A Review on Lightweight Mobile Flood Wall Barrier: Way Forward for Malaysia

Abstract

Flooding remains a persistent and ongoing challenge in Malaysia, posing continuous difficulties and hardships; therefore, combating flood risk has become a main priority for sustainable development in this country. The application of sophisticated engineering in hard structure approaches and flood control systems are often incongruous to the public. Therefore, there is a need to integrate soft engineering approaches and best practices of flood management to mitigate flood risk. There is also a need to integrate the concept of sustainable development into its planning policies towards flood hazard reduction. Mobile flood protection measures are useful as an alternative solution in flood protection and mitigation purposes. Mobile protective systems serve as a temporary solution to enhance the height of permanent flood defence structures during extreme events. They can also be deployed as emergency measures to mitigate flooding in vulnerable low-lying regions. As the available mobile systems differ in the type of material, method of installation and available protection height, a description of their features, and potential application are examined including their respective opportunities and drawbacks. This paper presents a review on different types of lightweight mobile flood wall barrier (MFWB) that were implemented to cope with floods in Malaysia with examples of application in other countries such as United Kingdom, Slovakia, and Netherlands. The MFWB products are reviewed and compared to each other according to the types, characteristics, mechanisms, drawbacks, and how these measures are integrated into spatial planning. Based on the findings, several recommendations are provided regarding enhancing flood risk management in areas prone to flooding and the way forward for Malaysia.

Full text

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023)
22
WOON YANG TAN, XIN YI CHONG, CHA YAO TAN, CHOW HOCK LIM, FANG YENN TEO
ABSTRACT
Flooding remains a persistent and ongoing challenge in Malaysia, posing continuous difculties and hardships; therefore,
combating ood risk has become a main priority for sustainable development in this country. The application of sophisticated
engineering in hard structure approaches and ood control systems are often incongruous to the public. Therefore, there is
a need to integrate soft engineering approaches and best practices of ood management to mitigate ood risk. There is also
a need to integrate the concept of sustainable development into its planning policies towards ood hazard reduction. Mobile
ood protection measures are useful as an alternative solution in ood protection and mitigation purposes. Mobile protective
systems serve as a temporary solution to enhance the height of permanent ood defence structures during extreme events. They
can also be deployed as emergency measures to mitigate ooding in vulnerable low-lying regions. As the available mobile
systems differ in the type of material, method of installation and available protection height, a description of their features,
and potential application are examined including their respective opportunities and drawbacks. This paper presents a review
on different types of lightweight mobile ood wall barrier (MFWB) that were implemented to cope with oods in Malaysia
with examples of application in other countries such as United Kingdom, Slovakia, and Netherlands. The MFWB products are
reviewed and compared to each other according to the types, characteristics, mechanisms, drawbacks, and how these measures
are integrated into spatial planning. Based on the ndings, several recommendations are provided regarding enhancing ood
risk management in areas prone to ooding and the way forward for Malaysia.
Keywords: Flood Protection System, Lightweight, Malaysia, Mobile Flood Wall Barrier
1.0 INTRODUCTION
Severe and increasing number of ood events continue to
imperil communities globally (Munich, 2017; Shah et al., 2020;
Rentschler et al., 2023; Rezvani et al., 2023). In Malaysia, this
remains a persisting issue, exemplied by signicant historical
incidents such as the devastating oods in Kuala Lumpur
in 1971, which resulted in tragic loss of life and inicted
widespread damages, serving as poignant reminders of the
vulnerability of the region to such natural calamities (Shaari
et al., 2016; Rosmadi et al., 2023). Moreover, recent ood
events have further underscored this vulnerability. These recent
occurrences highlight the persistent threat posed by ooding
in Malaysia and the urgent need for effective mitigation and
preparedness measures to mitigate its impact on communities
and infrastructure. Recent ood occurrences, such as those in
Selangor in December 2021, are estimated to have potential
damages surpassing RM 20 billion (Aiman, 2021). It arose
due to irregular rainfall patterns and sudden heavy downpours
in a conned area. The rapid urbanisation in the Klang Valley
oodplain, intensied the ood damages by obstructing the
natural drainage system. Additionally, in March 2023, at least
16 locations in Johor, Malaysia experienced rivers surpassing
the danger mark, leading to the evacuation of thousands due
to nearly 630 mm of rain in under 48 hours, aggravating the
ood scenario (Davies, 2023). According to the United States
Department of Agriculture (USDA; 2015), the gravity of this
ood risk in Malaysia was vividly demonstrated in 2014 when
an event led to the loss of 21 lives and caused economic damages
estimated to exceed USD$500 million.
Combating ood risk has become a recognised prerequisite
and national priority for sustainable development in Malaysia
(Caddis et al., 2012). With the acceleration of urban growth, the
population, level of prosperity and urban area have all escalated
signicantly. In turn, the economic assets, the number of people,
and properties that are at risk of ooding, have also increased
and these trends are likely to continue. As a result, the likelihood
of ooding in Kuala Lumpur and similar coastal cities have risen
due to factors such as the elevation in relative sea levels and the
effects of climate change. This is compounded by the expansion
of impermeable surfaces and deciencies in the drainage
infrastructure (Tang et al., 2018; Cheah et al., 2019).
