HEC-HMS Based Hydrological Modeling for Assessing Reservoir Impacts on Flood Hydrographs in the Pacal Watershed
DOI:
https://doi.org/10.70716/reswara.v4i3.725Keywords:
Reservoir, Flood Hydrograph, HEC-HMSAbstract
The Pacal Watershed in Bojonegoro Regency faces severe periodic flooding driven by intense tropical rainfall and land-use change, making the modeling of how the integration of the Pacal and Gongseng reservoirs attenuates flood hydrographs in small tropical catchments a critical issue. This study introduces a novel framework modeling hydrograph transformations resulting from the interaction between the historical Pacal Reservoir and the modern Gongseng Reservoir using HEC-HMS employing the SCS Curve Number loss method and Nakayasu SUH transformation achieving high predictive reliability with a Nash-Sutcliffe Efficiency score of NSE = 0,81. Simulation results demonstrate that dual-reservoir integration significantly mitigates downstream flood risks across 100-year to 1,000-year return periods, achieving peak discharge reductions of 55,46% to 59,38% (320,9 m3/s to 379,6 m3/s) and delaying peak arrival times by 2 to 6 hours with Pacal Reservoir attenuating 163,1 m3/s – 195,3 m3/s and Gongseng Reservoir reducing 107,2 m3/s – 115,6 m3/s. This study proves that the reservoirs function as reliable hydraulic shock absorbers that extend the emergency evacuation lead-time window for vulnerable downstream communities. Furthermore, it reveals a storage efficiency decay phenomenon during extreme storm events due to finite surcharge storage capacity, underscoring the necessity of pre-release operational rule curves despite modeling limitations that omit sedimentation, baseflow, and channel routing.
References
Aggarwal, S. P., Barman, D., Kundu, S. S., Kurbah, S., & Das, R. (2025). EO aided comprehensive flood management for the Brahmaputra and Barak river basin in NE India. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLVIII-G-2(April), 6–11. https://doi.org/10.5194/isprs-archives-xlviii-g-2025-63-2025
Bartos, M., & Kerkez, B. (2019). Hydrograph peak-shaving using a graph-theoretic algorithm for placement of hydraulic control structures. Advances in Water Resources, 127, 167–179. https://doi.org/10.1016/j.advwatres.2019.03.016
Buana, H., Limantara, L. M., Juwono, P. T., & Sholichin, M. (2022). Time Lag Modeling in Modification of Nakayasu Synthetic Unit Hydrograph. Journal of Hunan University Natural Sciences, 49(7), 9–17. https://doi.org/10.55463/issn.1674-2974.49.7.2
Buda, A. R., Millar, D. J., Kennedy, C. D., Welsh, M. K., & Wiegman, A. R. H. (2024). Trends in extreme rainfall over the past 55 years suggest springtime subhourly rainfall extremes have intensified in Mahantango Creek , Pennsylvania. Nature, 14(1), 1–19. https://doi.org/10.1038/s41598-024-79196-3
Cirella, G. T., Iyalomhe, F. O., & Adekola, P. O. (2019). Determinants of flooding and strategies for mitigation: Two-year case study of Benin city. Geosciences (Switzerland), 9(3), 1–15. https://doi.org/10.3390/geosciences9030136
Erena, S. H., & Worku, H. (2018). Flood risk analysis: causes and landscape based mitigation strategies in Dire Dawa city, Ethiopia. Geoenvironmental Disasters, 5(1). https://doi.org/10.1186/s40677-018-0110-8
Evangelista, G., Bertola, M., Blöschl, G., & Claps, P. (2025). Non-Linear Influence of Reservoir Initial Condition on Flood Reduction. Journal of Flood Risk Management, 18(4), e70142. https://doi.org/10.1111/jfr3.70142
Ferdian, D., Saggaff, A., & Sarino. (2020). Efektifitas Pengendalian Banjir dengan Embung: Studi Kasus Taman Firdaus Universitas Sriwijaya. Cantilever: Jurnal Penelitian dan Kajian Bidang Teknik Sipil, 9(1), 57–62. https://doi.org/10.35139/cantilever.v9i1.39
Ginting, B. M., Lidyana, P., Christopher, C., Yudianto, D., & Yuebo, X. (2023). Comparison of flood hydrograph prediction between synthetic unit hydrograph methods and rain-on-grid model for Katulampa watershed, Indonesia. Acta hydrotechnica, 36(64), 81–94. https://doi.org/10.15292/acta.hydro.2023.05
Hamdan, A. N. A., Almuktar, S., & Scholz, M. (2021). Rainfall-Runoff Modeling Using the HEC-HMS Model for the Al-Adhaim River Catchment, Northern Iraq. Hydrology, 8(2), 58. https://doi.org/10.3390/hydrology8020058
Harjono, H., & Widhiastuti, Y. (2019). Analisa Hidrologi dan Hidrolika Pada Daerah Aliran Sungai (DAS) Kali Pacal Bojonegoro. Rekayasa Sipil, 13(1), 16–23. https://doi.org/10.21776/ub.rekayasasipil.2019.013.01.3
Indarto. (2018). Hidrologi Motode Analisis dan Tool untuk Interpretasi Hidrograf Aliran Sungai (S. B. Hastuti (ed.)). Bumi Aksara.
