California Perspective Climate Change & Water Resources Adaptation Jeanine Jones

1. California Perspective Climate Change & Water Resources AdaptationJeanine Jones Department of Water Resources

2. Overview • California water background • Governor’s Executive Order • Water resources impacts & uncertainties • Research needs

4. Distribution of Average Annual Precipitation and Runoff

6. Governor’s June 2005 Climate Change Executive Order • Establishes greenhouse gas emissions targets • Directs state agencies to prepare report on impacts, and mitigation & adaptation plans for impacts

7. Climate Action Team Report • Based on results of multiple GCM runs through 2100 • Temperature increases – low range (1.7-3.0°C), high range (4.4-5.8°C) • Unclear outcome on precipitation trends • Water resources impacts -- hydrologic, sea level rise, water use

8. Hydrologic Impacts • Water storage capacity in Sierra Nevada snowpack now ≈ ½ total capacity of California’s major reservoirs • Northern Sierra (Sacramento River drainage basin) has substantial area in critical 5,000-7,000 ft elevation zone • Impacts modeled by statistically downscaling GCM outputs (via VIC model) and analyzing them in CALSIM (operational model for SWP/CVP)

9. Sierra Nevada Runoff Impacts • Possible reduction in Sierra Nevada snowpack of 10-40% by 2035-2064 • Possible Sierran snowpack decrease of up to 90% by 2100 • Actual water supply impact due to lost storage capacity depends on reservoir operations changes that can’t now be modeled (i.e. adaptation will occur)

10. Reservoir Operations Tradeoff • Tradeoff between operating Sierran reservoirs for water storage or flood control • Beginning evaluation of rule curve changes

11. Flood Control Considerations • Central Valley Flood Control Project includes dedicated storage in numerous reservoirs & and 1,600 miles of Project levees • Possible increase in magnitude/number of extreme storm events problematical for levee system

12. Impacts of Sea Level Rise -- Sacramento-San Joaquin Delta • Delta is hub of California water supply systems • 1100 miles of mostly non-engineered levees protecting below-sea level islands • Highly vulnerable to flooding & sea level rise

13. Colorado River Basin Impacts • Not modeled by CDWR in CAT report • Analyses in academic literature all show warming, and precipitation declines ranging from modest to large • Basin less affected by the storage/flood control reservoir operations trade-off than is the Sierra Nevada

14. Water Use Impacts • Changes in water use (ET) for agricultural crops & urban landscaping • Uncertain demographic impacts • Uncertain ecosystem-related water use impacts

15. Uncertainties– Water Use Impacts • Are 100-year socioeconomic projections meaningful? • Limitations of demographic models • Planning horizons – e.g. U.S. Census only to 2050 • Local land use planning based on timing of General Plan updates • Changes in agricultural water use dependent on urban land conversion, global trade patterns, not just local climate

16. Adaptation Strategies • Adaptability, flexibility key in future planning • Trends in water resources planning -- integrated regional water management, adaptive management, diversification • CDWR is requiring consideration of climate change in IRWM grants

17. Integrated Regional Water Management Delta Water Quality State Water Planning Colorado River San Joaquin River Restoration Proposition 84 State Bond Funding

18. Research Needs -- Background • National Research Council report evaluating progress of CCSP -- http://books.nap.edu/catalog.php?record_id=11934 • Proceedings of May 2007 CDWR-WSWC-WGA workshop on climate change research needs

19. May 2007 Workshop Findings – General Points • Good data collection programs important for change detection • Climate model outputs needed at regional & watershed scales • National and regional assessments needed (i.e., national/regional versions of IPCC assessments) • Need communication/translation function from academia to practitioners

20. Workshop Findings – Relationships with Academia • Sustained, ongoing interaction is needed • RISA centers are a good, although limited in scope, first step • Water managers must take the initiative to educate academics • Need to develop ways for recognizing academic interaction with practitioners

21. Workshop Findings – Relationships with CCSP Agencies • Need to establish an effective two-way communication process with CCSP agencies • Institutional structures – such as MOUs – are key to fostering continuity of joint activities/programs • Water managers must take the initiative to support desirable activities in the federal budget process

22. The Academics’ Perspective (Courtesy of an anonymous researcher) • Scientists, being brilliant, by definition only work on the most important and relevant questions (and society’s problems need to do a better job of conforming to scientists’ research interests) • While no model or analytical technique may be perfect, the research methods being used by any given scientist are by definition the best available (and a heck of a lotbetter than the methods anyone else uses) • Scientific success is measured more by the number of high quality publications produced than by delivering information providing solutions to your real world problems

23. Research Needs – Wrap-Up • Sustained effort by water managers needed • Good potential for transitioning existing research to applications, but requires technology transfer support • Role for WSWC/WGA (e.g. data collection programs)