By considering the amount of usable water per capita, Türkiye is considered a country that suffers from water stress. Therefore, Türkiye must set up procedures based on plans for the effective and planned use of its current water resources to deal with a potential future problem of water scarcity. The option of reusing treated wastewater is one of the most significant techniques for achieving the most effective use of water. A large amount of water is used in agriculture, and the burden on freshwater resources can be reduced through the use of treated wastewater for irrigation purposes. This study aimed to determine the amount of treated wastewater potential for irrigation purposes in Türkiye. To determine water reuse alternatives, a project entitled “Evaluation of Used Water Reuse Alternatives” was conducted by the Republic of Türkiye, Ministry of Agriculture and Forestry, General Directorate of Water Management between the years 2017 and 2019. Used water from wastewater treatment facilities in Türkiye has been assessed for the use in irrigation as part of the project. In this paper, decision-making steps for water reuse in Türkiye are given as a flowchart, and methods for determination of the total amount of the treated wastewater potential for irrigation purposes are explained. As a result of the study, the basin basis used water potential in Türkiye is reported.