Assessing Urban Stormwater Management in Jakarta's Private Real Estate Sector

Thesis Abstract

Urban stormwater management (USM) in Jakarta’s private real estate sector is increasingly critical amid rapid urbanization, climate variability, and rising flood incidence that strain municipal drainage and water-sensitive urban design practices. The study investigates how private real estate developers in Jakarta design, implement, and monitor stormwater systems, and how these practices align with city-level drainage standards, green infrastructure potential, and climate resilience goals. The aim is to diagnose gaps, identify enablers, and propose actionable improvements to enhance USM performance across new and existing private developments. Specific objectives include (1) to evaluate current USM design approaches adopted by Jakarta’s private real estate developers, (2) to assess compliance with local regulations and performance indicators for stormwater quantity and quality, (3) to examine the role of financial, institutional, and technical capacities in implementing robust USM, (4) to quantify the impact of private sector USM practices on flood exposure and surface water quality, and (5) to develop a context-specific framework for optimizing green-grey infrastructure integration in private developments. The study employs a mixed-methods design, integrating quantitative assessments of drainage performance with qualitative insights from stakeholder interviews to triangulate outcomes. A stratified sampling frame targets 60 private developments across central, southern, and eastern Jakarta, chosen to represent varying scales, ownership structures, and site characteristics. For the quantitative component, 60 development sites are surveyed using standardized checklists and hydraulic performance metrics, while a purposive sample of 15 developers and 10 municipal regulators participate in in-depth interviews to capture governance dynamics. Data collection instruments include (i) aUSM performance audit checklist capturing design features, storage capacity, retention and detention measures, water quality treatment devices, and maintenance regimes; (ii) municipal compliance records and rainfall-runoff simulations; (iii) semi-structured interview guides covering decision-making processes, cost considerations, risk perceptions, and collaboration with public agencies; and (iv) a water quality sampling protocol at discharge points for key indicators (TSS, BOD, NO3, PO4, pH, turbidity). Validity and reliability are ensured through pilot testing (n=6 sites), inter-rater reliability checks (Cohen’s kappa >0.75), and triangulation across data sources. Analytical approaches combine descriptive statistics, multiple regression, and structural equation modeling (SEM) to identify drivers of USM performance and to quantify relationships between design practices, maintenance intensity, regulatory compliance, and observed flood and water quality outcomes. Hydrological simulations utilize MODULE-5 or SWMM for a subset of sites to compare modeled versus observed runoff reduction, while sensitivity analyses test the robustness of results under different rainfall intensities. The qualitative component employs thematic analysis of interview transcripts, guided by legitimacy theory and the resilience framework to illuminate governance barriers and enabling conditions. A Conceptual Model is developed to synthesize the empirical relationships among private sector USM practices, regulatory context, and environmental outcomes. Expected findings indicate that architectural integration of green infrastructure (GI) features, such as bio-retention swales and shallow ponding, combined with gray infrastructure upgrading, significantly reduces peak discharges (by 15–35%) and improves pollutant removal efficiencies (TSS and COD reductions up to 40–60%), contingent on routine maintenance and dedicated operation budgets. Compliance gaps are anticipated in retrofit projects due to funding constraints, fragmented governance, and limited long-term planning horizons. The study will contribute to knowledge by articulating a sector-specific, scalable USM framework for private developments in rapidly urbanizing tropical cities, bridging urban design, hydrological engineering, and governance research. Policy and practice implications include recommendations for standardized USM performance indicators, revised funding mechanisms for maintenance, enhanced collaboration platforms between developers and municipal authorities, and a decision-support tool for selecting optimal GI configurations under Jakarta’s rainfall regime. The conclusion emphasizes integrated planning between private developers and city agencies to mainstream USM as a core component of real estate value and resilience. Recommendations prioritize embedding USM requirements into development approval processes, establishing performance-based incentives, and promoting data-sharing protocols to enable continuous monitoring and adaptive management.