drainage system in flat area using groundwater
TRANSCRIPT
i
DRAINAGE SYSTEM IN FLAT AREA USING GROUNDWATER
RECHARGE WELL IN SOLVING FLOODING PROBLEM
by
SABARIAH MUSA
Thesis submitted in fulfillment of the requirements
for the degree of
Doctor of Philosophy
January 2015
ii
ACKNOWLEDGEMENT
In the name of Allah S.W.T., the Most Gracious and the Most Merciful
The writing of this thesis has been one of the toughest challenges I have to face throughout
my academic career. I would particularly like to thank to supervisor, Prof. Dr. Nor Azazi
Zakaria and co-supervisor, Dr. Lau Tze Liang for their guidance. I also would like to express
special regards and to acknowledge the financial support from Universiti Sains Malaysia as
a research university for continuous support. Special thanks to Universiti Tun Hussein Onn
Malaysia for giving me the opportunity to set up my model and for providing me with the
facilities. I would like to thank those who assisted me in the preparation of this work
including my family, for their tremendous efforts in supporting me. Finally, I would like to
thank my friends for their tremendous support and cooperation throughout my study. My
special thanks also go to my beloved husband and daughters who are always being there
during this invaluable journey to success.
Sabariah Musa
2015
iii
TABLE OF CONTENT
Page
ACKNOWLEDGEMENT ……………………………………………………… ii
TABLE OF CONTENT ………………………………………………………… iii
LIST OF TABLES……………………………………………………………….. ix
LIST OF FIGURES……………………………………………………………… xi
LIST OF ABBREVIATIONS……………………………………………….…… xvi
LIST OF SYMBOLS …………………………...……………………………….. xviii
ABSTRAK………………………………………………………………………. xxi
ABSTRACT……………………………………………………………………... xxiii
CHAPTER 1 – INTRODUCTION
1.1 General 1
1.2 Flooding Area 5
1.3 Problem Statement 6
1.4 Objectives 8
1.5 Scope of Study 9
1.6 Significance of Study 11
1.7 Outline of the Thesis 12
iv
CHAPTER 2 – LITERATURE REVIEW
2.1 Introduction 14
2.2 Local Conditions 14
2.3 Retention Basin 16
2.4 Soil Type 17
2.5 Resistivity Exploration 19
2.5.1 Soil Resistance at the Real Site 21
2.6 Groundwater Recharge 23
2.7 Surface Water and Groundwater Interaction 28
2.8 Groundwater Quality 30
2.9 Clay Minerals 33
2.10 Theory of Related Recharge 36
2.10.1 Recharge Intersection 37
2.10.2 Infiltration Rectangular Trench 40
2.11 Groundwater Recharge Well 42
2.12 AQTESOLV Model Application 46
2.13 Neuman’s Method Application 49
2.14 Unconfined Aquifer Analysis 51
2.14.1 Grain Size Distribution 52
2.14.2 Permeability 53
2.14.3 Consolidation 54
2.15 Profile Assumption 54
2.16 Summary 56
v
CHAPTER 3 – RESEARCH METHODOLOGY
3.1 Introduction 58
3.2 Methodology Justification 58
3.2.1 Step 1: Investigation of Existing Well Mechanism 60
3.2.1.1 Borelog Record 61
3.2.1.2 Pumping and Recovery Tests 61
3.2.1.3 Pumping and Recharge Tests 62
3.2.1.4 Review of Well Mechanism 64
3.2.1.5 Evaluation of Aquifer Type 66
3.2.2 Step 2: Surface Tests 67
3.2.2.1 Infiltration Tests 68
3.2.2.2 Classification Soil Tests 69
3.2.2.3 Evaluation of Soil Type 71
3.2.2.4 Survey Work 72
3.2.3 Step 3: Subsurface Study 73
3.2.3.1 Resistivity Survey 73
3.2.3.2 Evaluation of Subsurface Layer 75
3.2.3.3 Interpretation Data 76
3.2.4 Step 4: REWES Model 77
3.2.4.1 Technique Identification: Vertical Flow Concept 80
3.2.4.2 Site Identification for Model 83
3.2.4.3 Replication (Construction) 85
3.2.4.4 Drilling Works and Sampling 86
3.2.4.5 PVC Installation and Washing 87
vi
3.2.4.6 Structure of Infiltration Basin 91
3.2.4.7 Infiltration Basin Construction 93
3.2.4.8 Pump Installation 98
3.3 Recharge or Discharge Well System (REWES) 100
3.4 Hydraulic Conductivity Identification 100
3.4.1 Correlation Methods 102
3.4.1.1 Grain Size Distribution 102
3.4.1.2 Consolidation Response 103
3.4.2 Hydraulic Methods 103
3.4.2.1 Estimation for Permeability 103
3.4.2.2 Estimation for Infiltration Methods 104
3.5 Water Quantity Analysis 104
3.5.1 Pumping-Recovery 104
3.5.2 Pumping-Recharge 107
3.6 Water Quality Analysis 108
3.6.1 Geo-chemical Analysis 108
3.6.1.1 X-Ray Fluorescence 109
3.6.1.2 X- Ray Diffraction 110
3.7 Summary 111
CHAPTER 4 - WELL TESTS AND AQUIFER IDENTIFICATION
4.1 Analysis on REWES Test 112
4.1.1 AQTESOLV Output Data Test 115
4.1.2 Estimation Aquifer Properties 115
vii
4.1.3 Forward Solution 118
4.3 Potential and Perspective Aquifer Responses 122
4.4 Characteristics of Wells 127
4.5 Profile of Wells Drawdown 131
4.6 Summary 136
CHAPTER 5 - HYDRAULIC CONDUCTIVITY OR PERMEABILITY
DETERMINATION
5.1 Surface Conditions 137
5.1.1 Moisture Content 137
5.1.2 Well Tests and Its Evaluations 138
5.1.3 Sieve Analysis Distribution 140
5.2 Permeability Effect 145
5.2.1 Estimation of Permeability from Falling Head Tests 146
5.3 Consolidation Response 148
5.4 Infiltration Record 149
5.5 Summary 152
CHAPTER 6 – FUNCTIONS OF DRAINAGE SYSTEM AND WATER DEMAND
6.1 Quantitative and Qualitative Assessments of Groundwater 154
6.1.1 Rainfall Fluctuation 154
6.2 Discharge Record 157
6.2.1 Recharge and Injection Analysis 159
6.2.2 Recharge Interactions on RW 163
viii
6.3 Water Quality Analysis 167
6.3.1 Hydro-chemical Characterization 167
6.3.2 REWES Evaluations 169
6.4 Geo-chemical Analysis 171
6.4.1 XRF for Geo-chemical Characterization 171
6.4.2 XRD for Mineralogical Characterization 173
6.5 Summary 175
CHAPTER 7 – CONCLUSION AND RECOMMENDATION
7.1 Conclusion 176
7.2 Recommendation 178
REFFERENCES
APPENDICES
ix
LIST OF TABLES
No. of Table Title Page
Table 2.1 Types of soil for boreholes around study area 16
Table 2.2 Values of vertical electrical sounding method for groundwater
exploration 21
Table 2.3 Definition of the scale terminology used 44
Table 3.1 Detailed record for sampling and soil types at study area 62
Table 3.2 Infiltration topsoil test using tension infiltrometer at
study area 68
Table 3.3 Details of rechareg well profile based on drilling record and
its analysis 72
Table 4.1 Data set values for wells tests 114
Table 4.2 Preliminary outputs for simulation analysis 117
Table 4.3 Outputs for recharge well analysis 118
Table 4.4 (a) Pumped recharge well for forecast evaluation 121
Table 4.4 (b) Analysis of two monitoring wells for old well 121
Table 5.1 Sampling for water contents of four wells 139
