Lotic ecosystems are disturbed by human activities that developed within watersheds. Activities such as agriculture, deforestation, and urban development can lead to structural and functional changes in rivers due to the close relationship they have with their surroundings. Human activities, such urban development, are the primary cause of degradation. The process of urbanization causes changes in natural characteristics, including water quality. The objective of this study was to evaluate the abundance and diversity of benthic macroinvertebrates to determinate water quality conditions in Antiguo Acueducto del río Piedras Natural Protected Area located in the city of San Juan, Puerto Rico. To characterize benthic macroinvertebrates communities, samples were collected from dominant microhabitats (i.e. riffles, pools, and runs). Volunteers participated and contributed to separating benthic macroinvertebrates samples. We assessed both a metric that uses the presence of families (i.e. BMWP’PR index) and a metric that combines tolerance values with abundance of each family (i.e. FBI’PR index). A total of ten orders and 32 families were identified in this assessment. Our results suggest that most of the time water quality oscillates between regular or poor in the study reach between May 2022 to January 2025. The non-profit organization Para la Naturaleza (PLN) used these results to design aquatic biomonitoring activities with the collaboration and support of volunteers. Aquatic biomonitoring efforts have impacted around 160 volunteers investing more than 320 hours in evaluating benthic macroinvertebrates communities. We can establish that with appropriate training and guidance, volunteers can contribute new insights into stream ecological conditions and effectively support researchers, communities, and NGOs efforts.