**Abstract**

The 1972 Clean Water Act (CWA) established goals and regulations regarding water quality in the U.S. water resources, including coastal waters. The U.S. Environmental Protection Agency (EPA) was charged with implementing the CWA's goals and with helping states, and tribes meet their mandate to periodically monitor and assess water quality in their jurisdictions. In response, the EPA initiated the Environmental Monitoring and Assessment Program (EMAP) to develop and test effective methods of assessing water quality in lakes, rivers and streams, and estuaries at state and national scales. EMAP-Estuaries commenced in 1990, devising sampling designs and protocols for estuaries, testing potential indicators, establishing assessment, and reporting methods. Estuarine research and development efforts continued in a series of subsequent programs, each adapting and adopting the best practices of earlier programs, each becoming more national in scale, and each integrating state and tribal participation to a greater degree. Recent surveys have included an assessment of coastal Great Lakes waters. This chapter recounts the history of assessments in coastal waters, emphasizing the current approach while highlighting examples of lessons learned over the 30-year development period leading to the National Coastal Condition Assessment.

**Keywords:** coastal assessment, EMAP, NCA, NCCA, NARS, indicators
