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The Resources Agency California Department of Water Resources DWR Program for the Repair of the Cali

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Title: The Resources Agency California Department of Water Resources DWR Program for the Repair of the Cali


1
The Resources AgencyCalifornia Department of
Water ResourcesDWR Program for the Repair of
the California Levee System
March 7, 2007
2
Presentation Outline
  • Background
  • Description of Projects
  • Critical Erosion Repairs
  • PL84-99
  • Urban Levee Geotechnical Evaluation

3
Central Valley Flood Control System Projects

2.5 million people

2 million acres of cultivated land

200,000 structures with an estimated value of 57
billion

Water supply to 2/3rds of the States population
and industry
The system is aging and under-funded
4
  • KEY CHALLENGES IN CENTRAL VALLEY
  • 1600 miles of Federal Project Levees
  • 700 miles of local Delta Levees
  • 2300 miles of Levees
  • Old levees, many originally built by farmers,
    most without adequate engineering

5
Methods and materials used during early
construction are inappropriate by todays
standards.
6
Some methods included manual labor only. Repair
was generally reactive (as a result of periodic
failures).
7
CRITICAL LEVEE EROSION REPAIRS PROJECT
  • Annual Survey Commissioned by U. S. Army Corps
    of Engineers
  • 2005 Survey reported 174 Erosion Sites

8
Levee and Bank Erosion
4
9
Levee Erosion
10
3 ft in 4-6 hours
7 ft in 12-20 hours
10 ft in 24-36 hours
17 ft in 6-8 days
7
11
(No Transcript)
12
  • State Emergency Declaration
  • Governor declared State of Emergency for States
    levee system (February 24, 2006)
  • Directed DWR to repair 24 Critical Erosion Sites
    before the next flood season
  • Directed DWR to evaluate additional sites to
    determine if other levee reaches require urgent
    repairs
  • Directed all state agencies to alleviate the
    emergency in accordance with the State Emergency
    Plan
  • USACE Declaration of Emergency
  • ( For 24 new levee erosion sites (November 7,
    2006)
  • Enables construction concurrent with
    environmental assessments and mitigation plans

13
  • Requested Federal Emergency Declaration
  • Requested federal
  • emergency assistance
  • Full state-federal cost share
  • Cooperation and assistance
  • from the Corps of Engineers
  • Expedite process for federal
  • permits, construction

14
Project Description Emergency LeveeErosion
Repairs
  • Repair 24 critical erosion sites before November
    1, 2006
  • 20 conventional rock reinforcement
  • 4 set-back levees
  • Identify and evaluate other sites degraded during
    sustained high flows throughout the wet season.
  • Evaluated 11 potential critical sites
    determined that an additional 5 sites had
    degraded to critical status
  • - need to repair these 5 newly critical
    sites!
  • Evaluated 19 additional erosion sites at the
    request of local officials for consideration for
    emergency repairs

15
Critical Site Sites where further erosion may
result in a bank failure, which encroaches near
or into the levee crown and is recommended as the
highest priority for repair
24 Original Critical Sites 5 Additional Sites
Found to be Critical (previously
potentially critical sites that have
deteriorated over the last year) _________________
___________________________________ 29 Current
Critical Sites 10 Critical Sites to be
repaired by USACE 19 Critical Sites to be
repaired by DWR __________________________________
______________ 29 Current Critical Sites
16
Task Activitiesfor Repair of the Critical
Erosion Sites
  • Environment Permitting
  • Right of way acquisition
  • Surveying and site assessments
  • Design and prepare construction contracts
  • Construct erosion repairs
  • Incorporation of self-mitigation features to
    reduce environmental impacts associated with the
    project repairs.

17
Typical Rock Fill Repair Design
  • Example of a Self-mitigating Repair

18
Typical Rock Fill Repair Design(Continued)
19
Project GoalLong-term Bank Erosion Control and
Levee Stabilization
Mitigation FeaturesGoal is Self-Mitigation
SAC 85.6R
20
  • Protection of Existing Trees
  • Installation of willow fascine bundles to
    propagate shaded riverine aquatic (SRA) habitat
    near the waters edge
  • Installation of willow pole cuttings

21
  • Riparian bench (planting to be completed next
    spring)
  • In-stream woody material (IWM) at multiple levels
    to maximize fisheries benefits
  • Revegetation of all soil slopes (including rill
    erosion control).

22
Key Regulatory Hurdles
  • Clean Water Act Section 404/ Rivers and Harbors
    Act Section 10 (Corps)
  • Endangered Species Act (NOAA and USFWS)
  • National Environmental Policy Act (Corps)
  • California Environmental Quality Act (DWR)
  • Other State Programs (401, 1602)

23
Land Access Critical Erosion Site Levee Repair
24
Water Access Critical Erosion Site Levee Repair
25
2005 Critical Repairs Status
  • TOTAL CONSTRUCTION
  • 29 of 33 sites (levee repairs) are structurally
    complete, with remaining mitigation vegetation
    planting planned for Spring 2007.
  • 4 of 33 sites (setback levees) are fully
    complete.
  • Cumulative Length of Repairs 33,800 LF (6.4
    mi.)
  • TOTAL COST for 33 Sites
  • 189.5 million dollars (150.3M State / 39.1M
    Federal)
  • (5,700 per LF of self-mitigating repair).

