The 11th International Student Conference at Ibaraki University,

Ibaraki, Japan, December 5-6, 2015

DESIGN OF ZERO RUNOFF SYSTEM AT IPB DRAMAGA CAMPUS,

BOGOR, WEST JAVA ○ Muhammad Ihsan*, Budi Indra Setiawan**, Nora H. Pandjaitan***

*, **, ***Civil and Environmental Engineering Department, Faculty of Agricultural Technology,

Bogor Agricultural University

E-Mail: *ihsansitepu@gmail.com, ** budindra@yahoo.com, ***noraherdiana12@gmail.com

Keywords: drainage, flood, runoff, water pocket, ZROS

1. Introduction Bogor Agricultural University (IPB) Campus is an

urban area that experienced flooding when heavy

rain occurred, especially at Graha Widya Wisuda

(GWW)’s parking lot, Kamper Street (FEMA), Meranti

Street, and Tanjung Street. The documentation of

flooding in GWW’s parking lot and Kamper Street

are presented in Fig. 1 .The drainage system of IPB

campus is a conventional system. It drain surface

runoff as fast as possible to the outlet. Zero Runoff

System (ZROS) is one of technologies to minimize

runoff using water storage. The advantages of ZROS

are runoff minimization, local aquifer’s recharge, and

damage mitigation on public facilities. This research

aimed to design ZROS at IPB Campus that capable

to minimize surface runoff.

(a) (b)

Fig. 1. Floodings Documentation in: (a) GWW’s parking

lot; and (b) Kamper Street

2. Methods This research was conducted from February to

August 2015. The scope locations of this research

are Graha Widya Wisuda (GWW)’s parking lot,

Kamper Street (FEMA), Meranti Street, and Tanjung

Street. The research methods consist of Water

Catchment Area (WCA) delineation, maximum rain

(R24) analysis, surface runoff and drainage channels

analysis, infiltration rate analysis, and ZROS water

pocket design.

2.1. Water Catchment Area Delineation WCA boundaries were delineated based on

topographical and drainage network system map.

Topographical map was created by surveying using

total station and Global Positioning System (GPS).

Drainage network system map was created by doing

direct observation in the field. The maps then

overlayed using GIS and delineated into WCA maps.

2.2. Maximum Rain (R24) Analysis R24 was analyzed using Normal, Log Normal,

Log Person III, dan Gumbel distribution analysis

based on 2004-2013 Dramaga Maximum Daily

Rainfall data. Bhim et al. (2012) [3] stated that every

distribution analysis have statistical parameters

requirement, which are Skewness and Kurtosis

Coefficient. Suripin (2004) [7] also stated that WCA

with area of 10-100 ha can use R24 with 2 years

return period.

2.3. Surface Runoff and Drainage

Analysis Asquith et al. (2011) [2] stated that rational

method can be used to analyze surface peak runoff

(Qpeak) in relatively small area. Runoff coefficient (C),

rainfall intensity (I), and WCA (A) are considered in

rational method. C was calculated based on land use

map. Rainfall intensity was calculated using

Mononobe equation (Suyono and Takeda 1983) [8].

Qpeak then compared with drainage channels

capacity to evaluate drainage system capability.

Drainage channels capacity were calculated using

Manning equation (Suripin 2004) [7]. Drainage

system evaluation was conducted in area that

experienced flooding.

2.4. Infiltration Rate Analysis Infiltration measurements were conducted in

three locations, which are GWW’s parking lot,

Kamper Street (FEMA), and Meranti-Tanjung Street

(near CCR building). Cumulative infiltration

measured using mini disc infiltrometer. Cumulative

infiltration data used to determine infiltration rate

using Philip model (Philip 1969) [6].

2.5. ZROS Water Pocket Design Campisano et al. (2014) [5] stated that the

dimension of drainage structures influence the

runoff minimization. Design of ZROS water pocket

referred to Indonesian National Standard or SNI

03-2453-2002 about Design Procedure of Rainwater

Recharge Well for Yards (BSN 2002) [4] with

modification of rainwater harvesting storage.

The 11th International Student Conference at Ibaraki University,

Ibaraki, Japan, December 5-6, 2015

3. Results and Discussion

3.1. Water Catchment Area Based on WCA delineation, the study location

was divided into 8 WCA, 13 sub-WCA, and 22

sub-sub WCA. The flooding location located in

sub-sub-WCA 1-1C (GWW’s parking lot, 3 locations),

sub-sub-WCA 1-1B (Kamper Street), sub-sub-WCA

2-1B (Meranti Street, CCR) and sub-sub-WCA 2-2A

(Tanjung Street, CCR). The area of flooding WCA and

the source of runoff presented in Table 1.

