EVALUATION FOR DRAINAGE PROBLEM IN JERUK ... - FTSL-ITB

EVALUATION FOR DRAINAGE PROBLEM IN JERUK PURUT
DRAINAGE SYSTEM, KECAMATAN PASAR MINGGU,
KOTAMADYA JAKARTA SELATAN
EVALUASI PERMASALAHAN SISTEM DRAINASE KAWASAN
JERUK PURUT,
KECAMATAN PASAR MINGGU,
KOTAMADYA JAKARTA SELATAN
Prayogi Akbar Putra 1 and Marisa Handajani 2
Environmental Engineering,
Faculty of Civil and Environmental Engineering, Bandung Institute of Technology, Jl. Ganesha 10
Bandung 40132
1 prayogiakbar@yahoo.com and 2 m_handajani@yahoo.com
Abstract: Jakarta as a capital city of Indonesia is one of big cities which frequently has flood problem. Flood
problem that occurred in Jakarta city is caused by typical matters in several regions in Jakarta itself, such as a
rapid transitional function of land due to the ongoing development process, topography condition of Jakarta city
which is located at a considerably flat area, and the drainage system that is no longer able to hold the rainwater
because of sedimentation and solid waste problem. The example of such region is at Jeruk Purut Area with the
Jeruk Purut water system in it which still has flood problem. The flood that happens at Jeruk Purut Area is
caused by the drainage channel in the Jeruk Purut drainage system is no longer able to hold rainwater that will
overflow to the road. This condition is getting worse because of the reduction of channel capacity by
sedimentations, solid wastes, and channel constringencies from the transitional land function made by the local
society. In order to handle the flood problem in Jeruk Purut Area, a whole observation of existing condition of
drainage system is needed to be done by evaluating the existing condition so that several alternative solutions
can be suggested. The evaluation shows that those problems are causing the difference between calculated and
existing discharge, so that the channel is no longer capable in flowing the rain water at this time.
Key words: Rainwater overflow, Jeruk Purut Drainage System, Channel capacity
Abstrak: Kota Jakarta, sebagai ibu kota Negara Republik Indonesia adalah salah satu kota besar yang kerap
kali mengalami banjir. Penyebab permasalahan banjir yang melanda Kota Jakarta ini merupakan hal yang
tipikal pada beberapa wilayah di Kota Jakarta, yaitu alih fungsi lahan yang terjadi dalam waktu yang sangat
cepat akibat pembangunan yang masih terus dilakukan, kondisi topografi Kota Jakarta yang terletak pada
wilayah yang relatif datar dan saluran drainase yang sudah tidak mampu menampung air hujan akibat
sedimentasi dan sampah. Salah satu contohnya adalah pada Kawasan Jeruk Purut, yang didalamnya terdapat
sistem tata air Jeruk Purut, yang masih mengalami permasalahan banjir. Banjir pada kawasan ini disebabkan
oleh saluran yang ada pada sistem drainase kawasan Jeruk Purut sudah tidak mampu menampung air hujan
sehingga air hujan melimpas ke jalan. Kondisi ini diperburuk dengan berkurangnya kapasitas saluran akibat
sedimentasi, sampah, dan penyempitan saluran yang terjadi karena perubahan fungsi lahan oleh masyarakat.
Untuk mengangani permasalahan banjir pada Kawasan Jeruk Purut ini perlu ditinjau kondisi eksisting saluran
secara keseluruhan, yaitu dengan melakukan evaluasi kondisi eksisting sehingga dapat diajukan beberapa
alternatif pemecahan masalah banjir pada Kawasan Jeruk Purut. Hasil evaluasi menunjukkan bahwa
permasalahan-permaaslahan tersebut menyebabkan perbedaan debit antara limpasan yang terjadi dan
eksisting, sehingga saluran tidak cukup lagi mengalirkan air hujan pada kondisi saat ini.
