Meeting Objectives
• Review inundation maps and selected OCOF scenarios
• Validate ART lower scenario maps (1, 2, 3, ft)
• Validate OCOF maps (3 scenarios)
• Summarize inventory of assets at risk
• Present recommendation for 30 draft assets/ explain rationale for their selection
• Begin soliciting feedback on the draft 30 assets
• Confirm asset manager support
Agenda
© ARCADIS11 December 20151
San Mateo County
Shoreline Risk & Vulnerability Assessment
Inundation Scenarios
December 10, 2015
Three sea level rise scenarios selected
• Based on the guidance in the California Coastal
Commission*
• Consistent with local SLR planning efforts
• Reflect conditions today and realistic future
conditions
• Used guidance from the County and
Conservancy and input from the Technical
Working Group
*August 2015 Sea Level Rise Guidance Document: Interpretive Guidelines for
Addressing Sea Level Rise in Local Coastal Programs and Coastal
Development Permits
Three sea level rise scenarios selected
The three selected scenarios are:
• MHHW with 1% AEP storm* with no SLR
(current conditions)
• MHHW with 1% AEP storm* with 3.3 feet SLR
(medium condition)
• MHHW with 1% AEP storm* with 6.6 feet SLR
(high condition)
In addition:
• Mapped Future Erosion Zones on the coast
*1% AEP storm is a storm event with a 1% annual exceedance probability.
MHHW = Mean high high water
Inundation calculated using Our Coast Our
Future (OCOF) Tool
• Online tool for Bay Area flood scenarios Pacific Coast and San Francisco Bay
• Combination of 40 different sea level rise and
storm scenarios, plus a King Tide scenario,
using the USGS Coastal Storm Modeling
System (CoSMoS)
• Interactive flood map including flood extent,
depth, duration, and minimum and maximum
flood potential, wave heights, and current
velocity
Inundation maps - Overview
Inundation maps - Detail
Inundation maps - Detail
OCOF / ART Maps Summary
• OCOF Inundation Maps
– First broad brush look at areas vulnerable to SLR and coastal flooding
– Identify WHERE sea level rise and storm exposure zone is
• Create detailed inventory of most vulnerable assets
• ART Inundation Maps
– Finer scale assessment
– Identify WHEN assets could be impacted
• (e.g., 24 or 36 inches of SLR?)
– Identify HOW they are at risk• (e.g., what are the pathways of inundation? from local or broad overtopping?)
• Methods and tools for San Mateo developed through previous Alameda County ART project
• Multi-agency effort (BCDC, MTC, Caltrans, BART, Alameda County)
• “One Map = Many Futures Approach” 1 water level can represent many possible futures
• Project includes: Vulnerability and risk assessment
Adaptation strategy development
Conceptual engineering of selected adaptation options
Adapting To Rising Tides (ART)
FEMA San Francisco Bay Area Coastal Study
• Large-scale regional modeling to characterize existing coastal hazards (tides, storm surge, and waves)
• Comprehensive data set that provides water level data along the entire complex shoreline
Water Level Analysis – Key Terms• Mean Higher High Water
(MHHW) Typical daily high tide
Frequent inundation (permanent)
• 100-yr (1% annual chance) Stillwater Elevation (SWEL) Extreme high tide + storm surge
Flooding (temporary) event
Wave effects not included
100-Year SWEL
MHHW
Topographic Data• LiDAR collected by USGS in
2010
• 1-meter grid spacing DEM
• DEM modified with As-Built survey data: SFO
Foster City
Redwood Shores
San Mateo
San Mateo SLR Inundation Maps• County Wide Inundation
Mapping (10 scenarios)– MHHW + 12” SLR
– MHHW + 24” SLR
– MHHW + 36” SLR
– MHHW + 48” SLR
– MHHW + 52” SLR
– MHHW + 66” SLR
– MHHW + 77” SLR
– MHHW + 84” SLR
– MHHW + 96” SLR
– MHHW + 108” SLR
Low-lying
areaLow-lying
area
MHHW
Low-lying
area
Low-lying
area
MHHW
MHHW
Sea Level Rise
Permanent
InundationLow-lying
area
Extreme Tide
Temporary
Flooding
Extreme Tide
Temporary
Flooding
Sea Level Rise
Permanent
Inundation
Extreme Tide (temporary)
Sea Level Rise(permanent)
Sea Level Rise + Extreme Tide
MHHW + 12 Inches SLR (King Tide)MHHW + 12 Inches SLR (King Tide)
MHHW + 24 Inches SLR
MHHW + 36 Inches SLR
Shoreline Delineation• Leverage SFEI shoreline
• Delineate structures that currently prevent floodwater conveyance Levees Engineered structures High ground Roadways Etc.