26
Catching up with 2006
  • Critical Repairs had focused on 2005-identified
    sites.
  • Two major storm events (January and April 2006)
    caused significant, additional flood damage
    throughout the State
  • The 2006 field reconnaissance by the USACE on the
    Sacramento River mainstem and delta identified 24
    newly designated critical sites (excludes
    tributaries and bypasses).

27
INCIDENTS
  • DWR responded to
  • over 60 incidents
  • Central Valley 29
  • Delta 27
  • Suisun Marsh 3
  • Coastal 3
  • Sierra 1

28
  • INCIDENTS
  • DWR responded to
  • over 45 incidents
  • Central Valley 21
  • Delta 3
  • Sierra 2
  • Advanced Measures 19

29
2006 Emergency Repairs Program
Priority 1 40 Order 1 (Urban) PL84-99
Sites Priority 2 24 2006 Ayres/USACE Critical
Erosion Priority 3 7 Order 2 (Rural) PL84-99
Sites (High B/C Ratios) 71 Critical
Levee Sites DEFERRED 44 Order 2 (Rural)
PL84-99 Sites (Low B/C Ratios)
75 Ineligible PL84-99 Sites
222 Non-Critical Order 3, 4, and 5
PL84-99 sites 341 Deferred Sites
30
Critical Repairs Schedule
  • Phased Construction of 24 Critical Sites
    (construct through the winter to place launch
    rock and abate scour to levee bank)
  • Final repairs to be constructed Summer / Fall
    2007
  • Complete repairs of 47 Order 1 2 PL84-99 sites
    by Summer / Fall 2007
  • USACE to Re-assess economic opportunities to
    repair DEFERRED sites (341)
  • USACE DWR - Continue monitoring known sites and
    conduct annual field reconnaissance to identify
    and prioritize new critical levee erosion sites.

31
Estimated Cost of 2006 Repairs
  • 24 Critical Levee Erosion Repairs
  • State 43.2 Million
  • Federal 61.5 Million
  • 104.7 Million
  • PL84-99 Repairs (47 sites)
  • State Federal 40.4 Million
  • EST. 2006 PROGRAM TOTAL 145.1 Million
  • Combined 2005/2006 Program 334.5 Million
  • (Source of funding AB-142)
  • Environmental mitigation costs account for
    between 25-50 of the
  • total capital construction cost.

32
Urban Levee Geotechnical Evaluation
  • Purpose Identify hidden deficiencies in levees
    that protect urban areas State and Federal
    Urban Levees.
  • Evaluate levees with respect to
  • Seepage
  • Static and seismic stability
  • Settlement
  • Erosion
  • 200-year level of flood protection
  • Meet USACE/FEMA criteria for certification
  • Preliminary design alternatives for identified
    deficiencies

33
Urbanized Regions
34
Hidden defects
Sand layer found in existing levee during
repairs. Layer goes through to other side
This area sustained significant seepage during
the 1997 event
35
Scope of Work
  • Geotechnical Evaluation
  • Exploration
  • Testing
  • Data Analysis and Characterization
  • Certification
  • Structural works a statement that the works are
    designed in accordance with sound engineering
    practice
  • As-built conditions a statement that the
    structures have been constructed according to
    the design, are in place and are fully
    functioning

Levee Decertified
GER
  • Structural Design
  • Embankment Height
  • Closures
  • Embankment Protection
  • Embankment and Foundation Stability
  • Settlement
  • Seepage

Review Levee Freeboard
Operation Maintenance Plan
Submit LOMR/PMR
FEMA Review
Interior Drainage Analysis
Levee Accredited
DFIRM Revised
36
Management Process Approach
37
Focused on3 Major Areas
  • This 35 million, 3-Yr effort is geographically
    executed
  • North Area (Yuba City and Marysville Region)
  • Central Area (Sacramento Region)
  • South Area (Stockton Region)

38
Program Schedule
39
Additional, Concurrent DWR Activities
  • American River Common Area provides for the
    improvement of American River levees protecting
    Sacramento (2.1M from AB-142 w/ USACE, Rec Bd,
    SAFCA)
  • Sutter Bypass Weir 2 Improvements provides
    analyses and design to improve facility to meet
    environmental compliance (2.5M)
  • Willow Slough Weir Improvements provides
    analyses and design to improve facility to meet
    environmental compliance (2.5M)
  • Pump Station Rehabilitation provides for the
    improvements to facilities near Yuba City (2.5M)
  • Fremont Weir Maintenance provides for the
    removal of approx. 800,000 CY of sediments near
    this flood control facility (2.0M)

40
For more informationvisit DWRs Levee Website
at
  • www.levees.water.ca.gov
  • For water conditions, go to
  • www.water.ca.gov
  • then select Water Conditions

41
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42
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