Proceedings of the World Environmental and Water Resources Congress 2021, held virtually June 7-11, 2021. Sponsored by the Environmental and Water Resources Institute of ASCE.This collection contains 104 peer-reviewed papers that discuss the latest innovative research, case studies, and best management practices in water resources and the environment with a focus on fresh water sources.Topics include: drinking water; groundwater; wastewater; stormwater; irrigation and drainage infrastructure; waterways; sustainability and smart water; and security and systems analysis.This proceedings will be of interest to engineers and scientists addressing challenges to drinking water and freshwater resources around the world.