Online analytical processing databases allow for the efficient analysis of vast amounts of data. In this paper, we describe the design of an online analytical processing data cube structure for use in the analysis of multiple measures of environmental water quality data. The measures, also known as facts, will be the quantitative values returned by various water quality tests while the dimensions will be the attributes that describe the what, when and where of the water quality test measures. The data model and build process presented here will allow for varying types of tests and for the insertion of new data as it becomes available. The overall goal of this design is to provide business intelligence capabilities to water quality decision makers.