Delta Risk Management Strategy

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Delta Risk Management Strategy
SCWC/SCWD MEETING JUNE 27, 2007
Delta-Suisun Marsh Branch Department of Water
Resources
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(No Transcript)
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DRMS

• Development of DRMS
• 2000 CALFED ROD Called for Risk Assessment of
  Delta Levees
• 2005 Levee Risk Analysis Team
• Did Preliminary Work Seismic only
• Also Developed Project Scope for DRMS
• 2005 AB 1200 Enacted
• 2006- Governors Executive Order- Delta Vision

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DRMS

• AB 1200 (CWC 139.2) Sets General Framework for
  DRSM
• DWR Shall Evaluate Potential Impacts on 50, 100,
  200-year projections on possible impacts to Delta
  from
• Subsidence
• Earthquakes
• Floods
• Climate Change
• Combination of above

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DRMS

• AB 1200 Continued (CWC 139.4)
• DWR/DFG to Determine Principal Options for Delta
  DWR to comparatively rate for ability to
• Prevent Disruption of Water Supplies Derived from
  Delta
• Improve the Quality of Water Supplies Derived
  from Delta
• Reduce Salts, Maintain Water Quality
• Preserve, Protect, Improve Delta Levees
• Protect Water Rights/Environments of River
  Systems
• Protect Infrastructure within Delta
• DFG shall rate all options for its ability to
  restore salmon other fisheries that use the
  Delta
• Report Due January 2008

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DRMS

• Contract Information
• URS Corporation, Oakland, CA
• Over 20 subcontractors
• Approved by DGS - March 6, 2006
• 3-year contract
• Includes a new LiDAR aerial survey of Delta
• Guidance to URS No new studies, use best
  available info, however, some limited exclusions
• Subsidence Seismic hazard
• DRMS report has several new models of Delta
  operations (i.e., Risk, Hydrodynamics, ERR,
  Water Analysis)

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DRMS

• DRMS Technical Memoranda
• Risk Analysis
• Seismology (PSHA)
• Ecological Impacts (Ecosystem)
• Subsidence
• Levee Vulnerability
• Flood Hazard
• Wind Wave Analysis
• Climate Change
• Water Analysis Module (Hydrodynamics)
• Geomorphology
• Impact to Infrastructure
• Economic Consequences
• Emergency Response Repair

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DRMS

• Phase 1
• Based on Business-As-Usual Assumptions
• Development of a Risk Analysis to Evaluate the
  Impact to Delta Levees from
• Floods
• Earthquakes
• Subsidence
• Normal Conditions
• Climate Change
• Determine Consequences to Economy Eco-System
  based on Risks Found
• Draft Risk Analysis Report submitted April 23 07
• Public Draft July 2007
• Independent Review by CALFED July August 07

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Summary of Key Findings from Phase 1
(preliminary)

• 160-260 flood-related island failures expected in
  the next 100 years
• 12-15 simultaneous island failures in a major
  flood event
• 15- 30 chance of 30 islands failing
  simultaneously in a major earthquake in the next
  25 years

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Summary of Key Findings (continued)

• Probability of flood-related levee failure
• increases by 10 in 2050
• Increases by 20 in 2100
• Probability of seismic-related levee failure
• increases by 12 in 2050
• increases by 27 in 2100
• 3 feet of sea level rise would push the salt line
  about 3 miles to the east

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DRMS

• Phase 2
• Development of Risk Reduction/Risk Management
  Strategies for Long-Term Management of Delta
• Draft Final Report Due August 07
• Public Review Draft Oct 07
• Independent Review by CALFED Oct Nov 07
• DRMS Final Report November 2007
• Includes Recommendations for Future Work/Studies
  in the Delta
• Will be provided to Delta Vision Blue Ribbon Task
  Force for Consideration in the Vision for the
  Delta

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• Delta Risk Management Strategy
• Phase 2 Development and Evaluation of Risk
  Reduction Strategies
• Develop a menu of risk reduction measures that
  could reduce risk building blocks
• Package the measures into different combinations
  -gt trial scenarios
• Use Risk Model to evaluate potential risk
  reductions
• Evaluate benefits and costs of risk reduction
  measures

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Delta Risk Management Strategy

• Potential Risk Reduction Building Blocks
• Improved Levee Maintenance
• Upgraded Delta Urban Levees
• Enhanced Emergency Preparedness/Response
• Pre-Flooding of Selected Western Islands
• Land Use Changes to Reduce Subsidence
• Armored Through Delta Pathway Conveyance
• Isolated Conveyance
• Elevation of State Highways on Piers
• Armored Infrastructure Corridor
• San Joaquin By-Pass
• Suisun Marsh Restoration
• Cache Slough Restoration
• Fish Screens
• Reduced Water Exports

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DRMS Phase 2 Trial Scenarios Being Proposed

• Improved Levees
• Armored Pathway
• Isolated Conveyance

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Thank You
For more information on the DMRS work, please
see the DRMS web site at http//www.drms.water
.ca.gov/