Urban Flood Management Strategies in Kapanewon Depok, Sleman Regency (A Simulation-Based Study Using EPA SWMM 5.2)

Abstract

Kapanewon Depok has experienced frequent urban flooding in recent years, driven by rapid urbanization and the compounding effects of climate change. In response, the Sleman Regency Government, through the 2023-2043 RDTR for the Central Sleman Area, plans to construct infiltration trenches as a flood mitigation strategy. This study aims to evaluate the effectiveness of infiltration trenches in Kapanewon Depok in reducing urban flooding. The EPA SWMM 5.2 software was utilized to simulate urban flooding scenarios using rainfall data with a 5-year return period. The first scenario simulated the current urban drainage system, while the second scenario incorporated Low-Impact Development (LID) controls, specifically infiltration trenches. Results from the initial scenario revealed 30 junctions experiencing overflows. The use of infiltration trenches covering 0.5% of the sub-catchment area served by the overflowing channel, successfully reduced the number of overflow points to 18, with an average reduction of 62.5% and 62% total flood volume and hours flooded, respectively. This research provides recommendations for urban flood management by implementing infiltration trenches and increasing the capacity of drainage infrastructure.