Ideas forjakberketahanan.org/wp-content/uploads/2018/12/... · Image credit: yourarticellibrary.com; Norcal Geophysical Consultants Inc; C Tech Development Corporation -Additional

Ideas for

Jakarta’s Future

by Geoffrey Delin

Hydrologist,

Scientist Emeritus,

U.S. Geological Survey

Supported by the U.S. Water Partnership,

U.S. Embassy, Jakarta, and

U.S. Agency for International Development

Photo credit: Public Radio International; Feri Yadi, a resident of Muara Baru in North Jakarta, stands atop the seawall

Talk Outline

- Scientific data and research needs

for Jakarta

- Potential future strategies for

Jakarta

Photo credit: Ria Tanisa

Scientific Data / Research Needs- Much additional research and

scientific data would be helpful to

develop a more comprehensive

understanding of the groundwater

system and in order to assess land

subsidence in Jakarta;

Image credits: Kdnuggets, InnoArchiTech; PNAS; California Groundwater Coalition; Geotechdata.info

- The ultimate goal is to better

define the causes of land

subsidence in Jakarta.

Scientific Data / Research Needs- It would be helpful to improve the

accuracy and accessibility of

databases, such as for

groundwater pumping rates from

the deep aquifer;

Image credits: Kdnuggets, InnoArchiTech; PNAS; California Groundwater Coalition; Geotechdata.info

- It would be helpful to conduct

laboratory and field experiments to

obtain geotechnical parameters

and obtain a better estimate of the

compaction rates and limits of the

clay or sand confining beds for the

deep aquifer.

Scientific Data / Research Needs

- It would be helpful to conduct

aquifer tests, and other hydraulic

tests, in the field to estimate the

hydraulic properties of the aquifers

and confining beds;

Image credit: yourarticellibrary.com; Norcal Geophysical Consultants Inc; C Tech Development Corporation

- Additional borehole and surface

geophysical data would be

helpful to better define the

hydrogeologic properties of the

underlying aquifers and

confining beds.

Scientific Data / Research Needs

Sources: Galloway et al., 2008; Kooy et al., 2018

Image credit: Enviro Check Australia; expressbusinessdirectory.com; yourarticellibrary.com;

- A groundwater flow model is one of the best tools

used to help answer questions of regional water

use, groundwater flow, and groundwater/surface-

water interaction;

- It would be helpful to build on existing models by

developing more accurate or updated geologic,

groundwater flow, and land subsidence models to

simulate future subsidence rates and their effects in

different development scenarios;

- A program to monitor

the water quality of the

groundwater and

surface water

resources in the

Jakarta area is needed

(DLH) (Kooy et al.,

2018); This will help to

monitor the improvement of water quality as new

water sanitation programs are implemented.

Land Subsidence Monitoring

Source: Bodemdaling bij Deltares, 2012-1013

- Better monitoring,

including additional

extensometers like

this one, are needed in

Jakarta to more

accurately monitor

land subsidence;

- It would be very

helpful to collect the

data frequently to

obtain a continuous

record such as shown

below.

Scientific Data / Research Needs- It would be helpful to improve the

network and monitoring of

groundwater levels in Jakarta;

Image credit: Kagabu et al., 2011; Solinst; USGS

- Use of automated,

continuous water-

level measuring

devices to generate

continuous water-

level records would

also be helpful.

Example of Monitoring System

Benefits

Source: Main

Report: Sinking

Jakarta, Causes

& Remedies

2015

As an example of the benefits of these types of data, data from the Utawa, Japan

monitoring station clearly shows the correlation between declining groundwater

levels due to intensified groundwater pumping, which contributes to subsidence.

Potential Future Strategies for

Jakarta

- Raise awareness about land

subsidence;

- Organize systematic monitoring

of reliable data;

- Develop in-depth knowledge

about the process of subsidence

and develop models;

- Assess vulnerabilities, risks and

impacts of subsidence;

- Develop responses and

solutions;

- Address governance;

- Support decision makers with

models and tools;

- Exchange of knowledge and

best practices.

Source: Sinking Cities, Deltares 2013 report

Driving forces

Pressures

StateImpacts

Responses

The Deltares (2013) “Sinking Cities” report recommends a

comprehensive and integrated approach to address subsidence:


Jakarta (continued)

- 1. Problem analysis stage (Jakarta, Dhaka, Manila, and New

Orleans are examples of major cities at this stage);

- 2. Planning stage (Ho Chi Minh City is an example of a major

city at this stage);

- 3. Implementation stage (Bangkok is an example of a major

city at this stage);

- 4. Evaluation stage (Tokyo and Shanghai are examples of

major cities at this stage).

Source: Sinking Cities, Deltares 2013 report

The comprehensive and integrated approach has 4 stages

(Deltares, 2013)


Jakarta (continued)

- Although the historical

subsidence in Jakarta

largely cannot be

reversed (~95% of land

subsidence is

unrecoverable), there

are nevertheless a

number of very helpful

things that can be done

to stop or mitigate the

subsidence.

