Processes of environmental transformation that currently occur in the climatic change context generate changes in ecosystems and biological communities. ?how populations respond to these stressors? ?what effects could occur on taxonomic and ecological diversity? The taxonomic composition and structure of the zooplankton was analyzed with relationship to environmental changes in a tropical water reservoir located at 6o 02’ 18” N and 73o 29’ 16” W. During four months, samples were taken weekly covering stations of low, medium, and high precipitation. A high degree of temporal variability was established, it associated with a short hydraulic retention time estimated at eight days. Nine species of zooplankton were Articulo de investigacion