{"nrhp_refnum":"89002282","name":"Mystic Dam","other_names":[],"category":"structure","location":{"address":"Between Lower and Upper Mystic Lakes","address_restricted":false,"city":"Winchester","county":"Middlesex County","state":"MA","lat":42.43060621700005,"lon":-71.14838751499997,"geom_source":"nps_gis"},"listed_date":"1990-01-18","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state","local"],"summary":{"what_it_is":"A dam built in 1864 between Upper and Lower Mystic Lakes at the edge of Edgewater Place in Winchester, Middlesex County, Massachusetts, as part of the Mystic Water Works. It is owned by the Metropolitan District Commission.","why_significant":"The nomination links the dam to the Mystic Water Works, a small, well-integrated mid-nineteenth-century municipal water system. It is also described as the oldest dam in the Metropolitan District Commission system in Metropolitan Boston. It retains integrity of location, design, setting, materials, workmanship and feeling.","narrative":"Mystic Dam is a 1,560-foot-long dam between Upper and Lower Mystic Lakes in Winchester, Massachusetts. Built in 1864 of granite, wood and earth, it runs between two earthen embankments lined with puddle and riprap and has a granite overfall with five grooved granite columns for stop logs. A wooden walkway with a plank railing crosses the overfall, and Barnes, Kingsley and Company of Brooklyn, New York, built the dam. It was part of the Mystic Water Works, constructed from 1862 to 1865 by the City of Charlestown, which pumped lake water to a reservoir on the site of today's Tufts University campus. Boston took over the system in 1874 and the Metropolitan Water Board in 1898, but poor water quality meant the supply was never used. The system as a whole has lost integrity, yet the dam remains a good example of its type and is the oldest dam in the Metropolitan District Commission system.","period_of_significance":null,"architect_builder":"Built by Barnes, Kingsley and Company, Brooklyn, New York","architectural_style":null,"criteria":["C"],"status_note":"Condition is described as fair to good; the dam is out of service and the wooden fish ladder is gone except for some posts.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:13:01.440631-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/72/7920/63792072/content/electronic-records/rg-079/NPS_MA/89002282.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/89002282/905d61ba96-800.webp","url_1600":"https://nationalhistoricalregister.com/media/89002282/905d61ba96-1600.webp","licence":"CC BY-SA 4.0","author":"User:Magicpiano","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:WinchesterMA_MysticDamAfter2010Modernization.jpg\" rel=\"noopener\">User:Magicpiano</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:WinchesterMA_MysticDamAfter2010Modernization.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63792072","wikipedia":"https://en.wikipedia.org/wiki/Mystic_Dam","wikidata":"https://www.wikidata.org/wiki/Q6948937"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/middlesex-county/mystic-dam-89002282/"}