HomeMy WebLinkAbout2017-08-15; City Council; ; Overview of Sea Level Rise Vulnerability Assessment (DEV 15-061) - staff presentation, City Council discussion and feedback to staff on the Sea Level Rise Vulnerability ACA Review ~
~ CITY COUNC I L
~ Staff Report
Meeting Date:
To:
From:
Staff Contact:
Subject:
August 15, 2017
Mayor and City Council
Kevin Crawford, City Manager
Carl Stiehl, Associate Planner
carl.stiehl@carlsbadca.gov or 760-602-4605
Overview of Sea Level Rise Vulnerability Assessment (DEV 15-061) -staff
presentation, City Council discussion and feedback to staff on the Sea
Level Rise Vulnerability Assessment
Recommended Action
That the City Council 1) receive the staff presentation on an overview of the Sea Level Rise
Vulnerability Assessment, 2) discuss the assessment, and 3) provide feedback to staff that will
guide in the preparation of the comprehensive Local Coastal Program and Zoning Ordinance
Update.
Executive Summary
The City of Carlsbad Sea Level Rise Vulnerability Assessment presents a city-specific sea level rise
analysis to support a comprehensive update to the Local Coastal Program and Zoning Ordinance.
The assessment evaluates the degree to which important community assets on or near the coast
and lagoons are susceptible to, and unable to, accommodate adverse effects of projected sea
level rise. Asset exposure, sensitivity and adaptive capacity are evaluated for two future planning
horizons (years 2050 and 2100). To address identified vulnerabilities, a menu of adaptation
strategies are described in the assessment that provide a range of options available for the city
and others to consider for how to adapt to future impacts from sea level rise.
During the City Council meeting on this item, staff and consultants will present an overview of
the Sea Level Rise Vulnerability Assessment, including an overview of community involvement
and regional sea level rise planning efforts. Following the presentation, staff requests that the
City Council discuss the information, ask questions and provide feedback that will guide staff in
preparing adaptation policies and regulations that will be incorporated into the Local Coastal
Program and Zoning Ordinance Update.
An overview of the Sea Level Rise Vulnerability Assessment was also presented to the Planning
Commission prior to this City Council meeting. This report was prepared prior to the Planning
Commission meeting; therefore, a summary of the Planning Commission's discussion will be
provided to the City Council separate from this report.
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#6
Discussion
BACKGROUND
As described in the City of Carlsbad Sea Level Rise Vulnerability Assessment, the earth is predicted
to warm and sea levels will rise as a result of the thermal expansion of water and increased
contributions from melting glaciers. While the California coast regularly experiences erosion,
flooding, and significant storm events, sea level rise will exacerbate these natural forces, and lead
to environmental, economic, and social impacts.
In 2008, Governor Schwarzenegger issued an Executive Order (S-13-08) directing state agencies
to consider sea level rise as part of planning projects. In response to the executive order, the
California Coastal Commission began efforts to encourage and require local jurisdictions to
evaluate and plan for sea level rise. To assist in this effort, the Coastal Commission and Ocean
Protection Council developed a grant program that provides funds to assist local jurisdictions in
planning for sea level rise.
In 2014, the California Coastal Commission and the Ocean Protection Council awarded the city
two grants ($228,000 total) to conduct a sea level rise analysis and update of the city's Local
Coastal Program and Zoning Ordinance. In 2015, the City Council approved an agreement with a
consultant team -Michael Baker International and Moffatt and Nichol -to assist the city with
the project.
SUMMARY OF SEA LEVEL RISE VULNERABILITY ASSESSMENT
The initial work on the project included preparation of a draft Sea Level Rise Vulnerability
Assessment, which evaluates two future planning horizons (years 2050 and 2100) and identifies
the projected sea level rise and the assets that are likely to be impacted in each planning horizon.