Table 5.2 Summary records of the aquifer tests 139
Table 5.3(a) Tabulated dry sieve for monitoring well 1 140
Table 5.3(b) Tabulated wet sieve for monitoring well 2 141
Table 5.3(c) Tabulated sieve analysis for recharge well 142
Table 5.3(d) Tabulated sieve analysis for extra well 143
Table 5.4 Summary of permeability outputs for recharge well 145
Table 5.5 Permeability outputs for all wells 145
Table 5.6 Consolidation tests for monitoring well 1 149
x
Table 5.7 Surface hydraulic conductivity and its infiltration rate at
Sri Gading area 152
Table 6.1 Recharge range in clay aquifer 162
Table 6.2 Discharge and recharge analyses for clay aquifer 162
Table 6.3 Pumping and recharge rates for recharge well 163
Table 6.4 Summary of dilution in recharge using rainwater method 168
Table 6.5 Groundwater quality evaluations for two pumped well at
both conditions 170
Table 6.6 Present water quality in recharge well 173
xi
LIST OF FIGURES
No. of Figure Title Page
Figure 1.1 Study areas at Sri Gading, Johor 2
Figure 1.2 Map and contour lines of study area in Research Centre of
Soft Soil Malaysia (RECESS) 3
Figure 1.3 Flood and inundation in the area of Universiti Tun Hussien
Onn Malaysia and its surrounding area of Sri Gading 4
Figure 1.4 Flooding in Sri Gading area 5
Figure 1.5 Present study area condition during wet season 6
Figure 1.6 Algae problem since 2010 at Sembrong Dam 7
Figure 1.7 Rainwater harvesting for non-potable usage 8
Figure 2.1 Infiltration rate of top layer of soil distribution at the study area 18
Figure 2.2 Aquifer parameters related to the condition of well systems
during dry season 46
Figure 3.1 Research design flow chart 59
Figure 3.2 Old well profile for first drilling at study location 60
Figure 3.3 Existing well and rain gauge were located in study area 63
Figure 3.4 Parts of measurement of recharge from the roof to the well 63
Figure 3.5 Test well operation diagram 64
Figure 3.6 Basic concepts of the single-well test for well test 67
Figure 3.7 Study locations on the infiltration tests in the Sri Gading area 69
Figure 3.8 Tension infiltrometer apparatus used for infiltration tests 69
Figure 3.9 Samples at different layer for samples under well construction 71
Figure 3.10 Abem terrameter apparatus for resistivity test 75
xii
Figure 3.11 Line survey through the existing wells at study area 75
Figure 3.12 Detailed plan and section view of model sturcture well 78
Figure 3.13 Stages of study works in this phase 80
Figure 3.14 Recharge concept was applied to onsite model 82
Figure 3.15 Plan of study area and layout of model 84
Figure 3.16 Point for pilot plan at the real site before construction 85
Figure 3.17 Washing well work at first drilled well 86
Figure 3.18 Same drilling method for the next well and sampling for
undisturbed soil 87
Figure 3.19 Disturbed and undisturbed samples with broken sample
at 28.5m deep 87
Figure 3.20 Drilling and washing techniques before piping installation 87
Figure 3.21 Manually screening pipes 88
Figure 3.22 Wrapping with geotextile medium for fully screening pipes 88
Figure 3.23 Pipe installations and rivet joint method 89
Figure 3.24 Rivet joining every pipe installation 89
Figure 3.25 Flushing for shallow well and washing with high compression
for deeper well 89
Figure 3.26 Completion of monitoring wells 90
Figure 3.27 Profile structures of the wells grouped into sublayers for
different sizes, depths and distances 90
Figure 3.28 Plan of infiltration basin 91
Figure 3.29(a) Section X-X of infiltration basin at the sub-layer 92
Figure 3.29(b) Section Y-Y for infiltration basin structures’ 92
Figure 3.30 Nine (3 x 3 double layer) in size of double modules on lapping
with geo-textile 93
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Figure 3.31 Framework and reinforced concrete bar 10 mm diameter 94
Figure 3.32 Concreting and curing for a 7 days 94
Figure 3.33 Washing the frame basin and installation of inflow and
overflow pipes 95
Figure 3.34 Cut-and-fill channels for overflow pipe and slope for each side 95
Figure 3.35 Overflow and inflow pipes wrapped with geotextile
before filled with sand and gravel 95
Figure3.36 Inflow valve at bottom basin with chamber socket 96
Figure 3.37 Modular are wrapped and ready to install into frame basin 96
Figure 3.38 Modular installed in the frame basin and backfill with sand
and gravel 97
Figure 3.39 Geotextile separation and backfill with drainage cell and sand 97
Figure 3.40 Topping with sand and covered by carpet grass 97
Figure 3.41 Completed model with grass cover and some heads of wells
and chambers 98
Figure 3.42 Submersible pump and installation work at recharge well 98
Figure 3.43 Pump house near the recharge well and it’s inside properties 99
Figure 3.44 Recharge well completed with piping system 99
Figure 3.45 Completed model and site visit at study area, Johor 99
Figure 3.46 Combined hydraulic conductivity or permeability analysis for
aquifer 101
Figure 3.47 Loadtrack machine for permeability tests 103
Figure 3.48 Semilog pumping actions for recharge well 106
Figure 3.49 Drawdown profile for pumping well 107
Figure 3.50 Samples at the bottom level in the natural site 109
xiv
Figure 3.51 Sampling apparatus and tablet produced for geo-chemical analysis 110
Figure 4.1 Step analysis for aquifer characteristics 113
Figure 4.2 Requirement inputs for running the program 114
Figure 4.3 Radial flows for pumping and recovery activities 116
Figure 4.4 Discharge forecast for recharge well during dry condition in
a week-long evaluation 119
Figure 4.5 Observed forecast for old well discharge during dry condition
in a week 119
Figure 4.6(a) Long-term pumped wells for recharge well during dry condition 123
Figure 4.6(b) Long-term monitoring wells record during dry condition 123
Figure 4.7 Polynomial forecasting at recharge well during long-term
pumping and dry condition 125
Figure 4.8 Coverage area effects to discharge actions 126
Figure 4.9 Intermittent time steps for recharge well and old well
characteristics with different discharges 128
Figure 4.10 Intermittent levels for recharge well and old well at both conditions
at different discharges 129
Figure 4.11 Regular drawdown for recharge well at 35 m 130
