Benefit estimates of water pollution control policies rely heavily on water quality indices. Since the 1970s, these measures of water quality have been used extensively in stated preference surveys to estimate willingness to pay for water quality that is suitable for recreational use. However, there is little empirical evidence of how well these indices correspond to observed recreational behavior. This paper utilizes a unique micro-dataset of individual household recreational use and water quality in a revealed preference framework to explore how well several major water quality indices explain water-based recreational use.