The Jakarta Post
Whether the season is dry or wet, Jakartans usually have difficulties accessing clean water.
During the peak of rainy season, residents are used to suffering floods and clean water shortages, while in dry season, the city generally sees a shortage of water supplies from Jatiluhur dam in West Java.
'When the floods come, we lack a raw water supply. Floodwater cannot be treated into clean water as our water installation facilities are not designed to treat water with high turbidity,' Firdaus Ali, a water specialist from the University of Indonesia (UI), said recently.
He added that when Bekasi, West Java, saw a high debit of water, its sluice gate needed to be opened to channel floodwater to the sea and prevent flooding.
Firdaus said that 13 main rivers, 76 smaller rivers and dozens of reservoirs in the city were too polluted to be used as raw water.
The floods do not only disturb the raw water supply, but also frequently disturb water production in inundated water pump facilities.
This month water operator PT PAM Lyonnaise Jaya (Palyja) reported that floodwater inundated water pumps in Taman Kota, West Jakarta and in Cilandak, South Jakarta for several days, disturbing production and affecting some areas.
'The water pumps in Cilandak were hit by a flood in 2007, but we leveled up the pump facility. It was never inundated again until this year's flooding, which reached 4 meters. The water pump in Taman Kota was also hit by floods last year,' Palyja spokesperson Meyritha Maryanie told The Jakarta Post on Friday.
She said in order to anticipate future floods, the company planned to level up the pumps, electricity facility and chemical warehouse again.
Experts believe the impacts of floods were exacerbated in areas that suffered from land subsidence.
Jan Sopaheluwakan, a senior Geology researcher from the Indonesian Institute of Sciences (LIPI), said the excessive use of deep groundwater had caused land subsidence that could increase the number of new inundation spots and dislocate the drainage system.
'On average, the city suffers from 20 to 40 centimeters of land subsidence annually, which has occurred in the past 14 years. The administration needs a radical change in managing the city,' he said.
He said stopping the use of groundwater for a while and building a huge reservoir in the capital could stop land subsidence.
The over-exploitation of groundwater in the capital has raised concerns about a lack of water supply and land subsidence.
According to the Amrta Institute for Water Literacy, an NGO that aims to raise public awareness over water-related issues, the administration only monitored 8 percent of the use of groundwater.
The city has a potential loss of groundwater tax of between Rp 800 billion (US$65.50 million) to Rp 1.4 trillion annually for the unrecorded use of groundwater.
Rapid infrastructure and population growth has left the city with limited green, open space to absorb rainwater.
Last year, the city's Park and Cemetery Agency claimed 11 percent of Jakarta comprised of public green spaces and 7.8 percent of private green space.
Firdaus said residents could help collect water by building percolation pits, and that the solution to land subsidence was to halt the exploitation of groundwater.