red round handle main water shut off valve

Water Shut Off Value

Originally contributed by Jeff Butler • last updated 1/22/2021

If you suddenly had to deal with a toilet overflowing, would you know how to shut off the water before you were up the proverbial creek without a paddle? If not, you’re probably going to want to learn how to find and use the water shut off valve for the toilet water supply line.


The term water shut off valve can refer to any of several water valves located throughout a home (or building) that open and close to allow or stop the flow of water. While the main water shut off valve controls the flow of water into the house, additional shut off valves, such as the toilet shut off valve or the washing machine valve, control the flow of water to individual faucets and appliances. Water valves can come in many different shapes, sizes, and materials, and selecting one is often determined by variables such as water pressure, connection type, and location along the water supply line.

Where Is The Main Water Shut Off Valve Located?

One of the most important things a homeowner can know is how to locate and operate the main water shut off valve. If you ever have a serious water emergency, closing this valve should stop all water coming into the house:

  • The main water shut off valve is most commonly located in the basement, crawl space or utility room on the side of the house closest to the street. The water valve handle typically comes in two types: either a round handle or a blade style handle, both of which can be turned to allow or stop the flow of water into the home.
  • It’s not always necessary to shut off the water at the main shut off valve. In many cases, individual faucets and appliances will have water shut off valves located near them, typically under them or behind them. This comes in handy to stop an overflowing toilet.