Question: The Sudbury Reservoir, is an emergency backup Boston metropolitan water reservoir located in Framingham, a town in the Commonwealth of Massachusetts, in which country?
Context: The Chestnut Hill Reservoir Historic District is a historic district encompassing the Chestnut Hill Reservoir and the surrounding water works facilities which were historically used to provide fresh water to Boston, Massachusetts, and surrounding towns.  The district is nearly coextensive with the Chestnut Hill Reservation, a state park managed by the Massachusetts Department of Conservation and Recreation (DCR); those elements of the water works that are still required as an emergency backup are managed by the Massachusetts Water Resources Authority (MWRA).  The reservoir is located between Beacon Street and Commonwealth Avenue in Boston, just east of the Boston College Main Campus Historic District and the Boston-Newton city line.  Most of the water works facilities are also located in Boston; the terminal house of the Sudbury Aqueduct, which is part of this district, is located just over the line in Newton. The Framingham Reservoir No. 2 Dam and Gatehouse is a historic water works facility in Framingham, Massachusetts.  The dam and gatehouse are located west of the junction of Winter and Fountain Streets, and impound a branch of the Sudbury River.  The reservoir, which is also known as the Brackett Reservoir, was built 1877-79 as part of an expansion of the water supply of the city of Boston.  The dam is 1376 ft in length, with a centered overfall area.  The core of the dam is granite rubble laid in cement, with earthen embankments.  The overfall area is faced on the downstream side with cut granite, and earthen embankment on the upstream side.  It is topped with granite and originally had iron mounts for flashboards.  The gatehouse is a rectangular granite structure with a steep hip roof, a brick chimney and an eyebrow dormer.  The door and windows are in round-arch openings.  It contains gate controls for regulating water flow from the reservoir and from a 4 ft pipe connected to Reservoir No. 1, and a 2 ft pipe connected to the Ashland Reservoir. The Framingham Reservoir No. 1 Dam and Gatehouse are a historic water works facility in Framingham, Massachusetts.  They are located at the end of Framingham Reservoir No. 1, which is also known as the Stearns Reservoir, off Winter Street and north of Long Avenue.  They were constructed 1876-78 as part of an expansion of the water supply of the city of Boston and were designed by its first city architect George A. Clough.  The historical purpose of the reservoir, which was located at the confluence of two branches of the Sudbury River, was primarily to control the river's water level, and secondarily to provide reserve supply capacity.  The reservoir's reserve capacity was generally used only as a backup supply as the reservoir's muddy bottom made it a less desirable source than reservoir 3 upstream.  However the reservoir no. 1 system was nonetheless important due to its role in controlling the flow of the river downstream and due to the gatehouse which controlled the water flows for all the Framingham reservoirs into the Sudbury Aqueduct.  Reservoir No. 1 is no longer maintained as a reserve water source, although it is still owned by the Massachusetts Water Resources Authority, successor to the Boston Water Board which oversaw its construction.  MWRA retains ownership as the gatehouse contains the connection between Reservoir No. 3 and the Sudbury Aqueudct which remain part of the emergency water systems. The Sudbury Reservoir (2.02 square miles) is an emergency backup Boston metropolitan water reservoir located in Framingham, Marlborough, Southborough, and Westborough, Massachusetts.  Nearly 5000 acre in the Sudbury Reservoir watershed are administered by the Massachusetts Department of Conservation and Recreation as a limited-access public recreation area. The Weston Aqueduct is an aqueduct operated by the Massachusetts Water Resources Authority.  Now part of the MWRA backup systems, it was designed to deliver water from the Sudbury Reservoir in Framingham to the Weston Reservoir in Weston.  The 13.5 mi aqueduct begins at the Sudbury Dam, and passes through the towns of Southborough, Framingham, Wayland, and Weston.  In 1990 the route, buildings and bridges of the aqueduct were added to the National Register of Historic Places as the Weston Aqueduct Linear District. The Sudbury Aqueduct is an aqueduct in Massachusetts.  It runs for 16 mi from Farm Pond at Waverly Street in Framingham to Chestnut Hill Reservoir in Boston.  A later built extension main runs from the Farm Pond gatehouse to the gatehouse at the Stearns Reservoir (Framingham Reservoir #1) where additional mains connect to the Brackett and Foss Reservoirs (Framingham #2 and #3.)  Going east from Framingham, it runs through Sherborn before entering Natick.  From Natick it runs east through Wellesley and Needham to the Charles River, which it crosses on the Echo Bridge into Newton.  It ends at the Chestnut Hill Reservoir on the Newton side of the Newton-Boston line.  The Massachusetts Water Resources Authority (MWRA) operates the aqueduct. The Sudbury Dam Historic District is a historic district on the southeastern end of Sudbury Reservoir off MA 30 in Framingham and Southborough, Massachusetts.  The district encompasses the Sudbury Dam (also known as the Fayville Dam for the nearby neighborhood of Southborough), which impounds the reservoir, and an area encompassing several historic structures located below the dam.  The area includes water-supply-related structures from three phases of development of the Greater Boston water supply system.  It was listed on the National Register of Historic Places in 1990. The Framingham Reservoir No. 3 Dam and Gatehouse is a historic waterworks facility in Framingham, Massachusetts.  The dam and gatehouse are located at the southeastern end of Framingham Reservoir No. 3, off Massachusetts Route 9.  They were built 1876–78 as part of an expansion of the public water supply of the city of Boston.  The dam is 2280 ft long, and impounds an area of 253 acre in the Sudbury River watershed.  The reservoir is the largest of the three Framingham reservoirs that were built at that time.  The dam's core is constructed of granite rubble laid in cement.  There is a granite-lined overfall area 100 ft long, which was originally topped by flashboards.  At the end of the overfall area nearest Route 9 stands the gatehouse, a granite structure with a rectangular main block and a smaller wing.  Both sections have a steeply pitched slate roof.  The door is in a round-arch recess, and the building is capped by a cupola.  It houses controls for two 4 ft mains connected to the Sudbury Aqueduct via the gatehouse at Reservoir No. 1.  The water is directed either directly beyond the dam into reservoir 1 or through the 4-foot mains to the Sudbury Aqueduct gatehouse. Framingham is a town in the Commonwealth of Massachusetts in the United States.  Incorporated in 1700, it is located within Middlesex County and the MetroWest subregion of the Greater Boston metropolitan area.  The town proper covers 25 mi2 with an estimated population of 68,318 in 2010, making it the 14th most populous municipality in Massachusetts.  Residents voted in favor of adopting a charter to transition from a representative town meeting system to a mayor–council government in April 2017, and will transition to city status on January 1, 2018. Chestnut Hill Reservoir is a reservoir created in 1870 on existing marshes and meadowland to supplement the city of Boston's water needs.  It is surrounded by Chestnut Hill, a neighborhood which consists of parts of Boston, Brookline, and Newton.  The reservoir, though, is located entirely within the city limits of Boston.  A 1.56 mile jogging loop abuts the reservoir.  Chestnut Hill Reservoir was taken offline in 1978 as it was no longer needed for regular water supply distribution, but is maintained in emergency backup status.  It is recognized today on the National Register of Historic Places and it has designation as a City of Boston Landmark.
Answer: United States