This article presents a GIS-based methodology to integrate community into the Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS). The proposed methodology was used for the identification, measurement, and comparison of community areas within and between the upstream and downstream watersheds of the Upper Pearl River Basin in Mississippi. Drawing on various sources of data, the communities situated in the upstream watershed were found to be significantly different from the communities situated in the downstream watershed. This information has two important implications relevant to BASINS. First, it provides insights into understanding the human dimension of water resource management. Second, it is instrumental for promoting environmental democracy: networks of association across federal, state, and local organizations that facilitate coordination and cooperation for advancing community-oriented collective action toward the environment.