The Jakarta Administration has expressed concerns about the "alarming" condition of the waterways that crisscross the capital, most notably the Ciliwung River.

Peni Susanti, head of Jakarta's Environmental Agency (BPLHD), told Berita Jakarta, the city's official news portal, that the pollution and illegal dumping of trash were the major factors behind the condition of the rivers.

There were currently 108 illegal waste disposal sites that began from near the University of Indonesia till the river flowed into Jakarta Bay, Peni said.

The city had only been able to close ten of the sites since 2009, she said.

"We have encountered many difficulties. One of them is the unavailability of access towards the illegal waste disposal locations. Therefore, our main focus is to build access to the locations first."

Peni was speaking during a "2011 Stop Littering" campaign in South Jakarta on Sunday. Its theme is "My River, My Front Yard."

She said littering on the riverbank breached city bylaws that carried sanctions of three months in jail or fines of Rp 5 million.

The Ciliwung is one of the world's most polluted rivers. Few if any companies have ever been charged with dumping industrial waste into the fetid river, which is still used by many for bathing.