Photo credit: Abidin et al., 2015

stage


Jakarta (continued)

- 1. Restriction of groundwater extraction;

- 2. Natural and artificial recharge of aquifers;

- 3. Development of alternative water supplies (instead of

groundwater);

- 4. Integrated (urban) flood water management;

- 5. Improving governance and decision-making;

- 6. Decision support models and tools;

- 7. Appropriate monitoring and database system;

- 8. Integration of geotechnical aspects in planning and design

of buildings and infrastructure;

- 9. Asset management, financing and public-private-

partnerships;

- 10. Exchange of knowledge and best practices.

Source: Sinking Cities, Deltares 2013 report; Image credit: captureindonesia.com

The Deltares (2013) “Sinking Cities” report mentions 10 key issues

to address subsidence:


Jakarta (Continued)

Photo credit: Abidin et al., 2015; spillwaynews.net; Santa Clara Water District

Central Valley

California Canals

And Aqueducts

- An improved network of

pipelines or canals may be

necessary to connect the

reservoirs to the city

distribution system.

- Jakarta currently depends on three

reservoirs and some natural lakes as

alternative source of water to

groundwater. The reservoirs are

owned by other jurisdictions. It would

be helpful to get an improved

agreement with them for long-term

usage.

Anderson Reservoir near

San Jose, California


Jakarta (continued)- It would be helpful for Jakarta to

develop an improved water

distribution system to distribute

potable water from the new

surface-water source throughout

the city;

- This would result in shifting of the

current use of groundwater over to

this new surface-water based

source;

Image credit: Reddit; Public Radio International; COF-COF

- It would be most helpful for the city to

work towards the goal of stopping (or

greatly reducing) the abstraction of

groundwater from the deep aquifer,

including enforcement of the current laws;


Jakarta (continued)

- Artificially recharge of the confined

aquifer via direct injection wells to

counter groundwater pumping and

help mitigate land subsidence is very

costly;

Photo credits: Galloway et al., 1999; iwindsurf.org

Satellite view of Los

Gatos, CA

percolation ponds

Typical artificial recharge well in Las Vegas

- The city could also install percolation

ponds in the recharge area for the

confined aquifer to the south of Jakarta;

- This likely will not have an immediate

effect on water levels, however, (because

of the long distance from the recharge

area to the main subsidence areas in

Jakarta) but will be of benefit long term.


Jakarta (continued)

- An improved network of wastewater

treatment plants and sewers is

needed to serve the entire city.

Currently only 2% of wastewater is

treated. Water quality in the cities

13 rivers would dramatically

improve if this were implemented;

Photo credit: Dhara Water; Walsh Group

- When the water quality in the

rivers improves, the rivers could

be tapped as a treatable source

of water for the city. Currently

the river water is untreatable.


Jakarta (continued)

Image credis: Feri Yadi, a resident of Muara Baru in North Jakarta, stands atop the seawall;

California Groundwater Coalition

- The city could use

reclaimed (or recycled)

and treated wastewater

is a potential source of

potable water as well.

- The city likely will need to raise

and improve the existing

seawall in the short term until

the shift from groundwater to an

alternate source of water can be

completed.


Jakarta (continued)

Photo credit: Minnesota DNR; Iowa DNR

- It would be helpful to require that all well

drillers report a location and geologic log for

all newly drilled wells to a government entity

that maintains hydrogeologic data in a

database (DPE);

- It would also be helpful

to require that all

municipal, commercial,

and industrial high-

capacity wells annually

report groundwater

usage to a government

entity that regulates

that usage.

Enforcement is needed

for this and all water-

related laws (DPE).


Jakarta (continued)- It would be helpful if a task force were established for the City focusing on

reducing subsidence in Jakarta;

- It would be helpful if the government took the lead in reducing groundwater

pumping by banning the use of groundwater in all government buildings;

- The city could take advantage of, and utilize the expertise of, local experts in

groundwater and land subsidence;

- The city could utilize the advice provided by world-renowned experts in land

subsidence who have held meetings and generated helpful solutions to

Jakarta’s problems.

Source: Main Report: Sinking Jakarta, Causes & Remedies, 2015

Roundtable meeting of

world-renowned

experts on land

subsidence in Jakarta,

May 26, 2015

Quick Fix ?

At least a partial “Quick Fix” to the Jakarta

land subsidence problem is possible for the

60% area of the city that is supplied by

municipal water:

- The city could locate all high-capacity water

users in those areas;

- Force them to stop pumping groundwater

and use the city water.

Summary

- Short term goals (5 years or less)

– Data collection;

– Data analysis;

– Establish task force on land subsidence.

- Long-term goals (more than 5 years)

– Improve access to alternative water source;

– Improve water distribution system;

– Improve wastewater treatment system.

Jakarta Future Needs

Questions?Image credis: Feri Yadi, a resident of Muara Baru in North Jakarta, stands atop the seawall

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