What is a Curb Stop Box?  The curb stop box is the tube that allows access to your home’s external shut off valve. It is located in your yard where your service line connects to the  Summit Water Distribution Company main line. The top lid should be at grade level. This valve is used to shut off water to your home in the case of an emergency and must be accessible and protected from damage. There should be no large trees or shrubs planted near this valve.  This valve is also the point of change of responsibility. Any problem after this valve is the responsibility of the homeowner.