• Delineate natural shorelines and wetlands
Overtopping Potential
• Overtopping: Water level (MHHW or SWEL) exceeds elevation of asset: “Depth of overtopping”.
• Freeboard: Elevation of asset exceeds water level (MHHW or SWEL). Freeboard = the height of the asset above the adjacent water surface.
Overtopping Example
SF Bay
Shoreline Delineation
Identify Critical Pathways
Identify Critical Pathways
© ARCADIS11 December 20151
San Mateo County Sea Level Rise
Vulnerability Assessment
December 10, 2015
Technical Working Group meeting #2
San Mateo County
© ARCADIS11 December 20152
We are here
Asset organization, mapping, and
inventories
Categorize and classify assets
Collect data and information on assets
Create asset exposure maps
Develop asset exposure inventory
Examples of asset types
Police Stations Caltrain Recreational Facilities
Airports Bart Parks
Highways 101, I-380 Businesses Public Health Facilities
Evacuation Routes Cultural Resources Housing
Hazardous Facilities Community Centers State Beaches
Critical Energy
FacilitiesCritical habitat
Schools
Telecom Wetlands Ports
What types of assets are we considering?
Over 120 asset types and this approach
enables consideration of all assets
Framework, which vulnerabilities to address first
Why categorize and classify assets?
Credit: Dave YuhasCredit: Anita Hart
Given the large number of assets in SMC
• Helps us think about things differently
• What does it mean to have a flooded asset?
Source: US Climate Resilience Toolkit
Reedsburg, WI
June, 2008
Part I-Asset Categories
• Airport
• Community land use, services,
facilities
• Contaminated lands
• Energy infrastructure and pipelines
• Ground transportation
• Hazardous materials
• Natural areas
• Parks and recreation areas
• Seaport
• Structural Shorelines
• Storm water
• Wastewater
Assets are organized into the categories identified
in Adapting to Rising Tides approach
Part II-Asset Classes
Assets are organized into classes based on:
Public health, safety, welfare (built assets)
Ecosystem and habitat (natural assets)
Built Assets (ASCE 24-14)
Class Description: Buildings or other assets
I • That represent a low risk to human health in the event of failure (flood)
II • All except those listed in categories I, III, IV
III The failure of which could pose a substantial risk to human health
With the potential to cause a substantial economic impact and/or mass
disruption of day to day civilian life in the event of a flood
IV Essential facilities
The failure of which could pose substantial hazard to the community
Containing highly toxic substances, dangerous to the public
Required to maintain function of other category IV structures
Natural Assets
Class Description
N-W Natural Assets- Wetlands/ Marsh/Estuaries
N-B Natural Assets- Beaches/ Dunes
N- R Natural Assets-Rocky intertidal
N-S Natural Assets-Species of concern
N-O Natural Assets-Other
What types of information did we collect?
• GIS Data from local, state, national datasets
Some more complete than others
County GIS portal has many of the layers
With supplementary information
• Kickoff Meeting
• TWG, PAC
• Stakeholder
discussions
• Draft maps &
inventories reflect data
collected thru
10/21/2015
Do you have additional data?
