California firefighters continue to struggle against a massive wildfire that has burned to the edge of Yosemite National Park.

Officials say that the fire is 7% contained. Unfortunately, strong winds are working against the firefighters.

“[The winds are] going to allow the fire to advance to the north-east,” Daniel Berland of the California Department of Forestry and Fire Protection told the press. More than 2,700 firefighters are now on the front lines of the fire.

The governor has issued a state of emergency for San Francisco 150 miles away because the major power lines that feed the city are being threatened by the flames. The city’s water supply could be seriously damaged if the flames reaches the Hetch Hetchy reservoir which provides the city with 85% of its water.

The fire is 4 miles from the reservoir.