Abstract A study aimed to assess the aquatic carrying capacity in the Bandar Kayangan Lembah Sari Reservoir, Rumbai Pesisir District, Pekanbaru City, Riau Province. The carrying capacity was determined based on primary productivity using chlorophyll-a concentration, which is indicating the existence of phytoplankton in waters. This research was conducted April-May 2018. Samples were taken at 4…