Engineered ponds, lagoons, and wetlands have been used for centuries to treat and manage wastewater, and they are still widely used today. They require very few external energy and material inputs and provide ecosystem services for communities. This book presents a compilation of guidelines to design ponds, lagoons, and wetlands for the treatment and management of domestic or municipal wastewater, agricultural wastewater, and industrial waste. Sufficient detail and clarity is provided for practitioners to use this book as a reference, and for senior year or graduate college students to develop an understanding of the design concepts for these engineered natural treatment systems.