Abstract
This paper aims to investigate the developments in water demand and use in Riyadh city between 2017 and 2030. It examines the effectiveness of desalination and groundwater supply on water demand based on the Water Evaluation and Planning (WEAP) model. Five scenarios are considered based on future water development strategies planned by Saudi national water authority to evaluate and manage the Riyadh water system to enable precise predictions. This investigation also explores the best combination of various water resources management alternatives that meet future water demands in 2030. This study evaluates the performance of Riyadh's water system by calculating the reliability, resiliency, and vulnerability indicators on unmet demand. The results demonstrate that the pressure will increase on the current water supply system in Riyadh by having an unmet demand of 1,076 MCM in 2030. After implementing several proposed strategies by the National Water Company (NWC) including water conservation in conjunction with leak reduction and reuse of recycled water, the unmet demand in 2030 reduced to a level below to those happened in the baseline of 2017. Moreover, the prevention of future unmet demand requires a combination of water conservation, leak reduction, and the use of new water supplies.