In the beginning of the 1990s, the Department of Irrigation
and Drainage (DID) has embraced the Integrated River Basin
Management and the Integrated Flood Management strategies in
its ood control initiatives. These approaches aim to achieve a
harmonious blend of structural and non-structural measures while
fostering greater public involvement (DID, 2009). A novel ood
management solution introduced by the Malaysian government
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
(Date received: 23.11.2023/Date accepted: 17.01.2024)
Woon Yang Tan1*, Xin Yi Chong2, Cha Yao Tan3, Chow Hock Lim4, Fang Yenn Teo5*
1Humid Tropics Centre Kuala Lumpur, Department of Irrigation and Drainage, 50480 Kuala Lumpur, Malaysia
2,3,4,5Faculty of Science and Engineering, University of Nottingham Malaysia, 43500 Semenyih, Selangor, Malaysia
*Corresponding author: fangyenn.teo@nottingham.edu.my

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023) 23
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
is the Mobile Flood Wall Barrier (MFWB). The MFWB is an
articial vertical barrier engineered to temporarily restrain the
rising waters of a river or waterway during seasonal or extreme
weather events (Kádár, 2015). The MFWB is a ood protection
system designed to protect a region from ood risks. It stands
apart from permanent ood protection systems like dikes due to
its mobility and swift installation capabilities, making it suitable
for congested or high-trafc areas. It can serve as an emergency
solution for areas with limited ood protection. MFWB can be
categorised into two types: heavy-duty and lightweight products;
and it can be designed in two ways-either as a partially pre-
installed stationary mobile system or a fully mobile system
(Koppe and Brinkmann, 2010).
The heavy-duty MFWB products have found extensive
application in numerous developed nations, mainly for ood
protection and enhancing resilience in the face of natural
disasters. However, the utilisation of lightweight MFWB is
still uncommon and has yet to be recognised as a prevalent
preventive measure against ooding in Malaysia, distinguishing
it from the practices adopted in numerous European countries
(Liem and Köngeter, 1999). Indeed, the diverse geographic
locations across different continents signicantly impact the
design and implementation of ood barriers. These variations
in geography, including topography, climate patterns, and
hydrological characteristics, necessitate the adaptation of ood
barriers to suit local conditions (Gralepois et al., 2016). For
instance, in European countries, where some lightweight mobile
ood wall barriers have been implemented, considerations might
prioritise densely populated urban areas, historical sites, and
intricate river networks (Ciampa et al., 2021). In regions prone
to heavy rainfall or rapid snowmelt, ood barriers might need
to accommodate high-water volumes and fast-owing currents
(Wiskow and van der Ploeg, 2003). Conversely, in areas with
lower annual precipitation or smaller water bodies, ood barriers
could focus more on rapid deployment and ease of installation.
Therefore, this review bears signicant importance as it aims
to shed light on the advantages, potential, and feasibility of
implementing lightweight mobile oodwall barriers in Malaysia,
offering insights into a novel approach that could revolutionise
ood mitigation strategies and contribute to the nation's resilience
against inundation risks.
The aim of this paper is to elucidate the practicality of
lightweight MFWB during ooding in Malaysia. This paper
includes the literature review relating to the lightweight MFWB
from different countries and provides the information on the
products that are feasible to be applied in the context of Malaysia.
This paper also focuses on the review according to the type,
characteristics, mechanism, drawbacks, and how these measures
are integrated into spatial planning. Several recommendations
are provided on how to improve the ood risk management in
ood-prone areas and the way forward for Malaysia.
2.0 LIGHTWEIGHT MOBILE FLOOD WALL
BARRIER (MFWB)
Generally, lightweight MFWB can be classied into two sub-
categories namely partly pre-installed stationary mobile systems
and completely mobile systems, as shown in Figure 1. These two
systems are further described in the following sections. Examples
of these commercial products can be found in the next section.
2.1 Partly Pre-Installed Stationary Mobile
System
Usually, a partly pre-installed stationary mobile system is outtted
with concrete foundations and mechanical systems designed to
transition the mobile component of the system from its inactive
state to the protective position. Some have pre-installed load
transfer points. These systems typically involve substantial
investment costs. An example of a lightweight MFWB product
is the partly mobile ap systems which comprises reinforced
plastic liners or plates that are secured along a pre-installed
foundation line and interconnected using either zip fasteners or
sealing tapes (e.g. AquaFence Inc., 2021). Table 1 summarises
the material, characteristics, mechanism, height, and drawbacks
of the partly pre-installed stationary mobile system.
2.2 Completely Mobile System
Completely mobile systems are commonly applied as emergency
system without prior planning (Koppe and Brinkmann, 2010;
Chen et al., 2018). There are several types of lightweight
completely mobile system, i.e. container, mobile aps, plates,
trestle and dam systems. The following sections (Sections 2.2
and 2.3) describe the details of these four types of system.
Flexible tubes and basins are classied under the category of
container system. Flexible tubes can be lled with sand or water
(e.g. Beaver® System, NOAQ tube walls). Challenges might
arise when trying to secure water-lled tubes, especially under
dynamic loads like wave forces where cylindrical components
could potentially shift and alter their position unpredictably.
