The Aim of our Project was to build an automatic water tank filling and Rainwater storage system using a VHDL-based interface. As we know, if we have 2 water tanks at our homes, we need to manually turn the motor direction of each tank for filling water. To solve this, we designed this automatic system that senses the level of water in each tank and operates the motor accordingly. Additionally, to conserve rainwater we use another tank which is placed underground where the sensors sense the level of water in the tanks and redirect it to the underground tank. We also incorporate an alarm and LED for indicating the filling of water in the tanks.