P

oor drainage is believed to have caused serious flooding in the Central Java city of Surakarta recently.

The city’s existing drainage system was proven unable to accommodate rainwater, causing a number of residential areas to be inundated, including Pucangsawit in Jebres sub-district, where the private residence of the Surakarta mayor is located.

In order to address the city’s poor drainage system in the short term, the Surakarta municipality will operate a number of sluice gates, which have been in existence since the Dutch colonial era, to address poor drainage. Two of the gates are urgently needed: first is the one leading to the Surakarta Kraton Palace and second is the one leading to the Sriwedari Park complex.

“We will operate the two sluice gates to deal with the drainage problem. The Surakarta municipality is currently submitting a budget proposal to the city council, or to the central government if need be,” said Surakarta Mayor FX Hadi “Rudy” Rudyatmo on Friday.

Separately, Surakarta Public Works Agency head Endah Sitaresmi said the Surakarta drainage system is divided into four drainage networks, specifically Bengawan Solo, Pepe Hilir, Anyar and Premulung rivers. The four major regions are further divided into sub-regional drainage sections across their respective areas.

Based on data from the agency, the length of the city’s drainage system stretched 35.7 kilometers for primary drainage, 67.5 km for secondary drainage and 455.3 km for tertiary drainage.

For a medium-term strategy, Endah said her office would design a blueprint to optimize the city’s drainage system by 2017. According to her, the agency was unable to draw up a detailed plan immediately because of a lack of funds.

“The city’s drainage condition is not in a satisfactory condition, as around 40 percent of the drains are not functioning optimally due to high sedimentation. This can lead to waterlogging after heavy rain in the city,” said Endah.

She added that a number of primary drains along Jl. Dr. Rajiman, Jl. Kotta Barat and Jl. Slamet Riyadi were clogged and in poor condition and would require approximately Rp 40 billion (US$3.05 million) to restore, but the legislative council had only allocated Rp 5 billion for drainage maintenance in the 2015 city budget.

“The entire drainage system could not be restored this year because of budget issues. The Public Works Agency has prioritized restoration of primary drainage and a number of secondary drains to prevent inundation,” she said.

Endah added that her agency was only able to carry out the drainage sediment-cleanup program in the three subdistricts of Gilingan, Semanggi and Serengan. She said the steps being taken were only limited to sediment cleanup and drainage repair.

“The city administration cannot work alone in taking care of the drainage system. We hope residents would be involved in drainage management in their respective areas,” she added.

A lecturer of civil engineering at Sebelas Maret University in Surakarta, Mamok Suprapto Meng, said the Surakarta municipality must dredge all the silted drains within the city.

He emphasized the need to review Surakarta’s drainage system in view of rapid urban growth, because the network of drains currently in use was inherited from the colonial era and must be modernized in accordance with the growth of the city.

“Solo [Surakarta] once had a master plan for its drainage system, but it’s no longer feasible now to meet the needs of the city so it must be revised,” said Mamok.