Locate your main water shut-off valve where the water line enters your home typically in the basement crawl space or near the water meter. Turn the valve clockwise for gate valves or perpendicular to the pipe for ball valves. The street-side shut-off near the meter requires a special key. Know your shut-off location before emergencies. Exercise the valve annually to prevent seizing. Label the valve clearly so all household members can find it quickly during a plumbing emergency.