Integrated Coastal Planning of Jakarta Waterfront

Integrated Coastal Planning of Jakarta WaterfrontAssignment week 4

Pratama Rizqi AriawanSriwijaya UniversityCoastal ConditionFloodingLand subsidence rate13 rivers flow to Jakarta bayGlobal sea levels

Jakarta, capital city of Indonesia, has suffered by flooding for many yearsLand subsidence due to groundwater extraction is a major cause of the flooding problemsThis figure shows land subsidence rate in Jakarta during 1974-2010Global sea levels have risen at a rate of about 1 to 2 millimeters per year on average, and this rate is expected to increase to 5 millimeters per year by 20502Jakarta Coastal DefenceJakarta waterfrontMuara AngkeMuara KarangPluitCilincingMarunda

Reclamation of north Jakarta bay

Some flood protections have been built in the past, however, those protections cannot be last longer. A number of dikes constructed by the city, including in Muara Angke, Muara Karang, Pluit, Cilincing and Marunda, are no longer capable of holding back the water

Jakarta needs bigger retention ponds to hold excessive water both from the river and the seaBut, there is no available area to build the ponds in the increasingly expensive land, so taking further the waterfront is the only option3Coastal Planning Giant SeawallPresidential Decree no. 54 year 2008Medium Development Plan 2013-2017 by Local LegislativeGiant Seawall?A.K.A Polder is a low-lying tract of land enclosed by embankments (barriers) known as dikes that forms an artificial hydrological entity, meaning it has no connection with outside water other than through manually operated devices

Fresh Water ReseroirWastewater TreatmentExtended Port DevelopmentRoadway ConnectionLuxury ResortWhy Giant Seawall?

Based on Presidential Decree number 54 year 2008 about Spatial Planning of Jakarta, Bogor, Depok, Tangerang, Bekasi, Puncak, Cianjur, and also Medium Development Plan 2013-2017 by Local Legislative, it is mentioned that the government has approved the plan to build the project.

First Stage of The Giant Seawall Construction

It is expected that the flood protections can also be used for fresh water reservoirs, wastewater treatment plants, the roadway connections within east sector (Bekasi) to west sector (Tangerang), luxury resorts, and extended port developments for cargo handling areas4The Mega ProjectThree Different SchemesFirst scheme involves integrated seawall with reclamation of north Jakarta baySecond scheme involves integrated seawall forward to the deeper sea (-16 m)Third scheme involves integrated seawall connecting the thousand islands

In planning this future project, the Government of Jakarta city has made three different schemes to construct the giant seawall, as can be seen as follows

The New Perspective of The Capital City of Indonesia5

Critics Related to The PlanCostInvestment cost (more than 200 Trillion rupiah)Operating, Repairing, Maintenance cost?

Time10 years predictionMore years for fully available facilities

EnvironmentDesigned to be fully enclosed embankmentReduce the water qualityMarine ecosystem degradationAlternative SolutionFlood ReductionConserve the upland areas to reduce runoffDredging sediment load in the canalElevating the river dikes to maximize the capacity

Flood PreventionUsing the river easement wiselyCleaning the river from rubbish to prevent clogging of the waterwaysBuilding the seawall alongside the coastline

Investment cost is always being the biggest problem in every development. To build an approximately 30 kilometers long and more than 16 meters deep of giant dikes will cost more than 200 trillion rupiah. Although the government of Jakarta city has the fund, but cost sharing with or fully granted by private sectors will be a better option.Operating, repairing and maintenance cost can be the other challenges, to maintain the water level in low-lying areas there is no other option other than using pump. Instead of using electric pump, wind powered pump can be used to reduce the cost.

To build this mega project, undeniably will take long time. It is predicted that the construction will be finish in about 10 years. Not to mention the development of the supporting facilities including the freshwater reservoir systems, the wastewater management plants, roadway connections, railway tracks, deep seaports, luxury resorts or even luxury yacht harbors will take couple of years.

The giant seawall is designed to be a fully enclosed to make it easier to control the water. This however will reduce quality of sea water and will lead to marine ecosystem degradation

Instead of building the giant seawall for either preventing or reducing the flood, it may be better to conserve the upland areas so that the runoff water can be minimized, dredging the silts and elevating the river embankment to maximize the capacity, using the river easement wisely, cleaning the river from rubbish to prevent clogging of the waterways, and building the dikes alongside the coastline

This alternative solution may be much cheaper, faster and last longer rather than constructing this ambitious project6