Drainage Capacity Analysis in The Area of Angke Jaya Tambora West Jakarta

Drainage is used to reduce and remove excess water in an area so that the area can be optimally enabled. This research aims to analyze and examine the drainage problems in the Angke Jaya Tambora West Jakarta Housing area, the drain channels are poorly maintained and often flooding. The data used in this study are primary and secondary, in the planning of flood debt calculations used 2nd anniversary. For the calculation of flood discharge plan to use rational method and coupled with the discharge of flood household, and the result will be compared with existing conditions of drainage channels in the residential area Angke Jaya Tambora West Jakarta. Obtained flood discharge plan of 13.225 m3/sec, for the existing condition of drainage channels 5 channels enter the category is not safe because the condition of existing capacity of channels is less than flood discharge plan, namely channels A4, D5, D6, D8, and D9. The planning of the wells to accommodate the excess discharge flooding, and it takes 19 pieces of replacement wells on the A4 channel, 1 on the D5, D, D8, and D9 channels.


Introduction
Population growth in Indonesia is increasing every year and requires a lot of land to be used as dwellings, especially in urban areas. The narrowness of the land and the large number of residential developments and supporting facilities make many unnecessary land uses. The impact of a large number of human activities and lack of attention to the environment gives rise to many natural disasters, such as floods that most often occur in urban areas. During high rainfall it is not uncommon for water to flood in the streets and until flooding can occur, this is due to a lack of community attention to land use and drainage channels. Stagnant water or flooding that can also occur due to lack of functioning drainage channels or channels that are inadequate in accommodating water discharge. If no action is taken to overcome this problem it will disrupt community activities and hamper economic, socialandcultural development.
Planning and maintenance of drainage channels is needed to maintain and regulate the flow of water to create a healthy and comfortable environment. Drainage system in general can be interpreted as a prsarana that functions to drain excess water from an area to receiving water bodies such as rivers. Drainage can also be interpreted as a system of drainage of clean water and wastewater from residential areas, industries, agriculture, road bodies and other pavement surfaces, as well as channeling excess water in general, whether in the form of rainwater, wastewater or other dirty water that comes out of the area concerned to water bodies or artificial recharge buildings.
In this study, researchers will conduct research on the Angke Jaya Housing area, Angke Village, Tambora District, West Jakarta, which is a residential area that pays little attention to the drainage system and not infrequently the streets in the housing area are flooded during high rainfall. VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174 Primary data is population data to determine household wastewater discharge for the purpose of calculating flood discharge plans, and existing conditions of drainage channels including channel length, channel width, depth, channel elevation, channel type and channel catchment area to determine channel capacity requirements to accommodate incoming water discharge.

2) Second Data
Secondary data is data of minimum daily maximum rainfall for the last 10 years obtained from relevant agencies for the purposes of calculating flood discharge plans, and maps of the Angke Jaya Housing Area, Kel. Angke, Kec. Tambora, West Jakarta.

Data Processing
At this stage after all the necessary data has been collected, data processing will be carried out with the stages of the calculation of the flood discharge plan and the calculation of the capacity of the existing drainage channels.

Data Processing Results
After the results of data processing will be obtained the results of planned discharge and channel discharge, and if the channel discharge is greater than the planned flood discharge then the calculation of the dimensions of the new drainage channel is not carried out, and vice versa if the planned flood discharge is greater than the channel discharge it will be taken into account dimensions of new drainage channels.

Research Methods
The research methodology used in this thesis is an evaluative descriptive analysis, a method that evaluates objective conditions in a situation that is the object of research, and the object of the study is the drainage channel in the Angke Jaya Housing Area, Kel. Angke, Kec. Tambora, West Jakarta.

Research Location and Time
In this final project, the research will be conducted in August 2019 until September 2019. The research location is in the Angke Jaya Housing Area, Kel. Angke, Kec. Tambora, West Jakarta. The location map of the study can be seen in Picture 2.1.

Hydrological Analysis
Hydrological analysis calculations are used to get flood discharge into the drainage channel being evaluated. The stages of the hydrological analysis calculation are as follows : 1. Calculate regional rainfall VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174 2. Analysis of the frequency of rainfall plans 3. Selection of distribution type 4. Test data compatibility

Rainfall Area Analysis
Rainfall data used is rainfall data for 10 years, namely from 2009 to 2018, rainfall data obtained from the Climatology and Geophysics Meteorological Agency.

