Flooding on Jalan Boulevard Barat Raya in Kelapa Gading, North Jakarta, on Sunday. (Antara Photo/Sigid Kurniawan)

More Than Dams Needed to Prevent Floods


FEBRUARY 24, 2020

Jakarta. The House of Representatives' Commission V, which oversees infrastructure and transportation development in Indonesia, said the Public Works and Housing Ministry's recent effort at improving flood prevention is often found wanting since the infrastructure development is often too focused on managing the country's rivers and neglecting other sources of flooding. 

"We need a comprehensive solution to overcome frequent flooding, not just river management but also improving flood prevention from the river source to the river mouth," the deputy chairman of the commission, Nurhayati, said in a press release on Monday.

Nurhayati recently led a team from the commission to inspect flood prevention measures implemented by the central and regional administrations in Bandung, the capital of West Java. 

She argued that the so-called "river normalization" – essentially widening rivers to increase their channel capacity and flow – is not enough to prevent floods. Other methods of environmental engineering must also be considered, from creating urban forests to building dams, levees and retention basins.

The United Development Party (PPP) politician said many areas near a river source have to be reforested with a 30-degree slope planted with trees with large roots to bind water to the soil.

She singled out the Public Works and Housing Ministry's Directorate General of Water Resources for praise for its attempt at creating a comprehensive infrastructure development plan to prevent flooding.

Many parts of Jakarta went under water again on Sunday after just several hours of heavy rains. Experts say the nature of the flooding shows that even the new, still-under-construction Ciawi and Sukamahi dams near the source of the Ciliwung River that runs through the capital will not be enough to prevent it from getting flooded regularly during the wet season. 

They say developing and maintaining water basins scattered along the Ciliwung River Stream (DAS), including in Bogor and Depok, south of Jakarta, are also crucial to prevent flooding in the capital.

The head of the Ciliwung and Cisadane River Basin Center (BBWS), Bambang Hidayah, said he agreed with the Public Works and Housing Ministry's plan to build more water basins along the Ciliwung River. 

According to Bambang, water basins or reservoirs can bring many benefits to flood-prone areas. First, they can be used to store water to be used during the dry season. Second, they can help prevent floods by acting as ersatz water catchment areas during periods of heavy rains. 

"If there are no water basins, all the rainwater will flow into the river, which has a limited capacity. The river will overflow, flooding will be inevitable," Bambang said.