Enhancing adoption studies of LID-BMP’S for Storm Water Management Drainage (SWMD) national stadium in Jayapura, Indonesia

The essential of this paper is implementing Low Impact Development (LID) type stormwater Best Management Practices (BMP’s) to reduce stormwater run-off in urban areas. The case study taken is the development area of Jayapura National Stadium. The drainage system at the main stadium is divided into subsurface and surface drainage. Meanwhile, the development area will enhance the study of adopting several LID-BMP’s practices to manage and optimize the design to control stormwater run-off in the stadium before it is discharged into the urban drainage system. The methodology in this study is divided into data collection and planning. The data collected include daily maximum rainfall data, stadium master plan, soil investigation, macro drainage system, drainage master plan, and topography around the stadium. Meanwhile, planning includes calculating rainfall design, soil structure analysis, hydraulic planning, pipe dimensions, and planning for water storage. The rainfall design used is a 5-year return period with Log Person III, the best design from the suitability test analysis, which is 134.39 mm/day. The study examined drainage design effectiveness to control stormwater run-off on the drainage design at the main stadium and surrounding stadiums using the LID-BMP’s framework and compared them. The LID-BMP’s adoption study was to optimize the drainage design to obtain maximum run-off control that can reduce up to 7-10% of stormwater run-off due to design and soil structure. The results provided recommendations to the authorities to modify the current design to achieve the benefits.


Introduction
Increased run-off, impeded groundwater recharge, poor water quality of surface water bodies, and rising water demand threaten population health and development [1], [2].Urban water reuse is a key process of urban hydrology since it closes the water cycle [3] in environments where soil and atmosphere are disconnected by large and highly populated impervious areas [4], [5], [6].
Sponge city construction is a new concept of urban stormwater management, which can effectively relieve urban flooding, reduce non-point source pollution, and promote the usage of rainwater resources, often including the application of Low Impact Development (LID) techniques [7], [8], [9].The basic concept of a "Sponge City" refers to the urban construction approach aimed at efficiently and sustainably absorbing and managing rainwater, thereby reducing flood risks, minimizing rainwater pollution, and harnessing rainwater resources.This involves applying various Low Impact Development (LID) techniques, such as using bio-retention, grassy green areas, submerged green spaces, permeable 1311 (2024) 012055 IOP Publishing doi:10.1088/1755-1315/1311/1/012055 2 pavements, and rainwater storage tanks on-site.This approach has a positive impact on the environment, the economy, and the social aspects of the city.It represents a progressive step in sustainable urban rainwater management.
Low Impact Development (LID) is an urban development approach that aims to reduce the impact of urbanization on the environment.It includes a range of strategies for stormwater management, land use, and environmentally friendly building design.One of the key strategies in the LID approach is sustainable stormwater management.This strategy includes using technologies such as permeable pavement, green roofs, rainwater harvesting, and others.Low Impact Development (LID) has been recommended for stormwater management and urban planning, which approaches sustainability and aims to reduce the negative impacts of rising urbanization and impervious surfaces [10], [11].LID refers to practices and principles concerning specific sustainable water conservation goals [12], such as reducing run-off, recharging groundwater, protecting streams, increasing infiltration, and assessing water quality [13].
Best Management Practice (BMP) is a term that refers to a technique, process, activity, or structure to minimize the pollutant of stormwater discharge, which can be implemented individually or in tandem to maximize effectiveness [14].In the context of stormwater management, BMPs associate nonstructural methods (e.g., good housekeeping and preventive maintenance) with structural deployments (such as bioretention systems or green infrastructure) to reach the whole goal of pollution prevention [15].LID-BMP's are low-impact development best management practices that are used to control urban stormwater run-off quantity and quality.These practices include using porous pavements, green roofs, and rainwater cisterns, among others.By implementing these strategies, the amount of stormwater runoff that enters the municipal drainage system can be reduced, which helps to prevent flooding and improve water quality.
Due to the celebration of the National Sports Event (PON) XX in Jayapura -Papua Province as the Ministry of Youth and Sports accord regarding the event location, the local authorities will develop the Main Stadium to optimize its event.The infrastructure of the main stadium becomes a concern, especially the drainage system as part of flood control to avoid inundation and extend the service life of connecting roads and sports arenas.
The paper is to review the drainage design with enhanced adoption studies of LID-BMP's practice for stormwater management at the main stadium.Some practices are already in place, such as biopori and rainwater cisterns.However, the present studies are to enhance more types of LID BMP's to determine the effectiveness of drainage design and sustainability.The performance LID design scenarios with different locations and sizes of the bio-retention facility, the grassed swale, the sunken green space, the permeable pavement, and the modular storage tank were analyzed for a sports center project [16].
A planning analysis of implementing low impact development (LID) type of stormwater best management practices (BMPs) for urban run-off control is presented [17].The drainage design is planned to drain stormwater run-off, both on the surface and above the soil surface at the main stadium and its surrounding stadium.The adoption studies of LID-BMP's are to occupy maximum run-off control and reduce by the design and soil structure.The results are used to form recommendations to the authorities for modifying the present design in order to achieve sustainable benefits.

