Performance and Effectiveness of Drainage Systems in Densely Populated Residential Areas

Drainage systems were an important component of urban infrastructure for controlling rainwater runoff and minimizing the risk of flooding, especially in densely populated residential areas. However, in many urban areas, flooding still occurred repeatedly despite the availability of drainage networks. This study aimed to evaluate the performance and effectiveness of drainage systems in the Pelita residential area and to identify technical and non-technical factors that affected the occurrence of inundation. This study used a quantitative approach with a descriptive-evaluative method supported by qualitative data. Technical performance analysis was carried out through channel dimension measurements, hydrological analysis using the rational method, and hydraulic analysis using Manning’s equation. In addition, community perceptions and levels of participation were analyzed through questionnaires that had been tested for validity and reliability and analyzed using Pearson correlation. The results of the study showed that the capacity of drainage channels was not sufficient to accommodate peak runoff discharge, as reflected in the relatively high frequency of flooding (3–4 times per year) and the relatively long duration of inundation. Statistically, the physical condition of the drainage system had a strong correlation with flood frequency, while community participation was moderately correlated with drainage effectiveness. These findings confirmed that the effectiveness of drainage systems in densely populated areas was strongly influenced by a combination of technical and social factors, indicating that an integrated drainage management approach was needed.