Auxiliary Water Supply System ( AWSS , though often referred to on manhole covers and hydrants as HPFS for High Pressure Fire System ) is a high pressure water supply network built for the city of San Francisco in response to the failure of the existing emergency water system during the 1906 earthquake . It was originally proposed by San Francisco Fire Department chief engineer Dennis T. Sullivan in 1903 , with construction beginning in 1909 and finishing in 1913 . The system is made up of a collection of water reservoirs , pump stations , cisterns , suction connections and fireboats . While the system can use both fresh or salt water , it is preferential to not use salt water , as it commonly causes galvanic corrosion in fire equipment
1906 earthquake
1906 San Francisco earthquake
San Francisco Fire Department Auxiliary Water Supply System