Shut off your water main by locating the main valve where the water line enters your home. Turn a gate valve clockwise until fully closed. Ball valves turn 90 degrees perpendicular to the pipe. The street-side shut-off at the curb requires a special meter key available at hardware stores. Turn off the main valve before any major plumbing repairs or during extended absences. Test the valve annually to ensure it operates smoothly and doesn’t seize from disuse.