Perencanaan Kolam Retensi dan Pola Operasi Pompa di Kecamatan Genuk untuk Pengendalian Banjir pada Sungai Babon

Hartono, Selindion Octa Viendra (2026) Perencanaan Kolam Retensi dan Pola Operasi Pompa di Kecamatan Genuk untuk Pengendalian Banjir pada Sungai Babon. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 2036221008-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (28MB)

Abstract

Wilayah hilir Sungai Babon, khususnya di Kelurahan Banjardowo, Kecamatan Genuk, Kota Semarang, secara rutin mengalami banjir akibat peningkatan limpasan permukaan serta pengaruh pasang surut air laut yang menimbulkan aliran balik (backwater effect). Proyek akhir ini bertujuan mengevaluasi upaya pengendalian banjir melalui pembangunan kolam retensi yang dipadukan dengan pola operasi pompa dan normalisasi penampang sungai. Analisis hidrologi dilakukan menggunakan data hujan jam-jaman durasi 3 jam dan 6 jam pada kala ulang 25 tahun Q25 untuk memperoleh debit banjir rencana. Hasil perhitungan menunjukkan debit banjir puncak sebesar 254.27 m³/detik (durasi 3 jam) dan 204.749 m³/detik (durasi 6 jam). Analisis hidraulika menggunakan perangkat lunak HEC-RAS dengan mempertimbangkan geometri penampang eksisting dan elevasi muka air laut tertinggi (Highest High Water Level/HHWL) sebesar +0.67 m menunjukkan bahwa penampang sungai eksisting berada di bawah kapasitas yang dibutuhkan (full bank capacity). Kondisi tersebut memicu luapan akibat pengaruh backwater dari titik kontrol hilir berupa kenaikan muka air sebesar 0.96 m ke arah hulu. Sebagai solusi, direncanakan kolam retensi berkapasitas 211.950 m³ dengan pola operasi pompa bertahap berbasis elevasi muka air (water level control). Sistem pompa otomatis ini dirancang: 1 unit pompa aktif pada elevasi -0.55 m hingga 0 m, 2 unit pada elevasi 0 m hingga +1 m, dan 3 unit saat muka air melebihi +1 m. Rekayasa normalisasi lanjutan direncanakan dengan lebar dasar saluran 10–20 meter menyesuaikan topografi lokal. Stabilitas dinding penahan tanah tipe Corrugated Concrete Sheet Pile (CCSP) 20 M W-600 Tipe B dinyatakan aman berdasarkan analisis manual (FS geser 1.72 dan FS guling 1.50) serta pemodelan Plaxis dengan nilai SF 2.623 (kondisi kolam terisi) dan 1.915 (kondisi kosong). Selain itu, untuk analisis stabilitas terhadap beban gempa diperoleh SF sebesar 1.98. Penerapan sistem ini efektif mereduksi luas genangan banjir total sebesar 73.11% (durasi 3 jam) dan 62.36% (durasi 6 jam), Total estimasi biaya konstruksi yang dibutuhkan adalah sebesar Rp 68,122,260,000.00.
=====================================================================================================================================
The downstream area of the Babon River, specifically in Banjardowo Village, Genuk District, Semarang City, routinely experiences flooding due to increased surface runoff and the influence of sea tides causing a backwater effect. This final project aims to evaluate flood control efforts through the construction of a retarding basin combined with pump operation patterns and river cross-section normalization. Hydrological analysis was conducted using hourly rainfall data for 3-hour and 6-hour durations at a 25-year return period Q25 to obtain the design flood discharge. The calculation results indicate peak flood discharges of 254.27 m³/s (3-hour duration) and 204.749 m³/s (6-hour duration). Hydraulic analysis using HEC-RAS software, considering existing cross-sectional geometry and the Highest High Water Level (HHWL) of +0.67 m, demonstrates that the existing river cross-section is below the required full bank capacity. This condition triggers overflowing due to the backwater effect from the downstream control point, resulting in a water level rise of 0.96 m upstream. As a solution, a retarding basin with a capacity of 211,950 m³ is planned, integrated with a phased pump operation pattern based on water level control. This automated pump system is designed as follows: 1 pump unit active at water levels from -0.55 m to 0 m, 2 units from 0 m to +1 m, and 3 units when the water level exceeds +1 m. Further normalization engineering is planned with a channel bottom width of 10–20 meters, adjusting to local topography. The stability of the Corrugated Concrete Sheet Pile (CCSP) 20 M W-600 Type B retaining wall is declared safe based on manual analysis (sliding FS of 1.72 and overturning FS of 1.50) as well as Plaxis modeling with SF values of 2.623 (filled basin condition) and 1.915 (empty condition). Additionally, stability analysis under seismic loading yields an SF of 1.98. The implementation of this system effectively reduces the total flood inundation area by 73.11% (3-hour duration) and 62.36% (6-hour duration). The total estimated construction cost required for this project is Rp 68,122,260,000.00.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Sungai Babon, pengendalian banjir, kolam retensi, pola operasi, pompa, Normalisasi, HEC-RAS, Babon River, flood mitigation, retarding basin, pump operation, Normalization, HEC-RAS
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TC Hydraulic engineering. Ocean engineering T Technology > TC Hydraulic engineering. Ocean engineering > TC530 Flood control
Divisions:	Faculty of Vocational > 22301-Civil Infrastructure Engineering (D4)
Depositing User:	Selindion Octa Viendra Hartono
Date Deposited:	04 Aug 2026 04:39
Last Modified:	04 Aug 2026 04:39
URI:	http://repository.its.ac.id/id/eprint/143054

Actions (login required)

View Item