Electronic Theses and Dissertation

Oxbow lake yang merupakan sisa belokan (meander) sungai asli berpotensi menjadi nature-based solution dari kedua permasalahan, yaitu banjir dan kekurangan air irigasi melalui pemanfaatannya menjadi kolam retensi. namun sayangnya belum ada studi detail mengenai pemanfaatan oxbow, bahkan oxbow ini terabaikan hingga berdampak buruk bagi lingkungan atau dijadikan kolam secara ilegal oleh masyarakat. tujuan penelitian ini adalah untuk menganalisis potensi pemanfaatan oxbow sebagai pengendali banjir dan penyedia air irigasi serta menghasilkan perhitungan intake dan saluran untuk pemenuhan air irigasi. penelitian dilakukan pada oxbow di das tamiang, sebagai salah satu das yang kerap terjadi banjir. penelitian ini diawali dengan perumusan masalah, studi literatur, pengumpulan data primer dan sekunder, perkiraan kebutuhan air irigasi, perhitungan kapasitas oxbow lake berdasarkan data survei, perencanaan dimensi kolam retensi oxbow, serta perencanaan intake dan sistem irigasi. hasil perhitungan kebutuhan air irigasi maksimum didapatkan sebesar 0,043 m3/detik. berdasarkan hasil survei, alternatif kolam oxbow memiliki kapasitas sebesar ± 1,12 juta m3 serta luas genangan 40,8 ha. selanjutnya, direncanakan intake air irigasi pada elevasi ±3,5 mdpl dengan pompa berdaya 15kw dilengkapi dengan satu buah bangunan bagi. direncanakan juga 3 buah saluran irigasi yaitu connecting channel sepanjang 676 m, dengan dua buah sub-channel masing-masing sepanjang 199 m dan 226 m.

Oxbow lakes, which are remnants of the original river meanders, have the potential to serve as nature-based solutions to two major issues—flooding and irrigation water shortages—through their utilization as retention ponds. Unfortunately, there has been no detailed study on the use of oxbow lakes, and they are often neglected, leading to environmental degradation or being used illegally as fishponds by local communities. The objective of this research is to analyze the potential use of oxbow lakes for flood control and irrigation water supply, as well as to design the intake and channel system required to meet irrigation demands. The study was conducted on an oxbow lake within the Tamiang Watershed, an area frequently affected by flooding. The study began with problem formulation, literature review, collection of primary and secondary data, estimation of irrigation water demand, calculation of oxbow lake storage capacity based on field surveys, planning of the retention pond dimensions, design of the connecting channel, and interpretation of results. The maximum irrigation water demand was calculated at 0.043 m³/s. Based on field surveys, the selected oxbow lake has an estimated storage capacity of ±1.12 million m³ and an inundation area of 40.8 hectares. An irrigation intake is planned at an elevation of ±3.5 meters above sea level, using a 15 kW pump and a single division structure. Additionally, three irrigation canals are planned: a connecting channel of 676 meters, and two sub-channels of 199 meters and 226 meters respectively.