Perencanaan Sistem Polder untuk Pengendalian Banjir di RW 09, Kelurahan Sepanjang Jaya, Kota Bekasi

Abstract

Terdapat 16 titik genangan di sembilan kecamatan di Kota Bekasi, salah satunya di Kelurahan Sepanjang Jaya dengan ketinggian air 20 cm hingga 1 meter. Untuk mengatasi permasalahan banjir, direncanakan pembangunan sistem polder yang mengacu pada Peraturan Menteri Pekerjaan Umum Nomor 12 Tahun 2014. Lokasi penelitian berada di RW 09, Kelurahan Sepanjang Jaya, Kecamatan Rawalumbu, dengan luas wilayah 17,07 Ha. Data curah hujan maksimum diperoleh dari data CHIRPS dan dikoreksi menggunakan data BMKG Tanjung Priok selama 10 tahun kebelakang. Perhitungan curah hujan rencana menggunakan metode Gumbel dan diuji dengan Chi-Kuadrat serta Smirnov-Kolmogorov. Hasil simulasi menunjukkan delapan saluran mengalami luapan parah, di antaranya C26, C62, C69, C76, C81, dan C95. Ketidakmampuan saluran dan lahan menyerap air menyebabkan perlunya peninjauan ulang melalui redesain saluran dan pembangunan polder berkapasitas 3,017 m³/detik. Dimensi polder yang direncanakan sebesar 50 × 46,04 meter, dengan kedalaman 2 meter dan tinggi jagaan 1 meter. Pemompaan membutuhkan debit rata-rata 0,84 m3/detik sehingga digunakan pompa submersible 600 m3/jam. Total biaya yang dibutuhkan mencapai Rp2.355.337.319.

There are 16 inundation points across nine sub-districts in Bekasi City, one of which is located in Sepanjang Jaya Urban Village, with water depths ranging from 20 cm to 1 meter. To address the flooding issue, the construction of a polder system is planned, referring to the Regulation of the Minister of Public Works No. 12 of 2014. The study area is located in RW 09, Sepanjang Jaya Urban Village, Rawalumbu Sub-district, covering an area of 17,07 Ha. Maximum rainfall data were obtained from CHIRPS and corrected using 10 years of data from BMKG Tanjung Priok. The design rainfall was calculated using the Gumbel method and tested with the Chi-Square and Smirnov-Kolmogorov tests. Simulation results showed that eight drainage channels experienced severe overflow, including channels C26, C62, C69, C76, C81, and C95. The inability of the drainage system and land to absorb water indicates the need for a redesign of the channels and the construction of a polder with a capacity of 3,017 m³/second. The planned polder dimensions are 50,00 × 46,04 meters, with a depth of 2 meters and a freeboard of 1 meter. Pumping requires an average discharge of 0,84 m³/second, for which a 600 m3/hour submersible pump is used. The total estimated cost is IDR 2.355.337.319.