Boston's water, sewer, and stormwater systems have a long, interesting history and development. Today, these systems are run by BWSC, which was created to maintain and improve the quality and reliability of water, sewer, and stormwater systems in Boston.
Boston is home to New England’s oldest and largest water, sewer, and stormwater systems. These systems serve approximately 20,500 acres, 70% of the total land area of Boston. The drinking water distribution system serves over 90,000 accounts, including residents, schools and universities, hospitals, businesses, industries, and private and public institutions.
Four major factors led to the development of the water, sewer, and stormwater systems to their present-day capacity and configuration:
- The expansion of the city limits. Boston grew from a peninsula of 1.2 square miles to its present size of 47.8 square miles through annexation and land reclamation.
- Boston’s steady increase in population and economic growth. When the first public water supply was introduced in 1848, the city had a population of about 127,000 and in 1877, the original sewer system was built in response to growing public health concerns. Presently, the population of Boston is over 650,000.
- Increased water consumption, forcing city planners to identify new sources of water in the western section of the state.
- Provisions for a fire protection system were sorely needed. The downtown business district of early Boston was constructed of wooden framed dwellings and businesses and particularly vulnerable to fires.
Water, Sewer & Stormwater Systems
Learn about sources of water, water quality, water infrastructure, and the history of the BWSC water system.
Learn about the BWSC sewer system, sewer infrastructure, and the history of the BWSC sewer system.
BWSC owns and operates a system for the collection and transport of stormwater in the City of Boston. The stormwater system collects stormwater runoff (rain and snowmelt) and discharges it into receiving waters around the city.
Learn more about how the BWSC manages stormwater, stormwater infrastructure, environmental regulations, and Illicit Discharge Detection and Elimination Program.
BWSC owns and operates various special structures within its sewer and stormwater systems, including regulators, tide gates, and siphons.
Combined Sewer Overflow Maps
BWSC is posting overflow information on this page that indicates the potential overflow of regulator. This program provides the public with information on CSO activations; where they occur, how often, and how long they occur.