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<br /> <br />In the Bay Area temperatures are projected to increase between 3 degrees (low emission <br />scenario) and 6 degrees Fahrenheit (high emission scenario).42 In the eastern regions of <br />the state the increase is 4 to 9 degrees. <br />The reduction in snowpack does not have direct impacts in the Bay Area as the region does <br />not accumulate meaningful levels of snow. The Bay Area is adversely impacted by the <br />severe reduction in snow pack in the Sierras, the source of two-thirds of the regions <br />water. By the end of the century the spring snow pack in the Sierra could be reduced by as <br />much as 70 to 90percent the historic average.43 <br /> <br />5.8.3 Water Supply <br />Drought can impact the entire Bay Area, not just one particular county or a few cities. In <br />addition, shortages in precipitation in the Sierra Nevada can have a more pronounced <br />impact on water supply in the region than a drought in the Bay Area itself because of the <br />reliance of the region on water from the Tuolumne, Mokelumne, Sacramento, and San <br />Joaquin watersheds. Thus, drought is not a hazard that can be depicted by a Bay Area map; <br />rather a map of Northern California is necessary to understand the impact of drought on <br />Bay Area water supply. <br />Figure 17 illustrates where the largest water districts in the region collect water. Only a <br />third of the water used in the Bay Area is from local rainfall collection and groundwater <br />pumping; the remainder comes from runoff in the Sierra Nevada Mountains. Figure 18 <br />highlights the severity of the current drought in watersheds Bay Area districts are <br />dependent on for their water. In 2015, portions of the Bay Area were downgraded slightly <br />because of average rainfall in micro climates of the region. Other portions of the Bay Area, <br />and most of the area the region relies on for its imported water, remain in exceptional <br />drought, the highest drought designation.44 <br /> <br />5.8.4 Increased Fire Hazard <br />Fire hazard increases where drought conditions are high. There are multiple drought <br />related factors that contribute to increased fire hazard: longer fire season, drier vegetation, <br />and hot days. Additionally, drought reduces the water supplies available to fight wildfires, <br />leading to larger and more extended fires. When in a drought, the fire risk is greater, and <br />the impacts remain the same, as those described in Section 0 on fire risk. <br /> <br />42 Cayan, D., et al. (2009) <br />43 Scripps Institute of Oceanography (2012) <br />44 National Drought Mitigation Center, (2015)