Nanomaterials with distinct characteristics due to their high surface area and wide range of applications such as photocatalytic activity, programmable surface chemistry, and antibacterial capabilities are recognized as noteworthy candidates for revolutionizing water management practices. Nanotechnology can increase access to clean, safe drinking water by developing novel nanomaterials for treating surface water, groundwater, and wastewater contaminated by hazardous metal ions, inorganic and organic solutes, and microbes. Researchers are looking into the use of nanomaterials as specialized adsorbents, photocatalytic degraders, antimicrobial agents, and sensors for water quality monitoring. The nanotechnology-based approaches for water treatment and monitoring bring about effective and eco-friendly techniques that enhance the pollutant removal, disinfection capabilities, and real-time monitoring of water quality parameters. Toxicity and environmental fate of a substance are two main factors to take into account when designing and selecting materials for water purification. This chapter covers the possible advantages and difficulties of integrating nanomaterials in water management, including cost considerations, risk reduction, and effects on public health. Moreover, it seeks to offer insightful information on the potential of platforms based on nanomaterials and their contribution to the development of effective and long-lasting water management techniques.