About This Location
The Wachusett Aqueduct Arch Bridge, located in Northborough, Massachusetts, is a magnificent historical structure that stands as one of the state's most visually stunning bridges. Constructed in the late 1800s, this bridge served as an integral component of the Wachusett Aqueduct, a remarkable engineering feat of its time.
The Wachusett Aqueduct was built from 1896 to 1898 and played a pivotal role in creating the Wachusett Reservoir. At that time, the Wachusett Reservoir was the world's largest public water supply reservoir, covering an impressive 7 square miles (18 square kilometers). The primary purpose of this reservoir was to meet Boston's ever-increasing demand for drinking water.
Stretching over 9 miles, the Wachusett Aqueduct traverses through Clinton, Berlin, and Northborough, finally reaching the John J. Carroll Water Treatment Plant at Walnut Hill in Marlborough, Massachusetts. The aqueduct consists of approximately 2 miles of hard rock tunnel and an additional 7 miles of underground aqueduct with an impressive height of 11 feet and a width of 12 feet. This underground section is constructed of non-reinforced concrete with a brick-lined invert. While most of the aqueduct is underground, there are several elevated sections. The final segment of the aqueduct, which was decommissioned in 2005 upon the opening of the treatment plant, comprises an open channel that extends from the treatment facility to Sudbury Reservoir.
For the crossing at the Assabet River, the architects opted for a bridge rather than an underground tunnel. The Wachusett Aqueduct Arch Bridge in Northborough, nestled in the Woodside neighborhood, stands as both a stunning architectural gem and a functional conduit for the aqueduct. This bridge, spanning a length of 359 feet, carries the Wachusett Aqueduct across a millpond on the Assabet River.
Constructed by the Metropolitan Water Works, which later became the Metropolitan District Commission and is now the Massachusetts Water Resources Authority, the bridge features seven round arches, each approximately 29 feet wide, made of mass concrete adorned with granite facades. Above the arches, a corbel table of blind segmental arches with keystones adds to the bridge's aesthetic appeal. As the aqueduct crosses the bridge, it is encased in 8 inches of brick lining, backed by sheet lead. The bridge was taken out of service in the 1930s, following the construction of a siphon beneath the river.
Until the 1960s, the Wachusett Aqueduct served as the primary conduit for delivering water from the Wachusett Reservoir, transporting a staggering 300 million US gallons of water daily. It was eventually replaced by the Cosgrove Tunnel in 1965. However, during the shutdown of the Cosgrove Tunnel in 2003, the Wachusett Aqueduct stepped in to transmit approximately 240 million US gallons of water daily. Today, while the Cosgrove Tunnel remains the primary water transmission route, the Wachusett Aqueduct is a standby backup pathway in case of tunnel unavailability.
In recognition of its historical significance and architectural marvel, the aqueduct's route and associated structures were added to the National Register of Historic Places on January 18, 1990. This prestigious distinction underscores the bridge's vital role in shaping the region's water supply and its exceptional engineering. It's reference number is 89002293.
The Wachusett Aqueduct Arch Bridge has earned a special place among historians and photographers alike. Its timeless character and well-preserved condition make it a captivating subject for photography throughout all four of New England's seasons.
For those wishing to visit this remarkable bridge, a small pull-over parking area can be found just south of the bridge. It provides parking space for approximately 2-3 cars, and parking is free. Notably, one of the archways of the bridge features a narrow roadway, adding to its unique charm and historical significance.