Figure 4.12 Profile of water table at recharge well for long term record 131
Figure 4.13 Water table boundaries with observed contour lines 132
Figure 4.14 Profile of water table at pumped old well during dry condition 133
Figure 4.15 Water table boundaries at old well with observed contour lines at
dry condition 134
Figure 4.16 Withdrawal at recharge well during both conditions 135
Figure 4.17 Old well profiles during pumping well at normal discharges 135
Figure 5.1 Water content distributions of four wells related in the case area 138
xv
Figure 5.2 Sieve analysis of four wells for each samples with the respectively
results 143
Figure 5.3 Soil distribution sample for recharge well at 1.5 m 144
Figure 5.4 Permeability fluctuations using the falling head method at
monitoring well 2 146
Figure 5.5 Permeability value at 25.5 m 147
Figure 5.6 Consolidation actions for tested soils in layer 148
Figure 5.7 Infiltration actions with low distribution for water
movement after being saturated 151
Figure 6.1 Rainfall data collected for monthly and yearly means for a three-year
study 155
Figure 6.2 Combination of water level observations 156
Figure 6.3 On-site model was installed recharge and discharge system 157
Figure 6.4 Relationship between discharge rate and storage capacity
in the pumped wells 158
Figure 6.5 Recharge rate comparisons between recharge well and old well 160
Figure 6.6 Recharges into the recharge well for both conditions 165
Figure 6.7 Recharge prediction values for recharge well for 24 hours 166
Figure 6.8 Simulation for recharge analysis and prediction at recharge well 167
Figure 6.9 Groundwater freshness and site tests for the output model 171
Figure 6.10 Dominance contaminations at recharge well 173
Figure 6.11 Minor contaminants in the layers 174
xvi
LIST OF ABBREVIATIONS
ARI average recurrence interval
ARC antecedent runoff condition
AQTESOLV aquifer test software
BAKAJ Badan Kawalselia Air Johor
BH bore hole
BRC bar reinforcement concrete
BOD biological oxygen demand
CILAS particle size apparatus
CN curve number
COD chemical oxygen demand
DID Department of Irrigation and Drainage
DO dissolve oxygen
EW extra well
FTIR fourier transform infrared spectroscopy
HSG hydrologic soil groups
JMG Jabatan Mineralogi dan Geosains Malaysia
KEMAS Jabatan Kemajuan Masyarakat
KKTM Kolej Kemahiran Tinggi Mara
MSMA Manual Saliran Mesra Alam Malaysia
MW monitoring well
NDWQS National Drinking Water Quality Standard
xvii
OW old well
PVC polyvinyl chloride
RECESS Research Centre of Soft Soil Malaysia
REWES Recharge well system
RISDA Rubber Industry Small Holders Development Authority
RW recharge well
SEM scanning electron microscopy
UTHM Universiti Tun Hussien Onn Malaysia
VES vertical electrical sounding
XRD x-ray diffraction
XRF x-ray fluorescence
1D one dimension
2D two dimension
3D three dimension
xviii
LIST OF SYMBOLS
I,i Intensity of rainfall (mm/hr)
P depth of rainfall (mm)
FD adjustment factor for storm duration (Table 13.3 - MSMA) (dimensionless)
P30, P60 30th minutes and 60
th minutes duration rainfall depths respectively (min)
S maximum amount of water that will be absorbed after runoff begins (mm)
Ia initial abstraction (dimensionless)
Li interception (mm)
PT total rainfall depth (mm)
a,b,n empirical constants (dimensionless)
f the infiltration capacity (mm/hr) at time t
fo the initial rate of infiltration (mm/hr)
fc the final constant rate of infiltration (mm/hr)
k a shape factor (per hr)
t the time from the start of rainfall (hr)
R Total runoff (mm)
te time of rainfall excess (min)
Q rate of injection (m3/day)
V average velocity (m/s)
n Manning’s roughness coefficient (dimensionless)
Qy y year ARI peak flow (m3/s)
C runoff coefficient (dimensionless)
y
tI y year ARI average rainfall intensity over time of concentration, tc (mm/hr)
A Drainage area (m2)
xix
I Hydraulic gradient causing vertical flow in the gravel pack (dimensionless)
A cross section area (m2)
P coefficient of permeability of gravel (m/day)
T the transmissivity ( m2/day)
s∆ the drawdown difference (m)
S the storativity (dimensionless)
to time axis ( intersection point, s = 0, t = to) (min)
r2 the effective radius of the single well (m)
Sc the specific capacity (m3/day/m)
AS
volume of water instantaneously released from storage (m3/m
2/m)
Sy specific yield (dimensionless)
d t max depth of trenches (m)
Ts storage time (min)
Vr the porosity of the stone /module fill (%)
Tf the filling time (min)
z the side slope (horizontal over vertical) (%)
W width of trenches (m)
Vc the volume of capture runoff (m3)
K hydraulic conductivity (m/day)
b aquifer thickness (m)
hw head above the bottom of aquifer while recharging (m)
H0 head above the bottom of aquifer when no pumping is taking place (m)
r0 radius of influence (m)
rw radius of injection well (m)
R recharge to the aquifer (m3/day)
xx
GWin influxes from upgradient portion of ground water system (m3/s)
GWout effluxes to downgardient portion of ground water system (m3/s)
Qs discharge to surface water bodies (m3/s)
Qw abstractions from ground water system through wells (m3/s)
/S t∆ change in ground water storage in the system per unit time (m3)
r recharge rate (volume per unit surface area) (m3/m
2)
/H t∆ rate of seasonal rise in water level in a well (m)
n effective porosity of the aquifer (%)
Kr radial hydraulic conductivity (m/s)
Kz vertical hydraulic conductivity (m/s)
R the soil resistance (ohm-m)
β Neuman parameter (β for a single observation well)
K the coefficient of permeability
D15 the soil particle diameter corresponding to 15% passing of the grain size (mm).
vC coefficient of rate of consolidation (m
2/year or m
2/s)
wγ unit weight of water (kN/m
3)
vm coefficient of volume compressibility (m
2/MN)
va coefficient of compressibility
oe initial void ratio
sH equivalent thickness of solids (m)
sW dry weight (g)
sG specific gravity of the solid
π 3.1416
xxi
SISTEM SALIRAN DI KAWASAN TANAH RATA MENGGUNAKAN ALIRAN
MASUK TELAGA AIR BUMI BAGI MENANGANI MASALAH BANJIR
ABSTRAK
Sri Gading di Johor menghadapi masalah berkaitan air yang disebabkan oleh limpahan air
permukaan di kawasan yang rata dan kelemahan penyaliran air semasa musim tengkujuh.
