The disclosed technology includes a valve assembly having a valve, an actuating system, and a trigger. The trigger can be in mechanical communication with the actuating system and the actuating system can be in mechanical communication with the valve. The trigger can be positioned such that the trigger can interact with liquid resulting from a leak in a plumbing system, and upon interaction with liquid, the trigger can release the actuating system such that the actuating system can cause the valve to transition from an open position to a closed position. In the closed position, the valve can restrict the passage of liquid through the plumbing system such that the leak can be mitigated or stopped.