Analysis of Frequency of Rainfall Plans
Rainfall analysis of this plan is carried out to find out the maximum daily rainfall that will be used to calculate the flood discharge plan. The following calculations use the Normal Distribution, Normal Log Distribution, Log-Person III Distribution, and Gumbel Distribution.

Normal Distribution
The following calculation is the probability of rainfall for a 10 year return period with a Normal distribution. Calculate the average value of variat ( ̅ ) VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id.

Log Normal Distribution
Following is the calculation of the rainfall probability re-distribution period of the Normal Log. Calculate the average value of variat (log X) ̅ ̅

Log Person III Distribution
Following is the calculation of the probability of rainfall with the Log Pearson III distribution.
Calculates the rain or flood logarithm with a return period T The K value (Interpolation) is a standardized variable for X, the magnitude of which depends on the coefficient of G, can be seen in the table K Value for the Distribution of Person Log III. VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id.

Gumbel Distribution
Calculate the average value of variat (log X) ̅ ̅

Selection of Distribution Type
Statistical parameters in the selection of this type of distribution needed are Standard Deviation (S), Skewness Coefficient (Cs), Kurtosis Measurement (Ck) and Variation Coefficient (Cv).
Here are the results of the calculation :

Chi Square Test
Before carrying out the calculation of the data suitability test, first carry out data processing, which is to sort data from the largest to the smallest as presented in table 4.12.
ISSN: 2656-1174 (online) G = + 3.33 ( ) = 4.33 ≈ 5 The distribution class used 10 pieces of data is 5. As an interval class that is used every 20%. Data intervals are taken from the reset period as follows : The results of the calculation of the distribution class above are then included as class interval classes in each probability distribution.

Smirnov Kolmogorov Test
The results of calculations can be seen in table 4.14, an example of calculation using data in 2008, which is as follows: VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174 a. Sorting rain data from large to small can be seen in table 4.12, and look for opportunities with the opportunity formula as follows :

Calculation of Flood Discharge Plan
The design of flood discharge calculation is carried out to get the flood discharge entering the drainage.

Flow Coefficient
Flow coefficient (C) is a constant price, a ratio between the rain that flows on the surface and the rain water that falls. In the Angke Jaya Tambora Housing Area of West Jakarta, the study was included in the character of multiunit housing (combined), so that the value obtained in accordance with table 2.9 was 0.60 to 0.75 and the highest value was taken, 0.75. VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656-1174 (online)

Calculation of Intensity of Rainfall Area
The return period that will be used in the calculation of rainfall intensity is a return period of 2 years. Rainfall intensity is calculated using the mononobe formula with the concentration time value (tc). Calculation of rainfall intensity on channel A1 is as follows: XT = 130,617 mm day TC = 22.92 minutes The results of a complete rainfall intensity calculation are presented in table 4.16. VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656-1174 (online)

Distribution of Catchment Areas
Catchment area calculations are done using the help of Autocad software. The catchment area can be seen in Figure 4.1, and the area of drainage catchment area can be seen in table 4.15.

Calculation of Rain Water Flow Discharge
Tabel 3.18. Rainwater Flow Discharge Source: Calculation Analysis Results Calculation of rainwater flowrate using the rational method formula, the following is the calculation of rainwater flowrate for channel D2, which is as follows: Qp = 0.278 C.I.A VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174

Calculation of Dirty Water Discharge
The calculated dirty water discharge is the water debit that comes from household waste, and other buildings. The amount is affected by the large number of residents and the average water needs of the population. Estimates for the average disposal of liquid waste per person per day are presented in table 2.10, and it is concluded that the amount of waste water per person per day is 400 liters. Following are the calculations for channel D2. Q_ak = Pn x 400 liters / person / day Q_ak = Pn x 0.00463 liter / person / sec Q_ak = 45 x 0.00463 liter / person / sec Q_ak = 0.2083 m3 / sec The complete calculation for dirty water discharge has been presented in

Calculation of Flood Discharge Plan
In the calculation of flood discharges in the Angke Jaya Tambora Housing Area of West Jakarta, namely rainwater flow discharges added with dirty water discharge. The following is a calculation on channel A1. m3/dt Complete calculations for flood discharge are presented in table 3.20. VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174

Calculation of Drainage Channel Dimensions
After knowing the planned flood discharge in the West Jakarta Angora Jaya Tambora Housing Area, the dimensions of the existing drainage channel will be calculated to determine whether or not the channel is sufficient to accommodate the planned flood discharge. Furthermore, if there are unsafe channels, a new drainage channel calculation will be performed to determine the dimensions of the safe channel.