Description of Jayapura National Stadium
The stadium is located in Sentani the capital of Jayapura Province, nestles at Kampung Harapan, Sentani Timur District, Jayapura Regency, Papua Province with a stadium project area boundary equal to 62 Ha.The city itself burgeons as a rapid district and potential economic growth, is determined by the width of the area and resources.The stadium offers some facilities main stadium, aquatic stadium, multipurpose stadium, velodrome, commercial parking area, and green area.The studies will focus on drainage design in the main stadium.The master plan of Jayapura National Stadium can be seen in Figure 1.

Data Collection
Completion of this study requires several data, consisting: 1. Maximum daily rainfall data from St. Sentani with data period from 1996-2016,   Analyses soil structure with an assumed load of people on the field to determine the thickness of the geocomposite.After that, the equivalent permeability coefficient is used to calculate infiltration rates and distances between pipes, soil porosity, and soil absorption rate to get the drain pipe capacity.Design run-off discharge, hydraulic planning, and dimensions of the pipe that will be used to channel and support the surface drainage system.Finally, planning the storage which then goes to the drainage channel.

Calculate rainfall design to determine channel of drainage design and use modular tank (rain save)
as LID-BMP's practice to optimize the infiltration and reduce the stormwater run-off.

Rainfall Design A. Rescaled Adjusted Partial Sums (RAPS)
The widely used rescaled adjusted partial sums (RAPS) approach was used to detect and quantify trends and fluctuations of LSWT and air temperature time series [18], [19], [20].It can highlight trends, shifts, irregular fluctuations, and periodicities of the time series and is given by: Where Tmean is the mean value of the time series, STD is the standard deviation of the time series, Tj is the value of a sample, j=1,2, N, N is the number of samples in the time series.Collection data are used for the rainfall probability distribution design: Probable Maximum Precipitation (PMP), which should have a more than 10-year length period [21].We used St. Sentani as the closest rain gauge station for analyses of rainfall design.In addition, we only use St. Sentani because there is limited rain station construction in the region.The return period was analyzed by adopting continuous probability distributions such as Normal, Log Normal, Gumbel, and Log Person III.Furthermore, the rainfall data will be procced for distribution compatibility test with Chi-quadrat and Smirnov-Kolmogorov Method, which it determined with the value of χ2 and ΔPmax whereas the distribution values should be smaller than the critical values.A standard framework for return period design has been provided for return period design based on urban typology and catchment area by the Public Ministry of Indonesia [21].

