Wachusett Reservoir

Wachusett Reservoir
source
Name	Wachusett Reservoir
Location	Worcester County, Massachusetts, United States
Type	Reservoir
Inflow	Nashua River, Quinapoxet River, Stillwater River
Outflow	Nashua River
Basin countries	United States
Cities	Clinton, West Boylston, Boylston

Wachusett Reservoir is a major drinking water supply for the Boston metropolitan area, located in central Massachusetts. It is the second-largest body of water in the state, created by the damming of the Nashua River. Managed by the Massachusetts Water Resources Authority (MWRA), it forms a critical link in a regional system that also includes the Quabbin Reservoir.

History

The reservoir's construction was authorized by the Massachusetts General Court in the late 19th century to address the growing water demands of Boston. Engineered by the prominent civil engineer John R. Freeman, the project involved the systematic dismantling and relocation of several communities, including the villages of West Boylston and Boylston. The Wachusett Dam, completed in 1905, was a significant feat of engineering for its time and impounded the waters of the Nashua River and its tributaries. This project followed the earlier creation of the Cochituate Aqueduct and preceded the even larger Quabbin Reservoir project, reflecting the Metropolitan Water Board's long-term planning. The filling of the reservoir was completed in 1908, permanently altering the landscape and hydrology of the region.

Geography and hydrology

Situated in northern Worcester County, the reservoir spans parts of the towns of Clinton, West Boylston, and Boylston. Its primary inflows are the Nashua River, the Quinapoxet River, and the Stillwater River. The reservoir's watershed encompasses a large area of central Massachusetts, draining portions of the Wachusett Mountain region. The Wachusett Dam at the southeastern end controls outflow back into the Nashua River, which eventually flows into the Merrimack River. The geology of the basin is characterized by glacial till and bedrock typical of New England.

Water supply system

Wachusett Reservoir is a cornerstone of the Massachusetts Water Resources Authority's integrated supply network. Water travels from the reservoir via the Cosgrove Tunnel and the MetroWest Water Supply Tunnel to the John J. Carroll Water Treatment Plant in Marlborough. After treatment, it is distributed to over three million people in dozens of communities, including Boston, Cambridge, and Somerville. The system is interconnected with the Quabbin Reservoir via the Quabbin Aqueduct, allowing for flexible management and redundancy. Operational control is maintained from the MWRA's headquarters in Charlestown, with water quality monitored continuously to meet standards set by the United States Environmental Protection Agency and the Massachusetts Department of Environmental Protection.

Recreation and access

Public access is carefully managed to protect water quality. The Massachusetts Department of Conservation and Recreation (DCR) maintains several restricted-use areas for fishing and walking. Permitted activities include shore fishing for species like lake trout and smallmouth bass, and walking along designated roadways such as the route along the Wachusett Dam. The Wachusett Reservoir Watershed is largely closed to boating, swimming, and other body-contact sports. Scenic views of the reservoir are available from points along Route 70 and from the grounds of the Tower Hill Botanic Garden in Boylston.

Environmental aspects

Protection of the watershed is a primary management goal for the Massachusetts Water Resources Authority. Extensive forests within the protected area act as natural filters, and land acquisition programs aim to prevent development. The MWRA collaborates with the Massachusetts Department of Environmental Protection and local communities on watershed protection initiatives. These efforts help maintain high water quality, allowing the use of ozone and chlorine as primary disinfectants rather than more intensive filtration. The reservoir and its surroundings provide habitat for wildlife, including bald eagles and various migratory birds, and are part of a larger regional ecosystem that includes the adjacent Quabbin Reservation.

Category:Reservoirs in Massachusetts Category:Buildings and structures in Worcester County, Massachusetts