Water & Sewer


The Division's responsibilities include:

  • Cleaning thousands of feet of sewer main
  • House service renewals
  • Rebuilding catch basins and manholes
  • Repair of house line service leaks, water main breaks, storm drain lines, and sewer system
  • Replacing fire hydrants and adding new hydrants and gate valves to the system
  • Responding to house line sewer backups and main line backups


The Water and Sewer Division bills quarterly, four annual bills per account.


The Division also meets the ever increasing reporting requirements of the EPA, DEP and MWRA for drinking water. Annually, the staff performs the six-week program of hydrant and water main flushing (Watertown has nearly 1,000 hydrants and 3,600 catch basins) and conducts weekly drinking water quality sampling, entailing more than 520 samples over the course of the year. The Division inspects and samples river outfalls for quality of the Charles River and continues our program for television inspection of sewer and drain lines, and conducts two annual rounds of sampling for lead in the drinking water.

Backflow Prevention

The Division continues its inspection of backflow prevention devices in compliance with the DEP. All existing or new building drains from plumbing fixtures liable to backflow from a Department of Public Works (DPW) sewer, or a private sewer connected to DPW sewer, shall be required to have backwater valves installed at the owner’s expense. Any plumbing fixtures located at an elevation below the top of the manhole on the DPW sewer serving the fixture shall be considered to be liable to backflow. Backflow valves shall be installed in accordance with 248 CMR Section 2.09(4) of the Uniform State Plumbing Code.

Water Piping

Did you know that Watertown has 80 miles of water piping running under its streets? The water mains measure from 6 inches in diameter to 16 inches. One is 72 inches in diameter!