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The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
IOP Publishing
doi:10.1088/1755-1315/426/1/012001
1
The impact of earthquake on clean water demand and supply
at North Lombok regency, Indonesia
Ari Ramadhan Hidayat
1
, Radianta Triatmadja
2*
, Intan Supraba
2
1
Graduate student, Master of Civil Engineering, Department of Civil and
Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada,
Indonesia.
2
Department of Civil and Environmental Engineering, Faculty of Engineering,
Universitas Gadjah Mada, Indonesia.
*) Corresponding author email: radianta@ugm.ac.id
Abstract: An earthquake of magnitude 6.4 Mw hit Lombok, Indonesia in July 2018, followed
by another 6.9 Mw earthquake magnitude in less than a month in August 2018. The earthquake
caused fatalities and damage to infrastructures, including the facilities of clean water. The main
objective of this study is to know the impact of the earthquake towards clean water facilities
damage, and to analyse clean water demand and supply after earthquakes in North Lombok
Regency. Another purpose is to propose disaster mitigation to be implemented in the other
disaster prone regions of Indonesia. The primary data were collected through field survey and
questionnaire samples of 110 respondents. Secondary data regarding the damage of clean water
network were collected from the Regional Water Company (PDAM) of North Lombok.
The results of this study show that many clean water facilities were damaged due to
earthquake. The amount of clean water demand in Lombok Island after the earthquake was
decreased by 19.03%. The number of wells users after the earthquake increased from 22.73%
to 57.27%. The potential groundwater for clean water in the Lombok Island is more than
sufficient to fulfil the requirement of clean water during disaster. However, further studies are
required to realize such idea.
Keywords: earthquakes, pipelines, clean water needs, mitigation.
1. Introduction
Earthquake has become a global disaster, especially for countries that are located between active
tectonic plates and Ring of Fire such as Indonesia. Both tectonic earthquake which is caused by the
shifting of earth plates and, volcanic earthquake which is caused by magma activities are frequently
happen in Indonesia. There are three tectonic plates within Indonesia archipelago, i.e. the Indo-
Australian plate, the Eurasian plate, and the Pacific plate [9]. Therefore, Indonesia frequently
experiences earthquakes with considerable magnitude. The earthquakes also cause damage to
infrastructure, including facilities of clean water. The following are some historical earthquakes in
Indonesia that affected clean water facilities.
a. Yogyakarta earthquake
In 2006, Yogyakarta was hit by an earthquake with a magnitude of 6.3 Mw [1]. The earthquake
caused the clean water source to shrink and even disappear in some places. Before the earthquake, an
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
IOP Publishing
doi:10.1088/1755-1315/426/1/012001
2
abundant water sources were available throughout the year. After the earthquake, people found
difficulties in finding the clean water during the dry season"[16].
b. Palu and Donggala earthquakes
In 2018, Palu and Donggala, Central Sulawesi Indonesia were hit by an earthquake. The
earthquake magnitude was 7.5 Mw and caused many fatalities [15]. Similar to that in Yogyakarta, the
earthquake also reduced the availability of clean water in Palu and Donggala since, the network of
clean water distribution in the area stopped functioning. According to Jannah [8], the earthquake also
damaged the pipeline networks due to landslide or soil movement that displaced the pipe line off it
tracks. In some areas, the ground conditions in Palu were cracked and collapsed, causing further
damage to clean water pipes in Palu. Another contributing factor to the disaster is the cut off of
electricity due to the damage of electrical lines. Such damage lead to disability of the Regional Water
Company (PDAM) and community wells to function properly. To overcome the issue of clean water
availability, the Ministry of Public Works and Public Housing operated public hydrants on artesian
wells and groundwater sources [17].