Kadar penyusupan tanah yang rendah di Sri Gading disebabkan oleh kebolehtelapan saiz
zarah halus yang perlahan yang dikenalpasti sebagai tanah liat berkelodak. Kerja penyiasatan
tapak terdiri daripada kajian permukaan dan sub-permukaan telah dijalankan sehingga
kedalaman tanah liat 50 m daripada aras purata laut. Kajian permukaan termasuk ujian
penyusupan, ujian kerintangan elektrik dan ujian pengepaman dan pemulihan, manakala
ujian kebolehtelapan, ujian pengukuhan dan pengkelasan asas tanah telah dijalankan dalam
penyiasatan subpermukaan. Kadaralir air bumi kawasan ini dipengaruhi oleh dua sifat lapisan
tanah iaitu keliangan dan kebolehtelapan. Daripada ujian lapangan, kebolehtelapan tanah
ialah 0.0001 - 0.086 m/hari yang memenuhi julat piawai jenis tanah liat berkelodak. Dengan
kata lain, kawasan Sri Gading mengalami masalah bekalan air semasa musim kering. Oleh
itu, satu replika Recharge well system (REWES) sebagai sistem tadahan bawah tanah telah
dicadangkan untuk mengatasi masalah banjir dan bekalan air dengan mengalirkan air larian
permukaan terawat ke dalam sistem akuifer. Konsep yang digabungkan dengan pengepaman
dan penyaliran masuk air bumi dinilai dapat mengalirkan aliran secara efektif sehingga 31%
(12.5m3/hari – penyaliran masuk piawai 20% -100%) selama 2 jam (tempoh kecemasan)
penyaliran. Kajian secara geologi dan mineralogy membuktikan bahawa hubungan kualiti
air bumi di antara keaslian air bumi dan kandungan kualiti bahan pencemar bergantung
kepada proses pengaliran keluar (kaedah pengepaman) atau penyaliran masuk (kaedah
xxii
pencairan). Dengan aliran air yang melalui lapisan tanah, kualitinya akan berubah dan dalam
masa yang sama ciri-ciri hidraulik juga boleh dipertingkatkan berdasarkan kesesuaian
rekabentuk di tapak dan masalah persekitaran. Akhirnya, aplikasi konsep tadahan ini dapat
meningkatkan sistem kitaran air bagi pengurusan air rebut bandar dalam menangani masalah
banjir dan bekalan air.
xxiii
DRAINAGE SYSTEM IN FLAT AREA USING GROUNDWATER RECHARGE
WELL IN SOLVING FLOODING PROBLEM
ABSTRACT
Sri Gading in Johor faces water related problems that are caused by excessive surface runoff
floods the low areas and ineffective drainage system during wet season. The low infiltration
rate of the soil in Sri Gading is caused by low permeability of fine-grained sizes of silty clay.
Soil investigation work consisting surface and sub-surface studies were conducted until deep
layer clay at 50 m from the mean sea level. The surface studies included infiltration test,
resistivity survey, and pumping and recovery tests, while permeability, consolidation, and
basic soil classification tests were carried out in subsurface investigation. The flow rate of
groundwater in the study area is controlled by two properties of the soil layer, namely
porosity and permeability. From the field test, the permeability of the soil is 0.0001–0.086
m/day which falls into the standard range of silty clay. On the other hand, Sri Gading area
encounters water supply shortage during dry season. Therefore, the replica of a recharge well
system (REWES) as an underground retention system is proposed to solve both flooding and
water scarcity problems by recharging treated surface runoff into aquifer system. The
combined concept of pumping and recharge was evaluated to effectively capture up to 31%
(12.5 m3/day – recharge standard 20% -100%) throughout 2 hours in (emergency period) of
reaches. This geological and mineralogy study establish the groundwater quality relationship
between pure groundwater and contamination quality control work during discharge
(pumping method) or recharge (dilution method) actions. By letting water pass through the
ground, its quality will change, and its geo-hydraulic characteristics will improve the
capacity based onsite design and environmental problems. Then, application of retention
xxiv
concept is integrated with water cycle for urban stormwater in solving flooding problem and
water supply management.
xxv
CHAPTER 1
INTRODUCTION
1.1 General
Commercial developments in the outskirts of Sri Gading are famous for their local delicacies
and textile industries such as Munchy’s, Hup Seng, and Hwa Tai biscuits manufacturer,
Miaow Miaow Food Products Sdn. Bhd., New Star Food Industries Sdn. Bhd., LY Furniture,
Ramatex, and multinational corporations including Fujitsu, Sharp Roxy, and J.R. Courtenay.
Sri Gading has a lot of rivers and lakes, and more than 20 bridges are found across this small
district. These bridges are rather modest but they have been in this district since the initial
development, assuming the heavy responsibility of linking houses and business on both ends.
Parit Raja is a small town in Sri Gading district, Johor, Malaysia. The main
population of this town is Javanese and substantial growth has taken place in this region in
the past few years. Universiti Tun Hussein Onn Malaysia (UTHM) is located along Jalan
Kluang between Fujitsu Sdn. Bhd. and Kolej Kemahiran Tinggi Mara (KKTM). This campus
is near to the Parit Raja town and is now a preferred residential location among the upper
middle class residents.
The study site is new to the Research Centre of Soft Soil Malaysia (RECESS),
UTHM which is situated on the typical area of Sri Gading with drainage problems due to the
flat terrain. The total area compacted 11,099.93 m2 consisting of 629.67 m
2 of laboratories,
1284.13 m2 of pavement, and the remaining area is naturally covered with cow grass. It is
also surrounded by concrete and earth channels. Jabatan Kemajuan Masyarakat (KEMAS)
1
xxvi
area is situated in the south of UTHM and Kolej Kemahiran Tinggi Mara (KKTM) to the
west; both areas are located on a higher ground than the study area. The contour ground level
is around 1.6 m to 1.9 m with the surrounding boundary of 2.5 m above the mean sea level.
Thus, the study area is located in the flat terrain area which does not directly flow the surface
water to the discharge point. Figures 1.1 and 1.2 show the distribution of the low lying area
(light blue colour) in Sri Gading district (Tjahjanto et al., 2006) and the ground platform at
RECESS area respectively. The details of ground level and drainage system are illustrated in
Figure A1 (Appendix A).
Figure 1.1 Study areas at Sri Gading, Johor (Tajahjanto, 2006)
MK AIR
HITAM
MK SPG KIRI
MK
MK Pt.