Kata Kunci: Limpasan air hujan, Sistem Tata Air Jeruk Purut, Kapasitas Saluran
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INTRODUCTION
The growing number of people and in need of resettlement in an urban area and
surrounding land use will increase and green area / open area that serves to temporarily hold
and absorb rain water into the soil decreased (Lo Russo,2009). An imbalance between the cut
and fill land, equitable distribution of roads for transportation, and many portions of pavement
which causes more resistance to seepage and resulting smaller portion of rain water runoff
and flood enlarged. Environmental impacts that occur to the drainage system due to human
activity is a change in land use since the 20th century (Inbar, 2002). To overcome this, one of
the steps that need to be taken is to notice the rain water management systems in an area in
order to conserve water, namely by observing the drainage system and retention pond as a
way to control floods. Drainage is a natural process, humans adapted to their own purposes,
directing water in space and time by manipulating the water level height (Abdeldayem, 2005).
The need for adequate drainage system has been required since several centuries ago, as 300
BC during a walk at the time were built with higher elevation to avoid a runoff on the road
(Long, 2007).
Jakarta city is a city with a centralized development leading to urban concentration of
economic growth so that the orientation of the population into the city is very high. The
explosion in population migration to the region with the lack of catchment areas such as
Jakarta is a significant problem and will cause flooding due to drainage facilities are
inadequate (Amini, 2009), the explosion of migration requires proper facilities and adequate
infrastructure. Today, the construction of facilities and necessary infrastructure such as
housing, waste management, drinking water networks, installation of water treatment, waste
water treatment installation, drainage, and so on are not able to compensate for population
growth that arise.
Flood prone areas and puddles in the city of Jakarta, geographically have been
identified as being particularly vulnerable locations of flooding and puddles of water. This
condition is caused by the region with a relatively flat topography which caused rain water
can not flow (low river flow rate), annual rainfall is quite high (> 200 mm), and drainage
channel conditions (primary, secondary and tertiary) were not able to drain rain water. Those
conditions were worsened by the rapid change of existing land use due to the rapid population
growth.
Those kinds of problems are also occured in Kotamadya Jakarta Selatan which is a
good place for living, work, study, and recreation. In its development, Kotamadya Jakarta
Selatan still has a variety of urban problems that must be overhauled. The problem that
always faced is the lack of functioning water system that ultimately led to a pool of water in
various areas in Kotamadya Jakarta Selatan. Therefore, it needs many handlings of these
issues so that the area of Kotamadya Jakarta Selatan remains the site qualifies as a place to
live, work, study, and so on.
This study focused on the areas where the majority Jeruk Purut a residential area, in
this region are also several schools and vacant lots, and grave. Floods are also common in this
area so difficult mobilization and convenience of local residents.
This study aims to identify and evaluate the factors that cause flooding in Kotamadya
Jakarta Selatan that is focused on Jeruk Purut area, and is part of the final project that aims to
provide an alternative treatment to minimize problems of drainage and flooding routines in
Jeruk Purut area.
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METHODOLOGY
This study uses some of the design methodology steps. The first step is taking the
primary data that is the image of the location, and the secondary data that is site plan, master
plan, affecting physical factors, and the daily rainfall data for several years. The second step is
to make Hydrological Analysis of rainfall data obtained. This step consists of the analysis of
rainfall data, frequency analysis of rainfall, and rainfall intensity analysis with several
methods hydrology. The next step is to identify the problems that occurred based on the
existing condition and interviews. The final step is to evaluate the problems that have been
identified based on comparison of the calculated discharge using the existing dimensions or
the capacity of the existing channel with the discharge calculated using the hydrological
analysis results or the actual discharge occurred.
On the identified and problematic locations, the calculation of the existing discharge is
applied using Manning’s Equation (Hardjosuprapto, 1998) with the assumption that the water
flows full in the open channel. Discharge is equal to the Cross-sectional area of flow times the
Hydraulic Radius times the Slope divided by Manning’s Coefficient.
1
Q A ⋅ R
n
Information: Q = Discharge (m 3 /s)
A = Cross-sectional area of flow (m 2 )
n = Manning’s Coefficient
R = Hydraulic radius (m)
S = Slope
2 / 3 1/
2
= (1)
Then the result from the equation above is compared with the calculation of the actual
discharge based on the Rain Intensity from the Hydrological Analysis using the Rational
Modification Method Hardjosuprapto, 1998). Discharge is equal to the Conversion Factor
times Storage Coefficient times Runoff Coefficient times Catchment Area.
