The key highlights of the book include an innovative rainfall classification methodology based on stormwater quality to support the planning and design of stormwater treatment systems. Additionally, this book provides a practical approach to effective stormwater treatment design and development of a methodology for rainfall selection to optimize stormwater treatment based on both its quality and quantity. The case study presented in this book evaluates how pollutant buildup on urban surfaces and stormwater runoff quality varies with a range of catchment characteristics based on different rainfall types. The information presented will be of particular interest to practitioners such as stormwater-treatment designers, urban planners and hydrologic and stormwater-quality model developers since the outcomes presented provide practical approaches to and recommendations for urban stormwater-quality improvement. Readers will benefit from a state-of-the-art critical review of literature on urban stormwater quality, an in-depth discussion on stormwater-quality processes providing guidance for engineering practice such as stormwater treatment design and model development, a comprehensive overview on the application of multivariate data analysis techniques and a paradigm of the integrated use of commercial models and mathematical equations to undertake a comprehensive, urban stormwater-quality investigation.