Domestic wastewater management in emerging nations is a critical issue these days. While it is challenging to avoid the generation of wastewater, efficient treatment of this wastewater can yield potable water and preserve freshwater resources. Urban areas in developing countries often rely on centralised sanitation systems which are unstable and lead to environmental problems; on the other hand, decentralised systems are more flexible as they independently collect, treat and then dispose of the treated wastewater. Decentralised wastewater systems can be classified into three types: aerobic systems, anaerobic systems and natural treatment systems. This chapter specifically focuses on nature-based solutions, such as the use of aquatic macrophytes to treat wastewater, as they offer a cost-effective approach to decentralised wastewater treatment. It is important to understand the structure and function of macrophytes to conserve biodiversity and maintain ecological balance in aquatic systems. These plants are viable for sustainable wastewater treatment solutions because they play a vital role in eliminating contaminants through various mechanisms. This chapter delves into the efficiency, mechanisms, development and implementation of treatment systems based on floating macrophytes for treating wastewater.