Let us know!
Maps and inventories tell us what is at risk
And where it is located
DRAFT Asset Exposure Maps- built assets
DRAFT Asset Exposure Maps
Maps intended to tell a story
about where risks are.
DRAFT Asset Exposure Maps
Each map has a
corresponding inventory
Disadvantaged
community
DRAFT Asset Exposure Maps- natural
assets
DRAFT Asset Exposure Inventory
• Developed for each city/region
Identifies population and assets exposed to flood and SLR
Asset Exposure Inventories
San Mateo County at a Glance
Population: 131,722
(42,991 vuln. community)
Fire:11
Police: 3
Schools: 45
Power plants: 4
Beaches: 1,024 acres
Wetlands: 9,000 acres
Emergency room: 1
Credit: Roy Latham
Fitzgerald Marine Reserve
Assets at risk
Questions?
Asset Vulnerability Profiles (AVPs)
What is an AVP?
Purpose
Selection process
Next steps
Source: Mydoctor.kaiserpermanente.orgSource: Baytrail.org
AVP is a more detailed look into an asset
• Current vulnerability
Exposure
Sensitivity
Adaptive Capacity
Consequences
• Future vulnerabilities
Flooding and erosion
• Regulatory oversight
• Adaptation options
AVPs provide insight into
Vulnerabilities
Consequences
Stakeholders
On the ground
Types of vulnerabilities facing county assets.
Range and magnitude of potential impacts.
Cross section of individuals, agencies affected by
loss of an asset or service; challenges.
Better understanding of what could be
inundated and what that means.
Analysis AVP selection does not represent priorities.
AVP Process is interactive
Asset maps and inventories
Select 30 assets using criteria
Gather input on draft asset selection
Develop asset vulnerability profiles
AVP Selection Criteria
• Geographic coverage
• Representative across:
Asset types and categories
Agencies and jurisdictions
Sectors – private & public
• Service area
• Availability of data
• Asset owner support
• *see handout for how preliminary
selection meets criteria South San Francisco Water Quality Control Plant.
Photo by ssf.net
Ravenswood Salt Pond, Photo by baytrail.org
Preliminary AVP Selection
Preliminary AVP Selection
Name1 Mirada West-Coastal Trail
2 Mid Coastside Sewer Authority
WWTP
3 State Route 1 (segment)
4 Fitzgerald Marine Reserve
5 State Route 1 (segment)
6 Linda Mar/Pacifica State Beach
7 Mussel Rock Disposal Site/Dolger
8 Oyster Point Marina
9 Sanitary Pump Station no. 8
10 South San Francisco Water Quality
Control Plant
11 SamTrans Island (Depot)
12 Highline Canal Tide Gate
13 Caltrain/BART near SFO
Name14 Burlingame Fire Station no. 36
15 US Highway 101/92
16 San Mateo Police Department
17 Silicon Valley Clean Water WWTP
18 South Bay Salt Ponds/Bair Island
Area Wetlands
19 Shoreway Environmental
Center/Recology
20 San Carlos Airport
21 Port of Redwood City
22 InnVision Homeless Shelter
23 Kaiser Permanente Medical Center
24 Ravenswood Substation
25 State Route 84/101
26 East Palo Alto
What’s next? (This is where you all come in)
• Feedback and input on the assets (survey)
• Gather existing information on the assets
• Questionnaire
• Asset manager interviews
• Site visits
We need your help to make this a success
Pacifica during King Tides Photo by Jack Sutton, all rights reserved
Information we’ll need from you
• Exposure, sensitivity
and adaptive capacity
of the asset
Physical
Characteristics
Construction and site
drawings, elevation
Foundation materials
Known vulnerabilities
• Consequences
Historical flooding
documentation and
photos
Past damages
experienced
Impacts from loss of
service
Replacement or repair
costs
Questions?