This can be solved by, for instance, using one cylindrical outer
tube and two cylindrical inner tubes. The resistance between two
inner tubes together with the inner and the outer tubes minimise
the motion of the construction (Massolle et al., 2018).
Alternative solutions include using special shape forming
by incorporating inner reinforcements or joining two cylindrical
tubes together (Koppe and Brinkmann, 2010). The NOAQ tube
wall comprises tube-shape segments inated using an air pump
and organised in a chain-like conguration, along with a skirt
that remains secured by oodwater. The tube wall has been
recognised as the best solution and it’s implemented worldwide
(Chandra Mouli et al., 2018). Their design allows for relatively
quick deployment compared to many other ood barrier systems
available. While some logistics, manpower, and time are
required, the NOAQ walls offer a balance between speed and
efcacy in emergencies. Their classication as one of the best
solutions also stems from their adaptability and versatility. These
walls are designed to be modular and scalable, enabling them
Figure 1: Classification of the lightweight MFWB based on the systemisation
(Koppe and Brinkmann, 2010)

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023)
24
WOON YANG TAN, XIN YI CHONG, CHA YAO TAN, CHOW HOCK LIM, FANG YENN TEO
to t various terrains and ood scenarios. Their ability to offer
a reasonably quick response during emergencies, coupled with
their capacity to cover larger areas, makes them highly regarded.
Moreover, NOAQ walls are often constructed from lightweight
and portable materials, facilitating easier transportation and
setup in different locations (Kim et al., 2004). Basin systems
can also be lled with solid matters or water (e.g. Box Barrier).
Nevertheless, when early warning times are brief, the use of
sand or other solid materials for lling is less probable due to the
transportation time needed.
The mobile ap systems are mainly applied to dam frontal
ow of waters. To date, such systems are commonly applied
in United Kingdom to safeguard properties against ash oods
(Rapidam, 2010). Between the actual rise of oodwater levels and
the installation of the system, the system lies at on the ground,
allowing open access to the protected areas (Koppe and Brinkmann,
2010). An example of mobile ap system is the Rapidam product.
The trestle and dam systems are mobile means of ood
prevention in which any preparative structural work is not
required. This adaptable system is adequate for a notably diverse
array of settings. Its unique trait is that it harnesses the force
of water acting upon it to naturally create a restraining (i.e.
frictional) force, thereby providing stability to the structure.
The IBS® K- type product is an example of this system (IBS
Technics GMBH, 2021)
Plate systems have the potential for utilisation as emergency
systems (e.g. ood barrier shield). A similar product type is the
Box Wall/ NOAQ Flood Barrier. These ood barriers are self-
supporting, using the ood water's weight to stay in position.
Both consist of easily transportable block sections and can be
assembled by an individual (Koppe and Brinkmann, 2010).
Table 1 summarises the material, characteristics, mechanism,
height, and drawbacks of the various types of completely mobile
systems mentioned above.
2.3 Available Lightweight MFWB Commercial
Products
There are many lightweight MFWB commercial products that
are commonly used for ood protection. Table 2 shows examples
of lightweight MFWB commercial product including their
advantages and mechanisms.
Box Wall is an independent, quickly deployable temporary
ood barrier engineered for swift reaction to ood hazards in
urban settings, appropriate for use on level and solid surfaces, for
instance, asphalt, sidewalks, and concrete. Although the weight
of each box section is light, the Box Wall stands rm without
any external fastening, even when damming water reaches its
full height. The Box Wall ood barrier is secured by the weight
of the ood water itself. Figure 2 shows the Box Wall in pre-
assembled state.
Table 1: Partly pre-installed stationary and completely mobile system (Koppe and Brinkmann, 2010)
Types Materials/
Characteristics Mechanism Height
(m) Drawback(s)
Partly Mobile Flap
Systems
(Pre-installed
Stationary)
Reinforced plastic
liners or plates.
Raised manually with spacer or
automatically by water.
0.5 to 2
meters
The preinstalled foundation
may be an obstacle to daily
activities, and it requires
proper maintenance to avoid
malfunction.
Flexible Tubes
(Completely Mobile)
Reinforced plastic
liner length ranging
from 5 to 6 meters.
It needs to be lled with air for
structure alignment. No need for
supplementary anchoring. The
stability of the structure is depending
solely on their weight.
2 meters The lling material has the
same density as the load
source. Buoyancy becomes a
challenge when copping with
signicant storage heights
that could lead to the risk of
abrupt failure.
Basins
(Completely Mobile)
A frame construction
that uses a xed
plastic material or
tted textile.
Filling with water enables a fast
installation.
Varies Water lling with a low
density.
Mobile Flaps
(Completely Mobile)
Solid plastic sheets
or exible plastic
material could be 100
meters long.
The ap is orientated to open towards
the water, permitting the structure to
be naturally lled with water.
0.5 to
0.7
meters
Cannot protect against ood
that is higher than 0.7 meters.
Trestle and Dam
(Completely Mobile)
Consists of wall
units, load elements,
supporting elements,
and plastic liner.
The wall units are installed upon the
supporting elements and secured using
a plastic liner, which is anchored by
sandbags along the waterside base.
Often, ground anchors are deployed to
ensure they do not slide or shift.
up to 1.3
meters
Often ground anchors are
required to impede from
sliding.
