Global changes in rainfall frequency and quantity are increasing the impacts of drought in arid and semi-arid regions, and such impacts are projected to increase under climate-change scenarios. In water-scarce environments, the safe use of wastewater can be an option for irrigating certain agricultural and forestry crops, helping to conserve freshwater. The purpose of this module is to provide forest and land managers with information on the safe use of wastewater for irrigation and soil amelioration in forestry and agroforestry systems in dry and degraded lands. The module aims at guiding users in planning reforestation and afforestation in drylands through the use of water produced in constructed wetlands and fertigation plants.