The possibility of reusing the effluent from Cuena’s wastewater treatment plant WWTP is analyzed through the application of two treatments: conventional physical–chemical (coagulation, flocculation, sedimentation and filtration, and disinfection) and advanced oxidation with a combination of hydrogen peroxide/ozone. The results show that neither treatment method independently resolves all the limitations of the effluent for reuse, especially regarding organic matter, nutrients, and turbidity. Therefore, the compatibility of the quality of the treated water quality is evaluated for three potential reuses such as unrestricted urban use, recreational use with primary contact, and agricultural irrigation, referencing EPA and Ecuadorian TULSMA standards. This study highlights the need to establish a legal and regulatory framework for water reuse in Ecuador to enable decision-makers to implement sustainable water reuse practices and manage scarcity effectively.