Japan is also one of the countries that prone to earthquakes. Japan's geographical location is
similar to Indonesia, which is located between three active tectonic plates, i.e. the Pacific plate, the
Philippine Sea plate, and the Eurasian plate. Several major earthquakes have occurred in Japan, and
some were followed by Tsunami.
a. Sendai earthquake, 2011
In 2011 Japan was hit by a powerful earthquake on March 11, 2011, at 14:46 local time with a
magnitude of 9.0 Mw at the coast of East Japan and followed by a Tsunami. The earthquake caused
the disruption of water supply for 2.300.000 households in such a large area, from Tohoku to Kanto
[10]. Miyajima also mentioned that in Sendai City, the damage of pipe water supply network can be
classified in to two categories namely caused by ground shaking and ground failure such as
liquefaction and slope failure. Figure 1 shows a broken connection of pipe with diameter of 240 mm
due to ground movement [10]. An underground water tank was uplifted due to liquefaction is shown in
Figure 2 [10]. These two failures suggests the scale of destruction the earthquake can do to water
distribution network infrastructure.
b. Kumamoto earthquake 2016
In 2016, Japan was again hit by an earthquake around Kumamoto City. The earthquake
occurred on April 14, 2016, with the magnitude of 6.2 Mw and at 11 Km depth. A higher earthquake
magnitude of 7.0 Mw again rocked sporadically in 28 hours afterwards, on April 16, 2016 [11].
According to [11], the earthquake caused land movements and geological disaster (landslides,
liquefaction, and cracked soils) which resulted in damage to clean water networks. The pipeline
network condition in the liquefaction was ten times worse than in the non-liquefaction area [11]. In
addition, the earthquake on 14 April with the magnitude of 6.4 Mw caused the operation of clean
water distribution in 69 out of 96 wells in Kumamoto City were stopped due to unaccepted turbidity.
Figure 1.Broken pipe connection with diameter
of 240 mm due to ground movement
(Source: Miyajima [10])
Figure 2.Water tank lifted to the surface due to
liquefaction
(Source: Miyajima [10])
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
IOP Publishing
doi:10.1088/1755-1315/426/1/012001
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As a result, there were 85.000 households that did not get supply of clean water [19]. Later, due to the
April 16 earthquake with magnitude of 7.0 Mw, all wells in Kumamoto City stopped functioning due
to the same problem of water quality and ultimately 326.000 households were without clean water
supply [19].
This study explains further the impact of earthquakes on demand and fulfilment of clean water
on the post-earthquake disaster in North Lombok, Indonesia. Previously, the Lombok Island,
particularly in the district of North Lombok, was hit by two major earthquakes in Lombok. It
happened on July 29, 2018, at 04:47 local time with magnitude of 6.4 Mw, at the direction of 47 km
northeast area of Mataram city, with a depth of 24 km [2]. Twenty people died after this earthquake
and there were landslides in several points at the climbing area of Mount Rinjani. The second
earthquake occurred on August 5, 2018, at 19:46 local time with the magnitude of 6.9 Mw, which was
detected at 27 km northeast of North Lombok with a depth of 10 km [2]. There were 506 people died,
1,406 people were injured, and 430,946 people were relocated [13]. The earthquake also caused
infrastructure damage, including clean water facilities.
The sources of clean water facilities generally are wells, springs, PAMDES and PDAM
(Drinking Water Regional Company). They were not well-functioned after the quake. As a result,
most of the affected people could not get clean water from the sources. The objectives of this study are
studying the impact of earthquakes on the damage of clean water facilities, the water demand and
supply of clean water on post-earthquake in North Lombok. In addition, this study aims to determine
some possible forms of mitigation.
2. Research Methods
The study used questionnaires, interviews and field observations as the survey methods. The
collected data were categorized into primary and secondary data. Primary data were collected through
field survey, interview, and field observation. The number of samples was 110 respondents from the
total population of North Lombok Regency of 214.393 people [4]. The sample was selected randomly
by considering the sample distribution, thus it was not focused only on one area. The secondary data
were obtained from relevant stakeholders. In this case, most of the secondary data, such as the damage
of water network data, were collected from PDAM in North Lombok.
Figure 3. Map of the distribution of respondents
3. Field Survey Results of Effect of Earthquakes in North Lombok
3.1 The Clean Water Network Facilities Damage
The earthquake that hit North Lombok on July 29, 2018, and August 5, 2018, resulted in a
serious damage to the clean water facilities including the PDAM's piping network, the supply of
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
IOP Publishing
doi:10.1088/1755-1315/426/1/012001
4
village’s drinking water (PAMDES), and private wells owned by community. As a result of the
damage to clean water facilities, it is difficult for the people to get clean water. The facilities such as
piping networks for drinking water supply experienced most of the damaged.
