EVALUASI SISTEM DRAINASE PERUMAHAN BUMIAYU KECAMATAN SAMPANG KABUPATEN SAMPANG

Abstract

ABSTRACT

Population growth in Sampang Regency has led to land-use changes into residential areas such as Bumiayu Housing, resulting in reduced water infiltration areas and increased flooding during the rainy season. The existing drainage system is unable to accommodate stormwater runoff effectively, often causing water pooling with depths ranging from 20 to 50 cm. This study aims to evaluate the design rainfall, planned flood discharge, existing drainage capacity, and performance using the EPA SWMM 5.1 software, employing a quantitative descriptive method through the collection of rainfall, topographic, land cover, and existing drainage dimension data. The analysis includes maximum rainfall, population growth, design rainfall, runoff coefficient, flood discharge, wastewater discharge, and drainage storage capacity. The results show that the 10-year return period design rainfall is 107.16 mm, with the highest flood discharge of 0.614 m³/s occurring in channel Z1-Z6 and minimum flood discharge 0.003 m³/s occurring in channel F9-F11 and Q5-Q6, and 24 existing channels are unable to handle the flood discharge. The evaluation indicates the need for redesign, with the largest dimension change required for channels L7-Z1 and Z1-Z6 from 0.6 m × 0.6 m to 0.6 m × 1 m. EPA SWMM modeling shows that the highest rainfall intensity occurs in the second hour, and the redesigned channels are capable of handling the planned flood discharge.

Keywords: Bumiayu Housing, Drainage, EPA SWMM, Flood