Water is an essential, yet finite, asset for human survival. Owing to increasing climate change and population growth, water scarcity is already a reality, thus driving the search for sustainable solutions to the water crisis. In this context, the possibility of reusing treated wastewater as a source of non-potable water arises, an activity that can pose risks to society, therefore impelling a mandatory risk assessment. Therefore, this study aims to develop a risk assessment of water for reuse, in terms of public health and water resources, for production and internal use by the Wastewater Treatment Plant (WWTP) in Viseu Sul and for external use, for example for the irrigation of green spaces in Viseu. The methodology used was a semi-quantitative risk assessment of public health and resources. Eight receptors were identified, settled in 47 scenarios, and divided in terms of contact into ingestion, inhalation, and dermal adsorption. The results demonstrated the feasibility of the production and use of Water for Reuse (WfR) by the Viseu Sul WWTP, with an overall public health risk of 0.68, and for use in irrigating green spaces in Viseu, with an overall risk of 0.75. The overall risk to water resources was 2.33 for nitrogen and phosphorus and 0.78 for E.coli. All risks were found despicable, considering the criteria defined by the method. Based on the information presented, it can be inferred that the utilization of treated wastewater for meeting the water requirements of Viseu is a feasible op-tion.