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S
Q = F. Cs. (Σ C. A). I (2)
Information: Q = Discharge (m 3 /s)
F = Conversion Factor, F = 1/360 for Q in m 3 /s
F = 100/36 for Q in litre/s
Cs = Storage Coefficient
C = Runoff Coefficient
A = Catchment Area, for several catchment area the value of C.A
is changed to (ΣCi.Ai)
I = Rain Intensity (mm/hour) at concentrated time, tc (minute)
and Rain Recurrence, T (year)
HYDROLOGICAL ANALYSIS
Hidrological analysis is used to determine the rainfall intensity including Rainfall
Analysis, such as Complete the Rainfall Data from four rainfall catcher station, there are
Stasiun Penakar Hujan Pasar Minggu, Depok, Pakubuwono and Ciledug using Normal Ratio
Method, Consistency Test, Homogenity Test; Maximum Daily Rainfall Analysis using

Gumbel Method, Log Pearson Type III Method and Normal Distribution Method, then the
method selection using Chi Square Test which has change number bigger than 5%. Table 1
express maximum daily rainfall using chosen method.
Table 1. Maximum Daily Rainfall based on Gumbel Method
Recurrence
Interval (year)
Maximum Daily Rainfall
(mm/day)
2 162.34
5 203.97
10 231.53
25 266.35
50 292.19
100 317.83
Rain Intensity Analysis is performed using the Maximum Daily Rainfall with Van
Breen Method, Bell-Tanimoto Method, Hasper der Weduwen Method, and Mononobe’s
Method due to the insufficient data of the short-duration rain obtained that is only for the last
2 years (2007-2008). The selection of the will-be used Intensity Analysis Method is based on
the comparison of the deviation and visual comparison between the short-duration datas
obtained with the results from Van Breen Method, Bell-Tanimoto Method, Hasper der
Weduwen Method, and Mononobe’s Method.
The selected method is Van Breen Method because by visually and by the deviation
from this method is the most relevant to the short-duration datas, this method is applied to the
whole rain reccurence that is shown in Table 2, and from those results it can be formed the
IDF Curve that is shown in Figure 1.
Table 2. Rain Intensity with Van Breen Method
Duration
(minute)
2 5
Rainfall Intensity (mm/hour) for each
Recurrence Interval
10 25 50 100
162.34 203.97 231.53 266.35 292.19 317.83
5 197.59 210.40 218.31 227.89 234.79 241.50
10 180.76 195.62 204.57 215.22 222.76 230.04
20 154.45 171.53 181.70 193.67 202.07 210.09
40 119.63 137.63 148.50 161.37 170.41 179.05
60 97.62 114.91 125.56 138.30 147.33 156.00
80 82.45 98.64 108.76 121.00 129.76 138.21
120 62.90 76.86 85.80 96.79 104.76 112.53
240 36.75 46.24 52.53 60.48 66.39 72.27
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SITE DESCRIPTION
Figure 1. IDF Curve with Van Breen Method
The study plan site is at Jeruk Purut Area which is located in Kelurahan Cilandak
Timur, Kecamatan Pasar Minggu, Kotamadya Jakarta Selatan. The existing rain catchment
area is 70.233 ha with the majority land usage of residence and some part of the Jeruk Purut
Cemetery (BPS, 2008). In this area, it is located the major drainage channel which collects the
rainwater from Jeruk Purut minor channels that will be ended in Kali Krukut.
PROBLEMS IDENTIFICATION
Based on field observation, Jeruk Purut drainage system has some problem points that
need to be reviewed. The locations which the problems in Jeruk Purut drainage system are
occurred shown in Figure 2.
Inadequate Channel Capacity (Location I)
In some areas in the Jeruk Purut region, water overflow occurs flooding the road. The
overflow that caused the water puddle is found in the complex area of Jl. Kenanga. According
to the results of interviews with local residents, the water puddle is going up to ± 15 cm
during rain and has the time of 10 minutes to recede. Channels in the flooded region are open
minor channel and also passed through by Jeruk Purut major channel. Minor channels in the
overflow area has a width of 50 cm and 50 cm depth, while the Jeruk Purut major channel
which pass through this region has a width of 1.2 m and depth 1.2 m. The channels in this
location accommodate the load that comes from the minor channels ± 600 m along Jl.
