This document presents the design of an automated system that allows the reuse of gray water from a common washing machine. For the design, the amount of water used during the complete washing cycle was taken into account, which is approximately 180 liters, so around 2,160 liters will be reused monthly, and the uses that can be given to said water, called gray water. The automation process is executed by means of a Programmable Logic Controller (PLC) and the process sequence is presented in a Process Flow Diagram (PFD). Finally, with the help of a user-friendly Human Machine Interface (HMI), the status of the system (ON/OFF), the level of the gray water storage tanks, the activation of the electric pump and the final source of supply are displayed. of water, that is, from which tank water is being supplied for use in the home. Designed system effectively executes the established sequences, giving priority to the use of gray water. This development makes it possible to effectively obtain an alternative for saving water from a washing machine.