Knowing how to shut off your water is part of easy home maintenance so that you can quickly repair pipes and replace fixtures. Start by looking behind or under the sink where you are working for the water shutoff valve. Often it is placed between the sink and the wall or next to the wall below the sink. You should be able to shut the water off with a few turns of this valve. If you need to turn off the water at the main valve, this is also easy. In some regions, your main shutoff valve may be located in your front lawn near the road or street. Otherwise, follow the pipe to find where it comes into your house—perhaps the basement. When you locate the main shutoff valve, use a tool or your hand to turn the valve clockwise, which tightens it and closes down the water flow.