Ash from the massive fire now raging through 230 square miles of Yosemite National Park now threatens to contaminate the “pure” drinking water for 2.5 million residents of San Francisco’s Bay area nearly 150 miles away.
Although the ash raining on the Hetch Hetchy Reservoir, which supplies 85% of the area’s drinking water, has not yet sunk as far as the intake valves (located about half way down the 300-foot O’ShaunessyDam), the threat has prompted California Governor Jerry Brown to declare a state of emergency, calling for utility officials to begin using a new $4.6 billion gravity-operated pipeline to move water to replenish reservoirs closer to the city limits as rapidly as possible.
“We are taking advantage that the water we are receiving is still good quality,” stated San Francisco Public utilities general manager Harlan Kelly Jr., who added that they now have a six month supply of water on hand near the city.
While the ash is non-toxic, officials will begin filtering the water if they find any problems occuring as the fire situation worsens.
So far the fire, which broke out in the Sierra Nevada mountains on August 17th, has already damaged two out of the three hydroelectric power stations which supply energy to the international airport, San Francisco General Hospital, City Hall and other municipal buildings. To date, the 3,700 firefighters battling the conflagration report that they now have 20% of it contained.