Transcript No Slide Title

Stakeholder Meeting #2
July 20, 2001
March 11, 1995
Opening Remarks and Agenda Overview
Today’s Meeting Objectives
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July 20, 2001
Review Key Issues from Stakeholder
Meeting #1
Discuss Concept Plan and Element
Screening Approach
Evaluate 5 “Basic” Flood Protection
Elements
Provide Direction for Next Set of Project
Options
Opening Remarks and Agenda Overview
Today’s Agenda
July 20, 2001
I.
Welcome and Meeting
Overview
II.
Review of Stakeholder Meeting
#1
III.
Presentation of Concept Plan
and Evaluation Framework for
Flood Protection Elements
IV.
Basic Project Elements
Analysis
V.
Open Discussion
Review of Stakeholder Meeting #1
Desired outcome of the Community
Planning Process:

July 20, 2001
Achieve agreement on a
community-based concept plan
for Pajaro River flood protection.
Review of Stakeholder Meeting #1
How we are organized to accomplish Phase I
…
2001
MAY
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
Project Primer
Design Options
Design Options
Stakeholder
Issues
“Basic”
Elements
Continued
Draft
Concept
Stakeholder
Meeting #1
Stakeholder
Meeting #2
Stakeholder
Meeting #3
Stakeholder
Meeting #4
NOVEMBER
Final
Concept
Stakeholder
Meeting #5
Community Focus Groups, Stakeholder Interviews, Bi-lingual Outreach
Working
Group
July 20, 2001
Working
Group
Working
Group
Working
Group
Working
Group
Working
Group
Working
Group
Review of Stakeholder Meeting #1
Stakeholder Roles and
Responsibilities:

Stakeholders added since last
meeting:
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Central Coast Water Quality Control BoardBill Archfeld
CALTRANS-Don Steiger
Stakeholders are “Representatives” of
a constituency.
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July 20, 2001
Expected to represent constituency
viewpoint, as a whole.
Review of Stakeholder Meeting #1
Stakeholders:
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John Martinelli-Santa Cruz
Richard Uyematsu-Santa Cruz
Karen Miller-Monterey
Patricia Sakata-Monterey
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CA Coastal Commission-Tami Grove
CA Fish & Game-Patricia Anderson
US Fish & Wildlife-Amelia Orton-Palmer
National Marine Fisheries –Joyce Ambrosius
Monterey Bay Marine Sanctuary- Holly Price
CalTrans- Don Steiger
Regional Water Quality Control - Bill Arkfeld
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Virgie Neighbors-Santa Cruz
Dan Hernandez-Santa Cruz
Loraine Stucki – Santa Cruz
Diane Cooley-Monterey
John Kasunich-Monterey
TBA- Monterey
Community Organizations
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July 20, 2001
Wetlands Watch-Chris Johnson-Lyons
Sierra Club-JoAnn Baumgartner
Elkhorn Slough -Mark Silberstein
Melanie Mayer Gideon
Residents in Floodplain
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Regulatory Agencies
Larry Eddings-Santa Cruz
Ed Kelly-Santa Cruz
Diane Young-Monterey
Karen Sambraillo-Pajaro
Local Environmental Organizations
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Dave Tavarez-Town of Pajaro
Joseph Rosa-Town of Pajaro
TBA-Town of Pajaro
Farm Representatives in Floodplain
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Carlos Palacios-City Manager
Betty Bobeda – City Council
David Koch- Dept. Public Works & Utilities
Town of Pajaro
Business Representatives
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City of Watsonville
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Casa de la Cultura-Sister Rosa Delores
Action Pajaro Valley-Lisa Dobbins
Com. Alliance Family Farmers-Sam Earnshaw
Jim Rider-Farm Bureau
Vince Carrillo-Together In Pajaro
Review of Stakeholder Meeting #1
Stakeholder Meeting # 1-Key Issues
Raised
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Project, Goals and Expectations
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Provide flood protection for people,
economic development, quality of life,
and the environment.
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Establish a realistic system for
compromise.
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Talk to residents and businesses who
own land along the River-they have a
larger stake.
July 20, 2001
Review of Stakeholder Meeting #1
Project Design Comments
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July 20, 2001
Is the Pajaro a dynamic, “living” river
system or flood control channel?
