Studi Optimasi Ketersediaan Air Waduk Batujai Kabupaten Lombok Tengah

Livia, Rafa Amyra (2026) Studi Optimasi Ketersediaan Air Waduk Batujai Kabupaten Lombok Tengah. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 5012221022-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (10MB) | Request a copy

Abstract

Air merupakan salah satu elemen penting dalam kehidupan dan berbagai sektor yang sangat bergantung pada ketersediaan air seperti pertanian, perkotaan, dan industri. Kabupaten Lombok Tengah memiliki kebutuhan air yang tinggi sehingga membutuhkan pengelolaan sumber daya air yang baik. Salah satu strategi pengelolaan sumber daya air di Kabupaten Lombok Tengah adalah adanya bangunan air Waduk Batujai. Waduk ini dibangun dengan kapasitas tampungan bruto sekitar 25 juta m3 yang berfungsi untuk memenuhi kebutuhan irigasi seluas kurang lebih 3.390 ha, pengendalian banjir, serta sebagai sumber air baku bagi masyarakat. Namun, setelah 35 tahun beroperasi, Waduk Batujai mengalami penurunan kapasitas tampungan mati sebesar 85,71%, mempengaruhi kapasitas tampungan efektif dan membatasi umur guna waduk hingga 40 tahun. Pada musim kemarau tahun 2024, volume air waduk tersisa 18 juta m3, sehingga terjadi defisit antara kebutuhan dan ketersediaan air. Kondisi tersebut menyebabkan berkurangnya alokasi air untuk kebutuhan irigasi dan air baku sehingga berdampak pada penurunan intensitas tanam sebesar 4% pada tahun 2022 hingga 2023, serta berpotensi mengancam ketahanan pangan terutama di tengah perubahan iklim yang tidak menentu. Dalam penelitian ini direncanakan optimasi ketersediaan air Waduk Batujai untuk kebutuhan air irigasi dan air baku dengan metode program linier menggunakan program bantu POM-QM dan metode trial and error untuk luas tanam menggunakan analisis water balance. Berdasarkan analisis yang dilakukan, diperoleh kebutuhan air baku sebesar 142,217 lt/detik. Hasil optimasi menunjukkan bahwa alternatif II memberikan hasil optimal dengan intensitas tanam 28,84% pada POM-QM dan alternatif IV dengan intensitas tanam 226,49% pada analisis water balance. Pada analisis alternatif IV diperoleh kebutuhan air irigasi total dalam 1 tahun sebesar 37.157 lt/detik. Pola alternatif IV berturut-turut pada musim hujan (MH), musim kemarau I (MKI), dan musim kemarau II (MKII) adalah padi (1.864,8 ha)-palawija (2.000 ha)-palawija (665 ha) dengan keuntungan maksimum sebesar Rp105.679.955.476.

========================================================================================================================

Water is one of the essential elements in life and various sectors that are highly dependent on water availability such as agriculture, urban, and industry. Central Lombok Regency has high water needs that require good water resource management. One of the water resource management strategies in Central Lombok Regency is the Batujai Reservoir water structure. This reservoir was constructed with a gross storage capacity of around 25 million m3 which functions to meet the irrigation needs of approximately 3.080 ha, flood control, and as a source of raw water for the surrounding community. However, after 35 years of operation, the Batujai Reservoir has experienced an 85,71% decrease in dead storage capacity, which has affected its effective storage and limited its service life to only 40 years. During the dry season of 2024, the reservoir’s water volume dropped to 18 million m3, resulting in a deficit between water availability and demand. This situation has led to reduced water allocation for irrigation and raw water needs, contributing to a 4 % decrease in cropping intensity in 2022 to 2023 and posing a threat to food security, especially amid increasingly erratic climate conditions. Utilizing linear programming with POM-QM software, this study proposes optimizing Batujai Reservoir’s water allocation for irrigation and raw water supply. Based on the analysis conducted, the raw water requirement was determined to be 142,217 liters/second. The optimization results show that alternative II provides optimal results with planting intensity 28,84% in POM-QM and alternative IV with planting intensity of 226,49% in the water balance analysis. In the analysis of alternative IV, the total irrigation water requirement in 1 year is 37.157 lt/second. The pattern of alternative IV in succession in the rainy season (MH), dry season I (MKI), and dry season II (MKII) is rice (1.864,8 ha)-secondary crops (2.000 ha)-secondary crops (665 ha) with a maximum profit of Rp105.679.955.476.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Air Baku, Irigasi, Kab. Lombok Tengah, Optimasi, Program Linier, Waduk Batujai, Water Balance
Subjects:	S Agriculture > S Agriculture (General) T Technology > T Technology (General) T Technology > TA Engineering (General). Civil engineering (General) T Technology > TC Hydraulic engineering. Ocean engineering T Technology > TC Hydraulic engineering. Ocean engineering > TC812 Irrigation
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Civil Engineering > 22201-(S1) Undergraduate Thesis
Depositing User:	Rafa Amyra Livia
Date Deposited:	19 Jan 2026 05:53
Last Modified:	19 Jan 2026 05:53
URI:	http://repository.its.ac.id/id/eprint/129715

Actions (login required)

View Item