C. Drainage Design.
The principle of LID-BMP's practice is to manage excess water (surface discharge/stormwater run-off) to reduce the risk of flood disaster, water pollution and channel capacity.The final purpose is to optimally infiltrate the stormwater run-off and reduce the volume of run-off overflow into urban drainage systems or rivers.Meanwhile, the drainage design considers the stormwater run-off to infiltrate into the soil, hopefully increasing the groundwater supply for reserve in the dry season.Stormwater management is all the efforts made to improve surface discharge problems that later occur and to prevent new problems, such as flood disasters, with structural and non-structural methods [22].The principle design of urban stormwater run-off management was already developed by British Columbia [23] and is based on water balance which generally around 75% of the total volume of stormwater run-off falling in the catchment area is in the form of low-intensity rainfall (< 30 mm/24 hours), 25% in the form of moderate intensity rainfall (30 -60 mm/24 hours) and 5% of it is high-intensity rainfall (> 60 mm / 24 hours) and has potential to cause flooding.Conventional rain run-off management relies on its design for the risk of extreme rain, which only accommodates about 5% of the total rainwater volume, and the probability of occurrence is small (related to the return period).Whereas, for just the type of rain spectrum that is built, 95% of the other rainwater is lost flowing into the flood control system, designed to release water to the water body immediately.So that the condition of the catchment area becomes poor water reserves, both in the form of surface water and subsurface water.Based on this analysis, runoff management is developing and designed to accommodate the entire rain spectrum in an integrated strategy.
The Low Impact Development (LID) method manages rainfall for low intensity to moderate rainfall by decreasing the volume of stormwater run-off and controlling water quality at the microscale or catchment area.The rainfall design (precipitation) used is for moderate to low rainfall (rainfall ≤ 50mm), or with a return period between 2 -10 years (50 -10% probability).
LID Planning in urban stormwater run-off management is by managing stormwater run-off that has a minimum impact.There are at least 13 LID practices to be elaborated obtained from the US EPA; Bioretention, Wetland, Detention Pool (Dry Pond), Retention Pond (Wet Pond) Grassed Swale, Green Roof, Infiltration Tub, Porous Pavement, Rain Barrel/Rain Harvesting, Sand Filter and Vegetated Filter trip.At this point, the paper will be specified into the modular tank or rain save.

D. Subsurface Drainage System Planning.
There are some factors that must be considered for subsurface drainage design: planning of the structure and soil permeability; planning and thickness of the geocomposite; infiltration rate; pipe spacing (drain spacing); dimension of the pipe; and maximum discharge served by each pipe.There are two important components for the design main stadium, the football field, and the drainage system; the lateral channel, and the main channel.

E. Surface Drainage System Planning.
There are some factors that must be considered for surface drainage design: Run-off Discharge, Flow Coefficient, Hydraulics Section, and Channel Base Slope, Manning Coefficient and Allowable Velocity.

Hydrological Analysis
Rainfall design for further drainage design work at Jayapura National Stadium can be seen in Table 1, which is determined by some hydrological analyses;

Subsurface Drainage System Planning A. Soil Structure Planning.
Soil structure design for drainage at the main stadium, especially on the football field, requires some layers to optimize drainage of stormwater run-off, which used the geocomposite method [24].Geocomposite as soil structure analyses for football field design: The first layer is grass followed by sand and animal manure (4:1) with a depth equal to 15 cm, permeability coefficient (k) = 0.0028 cm/sec, and γ = 17 kN/m 3 .The second layer is sand dunes with a depth equal to 10 cm, permeability coefficient (k) = 0.0002 cm/sec, and γ = 20.5 kN/m 3 .The third layer is pure sand with a depth of 5 cm, permeability coefficient (k) = 0.001 cm/sec, and γ = 18 kN/m 3 .The final layer is coral stones with two types of diameter: [a] diameter of the stones between 3 -10 mm with a depth equal to 5 cm and [b] diameter of 10 -20 mm with a depth equal to 15 cm, permeability coefficient (k) = 1 cm/sec and γ = 17.5 kN/m 3 .Poly-flex is to composite geocomposite layers produced from America with permeability coefficient (k) = 0.1905 cm/sec.Pipelines are planned using the Dupuit method.Pipe placement within the depth of 3.00 m from the soil surface.With permeability coefficient (k) = 0.00168 cm/hour.

