EVALUASI DAN SOLUSI PERBAIKAN FISHWAY PADA GROUNDSILL BANTAR DI DESA ARGOSARI KECAMATAN SEDAYU KABUPATEN BANTUL

RAGIL TRIAS H, Dr.-Ing. Ir. Agus Maryono;M.Sulaiman, ST., MT., D.Eng;Dr. Ir. Sindu Nuranto, MS;Dr. Eng. Iman Haryanto, S.T., M.T

2018 | Tugas Akhir | D4 TEKNIK PENGELOLAAN DAN PEMELIHARAAN INFRASTRUKTUR SIPIL

Evaluasi konstruksi fishway pada groundsill Bantar dilakukan karena fishway belum berfungsi secara optimal. Dari evaluasi dihasilkan ukuran batu dilapangan tidak sesuai dengan ukuran batu perencanaan, belum adanya batu penghalang pada bagian hulu fishway, dan muka air hilir fishway lebih tinggi dari muka air sungai. Secara keseluruhan fishway Bantar belum memenuhi standar persyaratan umum bangunan fishway. Dilakukan percobaan permodelan fishway Bantar pada skala laboraturium dengan standar bangunan fishway secara umum, untuk membuktikan fishway dapat berfungsi secara optimal. Permodelan dilakukan menggunakan 2 tipe fishway yaitu fishway tipe fish ramp dengan batu disusun secara bebas atau berdasarkan tipe material batu (rockfill construction or loose construction) dan fishway tipe fish ramp dengan sekat rhomboid. Pada fishway tipe fish ramp dengan batu disusun secara bebas atau berdasarkan tipe material batu (rockfill construction or loose construction) dihasilkan 5 ikan yang berhasil melewati fishway yaitu lele, tawes, wader, grass carp dan red devil. Pada fishway tipe fish ramp dengan sekat rhomboid dihasilkan 2 ikan yang berhasil melewati fishway yaitu lele dan red devil. Rekomendasi perbaikan fishway Bantar dilakukan dengan cara menambahkan urugan batu yang ditebarkan pada seluruh permukaan fishway dan menggunakan pemilihan formasi seperti batu disusun secara bebas atau berdasarkan tipe urugan batu (rockfill construction or loose construction). Rekomendasi bagian muka air hilir fishway dengan menambahkan tumpukan batu besar dan balok dibagian hilir sehingga muka air fishway dapat sejajar dengan muka air sungai.

Fishway construction in groundsill Bantar is evaluated because it wasn�toptimally functioned. Evaluation results had shown that the size of the stones on the fishway construction wasn�t according to the size of the stones in the planning, there wasn�tstone barrier at the upstream of the fishway construction,as well as the higher water level in the downstream of the fishway construction compared to the water level of the river. Overall, Bantar Fishway Construction wasn�t built according to the general standard of fishway construction. The modeling of Bantar Fishway Construction on a laboratory scale using the general standard of fishway construction has been carried out to prove that the fishway construction can work optimally if it built according to the general standard of fishway construction. The modeling is done using 2 types of fishway construction. The first type is fish ramp fishway with stones arranged freely or arranged based on the type of the stone material (rockfill construction or loose construction) and the second type is fish ramp fishway with rhomboid partition. On the type of fish ramp fishway with stones arranged freely or arrange based on the type of the stone material (rockfill construction or loose construction), 5 fishescan swim up tothrough the fishway. There are catfish (Clarias), tawes (Barbonymus gonionotus), wader (Barbodes binotatus), grass carp (Ctenopharyngodon idella) and red devil (Amphilophus labiatus). On the type of fish ramp fishway with rhomboid partition, 2 fishes can swim up to through the fishway. There are catfish (Clarias) and red devil (Amphilophus labiatus). The recommendations for improving Bantar fishway construction is by adding and spreading more pile of rocks along the surface and then using fish ramp fishway with stones arranged freely or arrange based on the type of the stone material (rockfill construction or loose construction). Meanwhile, the recommendation for the higher water level in the downstream of the fishway construction is by adding more pile of rocks and beam in the downstream of the fishway until the water level of the fishway is equal with the water level of the river.

Kata Kunci : Sungai, Groundsill, Fishway/ River, Groundsill, Fishway