MATEC Web of Conferences 147, 03006 (2018) https://doi.org/10.1051/matecconf/201814703006 SIBE 2017

Diversion Canal to Decrease Flooding (Case Study : Kebon Jati- Kalibata Segment, River Basin)

Dian Indrawati1,*, Iwan K. Hadihardaja2, M. Bagus Adityawan2, Syambali F. Pahrizal1 and Fajar Taufik1

1Faculty of Engineering, Jenderal Achmad Yani University, Jalan Terusan Jenderal Sudirman, PO BOX 148, Cimahi, West , 2Faculty of Civil and Environmental Engineering, Institut Teknologi Bandung, Jl. Ganesha No.10 Bandung 40132, , Indonesia

Abstract. The flood in has become a national concern in Indonesia. It is a haunting disaster, with a high probability to happen when heavy rainfalls in Jakarta and/or its upstream area. Based on data that was provided by Public Work Agency of DKI Jakarta, there are 78 vulnerable points of inundation in which, most of them are located in Ciliwung river basin, commonly in the meandering segments. One of the worst flooding occurs in Pancoran, at Kebonjati to Kalibata segment in particular. The river discharge in this segment is much higher as compared to the carrying capacity. In addition, this area has a high density of population and thus, difficult to increase the *river capacity* by enlarging the river dimension. In this research, a closed diversion canal is proposed as a solution. The effectiveness of the solution is evaluated using a numerical model, HEC-RAS 4.1. The diversion canal is designed as two culverts, with 2.0 m in diameter. Nevertheless, hydraulic jump may occur at the outlet of the canal due to the relatively steep slope. Therefore, the canal outlet should be designed accordingly. A Hydraulic structure such as a stilling basin can be employed to reduce the energy. The results show that the diversion canal has a good performance in decreasing water level and flood discharge in the study area. The canal has the capacity of 17,72 m3/sec and succesfully decreases the water level by 4.71 – 5.66 m from flood level for 2 – 100 years returned period.

1 Introduction for Ciliwung river flood based on FESWMS modelling, Emam [2] using HEC-HMS modelling in order to Based on data from Indonesian National Board for analyse land-use changes and assesment of climate in Disaster Management (BNPB), since 1815, flood upper Ciliwung river basin, and Murniningsing [3] become the most frequently disaster with 31.5% of shows that the developing of Ciawi, Sukamahi and events compare to others such as puting beliung, Katulampa weir DAM takes less significant values terorism, fire and earthquake. Specially for DKI Jakarta, compared to its huge cost. during period 2011-2015, there are 98 flood events occur This study will analyze the effectiveness of diversion and most of them were happened on Ciliwung river canal in order to decrease the flooding specially in basin and make these a national concern in Indonesia. It Kebonjati- Kalibata segment which indicated as the is a haunting disaster with a high probability hazard in source of problem in Pancoran area. every heavy rainfall occurs in DKI Jakarta area and/or its Although in some of researches show lackness of this upstream of river basin. method because of its impacts regard to sedimentation Flood in the Ciliwung river basin had presented annually [4] and [5], the river diversion recomended for river on since the 1600’s and in order to manage its disaster, flattened area [6] with dense population. several projects have been developing such as Amanus straits digging in North Bandengan in 1647, Bageracht 2 Literature Study and Mookervart from 1678 to 1686, and The Jakarta The flow in diversion chute canal should be occoring in Flood Canal i.e. West Flood Canal (KBB) and East supercritical scheme as the result of the deployed flow Flood Canal (KBT) recently. on the upstream structure which is requiring quick Furthermore, a numerous sources of this disaster had acceleration. So in the design flow, its depth in this been identifying, and one of them is the insufficient of section should be in uniform depth. Thus, it is necessary the carrying capacity of the river specially in meandering to define which condition the flow occur along the canal. segments. One of the worst flooding occurs in Pancoran Also whileas a possibility of occuring the hydraulics area whileas in a year several spots in this area reach 2 jumps inside, if it is happen, the location of it should be meter-height. determined. The last thing, back water curves probably Several studies related to this flood had conducted i.e occur inside and need to be analyzed along the canal [7]. Formanek [1] studied about Regional Flood Map Index

* Corresponding author: [email protected]

© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/). MATEC Web of Conferences 147, 03006 (2018) https://doi.org/10.1051/matecconf/201814703006 SIBE 2017

n , the diersion chte cana is modeing diersion cana hich ocated on 6116 as the cert condition hich is the assmtion o inet 6111 and 10616 10610 contro is that the o asses throgh critica deth near descries on igre 1 eo the inet and transiting to sercritica o the hdraics m occred in this arre, it is assmed its case the ie to ressirie aong the ength and o i act ie an orriice te this occrs, then the otet contro i ecome the anser or comting inet contro headater ith smerged inet, the eation are HW  Q  i    1 c  Y S D  AD 

hereas i is the headater energ deth aoe the inert o the cert inet m, is the interior height o the cert arre m, is the discharge throgh the cert ms, is the cross sectiona area o the cert arre m, is the soe o cert arre mm and ,,c, is eation constants, hich ar deending on cert shae and entrance conditions On contrary, for the outlet control flow using Bernoulli’s Fig. 1. eation in order to comte the change o energ

throgh the arre nder otet condition is ooing he diersion, hich ocated eore the anggarai ater a V a V gate, is a ssstem o ood management in aarta Z  Y   Z  Y   H g g L roince and eing a art o

here is the stream inert eeation o the cert

m, is the deth o ater aoe the stream cert EAST FLOOD CANAL (KBB) KBT INLET - CAKUNG inet m, is the aerage eocit stream o the KBT INLET - JATIKRAMAT KBT INLET - BUARAN cert ms, a is the eocit eighting coeicient KBT INLET - SUNTER KBT INLET - CIPINANG stream o the cert dimensioness, g is the EAST KALI BARU

acceeration o grait ms, is the donstream MANGGARAI WATER inert eeation o the cert m, is the deth o GATE CILIWUNG RIVER

ater aoe the donstream cert inet m, is the KEBON JATI –

JAVA SEA KALIBATA SEGMENT aerage eocit donstream o the cert ms, a is WEST FLOOD the eocit eighting coeicient donstream o the CANAL (KBB) KRUKUT RIVER cert dimensioness and is the tota energ oss KRUKUT SUB RIVER throgh the cert m he head oss is comted sing the orma SEPAK MERUYA    H h h h MOOKERVART L en f ex hich hen is the entrance oss m, h is the riction oss Fig. 2. – m and he is the eit oss m he riction oss in the culvert is computing using Manning’s formula derived as oo 3.2 Methodology  Qn  h  L  f AR his std consists o hdroogica and hdraics mode   hich are hdroogica mode as sed to otain ood here h is the riction oss m, is the cert ength hdrograh and hdraics mode as sed to simate m, is the o rate in the cert ms, n is the the o on the rier n order to estimate seera raina Manning’s roughness coefficient (dimensionless), A is retrned eriod, the data as etraoated sing anasis the o area m and is the hdraic radis m reenc method or the hdraics mode, its een cairated 3 Study Site and Methodology comaring ear ood retrn eriod ith caacit o rier an in the inet o diersion cana nd aaash has cosed enogh aes comares to 3.1 Study Site ationa, asers and nderee oreoer, n order to manage the ood in ancoran area, secia the schematication o the modeing shos in igre at eonati to aiata segment, ic or egiona eo ice o aarta roince i deeo the

2 MATEC Web of Conferences 147, 03006 (2018) https://doi.org/10.1051/matecconf/201814703006 SIBE 2017

Data Collecting : Flood Table 1. nfluence surfaces of ainfall tation in iliwung Climatology, Hydrograph Hydrological Frequency Start Hydrology, on Several iver Basin Analysis Analysis Long&Cross, Returned Infuence Area Land-Use Period Stations (km2) Flood Modelling of Bankfull Designed of Modelling in Hydraulics Diversion Capacity Diversion Canal Existing Analysis Canal Analysis Condition

Effectiveness Analysis of Diversion Canal for Several Finish Flood Returned Periods

Fig. 2.

4 Results and Discussion

4.1 Boundary and Initial Condition he model was etended aout m which is divided into cross sections namely y to rom the upstream to the canal, ie to , has , meter distance for mufflling the model dissipation and analye the accurve current And there are meter along after the tunel in order to analye Fig. 3. the effect of canal on the downstream river which defined as to Table 1. ainfall Area in iliwung iver Basin using olygon or the oundary condition, the model using flood hiessen hydrograph on the upstream and water elevation in the No. Year Bendung Cawang FT Gunung Average downstream, which are the water surface will compute Gadog UI Mas through eisting (without canal) and design (with canal) condition, each running , , , , , and of the return periods of flood hydrograph n order to validation, the years of hydraulics river model is comparing y anfull capacity of the river to adust the appropriate flood hydrograph for the A model as mention in the previous section 4.2 Diversion Canal Data and Coefficient ource uslitang A,

