{"nrhp_refnum":"74001324","name":"Croton Aqueduct, Old","other_names":["See Also:Old Croton Dam, Site of","High Bridges Aqueduct","Water"],"category":"structure","location":{"address":"Runs N from Yonkers to New Croton Dam","address_restricted":false,"city":"Yonkers and","county":"Westchester County","state":"NY","lat":41.03997672150007,"lon":-73.86663945090623,"geom_source":"nps_gis"},"listed_date":"1974-12-02","is_nhl":true,"nhl_designated_date":"1992-04-27","areas_of_significance":["Commerce","Health/Medicine","Engineering"],"significance_levels":["national","local"],"summary":{"what_it_is":"A 26-mile stretch of the Old Croton Aqueduct, mostly underground, running through Westchester County, New York, from the Old Croton Dam to the New York City line, including Yonkers. It was built between 1837 and 1842.","why_significant":"It was the first major water supply system for New York City and a notable engineering achievement of its day. It was one of the first aqueducts to reach beyond a city for water, and its cross-section and use of the siphon exceeded earlier aqueducts. It supplied the city's water from 1842 until it went out of use in 1965.","narrative":"Running twenty-six miles through Westchester County, the Old Croton Aqueduct carried water from Croton Lake to New York City beginning in 1842. Built between 1837 and 1842 under chief engineer John B. Jervis, it was the city's first major water supply project, answering a long crisis of contaminated wells, fire risk and disease. Most of the line is underground, constructed of brick and stone with a concrete foundation. Surface clues include twenty-two ventilator shafts about fourteen feet tall, stone gatehouses, seven viaducts and six culverts. The aqueduct surpassed earlier European aqueducts in cross-section and used a siphon on a scale not seen before. Demand outgrew it by 1875, and newer aqueducts followed. Water flowed through it to the city until 1955, and some communities drew from it for ten more years. The gates were closed in 1965, and the State of New York took title in 1968. A recreational trailway is planned along the right-of-way.","period_of_significance":"1837-1842","architect_builder":"John B. Jervis, chief engineer","architectural_style":null,"criteria":[],"status_note":"Out of use since 1965; State of New York took title in 1968; about 85% of the Westchester length is sound and 15% has minor structural defects; a trailway is being planned along the right-of-way.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:39.990474-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/74001324.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/74001324/147728a4f2-800.webp","url_1600":"https://nationalhistoricalregister.com/media/74001324/147728a4f2-1600.webp","licence":"Public domain","author":"Related names: Jervis, John B Boucher, Jack Troup, Gregg Clement, Daniel","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:AERIAL_VIEW_SHOWING_AQUEDUCT_RIGHT-OF-WAY_AT_SAW_MILL_RIVER_CULVERT._-_Old_Croton_Aqueduct,_Saw_Mill_River_Culvert,_Spanning_Nepperhan_Avenue,_Yonkers,_Westchester_County,_NY_HAER_NY,60-YONK,1A-2.tif\" rel=\"noopener\">Related names: Jervis, John B Boucher, Jack Troup, Gregg Clement, Daniel</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:AERIAL_VIEW_SHOWING_AQUEDUCT_RIGHT-OF-WAY_AT_SAW_MILL_RIVER_CULVERT._-_Old_Croton_Aqueduct,_Saw_Mill_River_Culvert,_Spanning_Nepperhan_Avenue,_Yonkers,_Westchester_County,_NY_HAER_NY,60-YONK,1A-2.tif"},"district":{"nrhp_refnum":"13001095","name":"Irvington Historic District","url":"https://nationalhistoricalregister.com/districts/new-york/irvington-historic-district-13001095/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75322997","wikipedia":"https://en.wikipedia.org/wiki/Croton_Aqueduct","wikidata":"https://www.wikidata.org/wiki/Q1141610"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/westchester-county/croton-aqueduct-old-74001324/"}