To identify areas and assets vulnerable to sea level rise, the assessment uses the United States
Geologic Survey Coastal Storm Modeling System (CoSMoS) version 3.0, which was released for
use in November 2015. CoSMoS 3.0 makes detailed predictions of coastal flooding and erosion
based on existing and future sea level scenarios in southern California. For the year 2050,
CoSMos 3.0 utilized a sea level scenario of 1.6 feet; and for year 2100, a sea level rise scenario of
6.6 feet was utilized. These sea level rise scenarios (1.6 feet and 6.6 feet) roughly align with the
National Research Council's 2012 sea level rise projections (2 feet in year 2050 and 5.5 feet in
year 2100).
Based on the sea level rise scenarios of 1.6 feet in year 2050 and 6.6 feet in year 2100, CoSMos
3.0 provides a model of an extreme coastal storm in southern California and identifies the areas
that may be vulnerable to waves and inundation. Areas that may not have been impacted by a
storm event in recent memory may be impacted in the future.
The vulnerable assets identified in the Sea Level Rise Vulnerability Assessment include beaches,
public access ways, parks, parcels of land (which may contain vulnerable structures), critical
infrastructure (like utilities), transportation infrastructure, and environmentally sensitive
resources. The assessment also provides a range of strategies that the city can consider to adapt
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to the impacts of sea level rise. Adaptation strategies include, but are not limited to, beach sand
nourishment, construction of winter berms/dunes, landward relocation of assets, revised
development regulations, development limitations, and coastal armoring. The assessment's
analysis and range of potential adaptation strategies are intended to support the development
of Local Coastal Program policies and regulations. The Local Coastal Program will guide how the
city adapts and protects natural resources, property and infrastructure from the impacts of
future sea level rise.
COASTAL COMMISSION AND REGIONAL COORDINATION
City staff has coordinated at regular monthly meetings with Coastal Commission staff while
preparing the Sea Level Rise Vulnerability Assessment and the Local Coastal Program update.
Coastal Commission comments received on the previous draft in 2016 have been considered and
addressed in the draft final vulnerability assessment attached to this staff report. Additional
comments have been received from the Coastal Commission staff in July 2017 and will be
reviewed and addressed as necessary to finalize the vulnerability assessment to be used with the
Local Coastal Program update.
In addition to coordinating with Coastal Commission staff, the city has participated in regional
sea level rise planning efforts. City staff has been an active participant with the San Diego Climate
Collaborative on the Greater San Diego Resilient Coastlines Project. The project is designed to
connect several local sea level rise initiatives through a regional strategy, fill existing knowledge
gaps that are barriers to resilience planning and implementation, and further engage scientific
experts and community members in building coastal resilience for the San Diego region.
Fiscal Analysis
There is no anticipated fiscal impact from this item.
Next Steps
As mentioned above, the Sea Level Rise Vulnerability Assessment will be used to develop sea
level rise planning/adaptation policies and regulations. City staff and consultants, in consultation
with Coastal Commission staff, will develop draft policies and regulations that will be brought to
the Planning Commission and City Council for consideration as part of the Local Coastal Program
and Zoning Ordinance update.
Staff estimates that the draft updated Local Coastal Program Land Use Plan will be scheduled for
public hearings with the Planning Commission and City Council late this year or early next year.
The draft updated Zoning Ordinance will follow with hearings anticipated in Spring 2018.
Environmental Evaluation (CEQA)
The preparation of a Sea Level Rise Vulnerability Assessment (research, analysis, preparation of
a draft document, and public outreach) does not involve or result in any disturbance to the
environment. The assessment is exempt from the California Environmental Quality Act (CEQA)
in accordance with CEQA guidelines section 15306, which describes the following as being
exempt from environmental review:
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" ... basic data collection, research, experimental management, and resource evaluation activities
which do not result in a serious or major disturbance to an environmental resource. These may
be strictly for information gathering purposes, or as part of a study leading to an action which a
public agency has not yet approved, adopted, or funded."
Public Notification
In an effort to inform and seek input from the Carlsbad community on the topic of sea level rise,
various outreach efforts have been implemented, including:
• Public review of the first draft of the Sea Level Rise Vulnerability Assessment
• Two public workshops
• Presentations to community groups
• Targeted outreach to affected property owners
Outreach efforts and input received are summarized in Exhibit 2.
