A Big Bear firefighter keeps a close eye on a "slop over" fire that jumped across Highway 120 in northern California. The Rim Fire, now the size of Chicago, continues to burn uncontrollably outside the Yosemite National Park.

Yosemite Wildfire Threatens Water Supply

The Rim Fire edges closer to a reservoir that supplies drinking water to 2.4 million people.

A Big Bear firefighter keeps a close eye on a "slop over" fire that jumped across Highway 120 in northern California. The Rim Fire, now the size of Chicago, continues to burn uncontrollably outside the Yosemite National Park.

A Big Bear firefighter keeps a close eye on a "slop over" fire that jumped across Highway 120 in northern California. The Rim Fire, now the size of Chicago, continues to burn uncontrollably outside the Yosemite National Park.

By SHARE

Inaccessible terrain and dry conditions continued to thwart nearly 3,500 personnel over the weekend in their efforts to extinguish the Rim Fire in Yosemite National Park in California, which has grown to 143,980 acres, according to the National Interagency Fire Center.

[PHOTOS: Rim Fire Threatens Yosemite, San Francisco]

Firefighters had only contained 7 percent of the Rim Fire by Monday morning, as it continued to grow on the northeast and eastern park areas, according to an incident report. Yosemite spokesman Tom Medema told the Associated Press that the blaze was edging closer to the Hetch Hetchy Reservoir, which provides drinking water to 2.4 million people in San Francisco as well as in Santa Clara, Alameda and San Mateo counties.

The Rim Fire burns near Groveland Ranger Station in Groveland, Calif., where more than 4,500 homes are in danger of being damaged. (U.S. Forest Service/AP)

USA Today reported an incident commander flew near the Hetch Hetchy area Sunday morning in an effort to evaluate the reservoir's state. Heavy smoke veiled the area, disabling the crew from making a clear assessment.

Cows walk through a section of burned forest outside of Camp Mather near Groveland, Calif. (Justin Sullivan/Getty Images)

San Francisco Public Utilities Commission reported no change or impact in water quality or delivery from Hetch Hetchy in a statement released Sunday. Should the Rim Fire interrupt water delivery from Hetch Hetchy, SFPUC can utilize reserves in Bay Area reservoirs, such as San Antonio and Crystal Springs.

A firefighter monitors the Rim Fire near Groveland, Calif. (Justin Sullivan/Getty Images)

However, Supplemental power supplies have cost the SFPUC about $600,000 since Aug. 19. Two of the system's three hydroelectric powerhouses have not been in use since then, and the difference has been made up by accessing power from an existing power bank and purchasing power on the open market.

[READ: Yosemite Wildfire Triples in Size]

Firefighters have been using Modular Airborne FireFighting Systems and air tankers to preemptively suppress the Rim Fire's potential spread toward the Highway 108 corridor along the eastern edge.

Firefighters from Tennessee and Los Angeles observe a smoke plume from the Rim Fire. (Jae C. Hong/AP)

The Rim Fire, which reportedly started on Aug. 17, is one of many wildfires plaguing the West. Investigators are currently working to discover a cause for the Yosemite wildfire. Firefighters were able to contain six fires on Saturday, according to the NIFC, bringing the total number of active wildfires down to 36 from more than 50 on Friday. The cost to fight the Rim Fire jumped from $12.4 million on Sunday to $20.1 million Monday.

The drought-fueled Rim Fire as captured by NASA's Terra satellite on Aug. 25, 2013. (Jeff Schmaltz/MODIS Rapid Response Team/GSFC/NASA)

More than 33,000 wildfires have burned through 3.5 million acres so far this year, 60 percent of the nationwide 10-year average. The Rim Fire is the 14th largest wildfire in California history.

 

More News: