This book and software package provides a concise, practical guide for those involved in studying, planning, and designing urban stormwater management practices. The emphasis is on engineering calculations rather than theory. Many facets of stormwater management, from rainfall analysis and design storm selection procedures to runoff calculations and the evaluation of wet ponds for long-term, efficient water quality control. The book presents broadly used conventional methods and innovative techniques that are in line with current trends and needs. The book also includes the Soil Conservation Service's TR-20 computer software and a new easy-to-follow user's guide. From the Preface There has been much interest in urban stormwater hydrology during the past two decades due to the widespread recognition of the adverse effects of urbanization on stormwater runoff. During this period, many individuals and organizations developed innovative techniques to estimate and control the quantity and the water quality of urban stormwater runoff.