Stakeholder Meeting

1
Stakeholder Meeting 6
March 28, 2002
2
Todays Agenda

• Project Status
• Review of Project Alternatives for the Pajaro
  River Mainstem
• Overview of Army Corps of Engineers Process
• Detailed analysis of project alternatives.
• Continued public and stakeholder involvement.
• Flood Protection Alternatives for Corralitos and
  Salsipuedes Creeks
• Financial Overview

March 28, 2002
3
Project Status

• Since June 2001
• Set out to achieve consensus on a single Flood
  Project Concept for Pajaro and tributaries.
• Evaluated over 10 concepts to achieve 100-year
  flood protection.
• Established agreement that final Project will
  involve a combination of flood project elements
  (Hybrid approach) including
• Some floodwalls/levee raising
• Bridge modification/replacements
• Some vegetation management
• Some dredging
• Some set-back onto agricultural land.

March 28, 2002
4
Project Status-Working Group Design Criteria

• Design Criteria for Maximum Consensus
• Urban Reach
• No Set-back
• Maximum Floodwall/Levee Raise 4 feet.
• Agricultural Reaches
• Maximum 100 set-back on each side
• Levee raise 5 feet.
• Vegetation and Channel Roughness
• Need vegetation for stability, permitting,
  riparian habitat and maintainability
• Levees need to be reconstructed
• 100-Year Level of Protection-if possible

March 28, 2002
5
Alternatives Advanced by Working Group
March 28, 2002
6
Alternative 1 Hybrid with 100-year Protection
Reach 1
Reach 2
Reach 3
Reach 4
7
Alternative 1a Variation Hybrid with 100-year
Protection
Reach 1
Reach 2
Reach 3
Reach 4
8
Alternative 2 Option with Lower Level of
Protection
Option for a Lower Level of Protection

• 30-year protection below urban area is a non
  starter
• 50-year protection in all reaches has been
  modeled (preliminary)
• 50-100 ft. setback on both sides in reaches1,2,4.
• 4 ft. levee raise throughout all reaches.
• Provides for 40,000 cfs protection (50 Year) with
  Alternative 1 roughness and three feet of
  freeboard.
• Highest flow since 194030,000 CFS
• FEMA insurance still required, but premiums
  reduced.
• Other options from Army Corps of Engineers

March 28, 2002
9
Project Alternatives
Alternative 1 and 1a
Alternative 2
100-year Protection Hybrid Option
Option with lower level of protection
Floodwalls/Levee Raising
Setbacks

• No Set-backs
• Levee/FW raise for 100-year flows
• Raise heights of 7-10 ft
• Velocities Scour not likely to be permittable

• 225setback each side
• Vegetation roughness to accommodate 300
  vegetated corridor
• Requires 517 acres agricultural land.

March 28, 2002
10
Corps of Engineers Process Overview

• 3 alternatives from Stakeholder process will be
  carried forward.
• Some alternatives will no longer be evaluated in
  depth.

• Further hydraulic analysis
• Cost estimating of alternatives
• Benefit/Cost Analysis
• Preliminary environmental analysis
• Coordination Act consultation with USFWS and NMFS

• Counties asked to comment and concur on a
  recommended plan.
• One recommended plan presented to Army Corps of
  Engineers Headquarters.

• Final Draft EIR/EIS.
• Public comment and response.
• Certification under NEPA.
• CEQA certification.

11
Corps of Engineers Process Overview

• 3 alternatives from Stakeholder process will be
  carried forward.
• Some alternatives will no longer be evaluated in
  depth.

• Further hydraulic analysis
• Cost estimating of alternatives
• Benefit/Cost Analysis
• Preliminary environmental analysis
• Coordination Act consultation with USFWS and NMFS

• Counties asked to comment and concur on a
  recommended plan.
• One recommended plan presented to Army Corps of
  Engineers Headquarters.

• Final Draft EIR/EIS.
• Public comment and response.
• Certification under NEPA.
• CEQA certification.

12
Further Evaluation of Project Alternatives
Alternative 1 and 1a
Alternative 2
Other Alternatives developed by the COE
100-year Protection Hybrid Option
Option with lower level of protection
Army Corps of Engineers is proceeding with
detailed evaluation
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act
13
Detailed Evaluation of Project Alternatives
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act

• Detailed alignments, heights, and effects of
  vegetation and roughness scenarios.
• Risk and uncertainty.

March 28, 2002
14
Detailed Evaluation of Project Alternatives
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act

• Each alternative will be analyzed for a detailed
  cost estimate.