The damage caused by earthquakes to drinking water pipe networks was due to several factors
including soil movement and slope stability. The major damages were broken transmission pipelines,
broken pipe joints, buried intake structures, and the destruction of pump house. Based on the data
obtained from PDAM and the results of field observation, the level of damage to the piped network
was varied from the water intake, transmission network, distribution network, and the connection to
customer's home. Figure 4 shows a landslide material covering the major part of an intake. Figure 5
shows the damage of a galvanized iron (GI) transmission pipe which has a diameter of 2 inches that
was crushed by avalanches material including stone with diameters ranging from 50-100 cm. Figure 6
shows the damage of distribution pipes caused by ground movement while, Figure 7 shows the
damage of the house connection at PDAM customers’ house which collapsed by the ruins of the house
materials.
In addition to the earthquake impacts on piping networks, the ground movement influenced the quality
and quantity of water resources from a number of local communities’ wells. The issues were varied,
such as the decreased amount of water, the contaminated water quality and the sand that covered part
of the wells. Such cases were mostly found on wells own by residents around the coastal area.
Figure 8. The location of shallow water wells covered by soil due to the earthquake. (a) A shallow
well after being recovered (deepened), the dash line indicates the original soil surface after earthquake
(b) A shallow well before being recovered
Figure 5. The broken transmission pipeline
due to the avalanche materials
Figure 4. An intake was burried by landslide
material
Figure 7. Home connection was buried by
building materials
Figure 6. The damage of distribution pipe
caused by ground movement
(a)
(b)
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
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doi:10.1088/1755-1315/426/1/012001
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3.2 Sources of Clean Water, Pre and Post-Earthquake
Table 1 shows some sources of clean water before the earthquake occurred. The survey results
show that 71 respondents are customers of PDAM and the remaining 39 respondents are users of other
water sources such as wells, water spring, local water supply, and rivers.
Table 1. The source of clean water before the earthquake.
No Source of water before
earthquake Total %
1 PDAM 71 64.55
2 Wells 25 22.73
3 Water Spring 12 10.91
4 Local Water Supply 2 1.82
Total 110 100
Based on the survey, the use of clean water sources can be classified based on geographical
zones. For example, springs and local water supply are mostly used in highland areas or around
mountainous areas. As for customers, PDAM and wells are generally located in lowland areas,
especially around the coast.
After the earthquake, there was a change in the preference of clean water sources usage. This is
caused by the damage of the clean water facilities during the earthquake, especially the pipe water
distribution system. To meet the needs of clean water after the earthquake, people usually use more
than one source.
Table 2. Changes in the usage of clean water sources after the earthquake.
No Source of water
before earthquake
Number of users after earthquake (%)
River Wells Water
Springs
Tanker Public
Hydrant Etc.
1 PDAM 42 39 10 38 6 5
2 Wells 8 23 1 10 1 0
3
Water Spring
5
1
4
8
0
4
4
Local Water Supply
1
0
1
1
0
1
Total 56 63 16 57 7 10
Table 2 shows that the utilization of wells to meet clean water needs after the earthquake was
increased. The survey found that there were 63 respondents (57.27%) who use wells after the
earthquake. This was because wells are mostly still available after the earthquake. However, there
were a number of wells that cannot be used after the earthquake where the soil inside the wells raised
above the water surface of the wells.
The increasing number of wells users was also caused by the operation of several deep wells
(drilled) from the Nusa Tenggara River Basin 1 (BWS NT 1) in North Lombok Regency. The wells
were originally intended to fulfil irrigation water needs, but then were temporarily operated to fulfil
the need for domestic water after the quake. The Ministry of Public Works and Public Housing
(PUPR) has added deep wells in several sub-districts. Table 3 shows the number of deep well
locations before the earthquake and the additional deep well points after the earthquake in several
areas in North Lombok Regency
Table 3. The number of drilled well points to meet clean water needs.
