The Wachusett Reservoir is the second largest body of water in the state of Massachusetts. It is located in central Massachusetts, northeast of Worcester. It is part of the water supply system for metropolitan Boston maintained by the Massachusetts Water Resources Authority (MWRA). It has an aggregate capacity of 65 billion US gallons (250,000,000 m3) and an area of almost 7 square miles (18.2 km?). Water from the Wachusett flows to the covered Norumbega Storage Facility via the Cosgrove Tunnel and the MetroWest Water Supply Tunnel. The reservoir has a maximum depth of 120 feet (36.5 m) and a mean depth of 48 feet (14.6 m).
The reservoir is fed by the Nashua, Quinapoxet, and Stillwater rivers, along with the Quabbin Aqueduct, which carries water from the Quabbin Reservoir. It is part of the Nashua River Watershed.
In 1897, the Nashua River above the town of Clinton was impounded by the Wachusett Dam. 4,380 acres (17.5 km?) were flooded in the towns of Boylston, West Boylston, Clinton, and Sterling. Work was completed in 1905 and the reservoir first filled in May 1908. Its water was originally delivered to the Sudbury Reservoir via the Wachusett Aqueduct, with the Cosgrove Tunnel (completed in 1965) providing redundancy. Interconnections at the Sudbury Reservoir eventually delivered the water to the Weston Reservoir via the Weston Aqueduct; these downstream facilities were relegated to backup roles in the late 20th and early 21st century by the construction of the MetroWest Water
Supply Tunnel and covered storage facilities.
West Boylston's prominent landmark Ч The Old Stone Church Ч was left remaining as a reminder of those that lost their homes and jobs to the building of the reservoir. It is one of the most photographed sites in the area.
When it was built, the Wachusett Reservoir was the largest public water supply reservoir in the world and the largest body of water in Massachusetts. It has since been surpassed by the Quabbin Reservoir. (See that article for a history of reservoir building in Massachusetts.)
Recreation and fishing
Because the reservoir is the water supply for Boston, not all areas around it are open to the public. To ensure pure water, there are a number of regulations prohibiting boats, ice fishing, wading, swimming, overnight camping, alcoholic beverages, littering, animals, bikes, and motor vehicles from the reservoir and abutting property. These regulations are controversial to recreation and fishing proponents, who argue the rules are not needed to protect water quality. A network of fire roads provides easy access for hikers and cross-country skiers.
As of 1999, the reservoir contained 12 native and 12 introduced species of fish. The limited access, combined with abundant, high-quality habitat, produced state records for brown trout, land-locked salmon, smallmouth bass, and white perch. Approximately 80% of the 37 mile (59.5 km) shoreline is usually open to angling from April 1 through November 30, depending on ice conditions.