Why Water Main Breaks So Often Lead to Boil Water Advisories — and Why Winter Makes It Worse

Every winter, a familiar pattern plays out across towns and cities in the U.S. A water main breaks, pressure drops, crews rush to repair the damage — and residents are suddenly told to boil their tap water.

Over the past week alone, precautionary boil water advisories have been issued in parts of Michigan, Indiana, and New York, following water main breaks and pressure losses reported by local utilities. While the locations differ, the response is remarkably consistent.

That consistency is not coincidence. It reflects how modern water systems are designed to protect public health when something goes wrong.

Pressure loss is the real trigger

When a water main breaks, the most immediate concern isn’t the break itself — it’s the loss of pressure inside the distribution system.

Public water systems rely on constant pressure to keep contaminants out. When pressure drops, even briefly, there is a small risk that bacteria or other contaminants could enter the pipes through cracks, joints, or damaged sections.

Because that risk cannot be ruled out instantly, utilities often issue a precautionary boil water advisory while they repair the system and begin testing.

This is why advisories are frequently issued even when no contamination has been detected.

Why winter makes breaks more common

Cold weather dramatically increases the likelihood of main breaks for a few reasons:

• Frozen ground expands and contracts, stressing older pipes
• Sudden temperature swings cause materials to weaken
• Many water mains in the U.S. are decades old and were not designed for modern freeze-thaw cycles

As a result, winter is consistently the busiest season for water utilities — and for boil water advisories.

Recent advisories reported in places like Genoa Township, Michigan and Benton Charter Township, Indiana followed exactly this pattern: a break, a pressure loss, then a temporary boil order while testing was underway.

Why advisories stay in place after repairs are finished

One of the most common questions residents ask is: “If the pipe is fixed, why can’t I use my water yet?”

The answer lies in laboratory testing.

After repairs, utilities flush the system and collect water samples. Those samples must then be analyzed for bacteria, which takes time. Until results confirm the water meets safety standards, the advisory stays in place — even if water service appears normal.

This delay isn’t bureaucratic caution; it’s a safeguard built into public health regulations.

What residents are usually advised to do

While details vary by location, most boil water advisories include similar guidance:

• Bring water to a rolling boil for at least one minute before drinking or cooking
• Use boiled or bottled water for ice, beverages, and food preparation
• Avoid swallowing tap water when brushing teeth
• Continue using tap water for bathing and cleaning, as long as it’s not ingested

Utilities typically lift advisories as soon as test results confirm the system is safe.

A system designed to err on the side of caution

Boil water advisories can feel alarming, especially when they occur repeatedly during winter. But they are usually preventive, not reactive — issued to protect residents while uncertainty is removed.

In most cases, advisories are lifted within a few days, and no contamination is ever found.

Understanding why advisories are issued — and why winter makes them more common — can help residents respond calmly when the next notice appears.