No sub-district
Before the Earthquake After the Earthquakes Total
(point)
Amount
(point)
Depth
(m)
Amount
(point)
Depth
(m)
1 Pemenang 2 60 – 90 6 50 – 150 8
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
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doi:10.1088/1755-1315/426/1/012001
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No sub-district
Before the Earthquake After the Earthquakes Total
(point)
Amount
(point)
Depth
(m)
Amount
(point)
Depth
(m)
2 Tanjung 1 90 4 50 5
3
Gangga
3
80 -90
4
50 – 150
7
4 Kayangan 2 50 – 90 0 0 2
5 Bayan 4 80 - 110 0 0 4
Total 12
14
26
Source:([6] and [5])
The addition of deep well increased the wells users in Tanjung and Gangga. The number of
wells users in Tanjung increased by 31.58%, and in Gangga increased by 18.42%. However, in
Pemenang, the number was not too large, which was only 7.89%. This is not proportional to the
number of additional deep wells in the area. It can be concluded that the determination of location and
number of additional deep wells should be conducted carefully. Meanwhile, in Kayangan and Bayan,
there were no additional deep well because of its geological conditions which is rocky soil.
Nevertheless, the increase of wells users in Bayan was quite large, at 28.95%. In these areas, it was
difficult for the resident to obtain clean water, especially those in the highland areas because of the
damage of the clean water facilities and the long dry season that happen at the same time. Many rivers
in the region dry up, thus people have to find other clean water sources, one of which was from BWS
NT 1 drill wells. For those who do not have any vehicle to transport the water, they have to wait for
clean water from the water tanker.
In highland areas, people used rivers water and clean water from water tankers. The distance
from river to evacuation area was between 100 – 2000 meters. Clean water from water tankers comes
from river flow and the deep well location of Nusa Tenggara River Basin Area 1 (BWS NT-1).
3.3 Needs and Fulfilment of Clean Water after the Earthquake
The survey results show the decreased amount of individual clean water demand in North
Lombok District after the earthquake. Table 4 shows the number of individual clean water demand in
North Lombok Regency before and after the earthquake. The reduction of clean water demand after
the earthquake was 19.03% (32.81 lt/person/day) from the total demand before the earthquake.
Table 4. Average amount of clean water demand.
No Type of Activity
Amount of Clean Water Demand
Before the
earthquake
After the
earthquake Difference
(lt/p/d) (lt/p/d) (lt/p/d) (%)
a B C D e=d-c h=e/c*100
1
Drinking and cooking
9.70
9.05
-0.65
-6.70
2 Bathing 72.23 57.86 -14.36 -19.89
3 Washing clothes 22.77 18.86 -3.91 -17.19
4
Washing dishes
8.85
7.92
-0.94
-10.60
5
Sanitation
45.68
38.27
-7.41
-16.22
6 Others (watering, drinking
supply for livestock, etc.) 13.17 7.64 -5.53 -42.01
Total 172.40 139.59 -32.81 -19.03
Note:
*lt/p/d = litre/person/day
The minus sign (-) in the table shows a reduction of clean water demand. The maximum
reduction of water demand was for other activities which include watering, drinking supply for
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
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doi:10.1088/1755-1315/426/1/012001
7
livestock, washing vehicles, i.e. 42.01% (5.53 lt/p/d) from the original needs before the earthquake.
On the other hand, the minimum reduction is happened for drinking and cooking, which equals to
6.70% (0.65 lt/p/d). The reduction of clean water demand after the earthquake was caused by a large
number of clean water facilities that was damaged due to the earthquake, hence local residents found it
difficult to get clean water.
There is a difference in clean water demand between PDAM customers and Non-PDAM
customers. Table 5 shows a comparison of clean water needs between PDAM customers and Non-
PDAM customers before and after the earthquake.
Table 5. Average number of clean water demand of PDAM and non-PDAM customers.
No Type of
activity
Use of Water by PDAM Customers Use of Water by non-PDAM Customers
Before the
earthquake
After the
earthquake Difference Before the
earthquake
After the
earthquake Difference
(lt/p/d)
(lt/p/d)
(lt/p/d)
(%)
(lt/p/d)
(lt/p/d)
(lt/p/d)
(%)
a
B
C
d
e=d-c
f=e/c
G
h
i=h-g
j=i/g
1 Drinking and
cooking 10.88 9.90 -0.97 -8.96 7.55 7.49 -0.06 -0.76
2 Bathing 70.49 53.45
-17.04
-24.18
75.38 65.90
-9.49
-12.59
3 Washing
clothes 23.51 19.09 -4.42 -18.81 21.42 18.43 -2.99 -13.95
4 Washing
dishes 9.32 8.31 -1.01 -10.80 8.01 7.20 -0.81 -10.16
5 Sanitation 46.48 38.24
-8.24
-17.73
44.23 38.33
-5.90
-13.33
6
Others
(watering,
drinking
supply for
livestock, etc.)