Plate
(Completely Mobile)
Basic components
can be obtained from
construction stock
grounds.
Casings are orientated in an upright
position and anchored by hammering
reinforcing steel into the ground.
Varies Constructions lacking
permanent installations
provide low protection
heights.

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023) 25
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
The Box Wall is especially benecial during ash oods,
this system efciently manages fast moving water, redirecting
it from vulnerable entry points. The Box Wall sections adhere
to the asphalt and efciently divert water. It can be constructed
by interlocking as many box sections as required. After a ood,
dismantling the Box Wall is straightforward, and cleaning can
be achieved using a garden hose. These box sections can be
piled up, requiring minimal storage space, and allowing them
to be easily transported (Humid Tropics Cenre, Kuala Lumpur
(HTC KL) and National Water Research Institute of Malaysia
(NAHRIM), 2020).
Similar to the Box Wall, the NOAQ ood ghting system
consists of two separate barriers that provide swift protection
with minimal manpower demands. This self-supporting ood
barrier utilises the water's weight to sustain its position. It
includes lightweight, conveniently transportable block sections
and can be assembled by a single individual. The NOAQ tube
wall is made of tube-shaped sections lled using an air pump and
arranged in a chain-like formation, together with a skirt anchored
by oodwater. The tube wall variant is notably effective and is
implemented worldwide (Chandra Mouli et al., 2018).
Aquafence ood protection system consists of fences
composed of a number of inter-linked, foldable elements and is
already proven to work. It is built for simple and fast handling,
installation and dismantling of its respective elements. The two
lengths of boarding are locked together by a system of bracket
to strengthen its which is shown in Figure 3. The fences are also
formed in such a way that the forces of the water will strengthen
it rather than weakening it.
Box Barrier is a product from Bataafsche Aanneming
Maatschappij (BAM) Infraconsult Besloten Vennootschap (BV),
Netherlands. It adapts the concept of sandbag, but instead of
using sand which is heavier and needs to be transported from
another place, the Box Barrier uses water itself as their strength
and this requires less manpower and time needed for the setup
of the ood wall. After the placement of the Box Barrier on the
frontline, water needs to be pumped into the box through the
hole on top so the weight of the water would anchor the box to
the ground. Figure 4 shows how box barrier is installed when
ood occurs.
Flood Barrier Shield is a product from Zero International
from Indianapolis, United States of America (USA). Flood
Barrier Shield is used on doors and windows on any premises to
safe keep it from the oods (Figure 5). This barrier is assembled
by slotting in an aluminium panel to a mount and sealed with
rubber seal on the sides and bottom of the aluminium panel. The
aluminium panel is made up of marine grade steel to prevent
corrosion or rusting from occurring. The panels are removable
when they are not needed and can be stored in a secure place
for future use. The sizes are available from 10 inches up until 36
inches of height. Flood Barrier Shield conforms to the regulations
established by the Federal Emergency Management Agency
(FEMA) and Federal Insurance Administration (FIA) for the
application of ood-resistant doors in ood-prone regions. Apart
from the rubber neoprene seal, the aluminium panels are also
secured by locks on both end sides.
Rapidam is a ood protection method that can be deployed
quickly. It is constructed from a customised PVC fabric and
can be efciently rolled up by just two or three individuals. The
freestanding models consist of individual 10-meter sections that
can be effortlessly expanded by connecting them, facilitating the
setup of a 20-meter section in approximately 15 minutes. (Figure
6). The height of this setup can differ between 18 to 180 cm.
Figure 2: Pre-assembled Box Wall/BW 50 Mobile Flood Barrier
(Flood Defense Group, 2021)
Figure 3: The Aquafence Mobile Flood Wall Barrier (AquaFence Inc., 2021)
Figure 4: The Box Barrier Mobile Flood Wall Barrier (Box Barrier, 2021)
Figure 5: The Flood Barrier Shield (Absupply.net, 2021)

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023)
26
WOON YANG TAN, XIN YI CHONG, CHA YAO TAN, CHOW HOCK LIM, FANG YENN TEO
Following the raising of the upper barrier section, the weeding
edge is solidly secured using specialised screw anchors. When
oodwater hits, the weight of the water sustains the barrier
in position. In the case of the Rapidam version, it needs to be
attached to a concrete beam with stainless steel bolts. These bolts
are pre-installed in the concrete, then removed and reattached
when rolling up the Rapidam. This system can effectively retain
a ton of water per meter (Chandra Mouli et al., 2018).
The Beaver® Storm and Flood Protection System comprises
of two polyvinyl chloride (PVC) tubes placed adjacent
permanently, connected to create a twin element (Figure 7).
