Male, born 1864-05-28, died 1934-10-12

Associated with the firm network

City and County of San Franciso, Chief Engineer, O'Shaughnessy, Michael M.

Professional History


Assistant Engineer, Sierra Valley and Mohawk Railroad, Plumas Junction, CA- Mohawk, CA-Blarisden, CA, 1885-1886; Surveying Engineer, Southern Pacific (SP) Railroad, San Francisco, CA, 1886-1889; for the SP, O'Shaughnessy participated in laying out the Marin County towns of Mill Valley, CA and Sausalito, CA.

Principal, M.M. O'Shaughnessy, Consulting Engineer, San Francisco, CA, 1889- 1895 ; Chief Engineer, Hawaiian plantation aqueducts, such as those at Koʻolau, Keanaiemaui, Kohala and Olokele, 1889-1890; Chief Engineer, California Midwinter International Exposition, San Francisco, CA, Golden Gate Park, 1890-1894; Consulting Engineer, Mountain Copper Company, Ltd., Redding, CA, 1895; for the Mountain Copper Company, he designed a narrow-gauge railroad.

Consulting Engineer, Spring Valley Water Company, San Francisco, CA, 1895-1912.

Chief Engineer, City and County of San Francisco, 09/1912-1932. During the Progressive Era, San Francisco, like many other US cities, purchased local utilities to break private monopolies that were seen as contrary to the public good; the City Government of San Francisco bought the Spring Valley Water Company to insure that water would flow without interruption to the city. During the city's critical rebuilding period after the Great Earthquake of 1906, O'Shaughnessy served as the influential City Engineer; it was under him, that many tunnels and reservoirs were built in the city and exploratory plans began for the Golden Gate Bridge in 1919; he also presided over the building of the mammoth and complex Hetch Hetchy Water and Power project, which involved constructing dams, reservoirs, pumping stations, power plants, a railroad and an aqueduct to provide water to post-Earthquake San Francisco; controversial as it was from an environmental standpoint, the completion of Hetch Hetchy enabled rapid growth in the Bay Area;

Michael O'Shaughnessy died, ironically, of heart failure just 16 days before water originating from the new Hetch Hetchy Reservoir in Yosemite began flowing through taps in San Francisco on 10/12/1934.


O'Shaughnessy attended secondary schools in Limerick and County Tipperary; coursework, University College, Cork, Ireland; engineering degree, Royal University of Ireland, University College, Galway, Ireland, 1884.



O'Shaughnessy emigrated to the US in 1885, arriving first on the East Coast. He made it to San Francisco, CA, by 03/30/1885.


His father, Patrick O'Shaughnessy, and mother, Margaret O'Donnell, worked as farmers.


San Francisco City Engineer Michael M. O'Shaughnessy married Mary Spottiswood on 10/21/1890.


The O'Shaughnessys' had five children.

Associated Locations

  • County Limerick, Ireland United Kingdom (Architect's Birth)
    County Limerick, Ireland United Kingdom

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PCAD id: 1636