Wow did it take a lot of effort to bring water from the Sierras:

Bringing water west from the Sierras was an idea that started as early as the 1860’s when a former Spring Valley Water Company employee decided to try and bring Sierra water to both the Central Valley and the Nevada Desert for irrigation. While he had little success, the idea tool root of moving water across huge distances, not to mention challenging geography. In 1882, getting water to San Francisco from the Tuolumne River Watershed was seen as a serious possibility. Numerous investigations and several studies were conducted and in 1900 the USGS recommended Hetch Hetchy Valley, at the headwaters of the Tuolumne River, as the best source for San Francisco’s water supply. During this time, in 1890, congress established Yosemite National Park, which includes Hetch Hetchy Valley.