One of the most important things to know about your plumbing is where your main water line shut-off valve is located and how to operate it. This valve stops the flow of water coming into your residence. Being able to quickly locate it and shut if off could be the difference between a little water that is easy to clean up or a massive mess that can cause thousands of dollars in damage. That may seem like a scare tactic, but a ¾ inch water main can push about 25 gallons per minute based on average pressure. Fortunately, most leaks don’t result in quite that much water at once, but being able to quickly stop it will save you much time and trouble.