During the last few months, some areas in Jakarta have been struck by flooding several times. Flooding is not a new issue in Jakarta, the capital city of Indonesia which is inhabited by more than 28 million populations. Flooding occurs annually during wet season. Based on climatology data, the rainfall intensity in Jakarta is typically increasing during period of November – January, and evidences show that adverse flooding usually occurs during those months. In fact, there have been significant works to solve flood problem in Jakarta, particularly structural works, but flooding is still happened continuously. Some people complaining why Jakarta is still struck by flooding during wet season after trillion rupiahs of money has been spent to stop the flood. Indeed, stop flooding at all in Jakarta is a kind of impossible mission. However, at least the negative impact of floods could be minimized using robust approach.
Generally speaking, flooding could be affected by some factors including climate, social, economical, cultural, and technical. Based on some studies summarised by Abbas K Jha et al (2012, Cities and Flooding : A Guide to Integrated Urban Flood Risk Management for the 21st Century), factors contributing to flood in Jakarta are including population pressure due to rapid urbanisation, insufficient maintenance and improper operation of flood control systems, poor waste management system, adverse land subsidence, rapid landuse changes in the river basin, and sea level rise due to climate change.
The government of Jakarta has implemented some flood control measures to diminish flood risk since decades, including apply dredging along Ciliwung River, construct Western and Eastern Floodway. Unfortunately, the floodway has been converted as a giant waste disposal which reduces the protection level to flooding. There is also a regulation that new building must construct infiltration well for recharging groundwater and storing excessive runoff. However, this regulation has not been implemented well without any consequence. The main river also has been full of garbage and the floodplain has been occupied by human settlement.
Jakarta is flat low lying region located within Ciliwung Cisadane River Basin with upstream area situated in different provinces, i.e West Java and Banten. According to Associate Program on Flood Management (APFM, 2007), there is a close relationship between water resources management, river management, land use management, forest management, erosion control, agriculture, urban drainage and sewerage within a river basin. The characteristic and magnitude of the flood regime will be affected by the characteristic of the catchment which consists of those aspects. Therefore, a multidisciplinary approach toward integrated flood management in the river basin is required to diminish the flood risk in the region.
A multidisciplinary approach will need to involve all stakeholders related to flood from upstream to downstream regions, including the river basin organisation, local and national government, local community, institutions related to land use management and urban planning, NGO’s and Ministry of Public Work. Furthermore, regulation, policy arrangement, institutional reform and law enforcement are absolutely important to succeed the implementation of integrated flood management program.
Good coordination and cooperation among authorities responsible for flood management is also important aspect on integrated flood risk management. Unfortunately, some studies summarized by Abbas K Jha et al (2012) reported that there is lack coordination and cooperation among authorities responsible for Jakarta flood management.
In addition, flood risk could be minimized by implementing both structural and non-structural approach in integrated framework. Both structural and non-structural approaches are complementary. Structural approach could be applying by constructing drainage channel, floodway, constructed wetland, retention basin, reservoir, etc. Whereas non-structural approach could include raising awareness of flooding to community, applying sustainable land use management in the upstream area, educating community to manage the waste and water wisely, ensuring law enforcement, developing early flood warning system, providing adequate flood emergency response and setting up recovery plan. Again, those actions require coordination and cooperation among related stakeholders. When each stakeholder doesn’t have understanding that they are interconnected and keep going on their ego, coordination and cooperation would be difficult to build. Therefore, scrapping the ego is also important to succeed the implementation of integrated flood risk management.
Jakarta, as a downstream area is interconnected with other regions in Banten and West Java which are situated in upstream area. Since the water flows downhill, the condition in upstream area will affect downstream. Consequently, coordination and cooperation with the regions is essential to minimise the flood risk downstream.
There are many lesson learnt from other cities around the world which have been successfully applying integrated flood risk management. However, it should be borne in mind that there is no flood management blueprint since every flood is different from one region to others. Jakarta could be better in managing the flood risk if all stakeholders are willing to scrap their ego and work together.