SP/Fana FS Putra – Booming construction in Jakarta and a precipitous decline in green space have exacerbated flooding despite the existence of years-old legislation requiring at least 30 percent of the capital be reserved for parks and undeveloped land, an influential academic said on Monday.

"This is the failure of previous leaders," University of Indonesia academic Firdaus Ali said. "The Kemang or TB Simatupang areas have been turned into business corridors. Both should have been water-catchment areas."

The official figure for "green space" is 9.8 percent of the city. A 2007 zoning law required that at least 30 percent of Jakarta be reserved for open land.

Almost half of Singapore today, for example, is classified as green space, but, according to Firdaus, more than 30 percent of the equivalent area in Jakarta was developed between 1985 and 2013.

Jakarta Governor Joko Widodo has said he is facing difficulties in reversing the tide. "Jokowi is facing a mafia both inside and outside his government," Fauzi said of people who violated zoning rules. "I'm sad, because [the developers] have all the necessary permits."

Firdaus said Joko should order a thorough zoning audit of the capital, complete with precise data on green spaces. The results should be made public, he said, allowing greater accountability, and enabling community groups to better engage in the process of approving construction projects.

Azas Tigor Nainggolan, the head of the Jakarta Residents Forum (Fakta), cautioned against blaming poor communities living along the banks of rivers.

"The Jakarta government should not only blame and evict the poor," he said on Monday. "It should also work to evict residential areas or malls built on water-catchment areas and areas reserved for green open spaces."

Yayat Supriatna, an urban planning specialist from Trisakti University, said the generous approach to issuing building permits was a longstanding problem.

"If buildings violate the zoning regulations and impact on flooding in a way that clearly disadvantages the population, then they should be pulled down," he said. "This has begun to be applied to many villas in the Puncak-Bogor areas."

Firdaus also emphasized the importance of realizing the city's plans for a deep drainage tunnel, that would begin in East Jakarta before emptying out into the sea near Pluit, North Jakarta.

"We already have the legal umbrella to do this," he said. "The next step should be the establishment of an ad hoc agency to handle tenders and other matters."