ANALISA INDEKS KINERJA SISTEM JARINGAN IRIGASI PADA DAERAH IRIGASI BENDUNGAN GAPIT KECAMATAN EMPANG KABUPATEN SUMBAWA

Abstract

Bendungan Gapit merupakan infrastruktur irigasi yang memegang peranan penting dalam memenuhi kebutuhan air pertanian di Kecamatan Empang, Kabupaten Sumbawa. Penelitian ini bertujuan untuk mengevaluasi kinerja Bendungan Gapit melalui analisis ketersediaan air, kondisi fisik infrastruktur, dan faktor-faktor yang memengaruhi efektivitas operasionalnya. Penelitian ini menggunakan pendekatan kuantitatif dengan menganalisis curah hujan efektif, debit andalan (Q80), kebutuhan air irigasi (NFR), dan neraca air. Selain itu, dilakukan penilaian kondisi fisik infrastruktur berdasarkan Peraturan Menteri Pekerjaan Umum dan Perumahan Rakyat Nomor 12/PRT/M/2015, serta pembobotan faktor penentu kinerja menggunakan metode Analytical Hierarchy Process (AHP). Hasil penelitian menunjukkan bahwa kondisi teknis merupakan faktor paling berpengaruh terhadap kinerja bendungan dengan bobot 52,44%, diikuti oleh aspek operasi dan pemeliharaan sebesar 25,28%, ketersediaan air sebesar 14,70%, dan layanan irigasi sebesar 7,59%. Evaluasi kondisi fisik infrastruktur menghasilkan skor rata-rata 82,50% yang dikategorikan sangat baik, meskipun Struktur Sadap Tersier dan Struktur Sadap Sekunder masih memerlukan perbaikan. Analisis neraca air menunjukkan bahwa debit andalan sebesar 3,894 m³/detik mampu memenuhi kebutuhan irigasi sepanjang sebagian besar tahun, namun masih terdapat defisit air sebesar 9,1% pada bulan November, sehingga diperlukan perbaikan pada infrastruktur distribusi air dan pengaturan pola tanam.
The Gapit Dam is an irrigation infrastructure that plays a crucial role in meeting agricultural water needs in Empang District, Sumbawa Regency. This study aims to evaluate the performance of the Gapit Dam through an analysis of water availability, physical infrastructure conditions, and factors influencing its operational effectiveness. The study used a quantitative approach, analyzing effective rainfall, reliable discharge (Q80), irrigation water demand (NFR), and the water balance. Additionally, an assessment of the physical infrastructure condition was conducted based on Ministerial Regulation of the Ministry of Public Works and Public Housing Number 12/PRT/M/2015, and the weighting of performance determining factors using the Analytical Hierarchy Process (AHP) method. The results indicate that technical conditions are the most influential factor affecting dam performance, with a weighting of 52.44%, followed by operational and maintenance aspects at 25.28%, water availability at 14.70%, and irrigation services at 7.59%. The evaluation of the physical infrastructure condition yielded an average score of 82.50%, which is categorized as very good, although the Tertiary Tapping Structure and Secondary Tapping Structure still require improvement. Water balance analysis shows that the mainstay discharge of 3,894 m³/sec is able to meet irrigation needs for most of the year, but there is still a water deficit of 9.1% in November, so that improvements to the water distribution infrastructure and cropping pattern regulation are needed.