EVALUASI KAPASITAS SALURAN DRAINASE PADA JALAN POROS SAMARINDA-BONTANG MENGGUNAKAN APLIKASI HEC-RAS --

ABSTRAK
Jalan Poros Samarinda-Bontang merupakan jalan yang menghubungkan
antara kota-kota di Kalimantan Timur menuju Bandara Udara Internasional Aji
Pangeran Tumenggung Pranoto dan sebagai jalan penghubung menuju kilang
minyak Bontang dan Tanjung Santan. Namun pada STA 0+000 sampai STA
4+250 sering mengalami banjir sehingga dapat menghambat masyarakat dalam
beraktivitas. Penyebab terjadinya banjir adalah dari perubahan tata guna lahan dan
kondisi eksisting saluran yang terlalu kecil. Oleh sebab itu dilakukan perencanaan
ulang saluran drainase dengan perhitungan hujan rancangan kala ulang 2, 5 dan 10
tahun. Perhitungan Debit banjir menggunakan metode HS Nakayasu dan
pemodelan aliran menggunakan program aplikasi Hydrologic Engineering Center
– River Analysis System (HEC-RAS). Hasil penelitian diperoleh kapasitas saluran
drainase saluran 1 kanan 2,323 m³/detik, saluran 2 kanan 4,211 m³/detik, saluran 3
kanan 12,469 m³/detik, saluran 1 kiri 11,163 m³/detik, saluran 2 kiri 14,759
m³/detik dan saluran 3 kiri 22,934 m³/detik.
Kata Kunci : Saluran Drainase, Metode HS Nakayasu, HEC-RAS
ABSTRACT
Poros road of Samarinda - Bontang is a road that connects cities in East
Kalimantan to Aji Prince Tumenggung Pranoto International Airport and as a
connecting road to the Bontang and Tanjung Santan oil refineries. However, at
STA 0+000 to STA 4+250 it often experiences flooding so that it can hinder the
community from doing their activities. The cause of flooding is from changes in
land use and the existing condition of the channel that is too small. Therefore, a
re-planning of the drainage channel was carried out by calculating the design
rain with a return period of 2, 5 and 10 years. Calculation of flood discharge
using the HS Nakayasu method and flow modeling using the Hydrologic
Engineering Center – River Analysis System (HEC-RAS) application program.
The results showed that the drainage capacity of the right channel 1 was 2.323
m³/s, the right channel 2 was 4.211 m³/s, the right channel 3 was 12.469 m³/s, the
left channel 1 was 11.163 m³/s, the left channel 2 was 14.759 m³/s and the left
channel 3 was 22.934 m³/s.
Keyword : Drainage Channels, Unit Hydrograph Method Nakayasu, HEC-RAS