Look at floodwalls first, and work to a
multi-objective project from there.
Study up-stream detention for flood
protection and water supply.
Integrate river/habitat restoration into
flood protection plan.
Look at Hwy 1 Bridge which backs up
water upstream.
Look at channel excavation and dredging
as a flood solution.
Review of Stakeholder Meeting #1
Project Design Comments Cont.
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July 20, 2001
Look at ring levees to protect urban
areas.
Study by-pass channels, both large and
small.
Increase the meandering areas of the
river with natural terraces and levee setbacks
Consider a multi-pronged approach,
including levees, by-passes, retention,
excavations.
Include safety components for
management of river overflow above
design capacity
Concept Plan and Evaluation Framework
Flood Protection Elements:
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July 20, 2001
Containment Walls and/or Levee
Raising
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Set-back Levees
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By-pass Channels
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Dredging
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Upstream Detention
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Ring Levees
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Bottle-neck removal
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Land / Easement Acquisition
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Facilities Relocation
Concept Plan and Evaluation Framework
Flood Protection Elements:
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July 20, 2001
Containment Walls and/or Levee
Raising
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Set-back Levees
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By-pass Channels
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Dredging
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Upstream Detention
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Ring Levees
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Bottle-neck removal
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Land / Easement Acquisition
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Facilities Relocation
Basic
Elements
Concept Plan and Evaluation Framework
How to get from flood protection
elements to a flood protection
concept plan…
July 20, 2001
Concept Plan and Evaluation Framework
Proposed Framework for evaluating Project
Elements:
I.
II.
III.
IV.
V.
Does the element provide adequate level of
flood protection?
Regulatory
Feasibility
Socio-Economic
Feasibility
Financial Feasibility
Feasible Flood Protection
Options
Combinations of
elements by
reach
Community Flood Protection
Concept Plan and Evaluation Framework
I. Does the element provide adequate level of
flood protection?
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Level of Flood
Protection
Containment height of
structures above
existing levees (if any)
Potential as a stand
alone solution?
Potential as a partial
solution?
July 20, 2001
Project ElementProject ElementProject ElementProject Element Project Element
4:
3:
2:
5:
1:
Bypass Channel Dredging
Upstream
Containment Set-back Levees
Retention
Walls
Concept Plan and Evaluation Framework
II. Environmental and Regulatory Feasibility
EVALUATION
CRITERIA
Environmental
Reg.
Pondand
Turtle
and
California Red Legged
Frog
•Migration
•Spawning
Nesting and foraging
birds
Steelhead Trout:
•Migration
•Spawning
Lagoon Environment
Overall Likelihood of
permitting
Project ElementProject ElementProject ElementProject Element Project Element
4:
3:
2:
5:
1:
Channel Dredging Upstream
Containment Set-back leveesBypass Channel
Retention
Walls
Pajaro River Reaches
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
July 20, 2001
Basic Project Elements
Hydrology and Hydraulics
Analysis…
--Ed Wallace, Northwest Hydraulics
July 20, 2001
Concept Plan and Evaluation Framework
I. Does the element provide adequate level of
flood protection?
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Level of Flood
Protection
Containment height of
structures above
existing levees (if any)
Potential as a stand
alone solution?
Potential as a partial
solution?
