Book excerpt: This book identifies the key hydrologic and hydraulic factors which influence the performance of stormwater quality treatment systems such as constructed wetlands and bioretention basins. Mathematical relationships derived using conceptual models underpinned by fundamental hydraulic theory are presented to predict treatment performance. The key highlights of the book will include the identification of the linkages between influential hydrologic and hydraulic factors for constructed wetlands and bioretention basins to support more accurate prediction of treatment performance and effective design of these types of stormwater treatment systems. Furthermore, this book will showcase an innovative approach for using conceptual models to analyze stormwater treatment system performance.