One of the largest wildfires in the state\u2019s history continues to burn in and around Yosemite. The Rim Fire, which has torched more than 300 square miles, continues to threaten San Francisco\u2019s hydropower and water supply. The state grid was not at risk, according to the California Independent System Operator. From August 19 to 28, two San Francisco Public Utilities Commission\u2019s hydroelectric powerhouses at Hetch Hetchy, with a total 285 MW of capacity, stopped supplying power. The off-line projects were the 165 MW Holms and 118 MW Kirkwood facilities. A third hydro facility, the 100 MW Moccasin Powerhouse, has continued to generate hydroelectric power. On Aug. 28, one the three 39.5 MW Kirkwood units went back on line. Unit two was undergoing repair. The fire\u2019s impact on the third Kirkwood unit was unclear at press time. \u201cCrews will work to clear hazard trees near the transmission lines and on access roads. Power transmission lines still need to be hot-washed to rid the insulators of dirt and other debris prior to energizing the transmission lines,\u201d stated the SFPUC. San Francisco is replacing the lost power by tapping into generation it \u201cstores\u201d in an existing power bank with Pacific Gas & Electric and other utilities. It also is buying supplemental power on the open market, said Charles Sheehan, SFPUC spokesperson. \t As of Aug. 29, the muni spent an estimated $780,000 on replacement power, according to Tyrone Jue, another San Francisco spokesperson. Under the \u201cbanking\u201d arrangement, the San Francisco muni stores megawatts instead of dollars, which it can draw on as needed. For example, if it banks 2,000 MWh at the beginning of the year with PG&E, San Francisco can tap into the stored power as needed through the end of the year. The Rim Fire was 30 percent contained on Thursday, CalFire reported. The bigger concern for the muni has been the ash deposits on the water supply in the Hetch Hetchy reservoir, which fills the taps of San Franciscans. \u201cAs a precautionary measure, we have increased the amount of the water delivery to the Bay Area from 292 million gallons a day to 302 million gallons a day,\u201d San Francisco said. Elsewhere, the Deer Fire in Tehama County had put the part of the California-Oregon intertie line at risk. The two 500 kV lines on Path 66 link, which were threatened, supply the Pacific Northwest and the Southwest. The Deer Fire, which burned more than 11,400 acres, was 98 percent contained Aug. 29, according to CalFire.