Abstract: A water delivery control system that may be retrofitted to an existing water delivery fixture by simply removing the existing valve handles and then mounting the control system over the existing valve stems. The control system includes an external housing, a control panel on which an operator may select a desired temperature and pressure, and a valve actuator assembly including at least one electromechanical valve actuator and valve actuator linkage for coupling the valve actuator to an existing valve stem. The spatial arrangement of the valve actuator assembly is such that the valve actuator linkage will couple with an existing valve stem when the control system is surface mounted on the wall or countertop that surrounds the existing water delivery fixture.