What Causes a Water Main Break?

Water main breaks can be disruptive and costly to organizations and municipalities. They can also be preventable through the awareness of their causes: winter temperatures can freeze water in or around the pipes, external and internal corrosion can cause metal deterioration of ductile iron, cast iron or steel, soil conditions, and even careless ground excavation can result in a water main rupture. Many of these issues can be mitigated through consistent pipeline analysis and repair.

Water Main Breaks Happen Frequently in Cold Weather

In colder climates, there are freeze/thaw cycles during the winter. During cold snaps, water can freeze in or around the pipelines. Water expands by 9% of it’s volume when it freezes; this causes an increase in pressure on the pipeline that causes the water main to break.

Water Main Breaks can be Caused by Corrosion

Corroded pipes are weakened and may develop cracks and holes if undetected and go without being repaired. As water leaks from the pipe, it causes these flaws in the pipe to become larger, and before you know it water is gushing from the pipe and you have a full scale water main break on your hands. Internal and external corrosion can be detected by ensuring that pipes are regularly inspected.

Water Main Breaks are more common in Ductile Iron Pipelines

Older pipelines are frequently made of cast iron. This material is extremely strong and durable, but it doesn’t respond well to seasonal temperature changes or ground movement. This is the reason why many companies and water utilities have switched to using ductile iron for water pipelines. However, ductile iron is much thinner than cast iron pipes, for the same pressure specification,  and therefore corrodes through the wall at a much faster rate if not protected by coating or concrete barrier.

Water Main Breaks due to Soil Conditions or Movement

The acidity and moisture content in the ground surrounding a pipeline can have a tremendous impact on the metal and lead to water main ruptures. If a region has acidic soil, organizations and municipalities should account for this and ensure that they have protective coatings applied to pipelines and have them assessed and inspected by professionals.

Water Main Breaks Can be Caused by Construction

Human activities can also be a cause of water main breaks. A construction crew could be excavating with heavy equipment and if they are not diligent about learning where the pipeline runs, and using caution when working around it, they may strike the water main and cause it to rupture. Contractors and homeowners should always contact their utility before starting any construction projects to find out the location of water pipelines that are buried in the vicinity.


PICA Corp. is a professional provider of pipeline inspection services. You can prevent water main breaks by contacting us at (780) 469-4463 or by e-mail: [email protected] to schedule a pipeline inspection.