Evaluasi berbasis risiko terhadap kepatuhan prinsip zero ΔQ runoff infrastruktur drainase pada pengembangan Cluster Royal Blossom

Land-use conversion from agricultural areas to residential development reduces infiltration capacity and increases surface runoff, potentially affecting the performance and sustainability of urban drainage infrastructure. This study evaluates the impact of land-use change on runoff discharge, assesses compliance with the Zero ΔQ Runoff principle, and examines the effectiveness of infiltration wells as a risk mitigation measure in the Royal Blossom Cluster, Tangerang Regency, Indonesia. Hydrological analysis was conducted using annual maximum rainfall data from the Pasar Baru Rainfall Station for the period 2010–2024. Design rainfall was determined through frequency analysis, rainfall intensity was calculated using the Mononobe method, and peak runoff discharge was estimated using the Rational Method. Infrastructure risk was evaluated using the Infrastructure Risk Index (IRI), while compliance with the Zero ΔQ Runoff principle was assessed using the Zero ΔQ Compliance Ratio (ZCR). The results indicate that land-use conversion from paddy fields (C = 0.45) to residential areas (C = 0.70) increased peak runoff discharge by 55.6%, from 0.331 m³/s to 0.514 m³/s for the 2-year return period. This increase generated an additional runoff volume of 3.305 m³ and resulted in an IRI value of 55.6%, indicating increased hydraulic loading on the drainage system. To mitigate the additional runoff, five infiltration wells with a diameter of 0.8 m and a depth of 1.5 m were designed, providing a total storage capacity of 3.273 m³. After mitigation, the ZCR reached 0.99 for the 2-year return period and 0.83 for the 5-year return period, indicating compliance with the Zero ΔQ Runoff principle. The results demonstrate that infiltration wells can effectively reduce drainage infrastructure risk while supporting sustainable stormwater management in residential developments.