10.71 4.44 -6.28 -58.59 17.64 13.46 -4.18 -23.68
Total 171.39 133.43 -37.96 -22.15 174.23 150.81 -23.42 -13.44
Table 5 shows that the amount of clean water demand for PDAM customers after the earthquake
decreased by an average of 22.15% (37.96 lt/p/d) from the total demand before the earthquake. As for
non-PDAM customers, there was a decrease of 13.44% (23.56 lt/p/d) from the total clean water
demand before the earthquake. Overall, based on the type of activities related to water requirement
shown in Table 5, the maximum decrease of water requirement was from PDAM customers because
after the earthquake, most vital pipes of PDAM system was damaged which caused ineffective clean
water distribution. Therefore, to meet the daily needs of clean water, customers should search for other
sources of clean water. After the earthquake, PDAM customers carefully use the clean water until the
PDAM water system become functional. On the other hand, the water demands of non-PDAM
customers only slightly reduced, as the clean water sources, such as wells, were mostly still available.
4. Analysis and Discussion
Based on the analysis of the data obtained by questionnaire, the earthquake impact on the
demands of clean water in North Lombok Regency was very significant. As a result of the earthquake,
most of the damage of the clean water facilities in North Lombok Regency caused difficulties of
people to get clean water. Table 6 shows the damage of clean water facilities due to an earthquake
which occurred in several regions. Types of damage due to the earthquake are grouped into 9 groups.
Group (1) Damaged pipe, group (2) Separated pipe connection, group (3) Malfunction of Intake, group
(4) Damaged house connection (SR), group (5) Buried pipe because of landslide, group (6)
Underground tank water rises to the surface, group (7) Clean water sources discharge
shrinks/disappears, group (8) Damage of pump houses, and group (9) Decreased of the quality and
quantity of clean water in wells.
The 3rd International Conference on Eco Engineering Development
IOP Conf. Series: Earth and Environmental Science 426 (2020) 012001
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doi:10.1088/1755-1315/426/1/012001
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Table 6. The damage to clean water facilities due to earthquakes in several regions.
No Location Year Magnitude
(Mw)
Type of Damage for clean water facilities
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
1
Yogyakarta
2006
6.3
√
2 Japan (Sendai) 2011 9.0 √ √ √ √
3 Japan (Kumamoto) 2016 6.4 and 7.0 √ √ √ √ √
4 Palu 2018 7.4 √
√ √
5
Lombok
2018
6.4 and 69
√
√
√
√
√
√
√
√
Table 6 shows that in general, the impact of earthquakes on the clean water facilities in North
Lombok District were similar to those in other places. The main factors of destruction are due to soil
movement and slope stability. In damage group (9), most type of damages to clean water facilities
occurred in North Lombok Regency. The damage to clean water piping system in North Lombok
Regency was mostly caused by landslides or material, such as the damage groups (1), (2), (3), and (5).
The damage that was caused by liquefaction (group damage 6) that was occurred in Japan was not
found in this study.
The process of fulfilling clean water demand, especially in Indonesia, were mostly conducted by
distributing the water with water tankers. The sources were from wells, artesian drill wells, and the
nearest river flow. However, this distribution method was ineffective because the number of water
tankers was not sufficient to serve the community. According to [18], in Selengen Village, since the
population was large in comparison with the water tankers availability, the residents had to queue to
get clean water. In addition, people also had to find other clean water sources which were quite far, if
the water tankers were not available in their location.
Figure 9. The residents of Selengen Village were queuing for clean water
(Source: Viva [18])
Since Indonesia's geographical location is between three tectonic plates (Indo-Australia,
Eurasia, and the Pacific plate), the earthquake disaster may happen again at any time. During the
earthquake disaster that happened in North Lombok Regency, the number of affected people was less
than the total number of people in the whole Lombok Island. It means that, it is possible that another
earthquake may affect even more people Lombok Island. More detail information about the population
of Lombok Island is shown in Table 7.
