The Jakarta Government's super-priority activity to build and rehabilitate nine polders, four reservoirs, and two rivers or known as 942 programs is still ongoing.

With polder system, water discharge from an area is accommodated and then flowed to rivers which controlled through sluice gates and water pumps

The multiyear (2021-2022) infrastructure program in five administrative cities is one of the important efforts in increasing the capacity of flood control systems to handle and overcome inundation and flooding in Jakarta, especially in areas prone to inundation.

For information, those nine polders are located in Muara Angke, Teluk Gong, Mangga Dua, Kelapa Gading, Pulomas, Marunda JGC, Green Garden, Kamal, and Tipala Pump - Adhyaksa Pump.

There are also four reservoirs in Pondok Ranggon Reservoir, Wirajasa Retention Basin, Brigief Reservoir, and Lebak Bulus Reservoir.

Meanwhile, two rivers spread over the Maritime Museum Canal Crossing Channel (Sodetan) of Kali Besar River and Ciliwung River downstream in Pasar Baru area.

"Work progress in each location varies. Because there are still many stages of work, such as manufacturing, design development, and preparation," said Dudi Gardesi Asikin Secretary of Jakarta Water Resources (SDA) Agency, Friday (3/18).

He explained that the polder is a regional drainage system equipped with pump infrastructure, sluice gates, and long storage to accommodate rainwater from the sea. Technically, it will divide water into several rivers to reduce the occurrence of flooding in an area.

"With polder system, water discharge from an area is accommodated and then flowed to rivers which controlled through sluice gates and water pumps," he explained.

According to him, there were differences in the scope of polder construction work in each location, including constructions of new pumps, sluice gates, parapet, and sheet piles, increased pump capacity, garbage filters, rotary screen, and hoist cranes.

"Polder's catchment area in each location ranging between 100-700 hectares. Its area will also be completed with supporting infrastructures based on the needs, existing conditions, and characteristics of the location," he mentioned.

To build a reservoir, his side designed it as a public space with green and blue concepts in order to maintain local wisdom which functioned to reduce flood discharge in the river flow system.

"Meanwhile revitalization is to increase water discharge capacity, control regional flooding, and arrange riverbank," he added.

The 942 programs were estimated to cost up to Rp 1 trillion. The budget was allocated by the Jakarta Government from loan funds from the central government through the National Economic Recovery (PEN) 2021 program.

The following is the progress of 9 polders, 4 reservoirs, and 2 rivers construction as of March 14, 2022:

Polder Cluster

- Construction of Kelapa Gading Polder (Betik and Artha Gading) and Pulomas Polder reached 12.13 percent

- Construction of Marunda Sub Polder (JGC-Metland) and Tipala Pump-Adhyaksa Pump reached 3.85 percent

- Construction of Muara Angka, Teluk Gong, and Mangga Dua Polders reached 2.46 percent

- Construction of the Green Garden Polder and its accessories reached 7.74 percent

- Construction of the Kamal Polder system (pump, slice gates, and accessories) reached 5.27 percent

Reservoir and Retention Basin Cluster

- Construction of Pondok Ranggon Reservoir and Wirajasa Retention Basin, as well as its accessories reached 21.55 percent

- Construction of Brigief Reservoir and Lebak Bulus Reservoir as well as its accessories reached 13.49 percent

River Cluster

- Construction or work on adding capacity of Kali Besar River and Maritime Museum Canal Crossing Channel reached 7.02 percent

- Construction or work on adding capacity of Ciliwung River downstream in Pasar Baru reached 3.53 percent