March 28, 2002
15
Detailed Evaluation of Project Alternatives
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act

• Determine which alternative provides the optimum
  flood damage avoidance, given the project cost.

March 28, 2002
16
Detailed Evaluation of Project Alternatives
Preliminary Environmental Analysis
Coordination Act
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
March 28, 2002
17
Detailed Evaluation of Project Alternatives
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act
March 28, 2002
18
Further Evaluation of Project Alternatives

• Fish and Wildlife Coordination Act
• Conducted by USFWS under contract with COE
• Determines impacts of alternatives on fish
  wildlife
• Recommends types and amounts of mitigation for
  losses
• Prepares Biological Assessment for NMFS for
  Steelhead
• This process will start early (April 2002) to
  address permitting standards regarding
  vegetation.
• Stakeholders will be involved through special
  subject focus group meetings and the October 2002
  Stakeholder Meeting will focus on this subject.
• In the absence of a local consensus on this
  subject, this process will determine the minimum
  requirements.

March 28, 2002
19
Further Evaluation of Project Alternatives

• Federal Agency Coordination Requirements
• Project that causes no further degradation of
  existing riparian/riverine habitat or
• Project that allows natural processes to improve
  habitat or ideally,
• Project that improves habitat while providing
  flood control.
• Because the Project will need some vegetation
  control as part of future maintenance, the Corps
  of Engineers must consult under Section 7.
• Source page 82 Status Report-COE Response to
  jurisdictional questions

March 28, 2002
20
Milestones and Opportunities for Public Input
2002 Milestones
21
Corps of Engineers Process Overview

• 3 alternatives from Stakeholder process will be
  carried forward.
• Some alternatives will no longer be evaluated in
  depth.

• Further hydraulic analysis
• Cost estimating of alternatives
• Benefit/Cost Analysis
• Preliminary environmental analysis
• Coordination Act consultation with USFWS and NMFS

• Counties asked to comment and concur on a
  recommended plan.
• One recommended plan presented to Army Corps of
  Engineers Headquarters.

• Final Draft EIR/EIS.
• Public comment and response.
• Certification under NEPA.
• CEQA certification.

22
Milestones and Opportunities for Public Input
2003 Milestones
23
Flood Protection for Corralitos and Salsipuedes
Creeks
24
Level of Flood Protection on Creeks
Capacity on Salsipuedes and Corralitos Creeks
With 0 Feet of Freeboard
25
Level of Flood Protection on Creeks
26
Flood Protection Concepts for the Creeks
Concepts evaluated for hydraulic proficiency

• Levee raise and floodwall
• Setback levee/floodwall
• Increased/improved storage in College Lake
• Flow bypass (Floodplain and Tunnel)

27
Flood Protection Concepts-Existing Conditions
28
Flood Protection Concepts for the Creeks
Questions from previous Stakeholder Meeting

• Interior Drainage
• Threats of flooding from more than just the
  creeks.
• Channel Maintenance
• It appeared that Salsipuedes is filling up with
  sediment, thus reducing the capacity and causing
  more flooding.

29
Channel Maintenance
CHANNEL INVERT PROFILES
110
110
100
100
90
90
80
80
HWY 152
HWY 152
GREEN VALLEY RD.
70
70
GREEN VALLEY RD.
Invert Elevation (ft)
60
60
50
50
40
40
HWY 129
HWY 129
55.0' (1968 Bridge Plans)
55.0' (1968 Bridge Plans)
30
30
52.9' (1936 Bridge Plans)
52.9' (1936 Bridge Plans)
51.6' (College Lake Outlet Invert)
51.6' (College Lake Outlet Invert)
20
20
10
10
Pajaro River
Pajaro River
0
0
0
4,000
8,000
12,000
16,000
20,000
24,000
28,000
0
4,000
8,000
12,000
16,000
20,000
24,000
28,000
River Station (ft)
River Station (ft)
1949
1969
1995
March 28, 2002
30
Flood Protection Concepts for the Creeks
Key Hydraulic Observations

• Sediment removal from Salsipuedes Creek is not a
  stand-alone solution.
• Although the existing system still handles design
  flow, we are attempting to manage 2-2 ½ times
  that amount.
• College Lake storage must be part of the
  solution.
• Corralitos Creek has the least capacity spills
  out first.
• Interior drainage problems exist resolution must
  be a part of the solution.
• Bridges at Highway 129 and 152 are constrictions
  and will likely need replacing.

