Alameda Watershed and the Muwekma-Ohlone

The present-day Muwekma-Ohlone Tribe have called the East Bay home for thousands of years. As the original inhabitants of the Sunol Valley and the entire Bay Area, their ancestors lived in societies with complex social, political, economic and religious institutions that connected them to neighboring tribal groups. The founding of Missions San Francisco (1776), Santa…

A Look Back in History: Tramway Play

The Early Intake (Lower Cherry) Powerhouse began commercial operation five years before the O’Shaughnessy Dam was completed. The following photos show a 1918 peek at the tramway that ran from the “ridge” to the river-side site, which was a long way down and very steep. The “emergency stop” in the foreground of one of the…

A Look Back in History: Life at the Dam

A gem from the Hetch Hetchy construction contract No. 61 proposal is a plan showing proximity of the construction crew camp to the proposed dam site. In the lower left quadrant of the drawing, the tramway location is reaching down from the loop of Hetch Hetchy Railroad upslope. Other interesting features in the drawing depict…

A Look Back in History: Lobos Creek 19th Century Water Supply

Lobos Creek is created from runoff in the Presidio and Seacliff areas, along with underground seepage from the springs that create Mountain Lake. It runs into the Pacific Ocean and marks the division between Baker Beach and China Beach. It is the Presidio’s primary source of potable water. About a million gallons per day –…

A Look Back in History: Bedrock Contour Map of Hetch Hetchy Dam Site

The original O’Shaughnessy Dam was 226 feet above riverbed. It was raised from its original height in 1938. Today the O’Shaughnessy Dam is 312 feet above riverbed and 430 feet above bedrock. Below is a bedrock contour map developed for the dam. This illustration is taken from Contract No. 61, “For the Construction of Hetch…