The components of the ood barrier are rst inated, easily
repositioned into the preferred location, and then lled with water
from a neighbouring water source or hydrant. These individual
elements are joined together through a patented linking system,
allowing the construction of ood barriers of varying lengths
Figure 6: The Rapidam Mobile Flood Wall Barrier (Chandra Mouli et al., 2018)
Figure 7: The Beaver® Storm and Flood Protection System Mobile Flood
Wall Barrier (Beaver® Protection Systems, 2019)
Table 2: Examples of lightweight MFWB product
Lightweight
MFWB Advantages Mechanisms
Box Wall/ NOAQ
Flood Barrier
(BW 50) (Flood
Defense Group,
2021)
• Friction and water pressure ensure barrier is stable
• Can be used in curves and corners
• Little storage space, faster defense, less manpower
• Anchored by the weight of the water
• Built by slotting together any number of box sections
• Stick with the asphalt and divert the water
Aquafence
(AquaFence Inc,
2021)
• Simple and fast handling, installation, and
dismantling
• Little storage space
• Cheap, can cover a wide area
• Locked together by a system of bracket
• Water force strengthens the structure
Box Barrier
(Box Barrier,
2021)
• Require less manpower and time to setup
• Robust, exible, stackable
• Can be worked out in any length and in any
direction
• Can form various shapes
• Water force strengthens the structure
• Water needs to be pumped through the hole on top
so the weight of the water would anchor the box to
the ground.
• Can automatically ll with rising ood water
Flood Barrier
Shield (Absupply.
net, 2021)
• Panels are removable and can be reused
• User friendly, fast deploy
• Uses rubber neoprene sealant for water tightness
• Used on doors and windows
• Acts by slotting in aluminum panel to a mount and
sealed with rubber seal on sides and bottom of the
aluminum panel
Rapidam (Chandra
Mouli et al., 2018)
• Time savvy • Barrier is secured by the weight of water
• Axed to the base using stainless steel bolts
that requires setup of a concrete beam. Initially
installed into the concrete, the bolts are
subsequently detached and reconnected when
rolling up the Rapidam.
Beaver ® System
(Beaver®
Protection
Systems, 2019)
• Rapid installation, versatile
• Can be dismantled quickly
• Take minimal storage
• The tube can be inated for setting up position,
then water from nearby source can be pumped in
to stabilise the tube.
• Multiple tube can be attached together with sleeve
system.
IBS® K-System
(IBS Engineered
Products Ltd.,
2019)
• Rapid and easy installation
• Lightweight aluminum construction
• Minimum manpower needed
• Location independent
• No discarding of any parts after use
• Limited training required for operators
• Trestle which is the main support system that
installed vertically with some angle.
• Ground seals placed on the ground before dam beam.
• Dam beam is slotted in between trestles.
• Pressing tool is used to press down the dam beams
for creating water seal.

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023) 27
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
that can adapt to distinct types of terrain (Beaver® Protection
Systems, 2019).
The IBS Engineered Products Ltd Katastrophe (IBS®
K-) requires no permanent installations for establishing on
tarmac, even up to a ood height of 1.3 meters. This versatility
permits it to be easily set up in different locations based on
ood conditions. (Figure 8). According to IBS Engineered
Products Ltd. (2019), in principle, this system consists of only
4 components ensuring that installation is quick and easy:
K-trestles, dam beams, pressing tools and the special ground
seal. The K-system functions through utilising the force exerted
by oodwater, generating a downward force on the beams to
ensure the stability and ood protection competencies of the
barrier (IBS Engineered Products Ltd, 2019).
3.0 LIGHTWEIGHT MFWB CASE STUDIES
Four case studies have been extracted from the literature to
compare the types of lightweight MFWB used in Malaysia
and other western countries (i.e. Netherlands, Slovakia, United
Kingdom).
3.1 Malaysia
Studies were carried out in a few areas in Malaysia to develop
MFWBs that are suitable for ood protection of individual
residences and government premises such as health clinics,
police stations and schools (HTC KL & NAHRIM, 2020).
MFWBs for individual residences were built in a smaller scale
compared to a MFWB for government premises, where these
government premises such as schools can also act as temporary
retention camps for the ood victims. Table 3 lists the three types
of ood wall barrier developed by HTC KL & NAHRIM (2020).
Figure 9 shows the technical drawings for all 3 products.
MFWB NADI 1
MFWB NADI 1 is specially designed to block water from entering buildings
through opening space at doors. The design comprises a strong and rigid
stainless-steel frame shaped like a wall, with a turning lever that enables it to
expand accordingly to different door sizes. Neoprene rubber is wrapped to the
frame used to ensure that the barrier stays watertight, and stainless-steel frames
ensure that the structure does not corrode and maintains durability and reliability.
It can hold excess water up to a meter high for ash ood protection and is able
to withstand and bear water pressure without leakage attributed to its handle and
knob locking system. It is easy to assemble and dismantle, and it is lightweight
and easy to store during non-ooding season, making it very user-friendly (HTC
KL & NAHRIM, 2020).
MFWB NADI 2
MFWB NADI 2 is designed mainly to block water from coming into the wall-
fenced area through the opened gates. MFWB NADI 2 comprises of steel frame
shaped like a gate, several steel poles and toggle clamps for ensuring watertight
purpose. Other than steel frames used for structural rigidity, EPDM Sponge
Rubber is also used to ensure MFWB NADI 2 is watertight, preventing water
from coming to the other side of the wall. Stainless steel frames are used to
ensure that the structure does not corrode, whilst maintaining its durability and
reliability. Its function is to hold excess water for ash ood protection up to
1-meter high. It is able to withstand and bear water pressure without leakage
using special clamps locking system. Awing to its slim and light design, MFWB
NADI 2 is easy to carry and store during non-ooding season (HTC KL &
NAHRIM, 2020).
