Everyone talks about the problems Jakarta faces with regard to water. Some have it as the fastest subsiding city, others look at the flooding, and the world watched in horror as Gary Bencheghib and his brother Sam paddled down the Citarum River in boats made for plastic bottles to see the pollution up close, and found it in massive quantities! The rivers are visibly polluted and the water from the taps is of very uneven quality. There are definitely serious problems so here we present an overview of the challenges facing Jakarta and some solutions in a straightforward report style presentation.
JAKARTA PROFILE
Jakarta, which is a province not a city, has a land area of 662.33 km2 and a sea area of 6,997.50 km2, and consists of 5 cities and 1 administrative district with 44 sub-districts and 267 urban villages.
The north coast of Jakarta, which is 32 km wide, is the estuary for 13 rivers, 2 channels/drains, and 2 flood canals.
There are two seasons in Jakarta with a tropical climate, namely the dry and rainy seasons.
Jakarta had a population of 10,562,088 in 2020 with a population growth of 0.92% per year (2010-2020) but is inter-connected to conurbation areas in Depok, Tangerang, Bekasi and Bogor which takes the total population to over 24,000,000
Jakarta's Gross Regional Domestic Product (GRDP) of US$ 14,297 (Rp 207.99 million) per capita per year (in 2016)
CHALLENGES
1.WATER QUALITY
Annually, the Jakarta Environmental Office monitors water quality of the rivers, lakes/reservoirs, groundwater, and seawater to evaluate environmental performance and calculate the water quality.
Water Quality Index (WQI) of Jakarta fluctuated with an increasing trend. The highest WQI was 42.73 in 2020 and the lowest was 22.31 in 2016.
Rivers in Jakarta have moderate to severe polluted status. The lakes/reservoirs in the north of Jakarta have worse water quality than those in the south. The seawater quality in Jakarta Bay is also lightly to moderately polluted. Meanwhile, groundwater quality tends to be better than surface water.
The pollution is mostly generated from domestic wastewater which is discharged into water bodies without proper treatment. Moreover, Jakarta is a downstream area which is burdened by pollutants from upstream.
2.FLOOD & INUNDATION
Jakarta is a lowland area which is mostly below sea level. As a result, it is prone to flood and inundation, either due to high rainfall or due to high tides, especially in developed areas due to impervious surfaces.
The average rainfall in Jakarta was around 161.2 mm/year in 2019. This number is quite large if compared to other areas in the Greater Jakarta region.
In 2019, the highest recorded rainfall occurred in December 2019, which reached 552 mm.
Land subsidence aggravates floods that have affected several regions of Jakarta due to building loads and excessive groundwater extraction.
3.CLIMATE CHANGE
Climate change is projected to cause an increase in the intensity of extreme weather and will occur more frequently, exacerbating the problem of flooding and other climate challenges in Jakarta.
From historical data of daily rainfall for 150 years (1866 – 2015), there is a tendency to increase the incidence of annual extreme rains, with an increase in probability of 2-3% when compared to 100 years ago.
In the Greater Jakarta area, the highest annual daily rainfall shows a trend of increasing intensity of 10 – 20 mm per 10 years from the last 43 years.
On the other hand, low rainfall can reduce groundwater availability and cause clean water scarcity. Drought can also increase air pollution, fire, and disease incidence.
4.WATER PROVISION
The indicative status of the water carrying capacity of Jakarta based on the performance of water provisioning services in aggregate is indicated to have been exceeded.
The calculation is based on water discharge data from five catchment areas which supply water to Jakarta, i.e. Ciliwung, Citarum Hilir, Cisadane Hulu Bendung Pasarbaru, Cisadane Hilir Bendung Pasarbaru, and Kepulauan Seribu, and water demand data for domestic and economic activities.
Jakarta relies heavily on its buffer zones, such as West Java and Banten, to supply water, which poses a risk to its environmental sustainability.
STRATEGIES
1. Spatial utilization control
Restrictions on permits for extractive activities in large capacities
Improve settlement and developed areas.
Control of land use change for green space
Spatial planning and integrated development with satellite cities
Watershed-based arrangement and management of upstream- downstream areas
Improve riverbank and groundwater basin zones as water conservation area.
2. Environmental pollution control
Integrated wastewater treatment system
Air pollution control using science and technology development.
Improve green space function.
Integrated waste management system
3. Allocation of investment for ecological infrastructure
Ecological infrastructure investment within Jakarta
Ecological infrastructure investment with integrated regional scale management
4. Integrated water resources management
Control of groundwater use
Improve tap water services.
Development of science and technology to find alternative water sources.
Integrated river maintenance from upstream to downstream
5. Disaster mitigation
Resettlement in areas prone to floods, earthquakes, and landslides
Apply the Zero Delta Q principle to reduce water discharge into water bodies
6. Optimization of the community-based business and services
Assistance to the community to increase understanding, awareness, and concern for environmental issues.
Encouraging environmentally friendly lifestyle as local culture
There you have it. The challenges are already there. The solutions? Well it’s good to see that the government has at least identified some of them. As to when they will all be implemented and safeguard the city from a Cape Town style water disaster…that is the question.
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