Wachusett Aqueduct at Northborough |
|
| Official name | Wachusett Aqueduct |
|---|---|
| Begins | Wachusett Reservoir |
| Ends | Marlborough, Massachusetts |
| Maintained by | MWRA |
| Length | 9 mi (14.5 km) |
| Conduit height | 11 ft (3.4 m) |
| Conduit width | 12 ft (3.6 m) |
| Capacity | 400 ft3/sec (11.32 m3/sec) |
| Construction began | 1897 |
| Opening date | 1905 |
The Wachusett Aqueduct carries water from the Wachusett Reservoir to the John J. Carroll Water Treatment Plant at Walnut Hill in Marlborough, Massachusetts. It is part of the Boston, Massachusetts public water supply system, maintained by the Massachusetts Water Resources Authority (MWRA) in the United States.
The Wachusett Aqueduct extends from the Wachusett Reservoir in Clinton, through Berlin and Northborough, to the John J. Carroll Water Treatment Plant at Walnut Hill in Marlborough, Massachusetts. (Before the treatment plant was activated in 2005, the aqueduct carried water to the nearby Sudbury Reservoir.) This 9-mile (14 km) long water system consists of 2 miles (3 km) of hard rock tunnel and 7 miles (11 km) of 11-foot (3.4 m) high horseshoe-shaped underground aqueduct constructed of non-reinforced concrete with a brick-lined invert. It is not constructed entirely underground and there are several elevated over crossings.
Until the 1960s, the Wachusett Aqueduct was the main conduit used to deliver water from the Wachusett Reservoir. At that time, it carried 300 million US gallons (1,100,000 m3) of water each day (13 m3/s). The Cosgrove Tunnel replaced it in 1965 as the primary water transmission aqueduct. Because of the construction of the Walnut Hill Water Treatment Plant in Marlborough, the Cosgrove Tunnel was shut down in 2003 in order to make the large piping connection between the new treatment plant and MWRA’s new MetroWest Water Supply Tunnel. The MetroWest Tunnel extends east 18.6 miles (29.9 km) from Walnut Hill to Weston. During that shutdown, the Wachusett Aqueduct was the primary method of transmission of about 240 million US gallons (910,000 m3) of water per day.