The South River in Atlanta, Georgia is one of few waterways in the United States whose headwaters originate in a highly urbanized area, providing innumerable ecosystem services to communities within the Upper Ocmulgee River Basin. Historically, the South River has been a site of both cultural significance and environmental racism, its health undermined by decades of impervious development, chronic sewage pollution, and infrastructural inequities. In response, partnerships between community-based organizations (CBOs) and higher-education institutions (HEIs) have developed to address the ongoing and systemic degradation of the South River, and advocate for the health and restoration of the watershed. Such partnerships can empower grassroots organizing with quantitative analysis, ultimately broadening local community’s efforts to diminish pollution impacts, strengthening community understanding, and accelerating advocacy for watershed protection and restoration. By weaving historical context with contemporary organizing, we explore grassroots advocacy efforts in fostering long-term engagement and resilience within Atlanta’s South River watershed.