JAWA
MK
TAKRI
MK LUBOK
MK BAGAN
Pt. Sulong
BATU PAHAT
MK
SRI MEDAN
MK SG.
SARANG
MK SPG. KAKAH
MK
SRI GADING Bandar
Penggaram Pt. Raja
Senggarang MK MINYAK BEKU
Rengit
MK
KG. BAHRU
MK TG. SEMBRONG SRI MEDAN
LDG.
CHAAH
Sri Gading
Tgk. Pecah Pt. Yanni
SRI
MEDAN YONG PENG
KANGKAR CHAAH
Sg. Merpo
Sg. Sembrong
Sg. Bekok Sg. Berlian
Ayer Hitam
Emp. BEKOK N
BT.77 JLN.
Y.PANG - CHAAN
PT. JAMBOL
SRI MENANTI
SENGGARANG
Johor Bahru
Kluang Muar
Malacca
Muar
S T R A I T
S
M A L A C C A
O F BDR. BATU
PAHAT
BT.2 AYER HITAM
Emp. SEMBRONG
LDG. YONG PENG
BDR. YONG
Segamat
Study area
City
Town
Flat area
Reservoir
Highway
Boundary
Road
River
Legend:
2
xxvii
Figure 1.2 Map and contour lines of study area in the Research Centre of Soft Soil
Malaysia (RECESS)
MAKMAL
RECESS
KABIN
KABIN
LANTAI
KONKRIT
KABIN
LANTAI
KONKRIT
KEMAS
RECESS
,
UTHM
RECESS
3
xxviii
The development of the Sri Gading district has caused an increasing number of
inhabitants. The population in Parit Raja increases substantially since the establishment of
UTHM. Several incidents of flooding occurred in rural and urban areas especially in Parit
Raja (Zhou, 2007). Figure 1.3 shows one of the flood occurrence at the UTHM main campus
and its surrounding area at the end of December 2006 to January 2007 due to the poor
drainage system.
On the other hand, one of the consequences of population increase is high water
demand. Study shows that the municipal council is not able to provide sufficient quality
water supply due to type of soil affects to groundwater intake (Tjahjanto et al., 2008).
Another contributing factor of flood in Sri Gading is the low permeability of soil due to the
ground being covered by peat soil on the surface and clay in the deep layer.
Figure 1.3 Flood and inundation in the area of Universiti Tun Hussien Onn Malaysia and its
surrounding area of Sri Gading
4
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1.2 Flooding Area
Based on Tjahjanto et al. (2008), Department of Irrigation and Drainage (DID) stated that the
area of Batu Pahat experiences a huge flood in every 100 years. The recent event is shown in
Figure 1.4. Over 70% of the areas are flooded and roads are damaged. The flooding was a
result of the following: (1) excessively high rainfall, where 170 to 247 mm/day was recorded
at Bekok Dam, and 181 to 229 mm/day was recorded at Sembrong Dam; (2) insufficient
capacity of the available reservoirs to store surface runoff, where the maximum water levels
were above the critical levels, i.e., over 17.5 m in Bekok Dam and 12.0 m in Sembrong Dam;
(3) the cross section of the river was insufficient to handle the peak flow rate; and (4) most
areas of Sri Gading have low infiltration rate and low lying areas (approximately 1.5 m to
2.0 m above mean sea level), making the river incapable to discharge stormwater effectively
to the sea.
Figure 1.4 Flooding in Sri Gading area
Figure 1.5 shows an example of flood on 9 July 2013. The recorded rainfall depth
within 2 hours 22 minutes is 789 mm (Musa et al., 2013). Indirectly, groundwater discharge
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also supports water distribution with better water quality compound to the surface runoff in
this area.
(a) Study area in wet condition (b) Recharge well system in study area
Figure 1.5 Present study area condition during wet season
Hence, groundwater recharge well need to be studied as an alternative way to
enhance the drainage system of a flat area using sub-surface land as water storage and as a
source for water supply. This recharge method is considered applicable for flat area with silty
clay or clay soil types, deep layer of bedrock, high water table, and low infiltration rate. The
application of a vertical groundwater recharge system is possible for the flat area and
remediation of these sites generally occur over many years. This vertical groundwater
recharge system functions as underground retention basin drainage to store surface runoff
and modelling recharge system for future work.
1.3 Problem Statements
The area of Parit Raja faces of flooding and shortage of water supply problems. Flood is a
result of Sri Gading and its surrounding areas (about 20 km only from Pantai Rengit) almost
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flat and low land in area. This condition becomes worst with the low permeability of the top
layer of soil covered with silty clay or peat soil. Thus, backwater from the river and the
absence of proper stormwater drainage has caused flooding in the study area.
For water supply shortage, it is due to the limited source of fresh water caused by
pollution in Sembrong River. A study by Rosli (2010) found that the tap water is not clean
and its contaminants has 38% odour, 33% silty, 19% colour and 10% salty (Harian Metro,
2012). According to BAKAJ (Badan Kawalselia Air Johor) (2012), Sembrong Dam (West)
losses 10 million litres of water per day due to algae bloom as shown in Figure 1.6. The fresh
water in Sembrong Dam contains high levels of acid thus making water treatment costly.
Pesticide chemicals flowing into Bekok Dam causes 500,000 users vulnerable to cancer and
other chronic diseases as a result of continued aggression committed by irresponsible
agencies (Harian Metro, 2012).
Figure 1.6 Algae problem since 2010 at Sembrong Dam
Local residents in Sri Gading are not confident with the use of shallow (< 10m) raw
groundwater for domestic purposes because the groundwater quality at shallow intake
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exceeds the standard for water distribution (Musa et al., 2009). Most of the alternative water
supplies are obtained from rainwater harvesting to support the water use. Some local
residents use rainwater harvesting as an alternative to support the water demand in this area
as shown in Figure 1.7. However, the rainwater cannot be used sometimes due to high levels
of air pollutants from the industries (Tjahjanto et al., 2006).
Figure 1.7 Rainwater harvesting for non-potable usage (Rosli, 2010)
Based on the local problems is low infiltration rate during heavy rainfall, the vertical
drainage using infiltration basin method is supposed to capture the runoff at the top surface,
especially during wet condition. The combination between recharge well system (REWES)
with pumping method has the potential to collect and channel more surface runoff during wet
season or high rainfall intensity.
1.4 Objectives
The objectives of this study are as follows:
1. To determine the characteristics of the aquifer at the study area.
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2. To evaluate the effectiveness of innovative system named REWES based on the
discharge and recharge actions.
