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Researchers :
Prof. Dr. Nor Azazi Zakaria <redac01@eng.usm.my>
Prof. Dr. Aminuddin Ab. Ghani <redac02@eng.usm.my>
Zorkeflee Abu Hasan <redac04@eng.usm.my>
Mohd Fazly Yusof <redac07@eng.usm.my>
Khairul Rahmah Ayub <redac03@eng.usm.my>
Leow Cheng Siang <redac21@eng.usm.my>
Chang Chun Kiat <redac10@eng.usm.my>
Project Reports
:
The project consists of five volumes as stated below:
Volume I: Executive Summary
Volume II: Introduction & Data Collection
Volume III: Hydrological & Hydraulic
Analyses
Volume IV: Water Quality Assessment
Volume V: Stormwater Master Plan
Executive Summary
:
The Stormwater Management and Drainage Master Plan Study
for the Town of Tanah Merah, Kelantan, is a master plan study initiated
by the Department of Irrigation and Drainage (DID) Malaysia. The master
plan aims to address stormwater related issues and problems in Tanah
Merah town area. This study also covers the immediate surrounding areas
set to undergo land use transformation from agriculture to commercial
and industrial area as planned in the District’s Local Plan and State’s
Structure Plan.
The objective of the study is as follows:
-
To formulate the long term solution for the flooding,
drainage and stormwater management problems in the existing built-up
areas in order to reduce the adverse effects of flooding on people
and property and to protect the existing and proposed development by
implementation of an integrated stormwater management plan by
providing an appropriate level of flood protection to community
expectations.
-
To optimise the effectiveness of the existing
stormwater infrastructure network within the study area taking into
account environmental effects and public expectations.
-
To control the excessive sediment in watercourses to
acceptable levels through the use of wetlands, green buffer zones
and other sediment control measures.
-
To collect and convey stormwater from a catchment to
its receiving water with minimal impact by managing and improving
the quality of stormwater runoff from urbanized catchment and its
pollution loads in order to reduce the adverse effects of non-point
source contamination of the receiving water environment.
-
To optimise cost-effectiveness of new plan by
incorporating rainwater harvesting strategies where appropriate to
attenuate peak from subcatchment runoff and hence avoid the need for
costly measures to widen channel sections and replace bridges or
utilities.
-
To protect and enhance the natural water-dependent
ecosystems and enhance community access to and enjoyment of water
courses environments and to protect and maintain river environments
to a high environmental and aesthetic quality while promoting
sustainable recreational opportunities, community health, aesthetics
amenity and healthy environment.
Study Area and Problem Statement :
Tanah Merah town is
located in District of Tanah Merah with a total catchment of 64 km
square. It is the second largest town in State of Kelantan with rapid
growth of development. The town is situated on the west bank of Kelantan
River with the railway line run across the middle of the town.
Parts of the town area
especially at the north and east where vast of the areas have been
developed for the housing project was the ex-paddy field with a lowland
topography. With the lack of the proper drainage system connecting the
affected area and insufficient in density, these areas have been flooded
during the heavy rainstorm. The situation has been even worst during the
monsoon where the overflow from the Sungai Kelantan will backflow into
the lowland areas through the existing Sungai Kepat, Sungai Tualang Bah,
Sungai Maka and Sungai Alor Pechong which are lying at the side of
Bandar Tanah Merah.
Future development is
also expected increase imperviousness of the catchment. A part from
disturbing hydrology, under designed drainage will also causes flash
flood. Worse still, urbanization brings even more pollution issue to the
area, which already has poor water quality due to lack of control.
Therefore, REDAC (Through USAINS Holdings Sdn Bhd,
Corporate wing of Universiti Sains Malaysia) was appointed by DID to
produce a drainage and stormwater management master plan for the area of
town Tanah Merah to address these stormwater issues.
