What should be located between the water main and the house if a meter is located in the basement?

In a residential water supply system, if a water meter is located in the basement, it is essential to have a curb stop situated between the water main and the house. A curb stop is a type of valve that allows the water supply to be turned on or off at the curb or property line. This is particularly important for maintenance purposes, as it allows for the water supply to be shut off without needing to enter the property, which can be crucial during repairs or emergencies.

Having a curb stop ensures that the water supply to the home can be controlled effectively, offering a means to isolate the house from the mains supply when necessary. This is vital for preventing water damage or controlling flow during any plumbing work.

Other components mentioned in the options serve different functions. A pressure regulator manages the water pressure entering the house, a flow meter measures the volume of water used, and a drain valve allows for draining of water from the system for maintenance. While these components are important in their respective contexts, they do not fulfill the same function as a curb stop, which specifically controls the main water supply to the house.