Winter Weather and Water Main Breaks

Winter Weather Strategy

WSSC is prepared to handle weather-related emergencies with different strategies, including:

  • A “24/7” rapid response center that handles emergency calls and quickly dispatches crews. For water or sewer emergencies, please call 1-800-828-6439 or (301) 206-4002;
  • More than 200 personnel trained to quickly respond to and repair water main breaks;
  • Teams strategically placed in both counties to respond to weekend and overnight emergencies;
  • Independent contractors available to supplement WSSC teams when necessary;
  • The latest technology used to pinpoint the exact locations of water main breaks;
  • Hundreds of pieces of heavy equipment to help teams excavate and repair breaks;
  • A Geographic Information System (GIS) computer program to help us better track and schedule water main maintenance and replacement activities; and

Fact Sheet

Winter’s lower temperatures increase the chances of water main breaks in Prince George’s and Montgomery counties by about 60 percent compared to warmer months. Breaks can not only leave hundreds of people without service, they can also cause traffic problems.  That’s why WSSC takes winter preparations very seriously.  We have skilled teams, contractors on standby, and trucks, heavy equipment and the latest technology ready to roll.

Water Mains

  • Serving a 1,000-square-mile area, WSSC maintains more than 5,600 miles of water mains. That's enough pipe to stretch from Washington, D.C. to California and back!  And we’re replacing more than 55 miles of pipe each year.
  • WSSC's water mains range in size from 1 inch to 96 inches (8 feet) in diameter.
  • Of the 5,600+ miles of water mains in our distribution system, 37% are more than 50 years old, 39% are 25-50 years old and 23% are less than 25 years old.
  • The most common size for a water main is 8 inches, followed by 6, 12, 10 and 16 inches.

How Temperature Impacts Water Mains

  • A 10-degree change in the air or water temperature can dramatically increase stress on a pipe.
  • Water temperature below 40 degrees F can cause pipes to become more brittle. 
  • Air temperature at or below freezing causes the ground above a pipe to freeze - increasing external stress on a pipe.
  • Since the drop in water temperature lags behind air temperature changes, water main breaks may occur one to two days after a cold spell.

Other Factors That Contribute To Breaks

  • Material -- Most breaks occur in cast iron water mains.
  • Soil Erosion -- A previous pipeline break, excavation or nearby construction activity often erodes soil around water mains, which can cause breaks.
  • Corrosion -- Older pipes are not cement lined and corrode inside and outside, increasing the chances of a break.
  • Pipe Diameter -- The smaller the diameter, the greater the risk of breakage.
  • Age -- The break rate for pipes increases after 60 years. Age alone, however, cannot always be used as an indicator of failure. Some pipes installed in the early 1900s have never broken.
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