PEMODELAN HUJAN-DEBIT MENGGUNAKAN STROM WATER MANAGEMENT MODEL UNTUK EVALUASI SISTEM DRAINASE STUDI KASUS : RW 08 KELURAHAN WONOREJO SURABAYA

Abstract

Rapid land-use changes driven by residential development have significantly disrupted the drainage system in RW 08, Wonorejo Village, Rungkut District, Surabaya, resulting in frequent flooding. This study employs the Storm Water Management Model (SWMM) to evaluate and model the local drainage network. Design rainfall intensities were computed and used as model inputs. The SWMM model comprises 117 subcatchments, 227 junction nodes, 4 outfalls, and 385 conduits. Simulation results yielded a continuity error of –0.25% and a flow-routing error of 0.00%, both well within the acceptable threshold of < 5%. During a two‑hour high-intensity rainfall event, 68 conduits experienced overflow. These findings identify specific vulnerable sections within the network that are prone to flooding under heavy rainfall. Future work should prioritize hydraulic upgrades—such as upsizing conduits or introducing retention facilities—to enhance the system’s resilience and reduce flood risk in similar urban residential settings.