Exhibits
1. City of Carlsbad Sea Level Rise Vulnerability Assessment May 2017
2. Sea Level Rise Community Participation
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CITY OF CARLSBAD
SEA LEVEL RISE VULNERABILITY
ASSESSMENT
DRAFT FINAL
May 2017
Exhibit 1
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TABLE OF CONTENTS
1. INTRODUCTION ............................................................................................................................. 1
2. SCOPE OF WORK ........................................................................................................................... 4
3. COASTAL HAZARD MAPPING ................................................................................................... 5
4. VULNERABILITY AND RISK ASSESSMENT METHODS ...................................................... 6
5. VULNERABILITY AND RISK ASSESSMENT ......................................................................... 10
5.1. Planning Zone 1 ...................................................................................................................... 10
5.1.1. Beaches ...................................................................................................................................... 11
5.1.2. Public Access Ways ................................................................................................................... 12
5.1.3. Parcels ....................................................................................................................................... 12
5.1.4. Critical Infrastructure ............................................................................................................... 12
5.1.5. Transportation Infrastructure (roadway, bike/pedestrian lanes) .............................................. 13
5.1.6. Environmentally Sensitive Lands ............................................................................................... 13
5.2. Planning Zone 2 ...................................................................................................................... 16
5.2.1. Beaches ...................................................................................................................................... 17
5.2.2. Public Access Ways ................................................................................................................... 17
5.2.3. State Parks ................................................................................................................................. 17
5.2.4. Parcels ....................................................................................................................................... 18
5.2.5. Critical Infrastructure ............................................................................................................... 18
5.2.6. Transportation Infrastructure .................................................................................................... 18
5.2.7. Environmentally Sensitive Lands ............................................................................................... 19
5.3. Planning Zone 3 ...................................................................................................................... 23
5.3.1. Beaches ...................................................................................................................................... 24
5.3.2. Public Access Ways ................................................................................................................... 24
5.3.3. State Parks ................................................................................................................................. 24
5.3.4. Parcels ....................................................................................................................................... 24
5.3.5. Transportation Infrastructure .................................................................................................... 25
5.3.6. Environmentally Sensitive Lands ............................................................................................... 25
6. ADAPTING TO SEA LEVEL RISE ............................................................................................. 28
6.1. Adaptation Strategies .............................................................................................................. 28
6.1.1. The Do Nothing Approach ......................................................................................................... 28
6.1.2. The Protection Approach ........................................................................................................... 28
6.1.3. The Accommodation Approach .................................................................................................. 29
6.1.4. The Retreat Approach ................................................................................................................ 29
6.2. Secondary Impacts .................................................................................................................. 30
6.2.1. Secondary Impacts of Doing Nothing ........................................................................................ 30
6.2.2. Secondary Impacts of Protection Strategies .............................................................................. 30
6.2.3. Secondary Impacts of Accommodation Strategies ..................................................................... 31
6.2.4. Secondary Impacts of Retreat Strategies ................................................................................... 32
6.2.5. Maladaptation ........................................................................................................................... 32
6.3. Understanding Tradeoffs ......................................................................................................... 32
6.4. Potential Adaptation Strategies for Carlsbad .......................................................................... 34