B. Geocomposite Hydraulic.
This study used poly-flex composite produced by American Wick Drain, a global geocomposite manufacturing company.Its thickness of geocomposite obtained 0.461 inches or equal to 1.171 cm.The soil structure design using the geocomposite method determines the depth of the drainage pipe, which is placed 0.51 m below the surface.The conjunction between run-off discharge, the thickness of the geocomposite, and the depth design is shown in Figure 2.

C. Permeability Coefficient of the Equivalent Soil.
Based on the total infiltration that enters the soil, the design rainfall used compared to the soil permeability coefficient can absorb how much total infiltration of the rain is planned [25].

R5
= 134.39mm/day kv(eq) = 732.00mm/day Then it can be concluded that total infiltration of rainwater can enter the soil thoroughly.So, the total infiltration of rainwater = 134.39mm/day.

D. Drain Spacing.
For planning drain spacing for the football field, the data for calculation is used as shown in Table 2. Drain spacing illustrations are shown in Figure 3. From the results of the calculations, the drain spacing on the football field is 4 meters.

E. Calculation of Soil Porosity.
On the surface of the football field a type of solid sand type with uniform granules, with the pore value equal to e = 0.45.So, the calculation of its soil porosity is about n = 0.31035.

F. Soil Absorption Velocity.
After conducting the calculation of infiltration rate and soil porosity, then can be calculated the soil absorption velocity with: V = q/n V = 134.39/0.31035V = 433.03mm/day G. Drain Pipe Capacity.Calculation of drainage pipe capacity, even though the soil is homogeneous, it is feared that lateral flow will continue to occur in the soil layer.With a pipe length of 33.54 m and the distance between the pipe/drain spacing of 4 m, the discharge flow is 0.010 lt/sec.

H. Diameter of Drain Pipe.
The pipe diameter obtained was 4 cm.Because it is assumed that water only fulfills 1/3 of the pipe diameter, then d = 4.728 inches.The total discharge flowed by the pipe on the football field is 0.0005515 m3/second.Thus, with the calculation result, the pipe used is in units of inches, and the pipe is perforated at the top of the pipe, so the pipe that can be used with the closest size is a PVC pipe with a diameter of 5 inches or equal to 12.7 cm.It is known that the width of the football field is 105 meters, and the distance between pipes/ drain spacing is 4 meters, so 54 pipes will be used.In this case, the planned width of channel I is 0,4 m so that the length of each pipe to the channel can be known.Design drain pipe illustrations are shown in Figure 4 below.

Surface Drainage System Planning
The surface drainage design will adopt the principle of Low Impact Development (LID), which is a method to manage run-off discharge and control water quality at the microscale or catchment area.Moreover, the design will be considered to infiltrate the run-off discharge, which is shown on channel based will be used a modular tank to save the rainfall as much as possible to reduce run-off discharge that also will reduce fill of the urban drainage system of the river especially when it comes to peak flood discharge.The principle of modular tank design for drainage channels can be seen in Figure S2 (Supplementary Material).
The technical design of the modular tank/rain save is based on the drainage channel as follows below 1.The benefit is that it is easier to set up, and the modular tank unit can load over 14 tons of truck with a volume per unit of 500x500x250 with a weight of up to 2.00 kg, vertical compressive strength of up to 90 kN/m 2 dan creep strength about 36 kN/m 2 , horizontal compressive strength up to 30 kN/m 2 , the porosity is about 95 %.The modular tank could be used for rainwater harvesting by adding a geomembrane sheet as a cover if needed.2. Some indicators must be considered for designing the modular tank, which is high maintenance, the construction work is expensive, the slope should be determined in low to moderate, and the height of groundwater affects the design.

A. Permeability Coefficient of the Equivalent Soil.
Based on the total infiltration that enters the soil, the design rainfall used compared to the soil permeability coefficient can absorb how much total infiltration of the rain is planned [25].With R5 = 134,39 mm/day and kv(eq) = 732.00mm/day.