Kenanga that have a majority of the land use is residential area. On the road that passed by the
Jeruk Purut major channel in the complex Jl. Kenanga there is no minor channel on the other
side of the road, it also supports the occurrence of water puddle problem on this road. This
area topographically is the upstream area of the Water System in the Jeruk Purut, but the flood
is still going when rain occurs. Of conditions that occur in that locations showed that the
channel capacity in that location can not accommodate the rain water coming down in the
area.
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Figure 2. Problems Location in Jeruk Purut Drainage System
Garbage Pile in The Channel (Location II)
Another thing that needs to be reviewed is also a heap of solid wastes cover the
drainage channel. Channel that is filled with garbage found in the area Jl. Taman Jeruk Purut
which is a minor channel that flows into the Jeruk Purut major channel. This channel is an
open channel that accommodates the loads from some of the Jl. Pemerintahan complex. This
channel have a width of 50 cm and depth of 50 cm. Waste piles that fill this channel have the
height about 15 cm and the width as same as the channel so that the channel’s depth that
passed by the flow is becoming about 35 cm. Those piles causes overflow at ± 20 cm to cover
the entire road and have the receding time of 10 minutes, but the flooded road is a blind alley
and not a main road.
Sedimentation in The Channel (Location III)
The channel that has the sedimentation is located at the minor channel in Jl. Taman
Jeruk Purut. This channel has a width of 60 cm and the depth of 60 cm and it is an open
channel. Sedimentation is caused by the mud that is in the channel. Those muds can be caused
by the soil that is brought by the runoff to the channel or it can also be caused by the domestic
waste that is dumped into the channel. In this case, the cause of the sedimentation is the soil
brought by the runoff; it is proved by the location of the channel that is around the open field
area. The existing sedimentation have the height about 15 cm and the width as same as the
channel so that the channel’s depth that passed by the flow is becoming about 45 cm. This
causes the channel capacity is reduced so that no longer can accommodate runoff flow which
will cause water overflow. According to interviews with residents around this area, the puddle
that happened was as high as 20 cm and has a 5-10 minutes receding time.
Channel Constringency (Location IV)
One of the problems that occurred in the drainage system of Jeruk Purut is there is
channel constrigency. This constringency occurred on Jeruk Purut major channel that is
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located in Jl. Melati complex. That channel that previously have the width of 1.2 m and the
depth of 1 m narrowed to 1 m in width and 1 m in depth due to the change of land usage
around that location. This problem is quite an important problem because the load that flowed
into this channel is coming from half of Jl. Jeruk Purut and the whole complex of Jl. Melati.
The water puddle that occured is about 15 cm with the receding time of 10 minutes.
Other problems
One of the other problems that occur on some point on the Jeruk Purut drainage water
system is them is a drainage channel closure by traders who sells at the top of the channel and
building up a semi-permanent above the channel. This will increase the runoff that occurred
on the road. The other problem is closed drainage channel by the home owner who enlarge
their houses to the road but does not include the street Inlet, which caused rain water can not
enter the channel is a channel that should be open.
There is some point on the Jeruk Purut area that have this same problem, which is
there is no drainage channel on the side road. This problem usually occurs on the streets or
alleys, the narrow alleys that can not be passed by vehicles. This will cause the rain water runs
on the road so that it will disrupt the mobility of local residents when it rains. Because of the
problems, in some particular location, there are several non-technical channel is created by
local people.
PROBLEMS EVALUATION
In areas that have been identified and problematic, evaluation is performed to the
identified problems by comparing the calculated discharge using the existing dimensions or
capacity of the existing channel with the discharge calculated using the hydrological analysis
results or the actual debit occurs. Existing channel capacity calculation is done using Manning
equation (Eq. 1) with the assumption of a full flowing stream in an open channel, and
discharge calculations based on the intensity of rain runoff from the Hydrology Analysis
using Modified Rational Equation (Eq. 2).
The results of the existing channel capacity calculations for all minor and major
channels on the location of the I-IV are shown in Table 3, while the calculated runoff
discharge in accordance with the intensity of the rain that happens to all minor and major
channels on the location of the I-IV are shown in Table 4.
