Climate Change. Lauma M. Jurkevics - DWR, Southern Region Senior Environmental Scientist

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1 Climate Change A n o t h e r F a c t o r i n M a n a g i n g S o u t h e r n C a l i f o r n i a s W a t e r R e s o u r c e s Lauma M. Jurkevics - DWR, Southern Region Senior Environmental Scientist USEPA-Region IX, Extreme Events and Climate Adaptation Planning Workshop April 1, 2015

2 Topics to Cover California Climate Current Trends and Observations Projections and Impacts Adaptation Wrap-Up

3 California Climate

4 California s topography affects our weather and climate Mediterranean climate (warm, dry summers & cool, wet winters) Lots of variability

5 Annual Precipitation Map

6 Storms and California Water Supply Just a few storms each year are the core of California s water supplies Dettinger et al., 2011

7 Key Phenomena Affecting California Water Supply/Flooding Storm Track changes Cyclogensis L Flooding & water supply MJO/Tropical Convection Easterly Wave ENSO The Size of the AR Results from the Alignment of Key Processes The Absence of AR Activity Important to Drought

8 Current Trends and Observations

9 High variability, no trend 11 year Mean WRCC s California Climate Tracker

10 Decadal Scale Variability Los Angeles County Sonoma Mendocino 8 Station Index 5 Station Index

11 Other Observations Warming Trend Less snow/more rain; changing snow thresholds Less Snowpack Earlier snowfed streamflow Earlier greenup dates; more tree mortalities; enhanced wildfires Animals moving north Mike Dettinger, USGS and SIO/UCSD

12 Indicators of Climate Change in California 36 indicators Decreasing spring snowmelt runoff Rising sea levels along the coast Shrinking glaciers Increasing wildfires Warming lakes and ocean waters Gradual migration of many plants and Cal/EPA and Health Hazards animals to higher elevations

13 GISS analysis of global surface temperature change. Base period = Green vertical bar is estimated 95% confidence range. Source: update of Hansen et al., GISS analysis of surface temperature change.

14 South Coast Hydrologic Region Temperature Increases (F) During Past Century Coastal Lo Coastal Hi Interior Lo Interior Hi Avg Temp Nighttime Min Daytime Max Western Region Climate Center, 2013

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18 Runoff (million acre-ft) Monthly Average Runoff in San Joaquin River System Runoff is dominated by snowmelt Increasing winter runoff, decreasing spring runoff Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month

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21 Projections and Impacts

22 Heat Days (Greater than City of Los Angeles 95 F)

23 Heat Days (Greater than 95 F) Southern CA

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25 Declining Snowpack in SoCal (source: Sun, et. al, 2012, UCLA & LARC) With Mitigation of GHGs Without Mitigation of GHGs

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27 In the Next 35 Years 25-40% reduction in snowpack Less summer runoff More intense wet and dry periods Increased salinity in the Delta Less supply and predictability of water resources for urban, agricultural and environmental uses More frequent and intense wildfires 5 to 24 inches rise in sea level

28 Five Major Impacts to Water Resources in CA Shift in runoff patterns resulting in more winter runoff and less spring and early summer runoff Sea level rise with levee and salinity problems in the Delta and low coastal areas Bigger floods due to larger winter rainflood producing areas and more water vapor in storms Somewhat higher crop and landscape water needs Water temperature problems for cold water fish like salmon and steelhead

29 Adaptation

30 Statewide Strategies Practice and promote integrated flood & water supply management Enhance and sustain ecosystems Expand water storage and conjunctive management of surface and groundwater resources Fix Delta water supply, quality and ecosystem conditions

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32 CC Handbook for Regional Water Planning Vulnerability Assessment Checklist Water Demand Water Supply Water Quality Sea Level Rise Flooding Hydropower Ecosystem and Habitat Vulnerability

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34 Climate Change and Water Management Adaptation Strategies Urban infrastructure upgrades Water use efficiency Groundwater recharge Watershed restoration Floodplain restoration to improve hydrologic function Wetland, vernal pool, riparian restoration Invasive species management Native plant revegetation

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36 California Water Plan, Update 2013 Climate Change Content Volume 1: CA Water Today Statewide Adaptation and Mitigation Volume 2: Regional Reports Volume 3: Resource Management Strategies

37 Water and Energy Connection Blue circles: Water in Energy Orange Circles: Energy in Water

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39 Wrap-Up

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41 For More Information California Department of Water Resources Data California Data Exchange Center (CDEC) Basin-specific climate data Water quality Groundwater California Water Update index.cfm

42 Take Home Points Variability (climate, topography, elevation) in California Trends evident (temp, runoff, snowpack) Strategies and resources exist to adapt to changes