A dishwasher for treating dishes according to a cycle of operation includes a tub at least partially defining a treating chamber, a liquid supply conduit, and a rotatable sprayer that is rotatable about a rotation axis and has an inlet and multiple nozzles collectively forming an outlet. The dishwasher further includes a hydraulic drive fluidly coupling the liquid supply conduit to the rotatable sprayer. The hydraulic drive is mechanically coupled to the rotatable sprayer.