Kalra, S., Madguni, O., & Rana, D. (2023). Sustainable Waste Management of Man-Made Dams and Reservoirs. In Advances in Waste Management (hal. 141–153). Springer Singapore. https://doi.org/10.1007/978-981-19-7506-6_11
Maulana, N. K., & Sutopo, Y. (2020). Design Flood Discharge of 50 Years in Garang River Using Nakasayu Synthetic Unit Hydrograph Method. Jurnal Teknik Sipil dan Perencanaan, 22(2), 146–151. https://doi.org/10.15294/JTSP.V22I2.26847
Msaddek, M., Kimbowa, G., & Garouani, A. El. (2020). Hydrological Modeling of Upper OumErRabia Basin ( Morocco ), Comparative Study of the Event-Based and Continuous-Process HEC-HMS Model Methods. 159–184. https://doi.org/10.4236/cweee.2020.94011
Mulyanti, H., Harjono, H., & Rendra, M. I. (2020). Penurunan Intensitas Hujan Ekstrem di Bengawan Solo Hilir dan Hubungannya dengan ENSO. Jurnal Ilmu Lingkungan, 18(1), 73–81. https://doi.org/10.14710/jil.18.1.73-81
Nada, F. M. H., & Sunariya, M. I. T. (2025). The impact of land cover change on runoff coefficient at Upper Garang Watershed, Jawa Tengah Province, Indonesia. IOP Conference Series: Earth and Environmental Science, 1438(1), 012021. https://doi.org/10.1088/1755-1315/1438/1/012021
Pabi, O., Egyir, S., & Attua, E. M. (2021). Flood hazard response to scenarios of rainfall dynamics and land use and land cover change in an urbanized river basin in Accra, Ghana. City and Environment Interactions, 12, 100075. https://doi.org/10.1016/j.cacint.2021.100075
Prastica, R. M. S., Widyatmoko, A., & Kurniawan, R. (2021). Mitigasi Banjir Struktural Menggunakan Model Hec-Ras Dan Geo-Studio Pada Wilayah Sungai Toba-Asahan, Sumatera Utara. Teras Jurnal, 11(2), 399. https://doi.org/10.29103/tj.v11i2.519
Rahmadani, S., Harahap, R., Yuzni, S. Z., Rani, C. M., Tinov, N., Waruwu, J. A., & Rahmadani, S. S. (2024). Hydrological Study of Deli River Flood Discharge Using the HSS Nakayasu Model. Journal of Physics: Conference Series, 2908(1), 012016. https://doi.org/10.1088/1742-6596/2908/1/012016
Saltalippi, C., Corradini, C., Dari, J., & Morbidelli, R. (2022). Rainfall and development of floods. In Rainfall (hal. 351–366). Elsevier. https://doi.org/10.1016/b978-0-12-822544-8.00015-9
Sarkar, A., & Drissia, T. K. (2024). Integrated Reservoir Simulation and Hydrological Modelling for Optimised Reservoir Operations in Kerala, India. In A. Agarwal, B. Yadav, M. Nema, M. Sharma, & A. Kumar (Ed.), Towards Water Circular Economy (hal. 50–60). Springer Nature Switzerland. https://doi.org/10.1007/978-3-031-60436-2_4
Soliman, A. H. (2022). Development of Rainfall Design Storm Hyetographs for Al-Quassim Region - Kingdom of Saudi Arabia. International Journal of Engineering Trends and Technology, 70(1), 362–372. https://doi.org/10.14445/22315381/IJETT-V70I1P240
Souza, D. N. de, Studart, T. M. de C., Lima Neto, I. E., & Campos, J. N. B. (2017). Flood damping by reservoirs: proposition of a graphical parametric method. RBRH, 22. https://doi.org/10.1590/2318-0331.0217170002
Subrata, O., & Putuhena, W. M. (2012). Pengelolaan Banjir Berbasis Masyarakat ( Studi Kasus : Kabupaten Bojonegoro ) Community-Based Flood Management ( Case Study : Kabupaten Bojonegoro ). Jurnal Sumber Daya Air, 8, 125–140.
Sukerte, N. (2022). Rekayasa Pengendalian Banjir Dan Konservasi Sumber Daya Air Pada Daerah Hulu. Jurnal Profesi Insinyur Universitas Lampung, 3(2), 78–84. https://doi.org/10.23960/jpi.v3n2.84
Wan, X., Hua, L., Yang, S., Gupta, H. V., & Zhong, P. (2018). Evaluating the Impacts of a Large-Scale Multi-Reservoir System on Flooding: Case of the Huai River in China. Water Resources Management, 32(3), 1013–1033. https://doi.org/10.1007/s11269-017-1852-x
Wang, J., Xu, J., & Kong, D. (2023). Time-Lagged Response of Streamflow in the Lower Yellow River to the Water Regulation by Xiaolangdi Reservoir: Implication for Efficient Water Supply. Water, 16(1), 78. https://doi.org/10.3390/w16010078
Wibowo, A. A., Sangkawati, S., & Nugroho, H. (2024). Kajian Kapasitas Pelimpah dan Terowongan Konduit Bendungan Sawangan dalam Mereduksi Debit Puncak Banjir. Al Qalam: Jurnal Ilmiah Keagamaan dan Kemasyarakatan, 18(3), 2084–2098. https://doi.org/10.35931/aq.v18i3.3313
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Yuliani Wahyu Sardana (Author)

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.