B. Soil Investigation.
Soil investigation is used to determine whether the soil condition in the project area could employ BMP LID's practice, such as modular tank/rain save, due to the design need to keep and infiltrate the run-off discharge.The depth of hoggin/rough sand is about 6.00 m, which is suitable for water harvesting, infiltration, and recharging the groundwater.The value of infiltration is k =10-103 mm/dt.

C. Calculation of Soil Porosity.
On the surface of the channel, a type of solid sand type with uniform granules, with the pore value equal to e = 0.45.So, the calculation of its soil porosity is about n = 0.31035 before planting the modular tank.

D. Modular Tank/Rain Save for Drainage Channel Design.
Based on the hydrology, soil structure, and hydraulic analyses, the channel calculation for Jayapura National Stadium can be seen in Table 3. and the master plan of a drainage system, which from the analyses, does not need to resize the channel dimension.The recommendation for imply studies of LID-BIM'S design and its reconstruction of the base of drainage channel to used modular tank Figure 5.The modular tank itself helps the run-off to infiltrate within the soil structure.The modular tank technology from our analyses can reduce the run-off discharge by about 7 -10%.The principles to imply LID-BIM's design with a modular tank for drainage channel are consideration of sustainability by which to infiltrate the stormwater run-off, to keep it in soil structure, and further recharge the groundwater.Moreover, the stormwater run-off is not as fast as it could drain into the river, which can help to reduce flood discharge on the river or urban primary drainage, and the change of the land use could reduce the flood risk.

Conclusions
In this paper, a planning analysis was conducted to implement Low Impact Development (LID) type of stormwater Best Management Practices (BMPs) to control stormwater flow in the national stadium area in Jayapura, Indonesia.The study involved data collection, such as daily maximum rainfall data, stadium master plan, soil investigation, macro drainage system, and topography around the stadium.In addition, rainfall design calculations, soil structure analyses, and hydraulic planning were conducted to determine the dimensions of pipes to be used in the surface and aboveground drainage systems.
The results of this study can be applied to other cases where stormwater flow is a problem in urban areas.Adoption of Low Impact Development (LID) type of stormwater Best Management Practices (BMPs) to optimize infiltration and reduce stormwater flow.Some examples of LID-BMPs that can be applied are the use of green roofs, rain gardens, bioswale, and permeable pavement.Secondly, careful planning and accurate data collection are also key in addressing stormwater flow problems in urban areas.In this study, data such as daily maximum rainfall data, soil investigation, macro drainage system, and topography around the stadium were collected.By having accurate data, it can facilitate the planning and calculation of rainfall design, soil structure analysis, and hydraulic planning to determine the dimensions of pipes to be used in surface and aboveground drainage systems.Thirdly, it can make modifications to existing designs to achieve sustainable benefits.

2 .
Master Plan of Jayapura National Stadium, 3. Soil Investigation at Jayapura National Stadium, 4. Macro Drainage System for Jayapura National Stadium, 5. Master Plan of drainage design at Jayapura National Stadium, 6. Topography of its surrounding stadium.

Figure 1 .
Figure 1.Master Plan of Jayapura National Stadium

Figure 2 .
Figure 2. The conjunction between run-off discharge, the thickness of geocomposite, and the depth design.

Figure 5 .
Figure 5. Detailed design of modular tank/rain save in the outer drainage channel of the main stadium.

Table 1 .
Resume of Rainfall Probability Distribution and Compatibility Test at St. The best rainfall probability distributions are determined by compatibility test, the value of χ2 and ΔPmax, whereas the distribution values are smaller than the critical values of Log Person III. 2. Rainfall frequency design peruses from the standard framework for return period design based on urban typology and catchment area referenced by the Public Ministry.The drainage design utilized of 5-year return period design, considering the project area is about 100 ha.

Table 2 .
Drain Spacing for Football Field.

Table 3 .
Resume of Channel Design Used Modular Tank.