Table 3. The calculation of the existing channel capacity on all channels at location I-IV
Location Segment
I
Point
Start End
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Condition
Existing
Q (m 3 /s)
48 C13 C14
0.141
49 C14 C15 0.183
56
57
C22
C23
C23
C24
-
0.279
0.206
59 C26 C27 0.243
Mayor 8 M11 M12 3.011
II 38 B11 B12
III 149 I32 I33
IV Mayor 5 M7 M8
Without Garbage 0.379
With Garbage 0.242
Without Sediment 0.898
With Sediment 0.628
Before Constriction 3.383
After Constriction 2.607

Table 4. The calculation of the actual discharge occured on all channels at Location I-IV
Location Segment
Point
Start End
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Runoff Q (m 3 /s)
48 C13 C14 0.831
49 C14 C15 0.926
I
56
57
C22
C23
C23
C24
0.601
0.677
59 C26 C27 0.800
Mayor 8 M11 M12 5.625
II 38 B11 B12 0.269
III 149 I32 I33 0.855
IV Mayor 5 M7 M8 3.335
Inadequate Channel Capacity (Location I)
From the results of calculations on the location I, it is obtained that some channel
segments in this region aree no longer can accommodate the rain water. These segments of
the major channels (M11 - M12) and several minor channel segments (C13 - C15 and C22 -
C27). For minor and major channels in the location I, the value of Manning coefficient (n)
used in the Manning equation is of 0.014 (for the ordinary concrete channels, steel mold good
condition).
In the calculation of runoff discharge in minor and major channels in the location I the
conversion factor used is 1/360 (Q in m 3 /s) and storage coefficient value (Cs) is 1 because it is
assumed there are no storation occured in the channels because of the dense residential and
the channel length is not too long. As for the value of rain intensity in the calculation of the
minor channel is 76.83 mm/h at time concentrations of 120 minutes and 5 Years Recurrence
Interval, and the calculation of the major channel is 82.9 mm/h at time concentrations of 120
minutes and 5 Years Recurrence Interval.
The results of calculations on the location I suggest that minor and major channels that
have been identified and the problem was no longer able to stream flow runoff occurs. This
may occur because of changes in land use in catchment areas such channels. Based on field
observations, catchment area for these channels are coming from a fairly dense residential.
Overflow discharge that occurs in the channels in location I shown in Table 5.
Table 5. Comparison between the existing discharge and runoff discharge for Location I
Segment Existing Q (m 3 /s) Runoff Q (m 3 /s) Q Difference (m 3 /s)
C13 - C15 0.141 0.831 0.690
C14 - C15 0.183 0.926 0.742
C22 - C23 0.279 0.601 0.321
C23 - C24 0.206 0.677 0.471
C26 - C27 0.243 0.800 0.556
M11 - M12 3.011 5.625 2.613
Garbage Pile in The Channel (Location II)
For channels in the location II, the value of Manning coefficient (n) used in the
Manning equation is of 0.014 (for the ordinary concrete channels, steel mold good condition).
In the calculation of runoff discharge in the channel at location II the conversion factor used is
1/360 (Q in m 3 /s) and storage coefficient value (Cs) is 1 because it is assumed there are no
storation occured in the channels because of the dense residential and the channel length is not

too long. As for the value of rain intensity in the calculation of the minor channel is 76.83
mm/h at time concentrations of 120 minutes and 5 Years Recurrence Interval.
The results of calculations on the location of II show that the presence of the waste in
the channel causes a change in the existing capacity of the channel. This can occur because of
the reduced depth of the channel due to the garbage pile. The reduced depth of the channel
will reduce the cross-sectional area through which flow so that the channel capacity will be
reduced. The overflow discharge is 0.027 m 3 /s at location II. Calculation comparison between
the existing discharge with the runoff discharge at location II shown in Table 6.
Table 6. Comparison between the existing discharge and runoff discharge for Location II
Condition Existing Q (m 3 /s) Runoff Q (m 3 /s) Q Difference (m 3 /s)
Without Garbage 0.379
-0.109
0.269
With Garbage 0.242 0.027
Sedimentation in The Channel (Location III)
For channels in the location III, the value of Manning coefficient (n) used in the
Manning equation is of 0.014 (for the ordinary concrete channels, steel mold good condition).
