On this paper an evaluation of an energy harvesting system is presented. The system scavenges energy from a water flow using induced vortexes and piezoelectric materials. Cylinders of different size generate the vortexes and are attached to a cantilever that holds the piezoelectric generators. The evaluations consist on testing the performance of the cylinders and observe the frequencies and voltages generated. The preliminary results show that some of the configurations can generate a power of up to 0.31 μW.