Planning For Kucica Residential Drainage System in South Tangerang City Using SWMM Modelling

Planning an efficient drainage facility in residential areas is necessary to drain run-off water on the surface. To minimize the potential for inundation that can cause flooding. This research aims to design an efficient drainage system in one of the residential areas in BSD and to analyze the ability of drainage channels using the EPA SWMM 5.1 application for a 10-year return period. The results of this study for secondary channels with a maximum discharge plan of 0.101 m3/s can use a U-Ditch with dimensions of 30 cm × 40 cm, while primary channels with a maximum discharge plan of 0.288 m3/s can use a U-Ditch with dimensions of 40 cm × 60 cm. In this analysis only taking into account rainwater run-off from household sewage is not taken into account. In the main channel, using retention pond only can reduce around 12% of maximum discharge, so the alternative of flood prevention for this residential area can be implemented by using bio pore holes, which reduce 27.85% of maximum discharge. From these analyses, it can be concluded that the drainage system design can already accommodate the flood discharge, and adding retention pond does not affect decreasing flood discharge on the main channel too much.


Introduction
South Tangerang City, which is one of the cities for DKI Jakarta Province, is experiencing rapid development.This development also made investors in the property sector make the city of South Tangerang one of the strategic areas to build housing.Housing itself is a group of houses that function as a residential area or residential area equipped with environmental infrastructure and facilities [1].If in the construction of the housing, there is no review of the drainage system that will be applied to the housing area, this can cause the problem of flooding to get bigger and wider.Making good drainage facilities in housing is needed to drain rainfall run-off on the surface and minimize the potential for inundation that can cause flooding.Drainage is a technical activity carried out to handle excess air caused by rain, seepage, excess water sprinkling, or wastewater from household buildings by draining, draining, disposing of, absorbing, and other actions that aim to restore or maximize the function area and avoid water bridges [2].The problem to be studied is the design of an efficient residential drainage system in accordance with the needs of the area.To create a healthy, clean, safe, and comfortable life, as well as one of the factors to control floods or floods that often occur in the security area.One way to evaluate urban drainage systems is to use run-off modeling simulations, namely the EPA SWMM 5.1 software [3].With an adequate drainage channel system, the water overflow on the surface can be controlled to prevent stagnant water or flooding in the area.The method that will be used to carry out this run-off 1311 (2024) 012049 IOP Publishing doi:10.1088/1755-1315/1311/1/012049 2 modeling simulation is the EPA SWMM 5.1 model.This modeling can be used to plan the ability of a channel to accommodate the overflow of rainfall in a drainage system.As well as to find and determine the right drainage system.Other studies have analyzed similar problems using SWMM and Rational Method [4], [5], [6], [7], [8], [9], [10], [11], [12], [13].

Study Locations
The location for this research is Kucica Residential, Jl.Kucica Pondok Pucung, South Tangerang City, Banten In Figure 1, we can see that only using piping system is not enough.However, we need a structure to accumulate the water before distributing it.For this case, Broncaptering is used.Broncaptering is one type of storage building that accommodates or captures water from springs [5].Broncaptering volume that will be planned is made by considering topographic conditions, geology, and optimum storage capacity.Broncaptering functions as an intake building that functions to tap the flow from springs, regulates the supply of water, sediment, and prevents the presence of bottom sediment and garbage that will enter the Broncaptering.In short, Broncaptering is used to gather the water like a reservoir before distributing it using pipe system.

