In Pakistan, one of the basic challenges the urban areas are facing is the lack of high-quality water for people due to rapid population growth, unplanned urbanization and increasing climate uncertainty. The Indus river system is the major source of water for people and agriculture in Pakistan. Due to dramatic population growth, water demand has also increased but water availability is declining so sharply that in future urban water management may meet with severe challenges. Pakistan is the eighth most climate-vulnerable country in the world. This extreme climatic variability has intensified the need to manage Pakistan’s water resources more sustainably. In 2018, the government of Pakistan developed a National Water Policy (NWP) to provide the guidelines for the development of sustainable water management solutions. To implement this policy, there is a decision support tool called the Urban Water Optioneering Tool (UWOT), which aims at facilitating the selection of combinations for water saving technologies and supporting the implementation of integrated and sustainable water management in new developments. The tool is based on a water balance model which enables the investigation and analysis of interactions within the major urban water cycle streams. The technology options are determined by a genetic algorithm (GA) allowing the efficient exploration of decision possibilities. GA is applied to address multiple contaminants in the water system. In essence, UWOT is a tool that aids decision-making by finding the best combination of water-saving technologies to ensure sustainable water management in urban developments. It has been successfully tested in the UK. This tool considers both the quantitative data and qualitative insights, and provides a complete picture of challenges in water management.