MFWB NADI 3
MFWB NADI 3 serves as a quick and simple barrier system, and it could
provide oodwater protection of up to 1-meter-high for individual residence. It
is able to withstand and bear water pressure without leakage using toggle clamp
locking system. MFWB NADI 3 comprises of steel wall shaped frame and toggle
clamps to ensure watertight purpose accordingly to the door size (HTC KL
& NAHRIM, 2020).
Figure 8: The IBS® K-System Mobile Flood Wall Barrier
(IBS Engineered Products Ltd., 2019)
Table 3: Applications of various MFWB NAHRIM-DID (NADI)
types for specific targets
Type Target
MFWB NADI 1 Residential area, opening space at doors
MFWB NADI 2 Wall-fenced area, opened gates
MFWB NADI 3 Government premises
(a) MFWB NADI 1 and its application
(b) MFWB NADI 2 and its application
(c) MFWB NADI 3 and its application
Figure 9: MFWB NADI 1, 2 and 3 (HTC KL & NAHRIM, 2020)

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023)
28
WOON YANG TAN, XIN YI CHONG, CHA YAO TAN, CHOW HOCK LIM, FANG YENN TEO
3.2 Slovakia
The Danube River located in Bratislava, stretches 65 kilometers
from Bratislava to Vienna, creating particular zones of
Bratislava prone to ooding. These areas have a lengthy past of
ood vulnerability, mainly associated to storm rainfall events,
especially during the snowmelt season (Kryzanowski et al., 2013).
The principal protective measures were carried out to rectify
the gaps in the current Danube ood protection system and to
address areas in Slovakia, especially in the Bratislava region, that
deprived sufcient protection. The Danube River can encounter
incredibly high ows during extreme ood events, presenting a
substantial danger to around 490,000 individuals. These ood
mitigation measures incorporate the enhancement of existing
ood control structures and the construction of new ones on both
banks of the Danube River (Figure 10). The designated buffer
zone along the Danube River is xed at 0.5 meters above the
stipulated oodwater level. The "Bratislava - Flood protection"
initiative was implemented by the Slovakian government
(Kryzanowski et al., 2013).
3.3 Netherlands
The Pitt review, guided by Sir Michael Pitt in the consequences
following the widespread oods in England during June
and July 2007, highlights the essentiality to give adequate
safeguard for signicant infrastructure within the utility sector,
identied as "at risk." It reinforces that oods can lead to vital
indirect implications, such as harm to critical energy, water,
communication, and transportation facilities. Moreover, they can
hinder essential public services like schools and hospitals. For
example, the oods in 2007 signicantly impacted infrastructure
in Gloucestershire. Flooding at Tewkesbury's Mythe water
treatment plant deserted 140,000 residences deprived to clean
water for as many as 17 days. Furthermore, it was necessary to
close the Castle Meads electricity substation, leading to a 24-hour
power outage for 42,000 residents in Gloucester. Flooding on the
M5 motorway isolated 10,000 individuals, with many others stuck
on the railway network. Temporary ood defenses at the Walham
electricity substation were credited with safeguarding the power
supply for 500,000 people in South Wales and Gloucestershire.
Other susceptible infrastructure involves emergency service
stations and their main headquarters, which are integral to the
response efforts, as well as critical public services like hospitals,
schools, and care homes (Corrie, 2012).
The Alteau Mobile Barrier was used in the Netherlands ood
protection case study. Figure 11 shows the Alteau mobile barrier
after it is deployed. The Alteau Barrier is made from polyethylene
fabric weighing 450 g and 610 g. This barrier automatically elevates
to a maximum height of 1 meter and extends over several hundred
meters by harnessing the water’s force. It has been deliberately
crafted for rapid emergency response operations. This self-
inating, portable water barrier is sustainable and operates
without needing pre-ination or an external power source. The
setup procedure is rapid, and it can be easily repacked and reused
for different intentions by simply rinsing it down and rolling it up.
The portable barrier can be conveniently carried using
small vehicles to the intended destination and then transported
by two individuals. It comes in different height and length
congurations, with options attainable for water levels of up to
1000 mm. Multiple connections can be swiftly connected using
the Velcro fastening system. Furthermore, it can be connected to a
corner element to create a 90-degree turn, improving its exibility
for enclosing buildings (AET Flood Defence Limited, 2021).
3.4 United Kingdom
The town of Northwich has an extended duration of coping
with ooding, notably in 1946, and more recently in 2000
and 2012. These ooding events not only brought anguish to
residents and businesses but also led to substantial nancial
losses for enterprises and homes. Recognising this ongoing risk,
the Environment Agency (EA), jointly with Cheshire West and
Chester Council, formulated a ood alleviation plan with the aim
to mitigate the risk of future ooding.
The Northwich project comprises of 1.7 kilometers of ood
protection facilities, integrating a mixture of embankments
and ood walls in place along the banks of the River Weaver
and River Dane. With the aim to preserve the town's historic
appearance, the initiative has utilised outstanding materials
for the walls and incorporated cutting-edge technologies, for
instance, glass panels and oating ecosystems to minimise the
aesthetic impression of these defenses. Besides permanent ood
barriers, the plan also incorporates removable defenses and
ood gates strategically positioned along crucial roadways and
footpaths (IBS Engineered Products Ltd, 2019).
