California is no stranger to earthquakes, with the Sunshine State sitting atop of several fault lines. Residents of the southwestern state are familiar with tremors and the perils they bring with them, and now experts are calling for a large reservoir in San Jose to be drained out of fears a major earthquake could rupture the dam.
The damn can hold 90,000 acre-feet – a staggering 111,013,365,379 litres – of water so if it were to break, the consequences could be devastating, sending a huge gush of water into the nearby Silicon Valley.
Since 2009, the reservoir has been kept at 74 percent capacity, as a 7.1 magnitude quake could cause the dam to break.
The Federal Energy Regulatory Commission (FERC) has ordered the reservoir be completely drained by October 1 this year.
David Capka, director of FERC’s Division of Dam Safety and Inspections, wrote in a letter Thursday to the Santa Clara Valley Water District: “It is unacceptable to maintain the reservoir at an elevation higher than necessary when it can be reduced, thereby decreasing the risk to public safety and the large population downstream.”
The water district said: “Studies have shown a large earthquake could damage Anderson Dam, causing an uncontrolled release of water that could inundate cities and rural areas from San Francisco Bay south to Monterey Bay, including much of Silicon Valley.”
The district added the dam should be drained ahead of the “complicated and time consuming” retrofit project.
Valley Water CEO Norma Camacho said: “Valley Water has been working with several state and federal agencies through the years to secure the proper permits as the scope of the project has increased due to additional safety and design requirements.
“A priority will be to design and build a large outlet pipe, which will provide greater control over the water levels and increase public safety.”
Experts have for some time been warning of the Big One – a huge earthquake measuring at least a magnitude 7.9, according to the US Geological Survey (USGS) – as centuries’ worth of tension builds along the fault lines beneath California.
Part of the reason the west coast of the US is so seismically active is because it sits upon the dreaded Pacific Ring of Fire.
The Ring of Fire is the largest and most active fault line in the world, stretching from New Zealand, around the east coast of Asia, over to Canada and the USA and all the way down to the southern tip of South America.
The Ring of Fire runs along the rim of the Pacific Ocean and causes more than 90 percent of the world’s earthquakes.
The plates which make up the Ring of Fire are so huge even the slightest shift results in massive tremors, volcano activity and tsunamis.