{"nrhp_refnum":"89002265","name":"Sudbury Dam Historic District","other_names":[],"category":"district","location":{"address":"SE end of Sudbury Reservoir off MA 30","address_restricted":false,"city":"Sudbury","county":"Middlesex County","state":"MA","lat":42.30622750000006,"lon":-71.4910966926133,"geom_source":"nps_gis"},"listed_date":"1990-01-18","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Community Planning and Development","Engineering","Politics/Government","Architecture"],"significance_levels":["state","local"],"summary":{"what_it_is":"A district of about eight acres at the foot of Sudbury Dam on Stony Brook, in the Fayville area of Southborough, Massachusetts. It includes the dam, gatehouse, spillway, bridges, chambers, a farmhouse with sheds, a storehouse and two modern laboratory buildings, built mainly between 1894 and 1940.","why_significant":"The district shows how local water supplies were absorbed into a coordinated regional system under the Metropolitan Water Board of 1895. It also produced hydroelectric power from 1915-16 until the 1970s. Its engineering and granite architecture are significant, and the dam was the largest in the system when built.","narrative":"Sudbury Dam Historic District occupies about eight acres below the Sudbury Reservoir in Southborough, Massachusetts. Its centerpiece is an earth embankment 1,800 feet long, with a 300-foot stone spillway, rising roughly seventy feet above the valley floor. Around it are a granite gatehouse, a Weston Aqueduct head chamber built in 1903, a storehouse of 1900, two bridges, and relocated farm buildings used as a foreman's house and storage. A 1940 headhouse and two laboratory buildings are non-contributing. The district records the third phase of Boston's metropolitan water supply, when the Metropolitan Water Board of 1895 brought local supplies under regional control and finished the reservoir begun in 1893. The gatehouse was altered in 1915 to generate hydroelectric power, which continued into the early 1970s. The coursed gray granite, round-arched openings and tiled roofs give the earlier structures a consistent look. The district was found significant for its history and its design.","period_of_significance":"1894-1926","architect_builder":"Wheelwright & Haven (Sudbury Dam components); Shepley, Rutan & Coolidge (Weston Aqueduct components)","architectural_style":null,"criteria":["A","C"],"status_note":"Present use is water supply; general condition is stated as good. The gatehouse generating equipment was removed after power production ended in the early 1970s.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:13:01.347736-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/14/7920/63792014/content/electronic-records/rg-079/NPS_MA/89002265.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/89002265/6809c3dff4-800.webp","url_1600":"https://nationalhistoricalregister.com/media/89002265/6809c3dff4-1600.webp","licence":"CC BY-SA 4.0","author":"User:Magicpiano","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:FraminghamMA_SudburyDamGatehouse.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:FraminghamMA_SudburyDamGatehouse.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63792014","wikipedia":"https://en.wikipedia.org/wiki/Sudbury_Dam_Historic_District","wikidata":"https://www.wikidata.org/wiki/Q14715868"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/middlesex-county/sudbury-dam-historic-district-89002265/"}