion), which will come from the city budget and the private sector. He estimated that the project will take four to five years to complete.
The drainage system on Jalan Thamrin was made more than 40 years ago.
"This was made in 1970 and it was in accordance with the rain intensity at the time, which was not as high as it is today," said Jakarta Public Works Agency head Ery Basworo.
Ery said that Jalan Thamrin didn’t have many water absorbers that could accommodate rainfall of more than 100 millimeters per second.
"The 60-centimeter diameter [drain] could only accommodate medium-intensity rains of about 55 millimeters per second, he said, adding adding that the tunnel should have a diameter of at least one meter.
Ery said he has proposed widening the tunnel to one meter for two kilometers. He added that the widening of the tunnel will start from the Sudirman area.
