Mystic Lakes
Encyclopedia
The Mystic Lakes, consisting of Upper Mystic Lake and Lower Mystic Lake, are closely linked bodies of water in the northwestern suburbs of Boston
, Massachusetts
.
The lakes lie at an elevation of 1 meter above sea level, within the towns of Winchester
, Arlington
, and Medford, Massachusetts
. Upper Mystic Lake is fed by the Aberjona River
, and drains south, over the Mystic Dam
, into Lower Mystic Lake, which in turn empties into the Mystic River
and then Boston Harbor
.
Lower Mystic Lake is a meromictic lake
, which means that the lake has a deep layer of water that rarely, if ever, mixes with its top waters. As a consequence, the sediments at the bottom of Lower Mystic Lake accumulate in annual layers (or varves) that have been nearly undisturbed for a thousand years. Such varves in meromictic lakes preserve an historical record something like tree rings do. In the case of Lower Mystic Lake, the varves have been used by Mark Besonen and his collaborators to study the historical incidence of hurricanes.
Although the Mystic Lakes are popular for swimming, sailing, and fishing, the Upper Mystic Lake suffers from contamination by arsenic
and other heavy metals from the Aberjona River
.
The eastern shore of the lakes is part of the Mystic River Reservation
managed by the Massachusetts Department of Conservation and Recreation
.
The lakes were previously part of the drinking water supply for Charlestown and later Boston (see Massachusetts Water Resources Authority
).
Boston
Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...
, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
.
The lakes lie at an elevation of 1 meter above sea level, within the towns of Winchester
Winchester, Massachusetts
Winchester is a town located in Middlesex County, Massachusetts, eight miles north of Boston. With its agricultural roots having mostly disappeared, it is now an affluent suburb...
, Arlington
Arlington, Massachusetts
Arlington is a town in Middlesex County, Massachusetts, United States, six miles northwest of Boston. The population was 42,844 at the 2010 census.-History:...
, and Medford, Massachusetts
Medford, Massachusetts
Medford is a city in Middlesex County, Massachusetts, in the United States, on the Mystic River, five miles northwest of downtown Boston. In the 2010 U.S. Census, Medford's population was 56,173...
. Upper Mystic Lake is fed by the Aberjona River
Aberjona River
The Aberjona River is a , heavily urbanized river in the northwestern suburbs of Boston, Massachusetts.The river arises in Reading, flows roughly south through Woburn and Winchester, and empties into the Mystic Lakes...
, and drains south, over the Mystic Dam
Mystic Dam
The Mystic Dam is a historic dam between Lower and Upper Mystic Lakes in Winchester, Massachusetts, USA.The dam was built in 1864 and added to the National Register of Historic Places in 1990. Listed as one of a number of unsafe dams in Massachusetts, it underwent major renovation in 2010 that...
, into Lower Mystic Lake, which in turn empties into the Mystic River
Mystic River
The Mystic River is a river in Massachusetts, in the United States. Its name derives from the Wampanoag word "muhs-uhtuq", which translates to "big river." In an Algonquian language, "Missi-Tuk" means "a great river whose waters are driven by waves", alluding to the natural tidal nature of the...
and then Boston Harbor
Boston Harbor
Boston Harbor is a natural harbor and estuary of Massachusetts Bay, and is located adjacent to the city of Boston, Massachusetts. It is home to the Port of Boston, a major shipping facility in the northeast.-History:...
.
Lower Mystic Lake is a meromictic lake
Meromictic
A meromictic lake has layers of water that do not intermix. In ordinary, "holomictic" lakes, at least once each year there is a physical mixing of the surface and the deep waters...
, which means that the lake has a deep layer of water that rarely, if ever, mixes with its top waters. As a consequence, the sediments at the bottom of Lower Mystic Lake accumulate in annual layers (or varves) that have been nearly undisturbed for a thousand years. Such varves in meromictic lakes preserve an historical record something like tree rings do. In the case of Lower Mystic Lake, the varves have been used by Mark Besonen and his collaborators to study the historical incidence of hurricanes.
Although the Mystic Lakes are popular for swimming, sailing, and fishing, the Upper Mystic Lake suffers from contamination by arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
and other heavy metals from the Aberjona River
Aberjona River
The Aberjona River is a , heavily urbanized river in the northwestern suburbs of Boston, Massachusetts.The river arises in Reading, flows roughly south through Woburn and Winchester, and empties into the Mystic Lakes...
.
The eastern shore of the lakes is part of the Mystic River Reservation
Mystic River Reservation
The Mystic River Reservation is a publicly owned nature preserve located along the Mystic River in Massachusetts, United States. It forms part of the Mystic River Watershed, and runs through the towns of Arlington, Medford, Somerville, Everett, and Chelsea....
managed by the Massachusetts Department of Conservation and Recreation
Department of Conservation and Recreation (Massachusetts)
The Department of Conservation and Recreation is a state agency of the Commonwealth of Massachusetts, situated in the Executive Office of Energy and Environmental Affairs. It is best known for its parks and parkways. As of May 24, 2011 the Commissioner of the DCR is Edward M. Lambert, Jr...
.
The lakes were previously part of the drinking water supply for Charlestown and later Boston (see Massachusetts Water Resources Authority
Massachusetts Water Resources Authority
The Massachusetts Water Resources Authority is a public authority in the Commonwealth of Massachusetts that provides wholesale drinking water and sewage services to certain municipalities and industrial users in the state, primarily in the Boston area.The authority receives water from the Quabbin...
).