This manual provides guidance for land development practices within the region. It provides developers, engineers and planners with flexible tools to reduce the volume of stormwater discharge while conserving water quality at the same time. This manual provides specific guidance for planning and implementing BMPs, and describes how to assess alternative site-design approaches to maximize the benefits for individual sites. It also defines BMPs, provides performance goals for site development and describes methods for determining development impacts. The second section contains design criteria and more detailed design guidance for non-structural and structural BMPs. If local communities decide to provide a particular "level of service," the formulas and methodology outlined in the manual help define the technical parameters needed to meet local water quality goals.