San Francisco Chronicle-
Federal water officials have ordered Silicon Valley’s chief water supplier to start draining its largest reservoir by Oct. 1 because a major earthquake could collapse the dam and send floodwaters into communities from Monterey Bay to the southern shore of San Francisco Bay.
But Valley Water, the agency that manages the Anderson Dam and Reservoir, says it has already lowered the reservoir’s water below the level initially sought by federal officials — and that the total drainage the federal government now demands would actually make the dam more vulnerable to earthquake damage, while also reducing water supplies and causing environmental harm.
The reservoir, in a gorge 3 miles east of U.S. 101 between Morgan Hill and San Jose, is one of 10 storing water for the Santa Clara Valley Water District, now known as Valley Water. Built in 1950, it can hold 89,073 acre-feet of water, more than half of the 170,000 acre-feet stored in all of the district’s reservoirs.