In the calculation of runoff discharge in the channel at location II the conversion factor used is
1/360 (Q in m 3 /s) and storage coefficient value (Cs) is 1 because it is assumed there are no
storation occured in the channels because of the dense residential and the channel length is not
too long. As for the value of rain intensity in the calculation of the minor channel is 76.83
mm/h at time concentrations of 120 minutes and 5 Years Recurrence Interval.
The results of calculations on the location of III show that the presence of the
sedimentation in the channel causes a change in the existing capacity of the channel. This can
occur because of the reduced depth of the channel due to the sedimentation. The reduced
depth of the channel will reduce the cross-sectional area through which flow so that the
channel capacity will be reduced. The overflow discharge is 0.227 m 3 /s at location III.
Calculation comparison between the existing discharge with the runoff discharge at location
III shown in Table 7.
Table 7. Comparison between the existing discharge and runoff discharge for Location III
Condition Existing Q (m 3 /s) Runoff Q (m 3 /s) Q Difference (m 3 /s)
Without Sedimentation 0.898
-0.043
0.855
With Sedimentation 0.628 0.227
Channel Constringency (Location IV)
For channels in the location IV, the value of Manning coefficient (n) used in the
Manning equation is of 0.014 (for the ordinary concrete channels, steel mold good condition).
In the calculation of runoff discharge in the channel at location IV the conversion factor used
is 1/360 (Q in m 3 /s) and storage coefficient value (Cs) is 1 because it is assumed there are no
storation occured in the channels because of the dense residential and the channel length is not
too long. As for the value of rain intensity in the calculation of the minor channel is 82.9
mm/h at time concentrations of 120 minutes and 5 Years Recurrence Interval.
The results of calculations on the location of IV show that the constriction causes a
change in the existing capacity of the channel. This can occur because of the reduced width of
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the channel due to narrowing of the channel. The reduced width of the channel will reduce the
cross-sectional area through which flow so that the channel capacity will be reduced. From
the results of calculations on the problem of debit differences in location IV shows that before
the constrigency channel capacity can still accommodate runoff flow, while the constriction
occurs the capacity of in the channel is not enough to stream flow runoff. The overflow
discharge is 0.728 m 3 /s. Calculation comparison between the existing discharge with the
runoff discharge at location IV shown in Table 8.
Table 8. Comparison between the existing discharge and runoff discharge for Location IV
CONCLUSION
Condition
Existing Q
(m 3 /s)
Runoff Q (m 3 /s)
Q Difference
(m 3 /s)
Before Constringency
After Constringency
3.383
2.607
3.335
-0.048
0.728
Based on field surveys and taking primary and secondary data can be identified that
Jeruk Purut drainage system has several problems which need to be reviewed. These problems
include channel capacity at some locations can not accommodate the rain water that caused
overflow, garbage piles that filled the drainage channel leading to a surge of up to cover the
entire section, sedimentation due to mud in the drainage channel, drainage channel narrowing
due to change in order to land around the channel. Evaluation results show that the problems
are the cause of the difference between the runoff discharge that occurs and the existing
discharge, so the channel is no longer enough rain water drains on the current conditions.
REFERENCES
Abdeldayem. S, 2005, Agricultural Drainage : Towards an Integrated Approach,
Irrigation and Drainage Systems, 19:71-87
Amini. A, 2009, Adjustment of Peak Streamflows of a Tropcial River for Urbanization,
American Journal of Environmental Sciences 5, 3:285-294
BPS. 2008. Jakarta Selatan Dalam Angka, Jakarta : BPS Kotamadya Jakarta Selatan.
Hardjosuprapto. Masduki, 1998. Drainase Perkotaan Volume 1, Bandung: Penerbit
ITB
Inbar. M, 2002, A Geeomorphic and Environmental Evaluation of the Hula Drainage
Project, Israel, Australian Geographical Studies, 40:155-166
Long. A.R , 2007, Drainage Evaluation at the U.S. 50 Joint Sealant Experiment,
Journal of Transportation Engineering, 133
Lo Russo. S, 2009, Groundwater in the Urban Environment: Management Needs and
Planning Strategies, American Journal of Environmental Sciences 5, 3:493-499
Suripin. 2004. Sistem Drainase Perkotaan yang Berkelanjutan. Yogyakarta: ANDI
Yogyakarta
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