There are a lot of curvy roads that wind around the mountains in Yosemite National Park, California, but the narrowest and scariest are into the Hetch Hetchy Valley. Once you are there, however, you realize it is well worth the trip. There you can see the O'Shaughnessy Dam. It is a 430-foot (131 m) high concrete arch-gravity dam. The dam and reservoir are the source for the Hetch Hetchy Aqueduct, which provides water for over 2 million people in San Francisco and other municipalities of the west Bay Area.
Although San Francisco had sought Tuolumne River water as early as the 1890s, this project did not move forward until the famous earthquake and fire of 1906, which highlighted the insufficiency of the existing water supply. The Hetch Hetchy Valley – then compared to Yosemite Valley for its scenic beauty – was chosen for its water quality and hydroelectric potential, but the location within Yosemite National Park generated controversy. It tool an act of Congress to circumvent federal protection of the Tuolumne River. The reasoning was that public land should be developed for the public benefit.
|Produces hydroelectric power|
Construction of the dam started in 1919 and was finished in 1923, The first of the water was delivered in 1934 after numerous delays. From 1935–38 the dam was raised to increase its capacity for water supply and power generation. Deriving from a largely wild and pristine area of the Sierra Nevada, the Hetch Hetchy supply is some of the cleanest municipal water in the US, requiring only primary filtration and disinfection.
The dam is named for engineer Michael O'Shaughnessy, who oversaw its construction. Unfortunately for him, he died a few days before its dedication. It is a very impressive feat of engineering. They had to build a railroad from a little town called Grove Point. We stopped in Grove Point to buy groceries earlier in the week so I had knowledge of its remote location in the mountains.
I discovered that there are surveyors marks on the dam that you used now to measure any shifting of the concert. You know all about the earthquake situation in California! I did see some large cracks there.
|Wapama Falls (dry falls in fall)|
We decided to go for a hike around the reservoir to the Wapama Falls. The walk started up hill on a good path. As we progressed, it go hotter and hotter and the path narrower and narrower with no humans in sight. We found a sign along the way which indicated the falls were a little over a mile. We can do that! Only problem was that there were more rocks and less path. When we finally spotted the falls we saw that they were dried up and there had been a rock slide which is why the path had all but disappeared. We turned back and along the way we found a bear track. This made us pick up the pace. We started to run into some other hikers who had gotten a later start. They were resting and talking about how the area looked like bear country. My thoughts exactly!
It was time to head back to our huge truck and tiny, windy roads. After all, I had to get back to camp to check on my BayMoonDesign Internet based store. Perhaps there are some sales.