In 1990, the Sacramento County Water Agency and the cities of Sacramento, Folsom, and Galt (see Figure 1) applied for and received one of the first stormwater NPDES permits in the United States. These agencies (referred to as Co-Permittees), working under a Memorandum of Understanding (MOU), initiated a proactive stormwater quality management program in advance of the EPA’s promulgation of the Final Rule for permit applications. This proactive step put Sacramento at the forefront of stormwater quality management and set the stage for a major municipal program. A key provision of the Sacramento NPDES Stormwater Permit is to evaluate the effectiveness of programs that are at different stages of development and implementation. A work plan has been prepared which lays out ways to measure program effectiveness by both qualitative and quantitative methods. This paper presents the major aspects of the work plan and how the program will be implemented.