6.4.1. Adaptation Policy Strategies ..................................................................................................... 34
6.4.2. Adaptation Project Strategies .................................................................................................... 38
6.4.3. Adaptation Strategy Costs ......................................................................................................... 38
7. CONCLUSIONS AND RECOMMENDATIONS ........................................................................ 40
8. REFERENCES ................................................................................................................................ 43
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ATTACHMENTS
Attachment A. Sea Level Rise Science and Coastal Hazard Mapping Assumptions
Attachment B. Year 2100 Sea Level Rise Hazard Maps
TABLE OF FIGURES
Figure 1. Vulnerability Assessment Planning Areas ................................................................................. 3
Figure 2: Village Shoreline Hazards in Year 2050 ................................................................................. 14
Figure 3: Buena Vista Lagoon Hazards in Year 2050 ............................................................................ 15
Figure 4: Tamarack Planning Area – Year 2050 ..................................................................................... 20
Figure 5: Terramar / Palomar Planning Area – Year 2050 ...................................................................... 21
Figure 6: Agua Hedionda Lagoon Planning Area – Year 2050 ............................................................... 22
Figure 7: Southern Shoreline Planning Area – Year 2050 ...................................................................... 26
Figure 8: Batiquitos Lagoon Planning Area – Year 2050 ....................................................................... 27
TABLE OF TABLES
Table 1: 2012 National Research Council Sea Level Rise Scenario versus CoSMoS 3.0 Sea Level Rise Scenarios .................................................................................................................. 5
Table 2: Vulnerability Rating System ...................................................................................................... 7
Table 3: Planning Zone 1 Vulnerability Assessment Summary ............................................................. 11
Table 4: Planning Zone 2 Vulnerability Assessment Summary ............................................................. 16
Table 5: Planning Zone 3 Vulnerability Assessment Summary ............................................................. 23
Table 6. Rough Order of Magnitude Costs for Coastal Protection Strategies ....................................... 39
Table 7. City-Wide Sea Level Rise Vulnerability Summary ................................................................. 40
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1. INTRODUCTION
There is broad agreement in the scientific community that the earth is predicted to warm and that sea levels will rise as a result of the thermal expansion of water and increased contributions from melting glaciers
(Coastal and Ocean Working Group of the California Climate Action Team (CO-CAT) 2013; California Coastal Commission 2015). Though there is consensus among the scientific community on these concepts, the timing and severity of sea level rise is relatively uncertain and is dependent on region-specific
conditions. The uncertainty in the sea level rise projections is a result of future global emissions of carbon dioxide (a function of future social behavior) and the non-linear response of the ocean to warmer
temperatures and contributions from land-based ice sources. Thus, planning for sea level rise must consider
high and low estimates of sea level rise. Planning for a range of potential future conditions provides the City of Carlsbad with the tools to make current and future planning decisions that allow the city’s resources to adapt to changing conditions.
This vulnerability assessment presents a Carlsbad-specific sea level rise analysis to support an update to the city’s Local Coastal Program and Zoning Ordinance. The assessment evaluates the degree to which
important community assets are susceptible to, and unable to, accommodate adverse effects of projected
sea level rise. The assessment identifies the assets that are likely to be impacted and the causes and components of each asset’s vulnerability. This document is considered “living” as it is to be updated as the
best available science changes and modeling improves.
The study area was divided into four shoreline and three lagoon planning areas, which were incorporated into three larger planning zones for the purposes of discussion. These planning zones are shown in Figure
1 and are described as follows:
Planning Zone 1 – Includes one shoreline and one lagoon planning area in the northern portion of Carlsbad, as follows:
The Village Shoreline – Approximately 1.4 miles of shoreline from the northern city boundary to Tamarack Avenue. From north to south, the sandy shoreline is backed by a low-lying residential area that transitions to a higher-relief, beach-front roadway (Carlsbad Boulevard). Approximately
80% of this portion of shoreline is armored with various coastal structures (i.e., rip rap, revetments and seawalls).
Buena Vista Lagoon – Includes the southern shore of the lagoon within Carlsbad city limits
(approximately 5.3 miles of shoreline). Land uses adjacent to this portion of the lagoon include residential, commercial and open space. The lagoon is primarily a freshwater system due to a weir system that controls tidal flushing at its outlet. The San Diego Association of Governments
(SANDAG) is currently considering the restoration of this lagoon. Alternatives being considered include removal of this weir system to allow for increased tidal flow into the lagoon. None of this
lagoon’s shoreline within the City of Carlsbad is armored.