he diversion canal will e held on for the inlet Based on the freuency analysis, og earson and for the outlet with meter length Based distriution was accepted with the deviation standar on the multiple choice analysis, circle culvert has een value is , the sewness coefficient (s) is and selected compare with o culvert or other shape of the urtosis coefficient () is urther, fit tests culvert using hi suare and mirnov olmogorov that show he shape of the culvert itself defined y circle the acceptance of og earson distriution culverts with diameter meter each he value of he values of calculated hiuare is , he ritical Manning’s is 0.013, the entrance loss coefficient is 0.5, hiuare value is , the freedom of degree is and the eit loss coefficient is he culvert also has and the significant degree is On contrary, for the ottom elevation on inlet meter and outlet smirnov olmogorov test results the ma value is meter , the significant degree is and the ritical is 4.3 Hydrological Model Because of the lac of hourly rainfall data in its location, the rainfall pattern assumed y using average pattern hese hydraulics model held y several hydrograph with rainfall in ndonesia specially in awa island with , , , , , and return periods, whereas these distriution , , , , and for si discharges are eing derivated from (eleven) year of hours of rainfall heras calculation of the returned maimum daily rainfall data since until from period of rainfall is selected stations and was transformed to the rainfall area using olygon hiessen which has influences area each descrie on ale elow

3 MATEC Web of Conferences 147, 03006 (2018) https://doi.org/10.1051/matecconf/201814703006 SIBE 2017

Table 2. ainfall istrition in iling ier asin

Parameter Returned Period 2 5 10 25 50 100 200 1000 Fig. 4. rtherore, the floo ischarge calclate sing aaash ase on fittest analsis. he reslts of aaash nit hrograh are shon in ale 3. igre 5 shos the oertoing of iling rier Table 3. igre 5 loo ischarge sing aaash seciall in the inlet location for all ears of retrn erios. he ischarge of each is 55. 3s, 3.50 3s, .0 3s, 10.5 3s, 15.1 3s an 15. 3s for , 5, 10, 5, 50 an 100 ear, resectiel. 4.5 Modelling of Diversion Canal ase on oel, the iersion canal has ser critical flo ith roe ner 1.1 insie an has ressre ifference 35.50 g.s. his oeling sing to conition in orer to calclate hea loss i.e noral an flooing. otal hea loss in floo conition is 0.0 eter an on noral conition an 0. eter on flooing conition hich the ater teeratre is 30. he iersion canal oiosl aing a significant 4.4 Modelling of Existing Condition iact for ecreasing ater eleation in eonati ase on its contor, iling rier has stee an tight aliata segent an clearl recing the flooi in toograh in the strea an ecoe ore il an iling rier asin. ith fll serge flo, the ien follos the onstrea. ecase of the lac of iersion canal col carrie 35. 3s ischarge fro oseration ischarge ata, the reslt fro hrolog inlet to otlet an shortct the a along eanering oelling is eing coare ith analsis of anfll segent in iling rier as shon on ale . caacit at 1. he oelling reslts for to ear Table 4. ecaitlation of nflence of the iersion anal to retrn erio of rainfall ill lea 10.5 3s of he ater eel leation on iling ier ischarge ith 5.1 of ater eleation an the rating cre reslte 103. 3s of ischarge ith 5.1 of Return Flood Diversion Total Water Elevation [m] Note Periode Discharge Canal Discharge Before After the ater eleation, resectiel. [m3/s] Discharge [m3/s] Diversion Diversion [m3/s] Canal Canal

a 5 Conclusions eslts of the silation of its iersion canal shos on igre elo, hereas on eer retrne erio, ater leel ecoes ecrease significantl fro .1 – 5. eter. ts eans the iersion canal achiee .5 3.1 ecrease of floo in this segent.

c

4 MATEC Web of Conferences 147, 03006 (2018) https://doi.org/10.1051/matecconf/201814703006 SIBE 2017

Fig. 5.

e for project title as “Planning and Detail Watergate to its Upstream” sp

7 References

45 8( 10 5 Bowles D.S, Grant J.L, Humphries W.E, O’hayre 21 Design of Small Dams River Diversion Structures: Conception, Design and Adaption to Definitive Structures HEC-RAS River Analysis System Hydraulic Reference Manual Version 4.1

5