Little hope for current airport road, experts say

Mustaqim Adamrah, The Jakarta Post, Jakarta

Recent flooding that submerged part of the Sedyatmo turnpike -- the main roadway to Soekarno-Hatta International Airport -- was primarily caused by the surrounding land's inability to absorb excess water, experts concluded Wednesday.

The head of the Meteorological and Geophysics Agency's climatology and air quality information division, Endro Santoso, said the land around the turnpike had lost its ability to absorb water.

"The poor quality of the soil was the main cause of the flooding. Heavy rainfall was only a trigger," he said in a press conference at the Agency for the Assessment and Application of Technology (BPPT).

The agency recorded 317 millimeters of rain in Cengkareng, West Jakarta, during last Friday's downpour, more than twice the level ordinarily categorized as "very high rainfall".

The flooding brought Jakarta to a standstill, submerging kilometers 25 to 28 of the Sedyatmo turnpike. Soekarno-Hatta airport detoured 58 flights and delayed another 177 leaving approximately 1,000 passengers stranded.

BPPT hydrologist Sutopo Purwo Nugroho said diminishing water catchment areas, overly exploited groundwater and population encroachment on lands adjacent to the turnpike also contributed to the flooding.

"Groundwater must tightly hold every layer of soil. In the area around the turnpike, it has been pumped out in massive quantities to meet local residential demands," he said, adding that the area south of the turnpike has experienced considerable development over the past several years.

"As a result, soil in the area has become more frail," he said. "The land around the turnpike subsided by 2 meters between 1982 to 1997 as structures were erected rapidly. The concave topography of the area makes the area more flood prone by preventing water from running off to the sea."

State-owned toll road operator PT Jasa Marga is planning to build elevated roads on the two sides of the turnpike as additional toll road lanes. Public Works Minister Djoko Kirmanto previously said the construction of the additional elevated lanes would start in March and was expected to be completed within a year, with Jasa Marga funding the project.

City Transportation Council member Soetanto Soehodho said elevated roads would not be a favorable solution if they were not complemented by the development railway-based transportation.

"Jakarta and the Sedyatmo turnpike will never be flood-free without trains to carry passengers and goods," he said. "Elevated roads will only encourage people's dependence on private vehicles or other road-based transportation modes. Without proper infrastructure, residents and visitors to Jakarta will continue to be trapped by flooding on the turnpike."