The massive Rim Fire burning in and around the Yosemite National Park has reached the area surrounding the Hetch Hetchy Reservoir. The Hetch Hetchy Reservoir provides water for San Francisco and the surrounding areas’ 2.6 million residents. While the San Francisco Public Utilities Commission (SFPUC) does not expect the fire to affect the quality of water because of the rocky terrain and limited brush along the reservoir, they are taking steps to ensure there will be no interruption in service.
Prior to the Rim Fire, the SFPUC was transferring water from the full Hetch Hetchy Reservoir to reservoirs closer to San Francisco. As a precaution, they will be increasing the transfer amount from 275 million gallons a day to 302 million gallons. The SFPUC will continue to test for water quality as burning wood ash has fallen onto the reservoir’s surface. The ash is not toxic and is currently not affecting the water turbidity, or water cloudiness. If problems are detected, the SFPUC will begin filtering the water for customers.
The Rim Fire has blackened more than 184,000 acres since starting on August 17th. The Rim Fire is currently 20% contained, but still is growing. Forest experts say unnaturally long intervals between wildfires, creating a forest floor thick with vegetation in steep river canyons and years of drought primed the area for the massive fire. The Rim Fire is the biggest in the Sierra Nevada’s recorded history and the 7th biggest in California history.