What is a curb stop / street-side shutoff?
A curb stop is the underground shut-off valve installed near the property line where the municipal water main connects to your home's water supply, operated by the water company or plumber to cut off water from the street side.
The curb stop sits in a small box or pit below ground level, typically just inside your property line near the street or sidewalk. It is the point where the water utility's main line transitions to your private service line. In Greater Hartford, municipal water departments maintain ownership of this valve, though plumbers regularly access it during repairs, emergencies, or system work.
This valve differs from the interior main shutoff found in your basement or crawl space. The interior shutoff controls water flow within your home and may be easier to locate and operate yourself. The curb stop, by contrast, sits underground and requires special tools to access. It serves as the municipality's primary control point and the property owner's backup when an interior valve fails or when work happens outside the home.
Knowing where your curb stop is located matters during water emergencies. If you have a burst main line, a failed interior shutoff, or need emergency repairs, a plumber will use the curb stop to stop the water supply immediately. The valve box cover may be marked, buried under soil or snow, or obscured by pavement, making professional help valuable for locating and operating it. Many homeowners benefit from having a plumber identify and mark their curb stop during routine service work.