1 / 19

Comparing Futures for the Sacramento-San Joaquin Delta

Comparing Futures for the Sacramento-San Joaquin Delta. Engineers: Jay Lund, UC Davis* William Fleenor, UC Davis Economists: Ellen Hanak, PPIC* Richard Howitt, UC Davis Biologists: Peter Moyle, UC Davis William Bennett, UC Davis Geologist: Jeffrey Mount, UC Davis *Lead authors.

lynda
Télécharger la présentation

Comparing Futures for the Sacramento-San Joaquin Delta

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Comparing Futures for the Sacramento-San Joaquin Delta Engineers: Jay Lund, UC Davis* William Fleenor, UC Davis Economists: Ellen Hanak, PPIC* Richard Howitt, UC Davis Biologists: Peter Moyle, UC Davis William Bennett, UC Davis Geologist: Jeffrey Mount, UC Davis *Lead authors Supported with funding fromStephen D. Bechtel, Jr.David and Lucile Packard Foundation

  2. Problems of California’s Sacramento-San Joaquin Delta • Physical instability • Land subsidence • Sea level rise • Floods • Future earthquakes • Ecosystem instability • Invasive species • Habitat alteration • Prohibitive costs for maintaining all islands • Worsening water quality for agric. & urban users

  3. Delta of Tomorrow Will be Different • Large bodies of open water and higher sea level • Increased salinity, habitat variability • Higher water quality costs – even if all islands remain intact Based on economic value of land and assets, many islands not worth repairing after flooding (blue)

  4. Comparing Water Export Strategies Long-Term (to Mid-Century) • Current Strategy: through the Delta • Peripheral Canal: around the Delta • Dual Conveyance: both through and around the Delta • No Exports:use other water sources and use less

  5. Evaluation Criteria: “Co-Equal” Goals • Delta ecosystem • Delta Vision: “sustainable environment” • Our report: viability of native fish populations • Expert judgment • Water supply • Delta Vision: “reliable water supply” • Our report: statewide economic costs • Construction & operations, water quality, supply cutbacks • Use ranges to capture uncertainty

  6. Fish Population Viability Estimates

  7. Decision Tree for Economic Cost

  8. 16 Questions with 32 Answers

  9. Through-Delta Pumping: Low Chance of Restoring Fish, High Costs Delta smelt 100 80 60 Likelihood of Fish Viability (%) 40 20 Through-DeltaExports 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  10. Ending Exports: Better for Fish, But Even More Costly Delta smelt 100 80 60 Likelihood of Fish Viability (%) No Exports 40 20 Through-DeltaExports 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  11. Peripheral Canal: Mid-range for Fish Viability, Least Costly Delta smelt 100 80 60 Likelihood of Fish Viability (%) No Exports 40 Peripheral Canal Through-Delta Exports 20 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  12. Dual Conveyance: Similar to PC for Fish, Probably More Costly Delta smelt 100 80 60 Dual Conveyance Likelihood of Fish Viability (%) No Exports 40 Peripheral Canal Through-Delta Exports 20 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  13. Similar Ranking for Chinook Salmon Chinook salmon 100 80 Dual Conveyance No Exports 60 Likelihood of Fish Viability (%) Peripheral Canal 40 Through-Delta Exports 20 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  14. Is there a better tradeoff? Delta smelt 100 80 60 Likelihood of Fish Viability (%) Peripheral Canal++? No Exports 40 Peripheral Canal Through-Delta Exports 20 0 0.5 1 1.5 2 2.5 3 Economic Cost ($Billions/year)

  15. Conclusions • No perfect solutions. • Delta inevitably more saline with more open water, for any water export strategy. • Changes harm water users, but likely better for fish – especially with export pumping removed. • Peripheral canal seems best for “co-equal” fish and water supply. No exports best for fish alone. • Don’t rely on Delta levees to protect water supply. • These conclusions are more robust than we expected.

  16. Build a Peripheral Canal for Economic, Environmental Goals • Export users commit up front to pay for facilities • Export water users and upstream diverters contribute funds/water for ecosystem • Water quality savings from a canal • Expand PC diversions with fish conditions • Do not arbitrarily limit canal size • Better environmental operations • Use governance & ownership safeguards • Use PC benefits to help fund environment

  17. Prepare for a Changing Delta Ecosystem • Habitat plans for • Climate change • Sea level rise • Permanent levee failures • New invasive species • Favor diverse habitat and flow for multiple species • Plan to make mistakes; they will happen. • Experimentation and detailed modeling needed • Include flooding at least one island

  18. Develop a New Framework for Delta Governance and Regulation • Build a more centralized, decision-capable system • Stakeholders cannot negotiate solution alone • State leadership (governor and legislature) is required • Prepare for regulatory consequences of sea level rise, climate warming, and island failures now

  19. For More Information • Research Brief, main report, technical appendices, animations, and spreadsheets available at: www.ppic.org

More Related