July 20, 2001
Project ElementProject ElementProject ElementProject Element Project Element
4:
3:
2:
5:
1:
Bypass Channel Dredging
Upstream
Containment Set-back Levees
Retention
Walls
Basic Project Elements
Hydrology
• U.S. Army Corps of Engineers, 1997
Hydrologic Engineering Report
– Flood Frequency-Pajaro River at Chittenden;
– Flood Frequency-Corralitos Creek at Freedom;
– Hydrologic models for Corralitos and Salsipuedes
Creeks;
– Routing through College Lake;
– Adjustment for future conditions
July 20, 2001
Basic Project Elements
35000
50-Year
30000
Peak Discharge (cfs)
25-Year
25000
20000
10-Year
15000
5-Year
10000
5000
2-Year
0
1940
1950
1960
1970
1980
1990
2000
Water Year
Annual Peak Discharges of the Pajaro River at Chittenden
July 20, 2001
Basic Project Elements
July 20, 2001
Basic Project Elements
Hydrology
• Factors Affecting Estimates of Peak Flows
– New data for observed peak flows
– New hydrologic modeling results
• increased urbanization/impervious surfaces
• decreased floodplain storage
• changes in analysis methods
• Evaluation of Basic Project Elements
– Use 100-Year discharge estimates
– Use 3 feet of freeboard
July 20, 2001
Basic Project Elements
Basic Project Elements
Hydraulics
Existing Capacity and Risk-Pajaro River
No Freeboard
Risk of Flooding over
10 Years
30 Years
Location
Capacity
(cfs)
Return
Period
Downstream of Hwy 1
27,500
20 Years
40%
79%
Upstream of Hwy 1
30,100/33,500
32 Years
27%
61%
With 3' Freeboard
Location
Capacity
(cfs)
Return
Period
Downstream of Hwy 1
19,000
10 Years
65%
96%
Upstream of Hwy 1
22,000/24,700
17 Years
45%
84%
Risk of Flooding over
10 Years
30 Years
* Capacity based on model calibration to 3 historical water surface profiles
(Feb 20, 1996 - 8,450 cfs/ Jan 3, 1997 - 15,800 cfs / Feb 3, 1998 - 25,100 cfs)
** March, 1995 peak discharge = 21,500 cfs
July 20, 2001
Basic Project Elements
Hydraulics
Existing Capacity and Risk-Salsipuedes and Corralitos Creeks
No Freeboard
Risk of Flooding over
10 Years
30 Years
Location
Capacity
(cfs)
Return
Period
Mouth to Highway 152
4,500-5,000
4-6 Years
85-95%
99%
Highway 152 to Greenvalley Road
2,900
12
58%
93%
Source: Corps of Engineers General Re-Evaluation Report, November 1999
July 20, 2001
Basic Project Elements
3 measures of roughness:
Medium Roughness
High Roughness
Low Roughness
July 20, 2001
Basic Project Elements
Basic Flood Protection Elements:
Containment
Walls and/or
Levee Raising
I.
July 20, 2001
Set-back
Levees
By-pass
Channels
Dredging
Upstream
Detention
Does the element provide adequate
level of flood protection?
Basic Project Elements
odwalls and/or Levee Raising
Basic Project Elements
oodwalls and/or Levee Raising
July 20, 2001
Basic Project Elements
oodwalls and/or Levee Raising
Average Levee Height for 100-Year Flood (Feet)
Existing
Additional
Total
Average
Maximum
Average
Maximum
Average
Maximum
Pajaro River
7.5
11.5
7.5
9.5
15.0
19.0
Salsipuedes Creek
4.5
9.0
5.5
11.0
9.5
17.5
0
0
5
9.5
5
9.5
Corralitos Creek
Medium Roughness on Pajaro River
Existing Roughness on Salsipuedes Creek
3 ' Freeboard
Additional Levee Height
Total Levee Height
Existing Levee Height
July 20, 2001
Basic Project Elements
odwalls and/or Levee Raising
Does the element provide adequate level of flood
protection?
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Level of Flood
Protection
Average Height of
structures above
existing levees (if any)
Project ElementProject Element Project Element
Project ElementProject Element
3:
2:
4:
1:
5:
Bypass Channel
Channel
Floodwalls Set-back Levees
Upstream
Excavation
Retention
100-year
5.0-7.5 Ft
Potential as a stand
alone solution?
Yes
Potential as a partial
solution?