Condition of Sungai Maka during flooding (right)
and normal condition (left)
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Flooding at Sungai Kepat cutting off
accessibility |
Scope of Works :
In order to produce a
comprehensive drainage master plan, the team had performed a series of
research works, which include:
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Perform Data and Information
Collection
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Conduct
Topographical and
Engineering Survey Supervisions as
well as Geotechnical Investigations
-
Conduct Site Investigations and Field
Inspections
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Perform
Analyses of Existing Conditions
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Identify Stormwater Issues and Problems
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Formulate Stormwater Management Alternatives
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Compare Alternatives and Select Recommended Plan
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Development
of Stormwater Management Master Plan
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Produce
Estimated Cost
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Prepare Implementation Plan
Data Collection :
The procedure of work
was made up of 3 general phases, data collection, analyses, as well as
design and planning. The study kicked off with data collection process
to gather all relevant information and data required for analyses. Data
Collection can be divided into desk work and field works. Desk work
includes gathering of all published data including rainfall and stream
flow records, Light Detection and Ranging (LiDAR) data, land use maps,
satellite images, and soil data.
Related reports and
studies are also reviewed, including the existing municipal Local Plans,
flood reports, and as built drawings.
The study team carried
out a series of field works to complement data collection. These field
works provided additional data to those collected through desk work.
These field works includes:
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Stormwater Asset
Inventory
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Water Quality
Monitoring and Sampling
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Geotechnical
Investigation
-
Ground Water
Monitoring and
-
Engineering Survey
Supervision.
Geotechnical Investigation Work
Water Quality Monitoring and Sampling
Existing Stormwater Planning from Local Plan
Stormwater Analyses :
Stormwater analyses
were carried out to quantitatively identify the severity of stormwater
related issues in Tanah Merah. Stormwater analyses include:
An integrated
hydrological and hydraulic model was applied to perform analyses on
Tanah Merah. InfoWorks CS was used to establish the hydrological and
hydraulic model. After calibration process against the December 2007
flood, the model was used to simulate various conditions including
future catchment land use, various design storms and boundary
conditions.
The simulations confirmed that Tanah Merah is heavily
affected by water levels and flood from Sungai Kelantan. Flood water
travel up Sungai Kepat and Sungai Maka and inundate many areas (many of
which are inhabited) within the town. The existing urban drain network
is poorly managed, under-designed and would definitely fail to cope with
future runoff increase.
The apparent effect of urbanization
(a)
Sungai Maka
Longitudinal water profile for 10 year ARI event without Sungai Kelantan
tailwater
(b) Sungai Maka Longitudinal water profile
for 10 year ARI event coinciding with Sungai Kelantan 5 year ARI water
level.
Apparent effect of Sungai Kelantan influence
Flood extent for 10 year ARI catchment coincide with 50
year ARI Sungai Kelantan event
Water Quality assessment was carried out through site and
laboratory testing to determine chemical parameters of water in Tanah
Merah. From 25 sampling sites, sample water was tested for 11 water
quality parameters from the simplest pH measurement to Total Coliform
determination. It was found that water quality in Tanah Merah is
generally poor with high ammoniacal nitrogen, bio-chemical oxygen
demand, oil and grease as well as total coliform count due to the lack
of proper sewage treatment system in the town.
Water quality indicator for stream/ river sampling
Water quality indicator for point-source pollution
Stormwater Master
Plan :
After identifying issues and considering
design constraints, the study team proposed a stormwater management
master plan consisting of two parts namely the structural stormwater
master plan and non-structural stormwater management plan. Both parts
will play equally important role to manage stormwater in Tanah Merah at
long term sustainably.
The proposed structural master plan
consisted of all physical modification and upgrades deemed necessary to
improve stormwater management in Tanah Merah by the study team. The
structural upgrades are designed based on two important design criteria,
which is to provide sufficient flood protection and to provide runoff
control in terms of water quantity and quality. Among the promoted
upgrade includes:
Proposed Structural Stormwater Master Plan for Tanah
Merah
Typical cross section design with confined floodplain for
Sungai Kepat
Non-structural
stormwater management plan was tailored to complement the structural
master plan to enhance stormwater management in Tanah Merah. This plan
consists of several components to provide management suggestions to the
local authorities in stormwater management. Non-structural measures
included were:
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Urban/ Development
Planning
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Low Impact
Development
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Operation and
Maintenance
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Public Outreach and
Education
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Flood Management
Plan
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