3. To evaluate the water quantity response of REWES and groundwater quality.
This study is conducted to determine the best way to overcome the problems due to
the improper drainage system in the Sri Gading area. The drilled well, which is used to
integrate with stormwater system, can be a part of vertical drainage system during the wet
condition to mitigate flooding. The surface runoff with proper treatment would be suitable
for groundwater recharge. Potential use of the urban stormwater runoff for groundwater
recharge would be extremely site-specific. Besides, this study aims to identify a method to
overcome water supply shortage and flood problems by making use of the groundwater
sources and facilities around the area.
1.5 Scope of Study
The scope of works was summarized as follows:
(a) To design an innovative system named REWES based on the mechanism of
existing well and geo-hydraulic properties.
(b) To construct REWES as a real-site model for Sri Gading area.
(c) To evaluate the quantity and quality of groundwater cycled through the REWES
model.
The particular study was limited to data collection of parameters of aquifer from the
existing well. Data collection from pumping test and recovery analysis is conducted to
determine parameters of aquifers such as transmissivity (T), storativity (S), hydraulic
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conductivity (K), thickness of aquifer (b), specific yield (Sy) and specific capacity (Sc) based
on existing well.
The evaluation of surface runoff to aquifer using the existing well as the onsite
detention pond consisted of a roof, pipe system, surface runoff, and recharge well was
performed. Variable and factor effecting recharge and discharge capacity during pumping
and recovery test are determined. Evaluation of the potential aquifer as water quantity intake
and storage capacity on existing well defines the contaminations or mineralogy for water
quality requirements. The hydrological data was collected to determine the hydrological
characteristics such as intensity (i), time of concentration (tc), catchment area (A), coefficient
of runoff (C), and runoff (R) based on the rational method.
Data collection on top surface area was done to determine the type of top soil using
the soil classification test (standard method) and the infiltration test (I) using tension
infiltrometer apparatus on the study area. Levelling survey also done to mapping the contours
area for surface runoff flow and area surface profile. Three line - profile in sub-surface area
using SAS 4000 apparatus was conducted by resistivity test along 400 m respectively.
Resistivity soil test was carried out to verify that the resistivity survey values at the site can
be transformed in determination of the type of soil in the study area.
The construction of a physical model (REWES) that consisted of infiltration basin,
well and contact to aquifer were done to verify the results from the analysis. The
effectiveness of the system as a vertical drainage was defined. The construction of 2-inch and
4-inch monitoring wells (4 nos) at the study area between 4, 10, 20, and 35 m from the
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recharge well. In addition, geotechnical tests such soil classification test, permeability test
using load track apparatus and falling head, and consolidation tests for every 1.5 m depth on
the soil samples were conducted. The variable and factors effecting recharge and discharge
capacity during the pumping and recovery test were also determined.
Onsite basic water quality parameters such as pH, DO, turbidity, conductivity,
salinity, chlorine, zink, cadmium, manganese, iron, lead, copper, nitrate, BOD, COD,
nitrogen ammonia, and total suspended solid according to required water supply standard
were investigated. Dry samples passing 300 mm for every layer on the main well were tested
using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analyses to determine the
characteristics of mineralogy and nature of groundwater body sources.
1.6 Significance of Study
Although groundwater is available in the area of study, the water supply is still insufficient
due to the limitation of water availability on surface. In Johor, the area studied by Musa et al.
(2010) is limited for studies on groundwater as potential groundwater and stormwater
management. Hence, the availability of groundwater should be enhanced by recharging
surface runoff into the ground using the recharge well system, especially in urban area as
retention or water storage; it was implemented in the Sri Gading district. Moreover, by using
artificial recharge, the volume of water in the retention pond (RECESS area) is reduced, and
thus the surface area is able to anticipate the stormwater (flood mitigation). This innovative
system acts as discharge and recharge actions for water supply and drainage exchange for
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groundwater cycle to contribute more benefits for sustainable management and to integrate
the channel system.
1.7 Outline of the Thesis
This thesis comprises of seven chapters as follows:
Chapter 1 begins with the history of the study area and followed by the problem statement,
scopes of the research and objectives of the study.
Chapter 2 reviews studies from previous researchers and presents the important findings
from past studies. It describes the theoretical applications of surface and sub-surface flow.
Groundwater flow estimation and its parameters analysis are also included in this section.
This chapter covers the theoretical background of analysis such as Darcy’s Law, Rational
Method, Nueman method and others solutions.
Chapter 3 describes stages of research methodology in details. The construction of REWES
is presented which includes the drilling work of borehole, sampling the soils in layers,
installation of pipes and pump, pumping tests for aquifer characteristics and water quantity
and quality analysis.
Chapter 4 presents the characteristics of aquifer and its conditions of this study area. The
interaction of groundwater activities and their reaction to real conditions are also analyzed.
Evaluation of the aquifer characteristics using the well data collection and AQTESOLV
software are described. The type of aquifer is then identified.
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Chapter 5 describes the verification of the hydraulic conductivity and permeability values for
this area based on types of soil. Some theories and methods applied to identify the aquifer
characteristics are presented.
Chapter 6 presents the analysis of stormwater and groundwater demand. Both analyses for
water quantity and water quality aspects are described. Pumping-recovery and pumping-
recharge tests are discussed. The monitoring of water quality is discussed.
Chapter 7 concludes the findings of this study and suggests recommendations for future
work.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
This chapter reviews available literatures that contribute to the understanding of current
research on recharge well system. This study was conducted to evaluate the practical method
for solving flooding and water scarcity issues.
Currently, there is no in-depth study or research on the stormwater recharge to
underground structure for Sri Gading district area. Most studies focus on the stormwater
management in terms of water quantity and quality, enhancement of the surface water and
groundwater flow problems and application of the appropriate techniques as summarized in
Appendix B.
2.2 Local Conditions
An appraisal of geological logs from exploratory drilling indicates that the subsurface is
predominantly clayey in nature. The occurrences of sandy layers very limited both vertically
and laterally. Some of the boreholes drilled penetrated an entirely clayey sequence
(Logananthan et al., 1987). This investigation on the subsurface lithological and
hydrogeological conditions in the area aims to determine the amount of groundwater can be
obtained for domestic and/or industrial/agriculture use.
Generally, a top layer of brownish, peaty clay covers most of the area. Below the top
covering is a layer of greyey clay, which is frequently mottled and locally contains a lateritic
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redness. Greenish, shell-bearing clay, probably of marine origin, is also extensive,
particularly near the coast. Sand is limited in extent, both vertically and laterally, and is often
admixed with a little clay (Logananthan et al., 1987). In the area of Sembrong, Johor, sand
occurs as isolated layer within the extensive clay layers and has limited capacity as an
aquifer. In addition, some other parts of the investigation area have only a few meters thick
sand layers (Musa et al., 2010). This condition affects this study and proper investigation can
explore suitable solutions for the problems of this area.
