Flood simulation using EPA SWMM 5.1 on small catchment urban drainage system

Junaidi Junaidi,Ahmad Junaidi,Lusi Marta Ermalizar,R Haigh,F.A Ismail,L Comfort,A Hakam

doi:10.1051/matecconf/201822904022

Abstract

The area around Sungai Sapih District Hospital of Padang is often flooded. The existing drainage system inadequate to accommodate the increasing of drainage loads due to the changing land use in the area. In order to evaluate the drainage system in the study area, EPA SWMM version 5.1 was used to develop the simulation model. This model was able to calculate the quantity and quality of surface runoff from each catchment area, flow discharge, flow depth, and water quality in each pipeline and drainage channel during the simulation period. The data used in this research are maps of land use, rain data, and drainage channel dimensions. Hourly time series rain data was used and as this was not directly unavailable at the train station at the study site, it was calculated by constructing a rain estimation hyetograph from the 5-year Intensity-Duration-Frequency (IDF) curve using the Alternating Block Method (ABM). After all EPA SWMM 5.1 parameters were specified and inputted, simulation with four simulation scenarios was performed based on the present and the future possible land use and the change of dimension and shape of the drainage channel. The first scenario produced 18 flooding occurrences, the second; 20, the third and fourth; 14. Of note were the 14 flooding points in the third and fourth scenario despite the shape and dimension of the drain used being in accordance with the detail of drainage planning of Sungai Sapih area according to the city master plan for 2010-2030. This shows that the drainage planning design (DED) for Sungai Sapih District Public Hospital is insufficient to contain the drainage load of the area, either now or in the future.

Highlights

One of the reasons for this is because this area is directly affected by the 2011 relocation of Padang City Government Center from Bagindo Aziz Chan Road to Air Pacah which is adjacent to Sungai Sapih District Public Hospital
The application of this SWMM model can be used in planning of dimensions of water catchment facilities for flood control such as retarding basins, mapping of flooded areas and natural drainage systems, planning of regulatory strategies to minimize drainage flow through evaluation of the influence of inflow and infiltration on the flow discharge of the drainage system, and identifying sources of pollutant transport
3.4 The result of drainage network modeling with EPA SWMM 5.1

Summary

Introduction

National Disaster Management Agency (BNPB) data shows the city of Padang includes areas that are at high-risk for flood disasters [1]. One area of the city that is often flooded is around Sungai Sapih hospital (Figure 1). One of the reasons for this is because this area is directly affected by the 2011 relocation of Padang City Government Center from Bagindo Aziz Chan Road to Air Pacah which is adjacent to Sungai Sapih District Public Hospital. By 2016 this land use was changing with increasing development of infrastructure, housing complexes and development of public facilities including a university and expansion of the Sungai Sapih hospital itself. Changes in land use inevitably lead to changes in the quantity of surface flow in existing drainage systems [3]

Methods

Results

Conclusion