Effects of Settlement Development and Green Drainage Facility to Surface Runoff in Bodo River Basin Malang
Ratih Indri Hapsari1, Syahrul Muhamad Ilham2, Utami Retno Pudjowati3, Suhartono4

1Ratih Indri Hapsari, Department of Civil Engineering, State Polytechnic of Malang.
2Syahrul Muhamad Ilham, Department of Civil Engineering, State Polytechnic of Malang.
3Utami Retno Pudjowati, Department of Civil Engineering, State Polytechnic of Malang.
4Suhartono, Department of Civil Engineering, State Polytechnic of Malang.
Manuscript received on 08 June 2019 | Revised Manuscript received on 30 June 2019 | Manuscript Published on 04 July 2019 | PP: 1058-1063 | Volume-8 Issue-1S4 June 2019 | Retrieval Number: A11980681S419/2019©BEIESP
Open Access | Editorial and Publishing Policies | Cite | Mendeley | Indexing and Abstracting
© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: The rapid urban development in Malang sub-urban area in Indonesia has increased the vulnerability of river basins to water-related disas-ters. Water sustainability in Malang, which is located in upper Brantas River Basin, becomes an important issue as the river serves as the most important source of water supply in East Java Province. The objective of this study is to evaluate the impact of a housing area (0.069 km2) and the green drainage facility in Malang Regency to the hydrological characteristic in Bodo River (4.937 km2), a tributary of Brantas River. The sustainable drainage system applied in this study is detention pond. This study requires land terrain data, daily rainfall data from Karangploso, Dau, and Singosari rain gauges, hourly rainfall data from JAXA global dataset, soil bore log and cone penetration data, and land use data. The designed rainfall is analysed by Log-Pearson Type III frequency distribution with 10 years return period. SCS hydrograph method from HEC-HMS software is applied to analyse the surface runoff and infiltration. Curve number is spatially analysed based on the soil properties and land use data, which has value of 83.37 and 96.9 for Bodoriver and housing area respectively. The hourly rainfall is assumed to have triangular distribution with 7 hours duration within a day. The analysis reveals that the existence of housing area increases the runoff of 0.46 m3/s. The designed flood in Bodo River for 10 years return period is 26.243 m3/s with 14 hours duration, while the runoff with contribution from housing area is 26.701 m3/s. In order to reduce the peak flood and extend the flood lag time as well travel time, the detention pond is designed in the housing area based on the land availability. The pond dimension is 67.25 m width, 205.83 m length, and 0.8 m depth. The pond could retain the water of 685.705 m3 volume and reduce the peak flood in the river 0.0013 m3/s. The results demonstrate the benefit of constructing green drainage facilities to complement urban development aggregately.
Keywords: Sustainable Drainage, Flood Discharge, Detention Pond, HEC-HMS.
Scope of the Article: Design and Performance of Green Building