STUDI EVALUASI DISTRIBUSI AIR PADA JARINGAN IRIGASI WADUK BERINGIN SILA DI KECAMATAN UTAN KABUPATEN SUMBAWA

Abstract

ABSTRAK

Daerah irigasi Waduk Beringin Sila terletak di WS Sumbawa (Kode WS 03.03.A3) dan berada di sistem DAS Utan (Kode DAS 024), terletak di Desa Tengah Kecamatan Utan Kabupaten Sumbawa, Nusa Tenggara Barat. Dimana secara geografis terletak sekitar 8°27'18.85"LS dan 117°07'37.36" BT atau pada koordinat X=513.984,24 m; Y=9.065.372,25 m. berada pada jarak 200 m di hilir Waduk Beringin Sila yang saat ini mengairi area irigasi seluas 2.400 hektar. Pada area persawahan jaringan irigasi mengalami beberapai kerusakan diakibatkan sering terjadi banjir apabila intensitas curah hujan tinggi, saluran irigasi pada daerah irigasi waduk beringin sila masih kurang memadai sehingga perlu adanya evaluasi dan perbaikan.

Perhitungan curah hujan rancangan waduk beringin sila menggunakan data curah hujan 1 stasiun penakar hujan yaitu stasiun beringin sila atau dengan metode RAPS (Rescaled Adjusted Partial Sums) dan metode FJ. Mock. Studi ini bertujuan untuk mengetahui kebutuhan air irigasi beringin sila, ketersediaan air irigasi waduk beringin sila, Dimensi saluran eksisting dan dimensi saluran rencana pada daerah irigasi  waduk beringin sila.

Hasil Studi ini diketahui kebutuhan air irigasi sebesar 0,00163 m³/detik dengan volume 2.106,35 m³, Ketersediaan air irigasi didapatkan nilai sebesar 45,621 m³/detik, dan dimensi saluran rencana I (trapesium): b = 1,25 m, h = 1,60 m, Q = 1,338 m³/detik, saluran rencana II (persegi): b = 0,90 m, h = 1,30 m, Q = 1,053 m³/detik. Dengan demikian saluran rencana mampu menampung debit air yang akan dialirkan.

Kata kunci : Waduk Beringin Sila, Evaluasi Dimensi Saluran, Desa Utan.

ABSTRACT

The Beringin Sila Reservoir irrigation area is located in the Sumbawa WAS (WS Code 03.03.A3) and is in the Utan DAS system (DAS Code 024), located in Tengah Village, Utan District, Sumbawa Regency, West Nusa Tenggara. Where geographically it is located around 8°27'18.85" South Latitude and 117°07'37.36" East Longitude or at coordinates X=513,984.24 m; Y=9,065,372.25 m. is located 200 m downstream of the Beringin Sila Reservoir which currently irrigates an irrigation area of 2,400 hectares. In the rice field area, the irrigation network experienced some damage due to frequent flooding when the intensity of rainfall was high, the irrigation channels in the Sila Banyan Reservoir irrigation area were still inadequate, so evaluation and repair were needed.

The rainfall calculation for the design of the Beringin Sila reservoir uses rainfall data from 1 rain measuring station, namely the Beringin Sila station or using the RAPS (Rescaled Adjusted Partial Sums) method and the FJ method. Mock. This study aims to determine the need for Sila Banyan irrigation water, the availability of Sila Banyan Reservoir irrigation water, the dimensions of existing canals and the dimensions of planned channels in the Sila Banyan Reservoir irrigation area.

The results of this study show that the need for irrigation water is 0.00163 m3/second with a volume of 2,106.35 m3, the availability of irrigation water is found to be 45.621 m3/second, and the dimensions of the plan I channel (trapezoidal): b = 1.25 m, h = 1.60 m, Q = 1.338 m3/sec, plan II channel (square): b = 0.90 m, h = 1.30 m, Q = 1.053 m3/sec. In this way, the planned channel is able to accommodate the water discharge that will be channeled.

Keywords : Beringin Sila Reservoir, Evaluation of Channel Dimensions, Utan Village.