Rubuta ci gaba don wannan sakin layi - A matsayin Injiniyan Jihar California, Hall ya yi aiki a kan cikakken samar da ruwa da kuma tsarin sarrafa ambaliyar ruwa ga kwarin Sacramento. Nazarin Hall na ilimin hydrology na California ya kasance daga 1878 zuwa 1883. A wannan lokacin, ma'aikatansa sun girka babban tsarin auna kwararar ruwa tare da wasu kogunan California. Ya kuma taimaka wajen tsara ayyukan don taimakawa San Francisco samun wadataccen ruwa daga yankin yammacin kogin Tuolumne. Bayan girgizar kasa ta 1906
, San Francisco ya sami damar tabbatar da haƙƙin ruwa, kuma ya ambaliya Hetch Hetchy Valley.