Unaccounted For Water

Historical values of Unaccounted for Water (UAW) for Topsfield are listed below.  Beginning in 2006, DEP requires UAW be kept below 10%.  We were able to do this for several years but in 2009 UAW jumped to 11.5% despite annual leak detection surveys.  We conducted an extra round of leak detection during Fiscal Year 2010 & 2011 to compensate for the increase.

We lost 7.16 million gallons of water during 2011 or 13.6 gallons per minute.  If the leakage were the only reason for the loss, we would be looking for a single hole slightly less than 5/16 inch diameter or up to twenty-four 1/16 inch leaks.  Large leaks are easier to find because the water will surface or the noise created by the water escaping from the pipe can be heard by a trained leak detector with the proper equipment.

The health of a water distribution system is commonly gauged by a statistic known as Unaccounted for Water (UAW).  It is normally expressed as a percentage of the total volume withdrawn during a given year. The volume lost is the difference between the volume withdrawn and the volume that is accounted for.

The easiest way to account for water is through billing.   All of the servcies in Topsfield are metered and we can quickly calculate the total volume of water billed in a year.  The  billing cycles for two-thirds of our customers do not match the calendar year but the differences occur in the winter time when water use is generally lower and more likely to be consistent from year to year. The Department of Environmental Protection allows us to also account for water use that can be 'confidently estimated'. Estimated use includes water used for fire fighting & training, hydrant flushing , water main breaks, drain cleaning and street sweeping.

Hydrant Flushing Completed

Hydrant flushing was completed on June 4th.  The next round will start in October 2019.

Pay your water bill online

81009 83017 0Please visit the Unibank site to pay your water or tax bills online.


Water Department

279 Boston Street

Topsfield, MA 01983


978.887.1543 (Fax)

911 -  After Hours Emergency

Hours: Monday-Friday 7 AM to 3:30 PM

Highway Department

279 Boston Street

Topsfield, MA 01983


978.887.1543 (Fax)

Hours: Monday-Friday 7 AM to 3 PM