Table 1. Area of flooding WCA and source of runoff

WCA Area (ha) Source of Runoff

1-1B 5.900 1-1B

1-1C 1.984 1-1; 1-2

2-1B 7.810 2-1B

2-2A 2.955 2-2A

3.2. Maximum Rain (R24) Based on distribution analysis results,

determined R24 value is 125.68 mm with 2 years

return period from Gumbel distribution. This value

will be used to determine Qpeak and water pocket

dimensions.

3.3. Surface Runoff and Drainage

Evaluation Qpeak calculated from rational method will be

compared with drainage channel capacity (Qchannel)

to determine the capability of drainage system.

Based on calculation results in Table 2, all flooding

WCAs were evaluated not having appropriate

drainage capacity. The drainage system will be

modified with addition of ZROS water pockets to

minimize the runoff.

Table 2. Comparison of Qpeak and Qchannel

Sub-sub-WCA Qchannel (m3/s) Qpeak (m3/s)

1-1B 2.737 2.979

1-1C 0.189 0.424

2-1B 0.747 1.381

2-2A 0.092 0.461

3.4. Infiltration Rate Soil infiltration rate is an important factor in

ZROS design since the main concept of ZROS is to

store rainwater and infiltrate it to the soil. The

cumulative infiltration measurement result in three

locations are presented in Fig. 2. Infiltration rates (K)

acquired from Philip model analysis based on

measurement results are also presented in Fig. 2.

GWW’s parking lot has the slowest K (0.513

cm/hour), followed by CCR building area (7.856

cm/hour), and FEMA area (18.955 cm/hour). Arsyad

(2010) [1] stated that soil with infiltration rate ranged

from 2 – 6.5 cm/hour were categorized as

intermediate rate, and more than 6.5 cm/jam were

categorized as fast rate.

Fig. 2 Cumulative infiltration and infiltration rate

3.5. ZROS Water Pocket Design The schematic design of ZROS water pocket is

presented in Fig. 3. Total water pockets designed to

minimize the runoff are 44 units in the flooding

areas. The water pocket dimensions are presented in

Table 3.

Fig. 3 Schematic design of ZROS Water Pocket

Table 3. Water pocket dimension in flooding areas

Sub-sub-

WCA

Water

pocke

t

L

(m)

H

(m)

Stored

(m3)

Infiltrated

(m3)

1-1C (A) 9

1.6

0 2.83 27.90 1.373

1-1C (B) 8

1.6

0 2.88 24.80 1.238

1-1C (C) 10

1.6

0 2.82 31.00 1.522

1-1B 7

1.2

0 3.40 8.40 13.535

The 11th International Student Conference at Ibaraki University,

Ibaraki, Japan, December 5-6, 2015

2-1B 5

1.2

0 2.98 6.00 20.850

2-2A 5

1.2

0 2.41 6.00 17.554

4. Conclusion Based on ZROS analysis, to reduce runoff with

maximum rainfall of 125.68 mm, 44 units of ZROS

water pocket is needed. The dimension of water

pocket are 1.20 m of length (sub-sub-WCA 1-1B,

2-1B, and 2-2A), 1.60 m of length (sub-sub-WCA

1-1C), and depth ranged from 2.41 m to 3.40 m).

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Bogor(ID): IPB Press.

[2]. Asquith WH, Cleveland TG, dan Roussel MC. 2011. A

method for estimating peak and time of peak

streamflow from excess rainfall for 10- to 640-acre

watersheds in the Houston, Texas, metropolitan area:

U.S. Geological Survey Scientific Investigations

Report. 41 :2011–5104

[3]. Bhim S, Deepak R, Amol V, dan Jitendra S. 2012.

Probability analysis for estimation of annual one day

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India. Plant Archives. 12(2): 1093-1100. ISSN:

0972-5210.

[4]. [BSN] Badan Standardisasi Nasional. 2002. Standar

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Tata Cara Perencanaan Sumur Resapan Air Hujan

Untuk Lahan Pekarangan. Jakarta (ID): BSN

[5]. Campisano A, Di Liberto D, Modica C, dan Reitano S.

2014.Potential for peak flow reduction by rainwater

harvesting tanks. Journal of Procedia Engineering.

89:1507-1514.

[6]. Philip, J.R. "Theory of infiltration." (1969). Advances

in Hydroscience. v. 5, p. 215-296.

[7]. Suripin. 2004. Sistem Drainase Perkotaan yang

Berkelanjutan. Yogyakarta: Andi.

[8]. Suyono S, dan Takeda K, 1983. Hidrologi Untuk

Pengairan. Jakarta: Pradnya Paramita.