Transcript Delta Wetlands Place of Use Environmental Impact Report

West Sacramento Area Flood Control Agency
November 10, 2011
Update on Current Levee
Construction Projects and
on the Southport
Sacramento River Levee
Early Implementation Project
Program History and Milestones
• Problem Identification Report completed for entire
perimeter levee system (2008)
• Alternatives Analysis Report completed for entire
perimeter levee system (2009)
• Construction of I-Street EIP (2008)
• Construction of CHP Academy and Rivers EIP’s
(2011)
• Initiation of Southport EIP Project (2010)
Program History and Milestones
(cont)
• USACE Construction of Yolo Bypass Slip Repairs
(2009, 2011, new south slip)
• USACE Sacramento Bank Protection Project Setback
Levee Improvement Project (2011/12)
• USACE General Reevaluation Report initiated in
2009, estimated completion (2015)
Goals for Southport EIP
• Summary of Project Goals and Criteria
– Protect safety and public health of residents within
the City while minimizing impacts to community as
much as possible
– Selected Southport EIP project based on repairing
highest risk sites
– Select least cost alternative that achieves public
safety goals and complies w/Federal and State
regulations
Federal and State Levee Design
Criteria
• Engineering design standards established by U.S. Army
Corps of Engineers, Central Valley Flood Protection
Board, and CA Department of Water Resources and
include:
– Freeboard
– Erosion
– Geotechnical Stability
– Under-seepage
– Vegetation
– Geometry
State Cost-Share Formulas
• State cost share ranges from 50% to 90%
• Base state cost share is 50%
• Objectives that increase state cost share:
– Habitat, open-space and/or recreation from 5% to 20%
– State facilities from 5% to 20%
– Setback levee from 20% to 40%
– Disadvantaged area up to 40%
*State cost share is limited at 70% except for disadvantaged areas and
setback levees which can achieve up to a 90% state cost share.
WSAFCA Role in EIPs
• Select Early Implementation Projects that utilize available
funds to improve the highest risk reaches of levee in
advance of USACE construction
• Provide local share of funds necessary for design and
construction of projects to meet the 200-year level of
protection mandated by the State Plan of Flood Control
• Design projects that provide the maximum reduction in flood
risk for the local funds invested, while considering project
impacts on the community and local landowners
• Provide a forum for public information and engagement in
the decision-making process
An “Inside Look” at a Levee
Typical Levee Deficiencies
Key Factors Limiting Use of
In-Place Measures
• Local conditions like soil layer thickness, type and depth can
determine whether cutoff walls or relief wells will correct a
seepage deficiency.
• Cutoff wall depth depends on soil type over depth of wall and
soil type at the bottom of the wall.
• Large particles - like gravels, cobbles and boulders - can limit
the cutoff wall depth due to alignment and mixing problems.
• Sacramento District Corps of Engineers recently shut down a
deep cutoff wall project for these reasons.
Relief Well with Confining Layer
Relief Well without Confining Layer
What Factors Can Require a
Landward Shift of the
Levee Template?
• Steep waterside slope with evidence of erosion or
potential for erosion
• Rapid drawdown instability
• Vegetation encroaching into Corps ‘vegetation free’
zone
Steep Slope with Erosion
Shifted Template
Rapid Drawdown Failure Plane
Intruding into Levee Template
Template Shifted Outside of
Failure Plane
Task Order No. 3 Scope and Status
• Scope items include: Hydrologic and hydraulic
analysis, geotechnical and groundwater investigations,
civil engineering analysis, environmental
documentation, and geomorphic investigations
• Develop 15% design for two project alternatives with
cost opinions
• Complete Administrative Draft Environmental Impact
Statement/Environmental Impact Report
• WSAFCA staff and consultant team present Task
Order No.3 analysis at December board meeting.
Projected Milestone Overview
• December 2011: Presentation of Task Order No. 3 Analysis
• January 2012:
– Presentation of 15% design with cost opinions and
consideration of approval of Task Order No. 4
– Public Workshop on preferred alternative (January 26)
• February 2012: WSAFCA Board selects preferred alternative
and provides direction on 60% design
• April 2012:
– 60% design complete
– Appraisal process initiated
Projected Milestone Overview
(cont)
• January 2013: Certify EIR – 100% design completed
• March-August 2013: Federal and state regulatory approvals
received
• September 2013: WSAFCA Board consideration of approval of
construction contract
Public Outreach Opportunities
• Monthly JPA Meetings (2nd Thursday of every month
at 10:30 a.m.)
• Public Meeting: January 26, 2012 (evening time TBD)
• One-on-one meetings w/WSAFCA staff on request
Questions?