Methods
The methods are divided into data collecting methods and analysis methods.The data collecting method consists of primary data and secondary data.Primary data is in the form of previous journals and books, while secondary data is data to be analyzed, such as residential site plans, research locations, and daily rainfall data.For analysis, here are the steps.
The first step is Hydrological analysis to obtain planned rainfall, using data from rain stations that affect the research location after doing the rainfall frequency analysis.The rain distribution compatibility test uses two types of probability tests with the suitability of the existing data.Chi Square Test and Smirnov Kolmogorov.After that, the chosen method of both tests, analysis of rainfall discharge for return periods of 2, 5, 10, 20, 25, 50, 100 and 200 years, is done using the selected method.From the rainfall analysis, rainfall intensity was determined using the Mononobe equation.From Mononobe equation, the flood discharge can be determined using rational equations, and the drainage dimension can also be determined using the Manning equation.After determining the drainage dimension, this system was modeled in SWMM.Analysis of flood discharge using SWMM modelling used to analyze the drainage performance that has been designed.The parameter of how the drainage is good if the drainage does not overflow to the main area and is capable of accommodating the 10-year flood of this design.

Hydrological Analysis
Hydrological analysis was carried out to determine rainfall intensity, with annual rainfall data used for 22 years, from 1998 to 2019.This rainfall data is the annual maximum rainfall data from daily rainfall data which has been obtained using the multi-rainfall analysis method.Satellite from NASA's https://disc.gsfc.nasa.gov/website by inputting data for the time and location of rainfall.Table 1 shows the maximum daily rainfall in the area for flood frequency analysis.From Table 2, it can be seen that distribution compatibility test in the table distribution compatibility test where the third distribution does not match the parameters for CS values and CK values, the frequency analysis uses the distribution of Log Person III, which is acceptable.The Kolmogorov Smirnov test also said the same result which Log Person III is acceptable as the right option for distribution which can be seen in Table 3.

B. Rainfall Analysis
Rainfall intensity is needed to determine the run-off discharge of rain.However, for calculations using the SWMM software, the rain intensity used for input in the time series is the hourly rain intensity.The calculation of rain intensity using the Mononobe formula is shown in Figure 2.

C. Flood Discharge Analysis
The overflow water discharge from rainfall is the volume of rainwater per unit of time that does not experience infiltration, so it must end through drainage.The flood discharge and drainage dimension can be calculated using a rational method.Results are shown below in Table 4.

Hydraulic Analysis
Drainage modelling is carried out to simulate the overflow of rainfall that occurs in the research area.This modelling consists of catchment area, hydrology and channel hydraulics.In planning this drainage channel, a time period of 10 years is used.Here are the results of SWMM Modelling.From Figure 3 to 5, it can be shown that all the channels able to accommodate the discharge.There is no flooding sighted on location.For another contingency plan in the study area, a retention pond is going to be constructed.The size of the pool used has an area of 85 m2 with a depth of 3 m and a pool capacity of 255 m3.Here is the comparison of flood discharge with and without the retention pond shown in more detail in Table 5.Using a retention pond in the SWMM simulation on channel 7 with an area of 85 m2 and a depth of 3 m with water flowing by gravity or without a pump.The maximum overflow discharge only decreased from 0.067 m3/s to 0.059 m3/s.This decrease in discharge does not have a major effect on the existing drainage system.Because the costs incurred for the construction of the retention pond will be very large while the impact of reducing the flow rate caused is not too large.From a previous study in the same location by Prabowo, results showed that using biopore holes reduces 27.85% of maximum discharge.It can be seen that eco drainage in this location is more effective than the conventional method of using a retention pond, which costs more to build.

Conclusions
From this analysis, there are several things that can be concluded.Using the Rational method, each of the drainage channel dimensions and flood discharge can be seen in Table 4, and it can accommodate the flood discharge.From SWMM Simulation, all the drainage channels are able to accommodate the flood discharge.In the main channel using retention pond only can reduce around 12% of the maximum discharge, so the alternative of flood prevention for this residential area can be implemented by using bio pore holes, which reduce 27,85% of the maximum discharge.

Table 1 .
Annual Maximum Rainfall DataAt this stage, a compatibility test is carried out based on frequency analysis, which is carried out on the skewness coefficient (CS) and kurtosis coefficient (CK) values following the requirements of each analysis.

Table 2 .
Distribution Compatibility Test

Table 3 .
Comparison of D Crit and D Max

Table 4 .
Flood Discharge and Channel Dimension

Table 5 .
Flood Discharge Comparison