The IBS® K system was used in the UK ood protection
case study as shown in Figure 12. No preparatory structural work
is required for the "K" system (from the German "Katastrophe").
It can provide a barrier height of as much as 1.3 meters. This
versatile system is appropriate for use in a wide variety of
Figure 10: MFWB built in Bratislava, Slovakia (Kryzanowski et al., 2013)
Figure 11: The Alteau Flood Barrier (AET Flood Defence Limited, 2021)
Figure 12: The IBS® K-System (IBS Engineered Products Ltd, 2019)

Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023) 29
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
locations. Particularly, it has a distinctive feature where the force
exerted by the water spontaneously creates a frictional retention
force, thus stabilising the structure (IBS Engineered Products
Ltd, 2019).
4.0 INSIGHTS FOR ENHANCED FLOOD
MANAGEMENT STRATEGIES IN
MALAYSIA
In addressing the multifaceted challenges of ood risk
management in Malaysia, the country has traditionally relied
upon top-down, government-controlled approaches primarily
spearheaded by the Department of Irrigation and Drainage
(DID). These strategies have involved a comprehensive range
of measures, including the establishment of ood control
commissions, structural interventions such as the development
of the Stormwater Management and Road Tunnel (SMART) in
Kuala Lumpur and the ood reservoir in Batu Jinjang, and the
implementation of non-structural measures like ood forecasting
and warning systems.
However, the emergence of lightweight mobile ood walls
presents a promising addition to Malaysia's ood management
arsenal. Notably, advancements in ood protection systems,
exemplied by NAHRIM and DID's Mobile Flood Wall Barrier
(MFWB) NADI series (1, 2, and 3), signify a shift towards
more adaptable and efcient ood protection mechanisms.
Comparative studies between these mobile barriers and European
ood walls have shown the NADI systems' increased coverage,
with NADI 1 capable of defending against up to 1 meter of
oodwater, surpassing certain European equivalents. Moreover,
each iteration within the MFWB NADI series is meticulously
engineered to cater to distinct targets, encompassing varied
settings such as residential areas, fortied spaces such as
hospitals or educational institutions, and governmental premises.
This strategic design approach aims to optimize ood prevention
measures by tailoring the barriers to suit the unique requirements
and vulnerabilities of each specic location, ensuring a more
targeted and effective ood defense system.
The lightweight and versatile nature of these temporary ood
protection systems renders them particularly suitable for regions
lacking permanent ood defenses or experiencing infrequent
ooding episodes that can be forecasted. Specically designed
for swift installation during ood warnings, these barriers are
strategically placed at vulnerable points like doorways, window
openings, and garage entrances. However, challenges such as
storage requirements and deployment logistics have been noted,
as the barriers can be bulky and may require two individuals for
installation, hindering rapid deployment in adverse weather or
constrained spaces.
Despite these challenges, the temporary ood walls offer
a cost-effective and adaptable solution for mitigating oods
up to 0.9 meters in depth, making them an initial choice for
safeguarding properties. Nevertheless, a comprehensive ood
management strategy in Malaysia necessitates a balanced
integration of both structural and non-structural measures.
Effective ood management should incorporate community
participation, long-term policy planning, and the integration
of innovative solutions like lightweight mobile ood walls.
Emphasizing community involvement, improving coordination
among agencies, and enforcing standard operating procedures
are critical steps toward enhancing ood management efciency
and resilience in Malaysia.
5.0 CONCLUSION
From the case studies reported, the application of MFWB have
been commonly used in most developed countries and they are
proven to be useful and effective. A variety of lightweight MFWB
products are satisfying different security and manageability
levels for the application in Malaysia. Therefore, it is essential to
carefully analyse the site conditions and requirements in every
application. Founded on such comprehensive investigations,
lightweight MFWB systems might be the tting remedy for
both, emergency use and planned ood protection. Typically,
the following opportunities of lightweight MFWB systems can
be summarised: 1) room-saving in densely populated areas, 2)
provides benets to urban planning due to open access to water
body, and 3) mobile protective constructions that are completely
movable provide advantages as emergency systems, particularly
when compared to labour and time-intensive sandbag systems.
On the other hand, the drawbacks are: 1) they may result in
higher costs compared to permanent solutions providing an
equivalent level of safety, 2) these structures provide limited
height protection due to the lack of permanent installations,
3) susceptible to sudden failure when overloaded beyond their
capacity.
Advancing research on lightweight mobile ood walls
holds signicant promise for addressing the persistent
challenge of ooding. Future investigations should prioritise
the exploration of innovative materials and design strategies
tailored to the Malaysia’s diverse geographical landscapes
and climatic variations. Emphasising extensive eld trials and
simulations under varying ood scenarios is crucial to evaluate
their performance accurately. Moreover, assessing the socio-
economic implications of implementing these ood defences
is essential to ascertain their practicality and acceptance within
Malaysian communities. Collaborative efforts involving diverse
expertise from engineers, urban planners, policymakers, and
local communities will be pivotal in developing resilient and
adaptable lightweight mobile ood wall solutions tailored to
Malaysia's unique ood risk management needs.
