Water availability for a self-sufficient water supply: A case study of the Pesanggrahan River, DKI Jakarta, Indonesia

Abstract

The research will explore the challenges of using local water sources inside the city for a self-sufficient urban water supply by developed a system dynamics model. This study aims to evaluate and understand the Pesanggrahan River appropriateness as a raw drinking water source through a conceptual model that can accurately represent the interactions between the water supply and demand system. A set of time series data for the monthly precipitation and river flow rates at two stations from 2002 to 2016 were used to calculate the 90% dependable river flow fluctuations over one year. The results showed that water availability becomes limited in July, August, and September. Simulation results demonstrated that the Pesanggrahan River could supply 450 liters/s. The water demand exceeded the supply if the average water consumption 150 liters/capita/day for 100% service coverage. However, they will balance when service coverage 66 %, but reducing water consumption to 99 liters/capita/day will increase service coverage to 100%. The average water consumption and service coverage forming a linear equation relationship Y = 99.20x-0.99 with a correlation factor R2 = 0.99. This research contributes to enhancing the resilience of the water supply system. It provides a well-founded, flexible, and realistic approach to recognize and deal with challenges to local raw water resources limitation that inherent with uncertainties in water resources management.