DESIGN OF THE DRAINAGE SYSTEM FOR PURI SAFIRA REGENCY RESIDENTIAL AREA, GRESIK REGENCY

Abstract

The significant expansion of residential areas in suburban regions, such as Menganti District in Gresik Regency, has led to increased stormwater runoff due to the reduction of natural infiltration areas. This study aims to design an optimal drainage system for the Puri Safira Regency residential area to mitigate the risk of waterlogging and flooding. A quantitative approach was employed, incorporating hydrological and hydraulic analyses. The results indicate that the total runoff discharge generated by the housing area is 3.505 m³/s. The drainage channels utilize U-Ditch sections produced by PT Dantosan Precon Perkasa, with the smallest cross-sectional dimension found in the tertiary channel (0.3 x 0.3 meters) and the largest in the primary channel (1.8 x 1.6 meters). Three detention ponds are planned, each designed to collect runoff from one section. Detention pond 1 is designed with dimensions of 50 x 30 x 1.5 meters and does not require a pump. Detention pond 2 measures 70 x 40 x 1.5 meters and includes a pumping system. Detention pond 3 measures 60 x 60 x 1.5 meters, also equipped with a pump. The maximum river discharge during high-intensity rainfall is estimated at 22.444 m³/s with a water level of approximately ±1.8 meters. This discharge remains below the river’s capacity of 28.254 m³/s, indicating that it will not result in flooding.