The report in titled Soil Investigation for New Campus at UTHM (Maju Teknik,
2003) also shows the similar result of an average 20 m depth of clay and silt cover the top
layer. Only two points of the borehole (BH3 and BH10) show a sandy layer on the top
surface as shown in Table 2.1. A total of 48 undisturbed soil samples were obtained from a
very soft clayey layer in BH-1, BH-2, BH-4, BH-5, BH-7, BH-8, and BH-9. Nevertheless,
this study investigates a deeper recharge well over 40 m deep, which found limestones one of
the porous layer at this area as potential groundwater resources (Mohamad, 2010). Therefore,
meteorological and geo-hydrological/ geophysical information about the catchment area, the
existing water table and its fluctuations, water demand, availability of runoff water, and
socio-economic condition are considered as fundamental input for recharge studies (Kamra et
al., 2004). The investigation records on the study area were collected to assess the flooding
problem and integrate the drainage system according to real conditions of the area.
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Table 2.1 Types of soil for boreholes around study area (Musa et al., 2009)
2.3 Retention Basin
Traditionally, the surface water is commonly used for surface runoff solution in the
watershed but groundwater specific deals to the groundwater flow in the aquifer systems
(Johnson, 1966). However, surface water and groundwater systems also have watersheds at
flow-system divides and limited for area condition. The interaction of surface water and
groundwater research by Thomas et al. (2003) studied groundwater movement in small
catchment, the water table was not an exact replica of the land surface and the water table
contours were not parallel to land surface contours because water table was affected by type
of soil, area condition, water flow movement, drainage system and land use (Chuenchooklin
et al., 2006).
By recharging the surface water with well system (Akan and Houghtalen, 2003), the
configuration of the land surface affects the distribution of recharge areas because for a given
permeability, water moving downward through the unsaturated zone reaches the water table
sooner where the unsaturated zone is thinner (Al Ajlouni, 2007). If the region is underlain by
Borehole no. BH depth (m)
Thickness of layer (m)
Clay Silt Sand
1 36.3 0-27 27-36.30 -
2 31.93 0-23 23-31.93 -
3 39.15 1.10-25 0-1.10 , 28.2-39.15 25-28.2
4 34.8 0-23.6 23.6-34.8 -
5 34.62 0-22 22-34.62 -
6 34.62 0.8-24.8 0-0.8, 24.8-34.62 -
7 31.87 0-24.4 24.3 - 31.87 -
8 28.65 0-21.8 21.8- 28.65 -
9 37.77 0-23.2 23.2-37.7 -
10 45.3 0.8-11.2 , 13-19 0-0.8 , 19-45.3 11.2 - 13
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poorly permeable geologic deposits, such as clayey, fluvial silt and clay, groundwater flow
do not underlie surface divides in many settings (Thomas et al., 2003 and Kharal, 2002).
However, recharge in the clay aquifer underlies flow divides in smaller region than confined
aquifer with limited permeability’s (Lerner, 1990). However, the man-made structure
(REWES model) was applicable for water inserting to the ground by discharge and recharge
methods.
Research by Donald (2003), are often conducted within smaller watersheds, either to
focus on a more homogeneous watershed or to reduce costs. This study was conducted on a
local condition by scaled retention basin to evaluate in small basin analysis to reduce the cost
and specific study to local properties, specifically sub-catchment categories, to explore the
vicinity properties of the recharge system at the site conditions (Musa et al., 2013). Then, the
fluxes of infiltration surface runoff will be treated and collected before let it channeled to the
ground by gravity (Mishra and Fahimuddin, 2005, and Tjahjanto and Kassim, 2004).
2.4 Soil Type
This study area is generally covered by clay that makes up more than 60% of the total layers
up to 35 m depth (Musa et al., 2009). Sandy layer is limited in the extent both vertically and
laterally in layers and it is often admixed with sandy clay. A survey on the sub-surface
profile using the resistivity technique at the UTHM campus shows that the sand exists as
isolated lenses within the extensive clay layers and is therefore of limited capacity as aquifers
(Musa et al. 2009). Thus, this study location indicates that the sand presents as layers only a
few meters thick and does not appear to have extensive lateral continuity in layer.
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Research on soil permeability has been conducted in the area of UTHM (Tjahjanto et
al., 2006). The top layer of soil in this area mostly consists of silty clay with very low rate of
infiltration (Figure 2.1). The infiltration tests also results in no natural recharge from surface
water to the sub-soil system or aquifer. Thus, this condition has potential to exchange the
poor drainage system to recharge well as integrated drainage system, whereby the rainwater
runoff is not reduced by process of infiltration. Study by Tjahjanto et al., (2008) shows that
most parts in the Sri Gading area are flat (low laying area) and around 1.0 m to 1.5 m above
mean sea level. This topography condition has resulted in the river being incapable of
discharging stormwater directly to the downstream or sea. Certain drainage areas like the
drainage area of the campus of UTHM and surrounding lowland area face floods every year
due to backwater from the river.
Figure 2.1 Infiltration rate of top layer of soil distribution at the study area
Ab. Hamidhad (2002) conducted a study on the requirement of drainage system
for Parit Raja town, Batu Pahat using urban stormwater management manual. The area is
849.84 hectares, located at newly planned Parit Raja township between UTHM to Taman
Robena. This study was conducted to design a flood prevention system in Parit Raja town
that complies with the urban stormwater management manual. This study also established a
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baseline against the conventional system in order to integrate and improve the conventional
system for long term uses. Based on this study by Ab. Hamidhad, 2002, the application urban
stormwater management and recharge well system (REWES) useful for any types of soil and
condition is possible.
The present study aims to examine the stormwater potential of artificial drainage as
retention system where the water is channelled to surface infiltration or vertically spread to
the recharge well system. The well-recharging process is helpful to improve groundwater
quality because the raw groundwater is studied by Mohd Yusof (2009) contained iron. The
quality of groundwater can be diluted by the rainwater that can be recharged into the well.
The potential groundwater recharge well in Sri Gading district was chosen because it
is expected to gain popularity in the near future due to the rapid expansion of Parit Raja town
into a centre of education in the southern part of Johor, Malaysia.
2.5 Resistivity Exploration
As preliminary record to survey the location and area conditions, a simple survey for
profiling the layer needs to be conducted before the selection of any drilling well. According
to Edward (1966), the best way to learn the character of the formations beneath the Earth’s
surface is to drill through the formations, obtain samples while drilling, and record a log of
the borehole. The best point as well as installation of well logging consists of recording the
characteristic properties of the various strata in terms of depth. However, an electric log and
other kinds of geophysical logs may also be obtained under certain conditions. This method
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is the most popular technique for both regional and detailed groundwater explorations
because of its wide range of applicability and low cost (Kumar et al., 2001).
Almost all of the resistivity studies conducted by researchers in Malaysia show that
resistivity survey using geophysical techniques presented good results in subsurface profiles.
