addressing climate change adaptation in regional transportation plans

Cal-Adapt ProjectionsTable 13. Summary of Cal-Adapt Climate Projections for Northern Central ValleyEffectTemperatureChange, 1990-2100PrecipitationHeat WaveWildfire RiskRangesJanuary increase in average temperature of 4°F to 6°F and between8°F and 12°F by 2100.July increase in average temperature of 6°F to 7°F in 2050 and 12°Fto 15°F by 2100.(Modeled high temperatures – average of all models; high carbonemissions scenario)Annual precipitation is projected to decline by approximately one totwo inches by 2050 and three to six inches by 2100.(CCSM3 climate model; high carbon emissions scenario)Heat wave is defined as five days over 102°F to 105°F, except in themountainous areas to the east. Two to three more heat waves peryear are expected by 2050 with five to eight more by 2100.By 2085, the north and eastern portions of the region willexperience an increase in wildfire risk, more than 4 times currentlevels in some areas.(GFDL model, high emissions scenario)[Public Interest Energy Research, 2011. Cal-Adapt. Retrieved from http://cal-adapt.org]Water SourcesTwo rivers, the San Joaquin and Sacramento, run through this region. The riversoriginate from snowmelt in the Sierra Nevada and the mountainous regions inthe north and flow toward San Francisco Bay, where the flows eventually reachthe Pacific Ocean. The confluence of the rivers occurs in the Sacramento-SanJoaquin Delta.Water moves through the region through natural waterways as well as a networkof canals and reservoirs. The reservoir and canal systems that hold much of theregion’s water allow it to be leveraged for energy generation and recreationaluse (DWR, 2009). The water supply network for the region is highly complex.One third of the regional water supply relies on groundwater pumping, whichcan increase during drought periods when more water may be pumped to makeup for surface water shortfalls. For the remaining majority of the water supply,there is heavy reliance on the surface water conveyance systems that provide theinflow to the Sacramento-San Joaquin Delta (also known as the California Deltaor the Bay-Delta.The Delta serves as a primary water source for the entire state, servingapproximately 25 million residents as far south as San Diego and an agriculturalindustry valued at over $25 billion (San Diego County Water Authority, n.d.).These supplies are delivered through the State Water Project, the Central ValleyAPG: UNDERSTANDING REGIONAL CHARACTERISTICS PAGE 38