Yes
July 20, 2001
Basic Project Elements
Set-back Levees
Basic Project Elements
Set-back Levees
July 20, 2001
Basic Project Alternatives
Set-back Levees
Hydraulic Constraints vs. Capacity:
12
3 ' Freeboard
H
Average Height, H (ft)
10
Existing
Levee Top
7' - 9'
8
High Manning's
Roughness
6
4
Medium Manning's
Roughness
Low Manning's
Roughness
2
0
0
200
400
600
800
1000
Approximate Levee Setback (ft)
Pajaro River Levee Setback Required for 100-Year Flood
1200
Basic Project Alternatives
Set-back Levees
Levee Height Increase required to contain the 100-year flood with 3' of Freeboard
Existing Height
Avg
Max
Pajaro River
7.5
11.5
0' Setback
Avg
Max
7.5
9.5
Height Increase
500' Setback
Avg
Max
4.0
7.5
1000' Setback
Avg
Max
2.5
6.5
Note: Roughness based on medium roughness
Height Increase
Existing Height
Avg
Max
Salsipuedes Creek
Corralitos Creek
0' Setback
Avg
Max
200' Setback
Avg
Max
4.5
9.0
5.5
11.0
2.5
6.0
-
-
5.0
9.5
3.5
7.5
Note: Roughness based on existing conditions
Additional Levee Height
3 ' Freeboard
Total Levee Height
Existing Levee Height
July 20, 2001
Basic Project Alternatives
Set-back Levees
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Project ElementProject Element Project Element
Project ElementProject Element
3:
2:
4:
1:
5:
Bypass Channel
Channel
Floodwalls Set-back Levees
Upstream
Excavation
Retention
100-year
100-year
5.0-7.5 Ft
2.5-4.0 Ft
Potential as a stand
alone solution?
Yes
Yes
Potential as a partial
solution?
Yes
Yes
Level of Flood
Protection
Average Height of
structures above
existing levees (if any)
July 20, 2001
Basic Project Alternatives
Bypass Channel
Basic Project Alternatives
Bypass Channel
July 20, 2001
Basic Project Elements
Bypass Channel
• Summary of bypass concept
– Begin bypass overflow at 5-Year to 10-Year flow
– Designed for the current channel capacity
downstream of highway 1
– 1000 foot average bypass width
– Average bypass levee height = 8 feet
– 900 Acres required for bypass to mouth
– 450 Acres required for bypass to Elkhorn Slough
July 20, 2001
Basic Project Alternatives
Bypass Channel
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Project ElementProject Element Project Element
Project ElementProject Element
3:
2:
4:
1:
5:
Bypass Channel
Channel
Floodwalls Set-back Levees
Upstream
Excavation
Retention
100-year
100-year
5.0-7.5 Ft
2.5-4.0 Ft
0-Ft
Potential as a stand
alone solution?
Yes
Yes
No
Potential as a partial
solution?
Yes
Yes
Yes
Level of Flood
Protection
Average Height of
structures above
existing levees (if any)
July 20, 2001
100-year
Basic Project Alternatives
Channel Excavation
Basic Project Alternatives
hannel Excavation
Basic Project Alternatives
Channel Excavation
July 20, 2001
Basic Project Alternatives
Channel Excavation
Comparison of Pajaro River Capacity, Existing and Excavated Condition
With 0 Feet of Freeboard
Reach
Downstream of Highway 1
Upstream of Highway 1
Existing Condition
Capacity
Return
(cfs)
Period
Channel Excavation
Capacity
Return
(cfs)
Period
27,500
20-Years
37,700
43-Years
30,100/33,500
32-Years
41,000/36,200
56-Years
With 3 Feet of Freeboard
Reach
Downstream of Highway 1
Upstream of Highway 1
July 20, 2001
Existing Condition
Capacity
Return
(cfs)
Period
Channel Excavation
Capacity
Return
(cfs)
Period
19,000
10-Years
22,800
14-Years
22,000/24,700
17-Years
30,000/27,000
25-Years
Basic Project Alternatives
hannel Excavation
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Project ElementProject Element Project Element
Project ElementProject Element
3:
2:
4:
1:
5:
Bypass Channel
Channel
Floodwalls Set-back Levees
Upstream
Excavation
Retention
100-year
100-year
5.0-7.5 Ft
2.5-4.0 Ft
0-Ft
NA
Potential as a stand
alone solution?
Yes
Yes
No
No
Potential as a partial
solution?