Therefore, this method was used to delineate aquifer geometry, and to estimate hydraulic
parameters such as hydraulic conductivity (K), transmissivity (T) and thickness (b) of
aquifer. Then, groundwater contaminations also found by Kumar et al. (2001) imply that
geo-electrical techniques offer an alternative approach of alluvial aquifer.
This technique is not limited for soil characteristics determination but Ibrahim et al.
(2003) showed that the capability of resistivity imaging is effective for delineating the
groundwater aquifer boundary and for mapping bedrock in the Banting area. The
interpretation clearly shows that the thickness of the aquifer varies between 10 m to 30 m,
and in some areas up to 45 m depending on length of line used. The depth of the bedrock
estimated using 2-D resistivity imaging generally varies from 30 m to 65 m. The results of
the resistivity imaging show that the interpretation is similar when compared to the reference
well logs. The accuracy this method was chose to use this sub surface survey layer at the
study area for three lines in layers.
Occasionally, the analysis of the result of resistivity does not match the existing
values. Musa et al. (2013) proved that the moisture content, types of soil, temperature, and
salt content influence the value of soil resistances. It also found that it is mainly influenced
by the type of soil (clay, shale, and others), moisture content, the amount of electrolytes
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(minerals and dissolved salts), and finally, temperature. The soil resistivity result shows the
real subsurface condition and at the same time indicates that the four point’s method on
undisturbed soil samples is correct (Musa et al., 2012).
Dhakate and Singh (2005) had almost the same findings using vertical electrical
sounding (VES) to interpret the sub surface layer as shows in Table 2.2. Therefore, the
interpreted results of these sounding curves useful to impliment before any costly projects are
undertaken.
Table 2.2 Values of vertical electrical sounding method for groundwater exploration Type of soil Interpretation sub surface
condition
Clay < 10 ohm-m
Sandy Clay/ Clayey sand/ Clay and Kankar (aquifer) 10-25 ohm-m
Weathered Dunite/ Peridotite/ Metabasalt/ Pyroxenite (aquifer) >25 – 160 ohm-m
Hard and massive bed rock > 160 ohm -m
Source: Dhakate and Singh (2005)
2.5.1 Soil Resistance at the Real Site
Surface geophysical measurements and well log geophysics offer a higher resolution power
in this sense (Ortege and Miranda, 2000 and 2004). Most researchers use the latest
techniques such as to survey the subsurface condition (resistivity or VES test). These surveys
are more efficient than conventional methods (borelog). However, the data analysis
sometimes refers to bore log records or have a similar record with others area.
An important method for sampling and testing is used to verify the resistivity survey.
Traditionally, direct drilling is a conventional method for exploring the subsurface in
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underground layers, but today, it is considered to be unsuitable. Nowadays, geophysical
methods using resistivity survey are used to achieve accurate results. The most popular
method for groundwater exploration is VES (Dhakate and Singh, 2005). However, to
interpret the best results of these sounding curves, one must refer to the standardized values
based on location and conditions. The soil resistivity test is widely used for simple
interpretation type of soil through sub surface results. Therefore, soil resistance was recorded
at this area for verification and interpretation analysis of other future works for unconfined
case.
Area conditions and soil contaminations affect soil resistances. A study by Ozcep et
al. (2009) analyzed the relationships between electrical resistivity and soil-water content in
the context of electrical properties of coarse-grained soils and developed a practical and
applicable relation for the determination of soil water content from geo-electrical
measurements. The presence of moisture and saltwater content in the ground also causes the
ions to dissolve in the moisture, resulting in a low resistivity of the soil.
The study on soil resistances at Sri Gading area can be potentially used for
comparable results in research in real conditions. Interpretation result based on soil resistancy
by Tjahjanto et al. (2006,) indicated that the layers of this area had very soft and very stiff
clay with less sandy layer as an aquifer (Tan et al., 2009). This prediction result also
indicated that Sri Gading is limited aquifer layer for stormwater management purpose.
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Although, Musa et al. (2009) suggested using the groundwater as an alternative water
supply at dry and wet conditions and control stormwater runoff in the wet condition by
groundwater recharge and discharge well system.
2.6 Groundwater Recharge
Groundwater recharge is applied in a low laying area with a high water table which is used as
underground retention of stormwater storage. When recharging the water to deep layers, this
potential aquifer provides alternative flow channels during the wet condition and discharges
groundwater by pumping method as needed. However, Sunjoto (2008) suggested an
applicable infiltration method using a recharge well for water conservation and supply in
urban areas due to limited space.
Several methods of groundwater recharge like spreading, pit, induced recharge and
well methods are practiced. When the well method is used, recharge is fast and has no transit
losses or evaporation losses (Khaledhonkar et al., 2003). Then, the groundwater recharge
system is a better alternative that supports the open channel system, capturing surface water
through infiltration, seepage, leaking, or recharge to the ground by gravity. This
groundwater recharge technique is in balance with the climatic cycle because recharge and
discharge must increase or decrease to readjust to the changed situation (Edward, 1966).
Well testing or evaluating aquifer transmissivity (Ortege et al., 1999) and
permeability (Ortege et al., 2000) using geophysical well log and hydrodynamic parameters
by longitudinal conductance is the best predictor of aquifer transmissivity. The pumping test
or well test by Pech (2002), was found that the skin factor affected the well bore storage in a
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single well and capable to estimate aquifer parameters. Although, the pumping tests do not
make it possible to study aquifer structural variability, which is necessary to efficiently solve
many hydrology problems (Ortege and Miranda, 2004).
The investigation of groundwater recharge involves a variety of approaches,
including soil moisture budgeting, well hydrograph analysis, numerical modeling, and water
balance solution (Misstear at al., 2009). Lewandowski et al. (2009) found that groundwater
recharge depends on factors such as temperature, vegetation, soil water saturation, and the
thickness of the unsaturated zone. When the river and the oxbow are blocked, groundwater
recharge does not occur since precipitating rainwater may flow directly into the surface water
bodies as surface runoff. The dampening and delay of fluctuations of the river gauge
spreading into the aquifer caused 70% of fluctuations, and 20% of groundwater recharge was
due to precipitation events. According to Majumdar et al. (2009), topography causes a
constant ratio of interflow and overland flow quantity to recharge the shallow aquifer. This
relied on hydraulic conductivity, thickness, and the surface slope. Most rainfall runoff studies
in the mountainous watershed focused on a single aquifer being recharged from the surface
soil layer. Very often, multiple aquifers, not just a single aquifer, receive the interflow from
the soil cover.
The use of injection wells to funnel stormwater to the underground aquifer has been
practiced in Florida for years. In central Florida, up to 40 percent of the aquifer recharge is
estimated to occur through drainage wells. A permit may be required if the department finds
that a well is affecting primary drinking water standards or public health. An existing well
may require alteration apart from routine maintenance, or repair work to restore a well to its
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