Infiltration Wells Plan
The infiltration well planning is used in draining excess water discharge in several "unsafe" channels by draining rainwater that falls from the roofs of residents' homes to seep into the ground by storing the water in the infiltration well. Channels that fall into the "unsafe" category will be presented in table 3.22, as follows : VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id.
ISSN: 2656-1174 (online) Based on table 3.22, there are channels that fall into the "unsafe" category, so that an infiltration well will be planned.

Infiltration Wells Construction
1. Channels of income / expenditure using pralon pipes. 2. The well wall can use masonry without plastering 3. The bottom of the well and the gaps between the soil excavation and the wall where the water is absorbed are filled with fibers / gravel.

Discharge of Rainfall Plans on the Roof Surface
To find out the flow of rain that enters the infiltration well, it is necessary to know in advance the flow of rain falling through the roof of the residents' houses. Example calculation using No. A4 channels as follows: Q masuk = 0.278. C.I.A Is known : Catap = 0.75 (based on Table 2.9. Runoff Coefficient Standard) IA4 = 29.14 mm / hour Aatap = 80 m2 = 0.0080 km2 So, Q masuk is: Qmasuk = 0.278. 0.75. 29.14. 0.008 = 0.048607 m3 / sec Calculation of rain discharges that fall to the roof surface will be presented in full in table 3.23, as follows :

Discharge of Absorption Well Absorption
Furthermore, it is necessary to know the discharge of rainwater that enters the absorption well (Qresapan). The calculation refers to No. Channel A4, as follows : VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656ISSN: -1174  -Qresapan = Discharge that can be absorbed by infiltration wells (m3 / sec) -Type of blank wells with circular appearance -The planned well diameter is 2 m = R = 1 m -F = geometric / circumference factor = = 2 x 3.14 x 1 = 3.14 m -K = For the soil permeability value, it is assumed that the value of K = 10-2 cm / s = 10-4 m / s for the shaft soil.

Residual Water Discharge Flowing into Drainage Channels
Furthermore, it will be found the difference in the remaining discharge from the rain discharge that has been accommodated into the infiltration well, by way of Qmasuk (

Total Infiltration Wells Needs
After knowing the difference in the remaining discharge from the rain discharge that has been accommodated into the infiltration well, it can be seen the amount of infiltration well needs in the area of the house in each Channel Number. Example calculation refers to No. A4 channel: Is known : Discharge Excess A4 = 0.92 m3 / sec (Table 4.22) Qtampung = 0.047979 m3 / sec Settlement : The calculation of the number of recharge well requirements in full is presented in table 4.26 as follows : 88 VOLUME 2 │ NUMBER 3 │ MAY 2020 Available online at http://proceedings.worldconference.id. ISSN: 2656-1174 (online)

Conclussion
From the results of the analysis and discussion in the previous chapter and answer from the formulation of the problem, the following conclusions can be drawn: 1. The condition of the drainage canal in Angke Jaya Tambora Housing Area West Jakarta is poorly maintained, there are many houses that progress to cover the existing channels, making the channel difficult to clean, so there is a lot of garbage in the channel and accumulation of sedimentation. There are 5 channels that are concluded to be "unsafe", because the planned flood discharge is greater than the drainage capacity, namely on channels A4, D5, D6, D8,andD9. 2. The need for flood drainage capacity in the Angke Jaya Tambora Housing Area of West Jakarta is 13,225 m3 / second.5.2 Suggestions Suggestions that can be delivered at the writing of this thesis after getting the results and solutions provided, the advice that will be given are as follows: 1. Regular cleaning of drainage channels, on sedimentation and rubbish in the drainage channel. 2. Construction of infiltration wells on channels A4, D5, D6, D8, D9 can be carried out, so that in the rainy season stagnant water can be diverted to infiltration wells.