San Francisco did not move forward with plans to divert the Tuolumne until the 1906 San Francisco earthquake and subsequent fires devastated the city , proving the inadequacy of the existing water system . After exploring fourteen sites throughout Central California , San Francisco had settled on the Tuolumne 's Hetch Hetchy Valley as the ideal location to develop storage and hydroelectric power . Because the area had been located inside Yosemite National Park since 1890 , the city petitioned for Congress to pass the Raker Act . Signed in 1913 by President Woodrow Wilson , the Act allowed San Francisco to dam the Tuolumne River , as long as the water and power provided would be reserved exclusively for public utility , not private sale
1906 San Francisco earthquake
1906 San Francisco earthquake
Tuolumne River