{"nrhp_refnum":"75000497","name":"San Buenaventura Mission Aqueduct","other_names":[],"category":"structure","location":{"address":"234 Canada Larga Rd.","address_restricted":false,"city":"Ventura","county":"Ventura County","state":"CA","lat":34.34202917400006,"lon":-119.29061407399996,"geom_source":"nps_gis"},"listed_date":"1975-03-07","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering"],"significance_levels":["state"],"summary":{"what_it_is":"A roughly 100-foot surviving section of cobble-and-mortar viaduct, the last remnant of the San Buenaventura Mission aqueduct, at 234 Canada Larga Road in Ventura, California. It was built between 1782 and 1794.","why_significant":"The nomination argues these ruins are likely the oldest man-made structure in Ventura County and a heritage of Indian, Spanish and American pioneer cultures. The aqueduct supplied water for the mission's fountains, reservoirs and agriculture for more than 70 years. Freeway construction and development destroyed the rest of the system, leaving only this portion.","narrative":"A short stretch of old stone viaduct on Canada Larga Road in Ventura is all that remains of the water system built for Mission San Buenaventura. Constructed between 1782 and 1794, the section is about 100 feet long and made of cobbles and mortar, once stuccoed. It stands about 12 feet high at the north end and falls to ground level at the south, with four heavy buttresses supporting the tall end. A tiled channel about two feet wide originally carried water along the top, but it has collapsed. Local Indian laborers built the aqueduct under the direction of Fr. Cambon, and it fed a settling basin, reservoirs and fountains used by the community and the mission's farming. Floods in the early 1860s ended its use, and later freeway construction and development erased the other sections. Because of this, it is regarded as probably the oldest man-made structure in Ventura County.","period_of_significance":"18th Century; built 1782-1794, used until the 1860s","architect_builder":"Built under the supervision of Fr. Cambon, as assigned by Fr. Serra, with local Indian laborers","architectural_style":null,"criteria":[],"status_note":"Ruins in deteriorated condition; the top trough has collapsed, the structure is surrounded by lemon orchard and a house and garden, and preservation work is noted as in progress.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:31.903433-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/75000497.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/75000497/17162bee0c-800.webp","url_1600":"https://nationalhistoricalregister.com/media/75000497/17162bee0c-1600.webp","licence":"CC BY-SA 3.0","author":"Los Angeles","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:San_Buenaventura_Mission_Aqueduct.jpg\" rel=\"noopener\">Los Angeles</a>, <a href=\"https://creativecommons.org/licenses/by-sa/3.0\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:San_Buenaventura_Mission_Aqueduct.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123862362","wikipedia":"https://en.wikipedia.org/wiki/San_Buenaventura_Mission_Aqueduct","wikidata":"https://www.wikidata.org/wiki/Q7413493"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/ventura-county/san-buenaventura-mission-aqueduct-75000497/"}