Redesigning Of Drainage Channels In The Griya Ampera Complex On Ujung Pandang Ii Street, Pontianak City

Abstract

The drainage channels in the Griya Ampera Complex on Ujung Pandang II Street in Pontianak City are facing water pooling and flooding problems due to the small size of the existing channels and sand or mud sedimentation blocking the channels at several end points. Therefore, this study aims to reorganize the drainage channels to handle the total flow. This research uses primary data from field surveys and secondary data in the form of maximum daily rainfall over 14 years (2011–2024) from BWSK I Pontianak. The data is analyzed using the Log Pearson Type III distribution method to obtain design rainfall. Rainfall runoff is calculated using the rational method, and the channel dimensions are planned in a rectangular shape. Unlike previous studies that used the best hydraulic cross-section, this study designs the channel dimensions based on field conditions. The study found a catchment area of 0.0196 km², a concentration time of 0.2050 hours, The rainfall intensity is 143.8000 mm/hour, the runoff coefficient is 0.4700, the rainfall runoff discharge is 0.4290 m³/s, the wastewater discharge is 0.0004 m³/s, and the total discharge is 0.4294 m³/s. The existing front channel has a discharge of 0.0244 m³/s and the back channel 0.1521 m³/s, so they cannot handle the total discharge. The new planned channel is rectangular with a width of 0.5000 m, a flow depth of 0.6000 m, and a freeboard height of 0.4000 m, which meets the required standards.