Eventually, the notion of ood defence systems will have
to be grounded on current world trends (e.g. living with oods
and application of mobile ood protection measures), which are
to be introduced by acknowledging the current best practices
throughout the world. However, the actualisation of this idea is
limited by the economic capabilities of the communities inhabiting
in ood-prone regions. Therefore, it is important that Malaysia
integrate this concept in mitigating oods as we advance towards
the future of achieving oodwater resilience at the property level,
both residential properties and government premises.
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Journal – The Institution of Engineers, Malaysia (Vol. 84, No. 2, December 2023) 31
A REVIEW ON LIGHTWEIGHT MOBILE FLOOD
WALL BARRIER: WAY FORWARD FOR MALAYSIA
PROFILES
WOON YANG TAN is a registered Professional Engineer with BEM and ASEAN Chartered, specialising in water resources management with
over two decades of experience. Driven by a passion for professional development, he holds a Ph.D. from the University of Malaya, a Master's
degree in Project Management, and a Bachelor's degree in Civil Engineering from the United States. Currently serving as Deputy Director at HTC
Kuala Lumpur under auspices of UNESCO and afliated with the Department of Irrigation and Drainage, Malaysia. Dr Tan has led signicant
initiatives in integrated basin management, ood mitigation, and ecohydrology. As a full member of Sigma Xi Scientic Research Honor Society,
he actively contributes to academia with notable publications. He is also an engaged member of various engineering associations and committees,
enriching his contributions to the eld.
Email address: wyang@water.gov.my
CELINE CHONG XIN YI is an environmental scientist specialising in eco-hydrology and uvial geomorphology. She holds a Ph.D.
in Environmental and Geographical Sciences from the University of Nottingham Malaysia. Dr Chong was conducted pioneering research in
developing environmental ows for the Baleh River in Sarawak, contributing signicantly to sustainable river management. With a degree in
Environmental Science and a year of experience as a research assistant, she brings a comprehensive understanding of environmental issues. As the
inaugural member of the Hydroecology lab at the University of Nottingham Malaysia, she led innovative research initiatives. Currently serving
as a Research Associate at Verisk, she applies her expertise in catastrophe models. She is a member of the British Society for Geomorphology,
the Malaysian Water Association, and ECoEnet, demonstrating her commitment to advancing environmental science and fostering collaboration
within the eld.
Email address: cchongxinyi@gmail.com
CHA YAO TAN is a Hydraulic Engineer at the Global Water Consultant Sdn. Bhd. He holds a M.Eng. in Civil Engineering from the University of
Nottingham Malaysia. His expertise is ood study, physical hydraulic modelling, numerical hydraulic modelling, and urban stormwater management.
Email address: tanchayao.gwc@gmail.com
CHOW HOCK LIM is an Honorary Fellow of The Institution of Engineers, Malaysia (IEM), a Fellow of the Academy of Sciences Malaysia
(ASM), and a Fellow of the Construction Industry Development Board (CIDB). YBhg. Dato’ Ir. Lim is registered with the Board of Engineers
Malaysia (BEM) as a Professional Engineer with a Practising Certicate. He was the President of the Institution of Engineers, Malaysia (IEM)
from 2014 to 2016, and currently sits in the IEM Council as Past President. He is retired from public service in 2014, after serving for 36 years
with the Department of Irrigation and Drainage Malaysia (DID). Upon retirement, he was called to serve as Commissioner of SPAN from 2015
to 2019, performing the regulatory role in the water supply and sewerage industries. In addition, he was also a Technical Advisor to the Penang
Development Corporation (PDC) from 2015 to 2020. He is currently a Member of the Board of Governors of the Infrastructure University Kuala
Lumpur, an Adjunct Professor as well as a Member of the Industry Advisory Panel of the Civil Engineering Department of University Malaya, and
a Member of the Industry Advisory Panel of the Civil Engineering Department of Monash University Malaysia.
Email address: limchowhock@gmail.com
FANG YENN TEO is a Professor of Water Engineering at the University of Nottingham Malaysia, and Chair of the International Association
for Hydro-Environment Engineering and Research (IAHR), Malaysia Chapter. He obtained a PhD in Civil Engineering from Cardiff University,
UK. He is the Professional Engineer (P.Eng.) with Practising Certicate; Professional Technologist (P.Tech.); International Professional Engineer
Register (Int.PEng.); ASEAN Chartered Professional Engineer (ACPE); Fellow of the Institution of Engineers, Malaysia (FIEM); Fellow of
Higher Education Academy (FHEA, UK); Fellow of ASEAN Academy of Engineering and Technology (FAAET); and Member of the Institution
of Engineering and Technology (MIET).
Email address: fangyenn.teo@nottingham.edu.my
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K.W., and Al-Qadami, E.H.H. (2020). A Review of the Flood
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Particularly Pakistan. Sci. Afr. 10, e00651.
[33] Tang, Y., Chan, F.K.S., O’Donnell, E., Grifths, J., Lau,
L., Higgitt, D., Thorne, C., and Thorne, T. (2018). Aligning
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Management in China: Ningbo as a “Blue-Green City” in the
“Sponge City” Campaign. J. Flood Risk Manag. 11.
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