Yes
Yes
Yes
Yes
Level of Flood
Protection
Average Height of
structures above
existing levees (if any)
July 20, 2001
100-year
14-year
Basic Project Alternatives
Upstream Retention
Basic Project Elements
pstream Retention
• Modify/Add Upper Watershed Storage
– 1975 SCVWD Report - Reservoir System Study
• Allocate flood storage in Uvas, Chesbro, North Fork and
Hernandez Reservoirs - 12,650 af
• New flood storage at Hayes Valley - 15,000af
• Effect = 10% reduction in 100-year flow on Pajaro River
– 1994 Corps Reconnaissance Report
• New flood storage at Mormon and Corralitos sites 10,000 af and 7,000 af
• College Lake modifications - 8,600 af
• Effect = 40%, 55% and 15% reduction in Corralitos
Creek peak flows
July 20, 2001
Basic Project Alternatives
pstream Retention
County Line Reservoir
Basic Project Alternatives
pstream Retention
EVALUATION
CRITERIA
Hydrology and
Hydraulics
Project ElementProject Element Project Element
Project ElementProject Element
3:
2:
4:
1:
5:
Bypass Channel
Channel
Floodwalls Set-back Levees
Upstream
Excavation
Retention
100-year
100-year
5.0-7.5 Ft
2.5-4.0 Ft
0-Ft
NA
NA
Potential as a stand
alone solution?
Yes
Yes
No
No
No
Potential as a partial
solution?
Yes
Yes
Yes
Yes
Yes
Level of Flood
Protection
Average Height of
structures above
existing levees (if any)
July 20, 2001
100-year
14-year
Varies
Basic Project Elements
Basic Flood Protection Elements:
Containment
Walls and/or
Levee Raising
I.
II.
July 20, 2001
Set-back
Levees
By-pass
Channels
Dredging
Upstream
Detention
Does the element provide adequate level of
flood protection?
Regulatory
Feasibility
Concept Plan and Evaluation Framework
II. Environmental and Regulatory Feasibility
EVALUATION
CRITERIA
Environmental
Reg.
Pondand
Turtle
and
California Red Legged
Frog
•Migration
•Spawning
Nesting and foraging
birds
Steelhead Trout:
•Migration
•Spawning
Lagoon Environment
Likelihood of
permitting
Project ElementProject ElementProject ElementProject Element Project Element
4:
3:
2:
5:
1:
Channel Dredging Upstream
Containment Set-back leveesBypass Channel
Retention
Walls
“Living River” or Flood Control Channel ?”
Environmental Permitting Authority Tells the
Story-it’s
both.
Resource
Document/
Effects to be
Category
Agency
Permit Issued
WATER QUALITY
Regional Water
Quality Control
Board
401 Certification
RIVER COORIDOR
Department of Fish
and Game
Streambed
Alteration Permit
FISH
National Marine
Fisheries Service
Biological Opinion
U.S. Fish and
Wildlife Service
Biological Opinion
Dept. of Fish and
Game
Section 2081 Permit
Biological Opinion
• Foraging and Nesting Birds
U.S. Fish and
Wildlife Service
LAND USE
California Coastal
Commission
Coastal Development
Permit/ Concurrence
letter
USF&WS, CAL F&G
Safe Harbor
Agreement
• Steelhead
• Saltwater Goby
WILDLIFE
• California Red Legged Frog
• Pond Turtle
PROJECT
MAINTENANCE
Whe
n
Permit after
CEQA
certification
Permit after CEQA
certification
Considered
Sediment, pollutants, dissolved
oxygen, PH, salinity, temperature
Alteration of river hydraulics &
geomorphology, impacts to plant,
fish, wildlife.
“No jeopardy”
opinion required
for NEPA
Water quality, river channel shapes,
sediment, bank stability, flow
velocities, temperature, spawning,
rearing, and resting areas.
“No jeopardy”
opinion required
for NEPA
Nesting, rearing, foraging habitat,
riparian cover, pools, migration
corridors and barriers.
Level of vegetation approved
in original permit and
EIR/EIS
Pajaro River Reaches
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
July 20, 2001
Pajaro River: Reach 1
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Existing
Levee Width
Pajaro River: Reach 2
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Existing
Levee Width
Pajaro River: Reach 3
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Pajaro River: Reach 4
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Existing
Levee Widths
Pajaro River: Reach 5
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Existing
Levee Width
Pajaro River: Reach 6
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Approximate
Creek Width
130 feet
Kelly
Lake
Pajaro River: Reach 7
Aerial Photography: Copyright 2000 AirPhotoUSA, LLC, All Rights Reserved
Corralitos Creek
Salsipuedes Creek
Stakeholder Meeting #2
July 20, 2001