1. Addressing Climate Change in PN Region Reservoir Studies Patrick McGrane

2. Conventional Hydrologic Studies Use historic values for runoff, river gains/losses, demands, etc. Adjust historic data to current or future level of development. Assume future weather will mimic the past.

3. “The future ain’t what it used to be.” Climate Impacts Group University of Washington

4. Customers Desire Climate Change Analysis Opportunities exist –new flood control requirements –new reservoir storage studies Legislation and litigation

5. Studying Less Space for Flood Control

6. New Storage Studies

8. Yakima Basin Storage Study (Black Rock)

10. EXECUTIVE ORDER S-3-05 by the Governor of the State of California June 1, 2005 … report … on the impacts to California of global warming, including impacts to water supply… prepare and report on mitigation and adaptation plans to combat these impacts California Water Plan 2005 - Recommendation 10. State government must help predict and prepare for the effects of global climate change in our water resources and water management systems.

11. Litigation 2004 Biological Assessment Long Term Central Valley Project and State Water Project Operating Criteria and Plan 2004 Delta-Mendota Canal/California Aqueduct Intertie - Finding of No Significant Impact Long Term Water Service Contracts

12. Options being considered 1.No climate change analysis. 2.Mention climate change literature but no qualitative or quantitative analysis. 3.Qualitative analysis of Proposed Action 4.Quantitative analysis of Proposed Action. 5.Ensemble of climate change scenarios of both No Action and Proposed Action. 6.Let others define the analysis.

13. In the meantime…

14. Studying Less Space for Flood Control

16. Climate Variability/Spill Prevention Adjustment (?)

17. What do you do with the results? How much weight do you give climate change scenario? Is it fair to adjust runoff without adjusting other hydrologic variables? –Runoff Forecasts –Demands Amount Timing How valid are climate adjusted daily flows? Whose climate change scenarios do you use? Are statistics, regressions, risk analyses based recent (or future) data better than long term record?

18. Final Message: Things are starting to happen. Standby…

19. The End