Table 7. Population, PDAM customers, the volume of water distribution, and clean water
infrastructure based on districts/cities in Lombok Island
No Regency / City Population PDAM
customers
Volume of
water
distribution
Water
Springs
Drill Well
BWS NT-1
Dam
(people)
(SR)
(m
3
)
(point)
(point)
(point)
1 West Lombok 675.222 52.836 10,198,584 41 6 3
2 Central Lombok 930.797 51.592 11,471,310 101 25 14
3 East Lombok 1.183.204 23.816 508,931,000 242 251 14
4 North Lombok 216.515 11.909 2,632,688 50 149 1
5 Mataram 468.509 74.090 17.407.772 - - -
Total 3.474.247 214.243 550.641.354 434 431 32
(Source: [3] and [5])
The 3rd International Conference on Eco Engineering Development
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doi:10.1088/1755-1315/426/1/012001
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Table 7 shows that the population mostly resides in East Lombok Regency, which is equal to
34.06% of the total population in Lombok Island, while the population in North Lombok Regency is
only 6.23% of the total population in Lombok Island. In East Lombok Regency, there are a lot of
infrastructure facilities of clean water that can be used to serve the need of clean water demand after
an earthquake. On the other hand, the population and customers of PDAM in Mataram City at West
Lombok are quite large, but the source of clean water from rivers, small reservoir is not sufficient. The
rivers that flow in the area are the downstream part of the rivers originated from West Lombok
Regency. The river water has been polluted mainly because of households waste from around the river
flow. This condition requires a form of mitigation plan to fulfil the clean water demand when the
facilities cannot function well.
Many countries that are prone to earthquake tried to mitigate the risk of earthquake disaster,
including Japan and Taiwan. Hu, N [7] stated that the same efforts must be taken in Taiwan to reduce
the impact of clean water facilities damage due to earthquakes by improving water supply plans in
highland areas, developing smart water system, conducting seismic and geological hazard surveys
throughout the system, replacing old pipes to maintain its work, capacity building and institutional
strengthening to reduce water loss, and improving training for management during emergencies
situation.
In Japan, in order to overcome water scarcity in Tokyo, earthquake resistant buildings are
promoted for water purification and clean water storage building, promoting earthquake resistant pipe
joints, establishing water supply system for emergency condition for example by providing temporary
hydrants, conducting promotion and training for local communities, and cooperating with other cities
and organizations [12].
5. Mitigation Plan
A mitigation plan for sustaining clean water distribution in Lombok Island may be conducted by
for example providing more drill wells in several strategic places. This is because drill wells have
proved to be effective in providing required clean water after the earthquake disaster as explained
above. There are two Groundwater Basins (CAT) in Lombok Island. Tanjung-Sambalia, with an area
of 1.124 km
2
with a potential groundwater about 224 million m
3
/year and a depressed groundwater at
22 million m
3
/year. The other groundwater basin is Mataram-Selong with an area of 2.366 km
2
. The
potential groundwater is 662 million m
3
/year and the potential of depressed groundwater is 8 million
m
3
/year [14]. These potent of ground water should be more than enough in term of volume to cater the
need of the population. As for the areas in the highlands, the water may be served by water tankers.
The proposed mitigation of increasing the number of wells should be studied with regard to water
quality and the best locations with regard to optimization of water distribution. Therefore, it is
necessary to do further research to implement this proposed mitigation efforts.
Another mitigation plan can be conducted by strengthening the pipe network infrastructure and
reducing the risk of pipe damage impact. The pipe network should be studied carefully to define the
hydraulics index of each important pipe along the network. When the hydraulics index of a pipe (pipe
A) is higher than certain number (for example 25%) an alternative pipe should be installed. The
alternative pipe should be able to replace whenever pipe A is broken.
Learning from the fact that people were queuing for water, it is also important to prepared more
truck for transporting water. In area, where the number of people is not so many, truck is not efficient.
Therefore, light vehicle (motor tricycle) is a good alternative. These facilities should be prepared and
ready whenever required.
6. Conclusion
The study conclude as follows:
a. Clean water supply with a piping network system has a greater risk of damage due to the
earthquake,
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b. The earthquake caused a decrease in the amount of clean water demand.
c. After the earthquake, people use more wells (shallow and deep) to meet their daily clean water
demands. Therefore, the existence of shallow wells is needed to fulfill the needs of clean water,
d. The bore wells have contributed significantly to provide clean water after an earthquake. According
to the survey, 57.27% of respondents used wells after the earthquake, where the number of wells
users is only 22.73% before the earthquake from the total respondents.
References
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