31
Flood Protection Concepts for the Creeks
Hydraulic Constraints

• RAISE ONLY

• SETBACK

• BYPASS

• STORAGE

32
Flood Protection Concepts for the Creeks
Illustration of Basic Dynamics

• Creek Width vs. Creek Water Surface
• Creek Width vs. College Lake Water Surface
• College Lake Outfall Size vs. Salsipuedes Creek
  Flow
• Increased College Lake Water Surface vs. Nearby
  Homes and Businesses

33
Flood Protection Concepts for the Creeks
Potential Elements of Solution

• Include some setbacks and bench excavation to
  lower water surface.
• Improve College Lake storage to limit downstream
  flows.
• Include interior drainage improvements.
• Include permittable maintenance activities.
• Use a combination of levees, floodwalls, and
  setbacks on both creeks.
• Address the need for bridge replacement.

34
Financial Framework
35
Financial Analysis of Flood Protection
Alternatives
Financial Analysis Framework will

• Overview of Project Costs
• Local Share vs Federal Share
• Unfunded Local Share
• Tax/Benefit Assessment Options

March 28, 2002
36
Total Project Costs (for discussion only)
37
Total Project Costs (for discussion only)
38
Total Project Costs (for discussion only)
39
Total Project Costs (for discussion only)
40
Total Project Costs (for discussion only)
41
Property in the Floodplain
Land Use Types
Totals
Monterey County
Santa Cruz County
Amount
Amount
Amount
AGRICULTURE
Acres
3401.43
5096.85
8498.28
COMMERCIAL
Acres
48.86
316.73
365.59
Parcels
65
265
330
INDUSTRIAL
Acres
60.33
0
60.33
Parcels
27
27
INSTITUTIONAL
Acres
24.81
549.2
574.01
Parcels
25
206
231
RESIDENTIAL
Parcels
202
2066
2268
Acres
74.68
719.42
794.1
TOTALS
Acres
3610.11
6682.2
10292.31
Parcels
319
2537
2856
Percent of Total
35
65
100
42
Stakeholder Meeting 6
March 28, 2002
43
Project Alternatives No Longer Being Evaluated
44
Project Alternatives No Longer Being Evaluated
Pure Floodwall/ Levee Raise

• Pure floodwall/levee raise with 100-year
  protection in all reaches
• Pure setbacks of 225 with 100-year protection in
  all reaches
• Loss of more than 500 acres of agricultural land.

Pure setbacks
March 28, 2002
45
Project Alternatives No Longer Being Evaluated
Pure Floodwall/ Levee Raise

• Pure floodwall/levee raise with 100-year
  protection in all reaches
• Pure setbacks of 225 with 100-year protection in
  all reaches
• Insufficient in fully addressing flood waters.
• -No viable upstream solutions which are cost
  effective
• -No legal authority
• -Refer to pages 31-Project Status Report

Pure setbacks
Full upstream Retention/ Detention
March 28, 2002
46
Project Alternatives No Longer Being Evaluated
Pure Floodwall/ Levee Raise

• Pure floodwall/levee raise with 100-year
  protection in all reaches
• Pure setbacks of 225 with 100-year protection in
  all reaches
• Insufficient in fully addressing flood waters.
• Unrealistic maintenance costs and lack of
  permittability.
• -Refer to Page 30-Project Status Report

Pure setbacks
Full upstream Retention/ Detention
Major Dredging
March 28, 2002
47
Project Alternatives No Longer Being Evaluated
Pure Floodwall/ Levee Raise

• Pure floodwall/levee raise with 100-year
  protection in all reaches
• Pure setbacks of 225 with 100-year protection in
  all reaches
• Insufficient in fully addressing flood waters.
• Unrealistic maintenance costs and lack of
  permittability.
• Not geographically feasible.
• -Requires 450 acres ag land
• -Refer to Page 29-Project Status Report

Pure setbacks
Full upstream Retention/ Detention
Major Dredging
Full Bypass channels
March 28, 2002
48
Alternatives Advanced by Working Group
March 28, 2002
49
Project Alternatives

• No Set-backs
• Levee/FW raise for 100-year flows
• Raise heights of 7-10 ft
• Velocities Scour not permittable

• 225setback each side
• Vegetation roughness to accommodate 300
  vegetated corridor
• Requires 517 acres agricultural land.

March 28, 2002
50
Further Evaluation of Project Alternatives
Alternative 1
Alternative 2
Alternative 3
Variation 100-year Protection Hybrid Option
Other Alternatives developed by the COE
100-year Protection Hybrid Option
Option with lower level of protection
Army Corps of Engineers is proceeding with
detailed evaluation
Hydraulic Analysis
Cost Estimates
Benefit/Cost Analysis
Preliminary Environmental Analysis
Coordination Act