Studi Perbandingan Desain Sistem Drainase Menggunakan Metode Rasional & Model SWMM Berdasarkan Multi Standar

Wardana, Dhimas Krisna (2026) Studi Perbandingan Desain Sistem Drainase Menggunakan Metode Rasional & Model SWMM Berdasarkan Multi Standar. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Sistem drainase perkotaan berperan dalam mengalirkan limpasan permukaan agar tidak terjadi genangan. Namun, peningkatan kawasan terbangun di Kota Surabaya menyebabkan limpasan permukaan meningkat sehingga kapasitas saluran sering tidak mampu menampung debit saat hujan. Metode Rasional sesuai SNI 2415:2016 masih menjadi acuan utama dalam perencanaan drainase, penggunaan waktu konsentrasi (Tc) yang dihitung pada setiap segmen saluran menghasilkan variasi intensitas hujan dalam satu kejadian hujan. Pendekatan tersebut berbeda dengan kondisi hujan aktual yang terjadi secara bersamaan pada seluruh daerah tangkapan. Selain itu, kajian yang membandingkan hasil desain Metode Rasional SNI dengan simulasi hujan debit SWMM dan standar internasional seperti Australian Rainfall and Runoff (ARR) masih terbatas. Penelitian bertujuan membandingkan hasil desain sistem drainase berdasarkan Metode Rasional SNI dan ARR, kemudian mengevaluasi performanya menggunakan model SWMM pada Daerah Tangkapan Air Medokan Semampir, Surabaya. Model SWMM dikalibrasi dan divalidasi menggunakan data genangan historis, kemudian digunakan untuk mengevaluasi kinerja desain terhadap distribusi hujan merata. Analisis dilakukan terhadap waktu konsentrasi, intensitas hujan, debit rencana, dimensi saluran, serta kinerja hidraulik berdasarkan parameter maximum capacity dan Lin's Concordance Correlation Coefficient (CCC). Hasil penelitian menunjukkan penggunaan waktu konsentrasi (Tc) per segmen pada Metode Rasional SNI menghasilkan variasi intensitas hujan pada setiap saluran, berbeda dengan distribusi hujan merata pada SWMM. Perencanaan berdasarkan Metode Rasional SNI menunjukkan dimensi saluran primer dan sekunder eksisting masih memenuhi kebutuhan kapasitas, sedangkan saluran tersier memerlukan penyesuaian dimensi. Evaluasi menggunakan SWMM menunjukkan desain saluran secara umum masih mampu mengakomodasi debit simulasi dengan kesetaraan debit terbaik pada saluran tersier dan sekunder terhadap SWMM hujan periode ulang 5 tahun durasi 4 jam, serta saluran primer terhadap SWMM hujan periode ulang 2 tahun durasi 4 jam. Berdasarkan evaluasi maximum capacity, saluran tersier masih mampu mengalirkan debit hingga hujan periode ulang 5 tahun, saluran sekunder hingga periode ulang 10 tahun tanpa luapan yang signifikan, sedangkan pada saluran primer hanya terdapat satu segmen yang melampaui kapasitas pada skenario hujan periode ulang 10 tahun durasi 3 jam. Dibandingkan SNI, ARR menghasilkan debit rencana yang lebih besar pada saluran primer sehingga setara dengan debit SWMM hujan periode ulang 5 tahun, sedangkan pada saluran sekunder dan tersier kedua metode sama-sama menunjukkan kesetaraan terhadap debit SWMM hujan periode ulang 5 tahun.
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Urban drainage systems play an essential role in conveying surface runoff to prevent inundation. However, the expansion of developed areas in Surabaya has increased surface runoff, causing drainage channels to frequently exceed their capacity during rainfall events. The Rational Method based on SNI 2415:2016 remains the primary approach for drainage system design. However, the use of the time of concentration (Tc), which is calculated for each channel segment, results in varying rainfall intensities within a single rainfall event. This approach differs from actual rainfall conditions, where rainfall occurs simultaneously across the entire catchment. In addition, studies comparing drainage designs based on the SNI Rational Method with SWMM rainfall-runoff simulations and international standards such as Australian Rainfall and Runoff (ARR) remain limited. This study aims to compare drainage system designs based on the SNI Rational Method and the ARR Rational Method, and to evaluate their performance using the SWMM model in the Medokan Semampir Catchment Area, Surabaya. The SWMM model was calibrated and validated using historical inundation data and subsequently used to evaluate the performance of the drainage designs under a uniform rainfall distribution. The analysis included the time of concentration, rainfall intensity, design discharge, channel dimensions, and hydraulic performance based on the maximum capacity parameter and Lin's Concordance Correlation Coefficient (CCC). The results indicate that the use of segment-based time of concentration (Tc) in the SNI Rational Method produces different rainfall intensities for each channel, unlike the uniform rainfall distribution applied in SWMM. The SNI Rational Method design shows that the existing primary and secondary channels still satisfy the required hydraulic capacity, whereas the tertiary channels require dimensional adjustments. SWMM evaluation demonstrates that the designed channels are generally capable of conveying the simulated discharge, with the best discharge agreement observed for the tertiary and secondary channels under the 5-year return period with a 4-hour rainfall duration, and for the primary channels under the 2-year return period with a 4-hour rainfall duration. Based on the maximum capacity evaluation, the tertiary channels are able to convey flow up to the 5-year return period, the secondary channels up to the 10-year return period without significant overflow, while only one primary channel segment exceeds its capacity under the 10-year return period with a 3-hour rainfall duration. Compared with the SNI Rational Method, the ARR Rational Method produces a larger design discharge for the primary channels, corresponding to the SWMM discharge under the 5-year return period, whereas both methods show equivalent discharge performance for the secondary and tertiary channels under the 5-year return period.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Drainase perkotaan, metode rasional, waktu konsentrasi (Tc), SWMM, Australia Rainfall Runoff, validasi model, desain sistem drainase, hujan merata, Saluran Primer Medokan Semampir, Urban drainage, Rational Method, time of concentration (Tc), SWMM, Australian Rainfall and Runoff (ARR), model validation, drainage system design, uniform rainfall, Medokan Semampir Primary Channel
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC530 Flood control T Technology > TE Highway engineering. Roads and pavements > TE215 Drainage
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Civil Engineering > 22101-(S2) Master Thesis
Depositing User:	Dhimas Krisna Wardana
Date Deposited:	28 Jul 2026 07:50
Last Modified:	28 Jul 2026 07:50
URI:	http://repository.its.ac.id/id/eprint/138943

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