Finding fossils can be a fact of life for construction crews excavating in California. That's what happened when crews broke ground to begin the new Bay Area Calaveras Dam in 2013. They just didn't expect to find so many.
The existing 93-year-old Calaveras Dam stands only about a thousand feet from the Calaveras Fault, a proximity that prompted earthquake safety concerns.
The dam impounds the Calaveras Reservoir, which holds 40% of the area's water supply capacity. It's the largest Bay Area reservoir, said Betsy Lauppe Rhodes, regional communications manager for the Hetch Hetchy Regional Water System.
With 2.7 million Bay Area customers relying on its water, the stability of the dam is critical. After careful study, a decision was made to rebuild the dam completely next to its existing location, Rhodes said in an email.
The dam's excavation required moving 10 million cubic yards of rock and soil. During initial project planning, shell fossils were noticed at the site, she said.=read more
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