Main Breaks

Under our feet are thousands of miles of pipe that bring water to our homes. Philadelphia is an old city, so we manage old infrastructure; some of our water mains were first installed in the 1800s. PWD inspects and maintains 3,200 miles of shared water mains and relies on building owners for maintenance of their water service lines and plumbing.

Call our emergency hotline: (215) 685-6300

to report a main break, loss of water, or other water emergency.

You can also check our Active Work Map to see if we’re already aware of it.

The main story
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Three different categories of pipes transport water from treatment plants to a customer’s property: transmission mains, distribution mains, and service connections.

Transmission mains are larger water mains with a diameter of 16 inches or larger and are used to move large amounts of water across the city between pump stations and reservoirs.

Distribution mains are smaller than 16 inches and are used to deliver water from transmission mains to customer service connections.

Service connections are the individual connections owned by the property owner that are tapped into the distribution mains that bring water into a building or house.

The service connection and internal household plumbing is owned and maintained by the customer. Learn more about customer responsibilities →

What to expect when a main breaks

When there is a loss of water, PWD crews are available to respond 24 hours a day, 7 days a week. The crews isolate the break site and stop the damage created by the flowing water, then repair the break and restore water services as safely and quickly as possible.

How will PWD respond?

PWD’s main break repair procedures are intended to minimize the length of disrupted service while maintaining safety for PWD’s field crew, customers, and affected traffic.

PWD crews will first determine where the main break has occurred since it is not always at the location where the water surfaces to the ground. By closing appropriate valves, PWD crews can isolate the broken section of the main and thereby maintain the system pressure and service to as many customers as possible.

After excavating the area around the main break, the PWD crew will clear and dewater the trench in order to repair or replace the broken segment. In addition to making necessary repairs, the crew will clean and disinfect the pipe.

After the repair has been completed, the main will be flushed with fresh water from a fire hydrant before it is put back into service.

Responding to main breaks

Loss of water

Main breaks can cause a loss of water pressure or even temporary loss of service as the main is shut down to isolate the emergency. Most interruptions to water service are fixed within six to eight hours. In some cases, such as water main breaks that occur in the middle of the night, water is usually restored by the following day. Affected customers are notified with a door hanger on the front door of the property.

System flushing tips

Pipe replacement or repairs to water service can allow sediment and debris into pipes. Here are some tips for clearing debris from your water pipes after street repairs have been made:

  • Read an illustrated fact sheet showing how to clean pipes after construction work
  • Run your cold water faucets for several minutes in order to release air and remove debris from the system.
  • Use bathtub, laundry faucets, and hose bibs when possible for flushing your system, as they generally have a larger capacity and do not have aerator screens to trap debris.
  • Clean faucet screens to remove debris that might clog the water fixture.

Understanding and preventing water main breaks

Why do water mains break?

Water mains fail when the stresses placed upon them are greater than the strength of the pipe. Water mains don’t get stronger with time; they may get weaker due to internal or external corrosion.

External forces on a water main include:

  • traffic loading
  • temperature changes
  • underground work with direct or indirect impact to the pipe

The imbalance of stresses to the strength of a pipe may evidence itself in various ways, such as:

  • joint leaks,
  • pipe breaks, or
  • service lines detached from a main.

How can we reduce water main breaks?

PWD has ongoing programs to prevent main breaks and other pipe failure, continually monitoring and improving our infrastructure to minimize disruptions, while continuing to provide safe and efficient service.

Main replacement

The goal of this program is to maintain a high level of water service and system reliability while still achieving a full, useful life of every water main. The main replacement program uses a scoring system to prioritize replacement and provide a systematic approach to the management of assets. Generally, the older the main and the more frequently it has experienced breaks, the higher the priority for its replacement. Currently, PWD replaces 30 miles of high-priority water mains every year at a cost of approximately $1 million per mile.

Corrosion testing

Our corrosion testing and rehabilitation program also prevents breaks in large, cast iron transmission mains. This cleaning and relining program can reduce leaks and extend the useful life of transmission mains.

Cathodic protection

The cathodic protection program guards against exterior corrosion from soil conditions or stray electric current that may cause weak spots in the water mains. During main replacement or repair, inspectors determine if the conditions require cathodic protection for the new main.

Leak detection

Leak detection analysis focuses on non-visible leaks on both transmission and distribution mains. Acoustic devices are used to analyze one third of the city water mains each year. The deeper, larger transmission mains are investigated by a specialized leak detection company.

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