Planning Zone 2 – Includes two shoreline and one lagoon planning area in the central portion of Carlsbad, as follows:
Tamarack/ Warm Waters Shoreline - Approximately 1 mile of shoreline from Tamarack Avenue
to the northern boundary of the Terramar neighborhood. This shoreline area consists of sandy beach backed by a coastal roadway (Carlsbad Boulevard) and pedestrian promenade. Approximately 71%
of this shoreline is armored with a vertical seawall. The shoreline armoring along this reach is either
vertical seawalls or revetment structures. The area also includes two jetty systems (four total structures) to control the mouth of the Agua Hedionda Lagoon and water-cooled effluent from the
Encina Power Station. The power station’s water effluent control structures are referred to as the
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“warm water jetties” and include a short groin on the downdrift side of these features to control erosion. In the near future, the Encina Power Station (a water-cooled facility) will be replaced by
an air-cooled, gas-fired, peaker plant that will not require seawater for cooling. The Carlsbad
Seawater Desalination Plant will use the Encina Power Station water intake/discharge system once Encina Power Station begins this conversion.
Terramar/Palomar Shoreline – Approximately 1.4 miles of shoreline from the northern boundary
of the Terramar neighborhood to Las Encinas Creek. The area consists of a bluff-top residential community (Terramar) to the north and transitions to a beach-front roadway (Carlsbad Boulevard)
to the south. Bluffs along this portion of shoreline are mostly moderate to high-relief bluffs with
the exception of its lowest point at the mouth of Las Encinas Creek. Approximately 15% of this portion of shoreline, primarily the bluffs in the northern portion (in the vicinity of Terramar) is
armored with seawalls protecting Carlsbad Boulevard and residential homes at Terramar.
Agua Hedionda Lagoon – Includes approximately 6.3 miles of lagoon shoreline, as well as lagoon waters and adjacent lands, which includes the 186-acre Agua Hedionda Lagoon Ecological
Reserve, owned by the State of California and managed by the California Department of Fish & Wildlife. The lagoon is used for commercial and recreational purposes. Land uses adjacent to the lagoon include residential, open space, agriculture, commercial, as well as the power station and
desalination plant. Approximately 37% of the lagoon shoreline is armored, primarily with rock revetments to stabilize inlet channels.
Planning Zone 3 - Includes one shoreline and one lagoon planning area in the southern portion of
Carlsbad, as follows:
Southern Shoreline – Approximately 2.4 miles of shoreline from Las Encinas Creek to the southern city boundary at South Carlsbad State Beach. The shoreline generally consists of narrow sandy
beaches backed by moderate to high relief bluffs. The bluff tops are developed with camping facilities owned and operated by the State of California Department of Parks and Recreation. This
portion of shoreline also includes the mouth of the Batiquitos Lagoon, which is controlled by a jetty
system. Approximately 9% of this portion of shoreline is armored, primarily with rock revetment at Las Encinas Creek and scattered rip rap within the State Parks.
Batiquitos Lagoon - Includes approximately 7.4 miles of lagoon shoreline, as well as the lagoon
waters and all adjacent lands. The lagoon was previously restored and is a nature preserve. Lands surrounding the lagoon have high-relief and are developed with residential, commercial and open
space uses. Approximately 11% of the lagoon shoreline is armored, primarily with rock revetments
in the vicinity of inlets and bridges.
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FIGURE 1. VULNERABILITY ASSESSMENT PLANNING AREAS
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2. SCOPE OF WORK
As part of a contract with the City of Carlsbad to conduct analysis of sea level rise and to update the city’s Local Coastal Program and Zoning Ordinance, Moffatt & Nichol and Revell Coastal, as sub-consultants to
Michael Baker International, are conducting the following services for the city:
1. Analysis and mapping of sea level rise hazards – Utilize Coastal Storm Modeling System (CoSMoS) 3.0 results to map sea level rise hazards for two future planning horizons (2050 and
2100).
2. Risk assessment – Determine and prioritize the relative risks to assets within each of the planning
areas based on potential consequences and likelihood of impacts. Develop adaptation strategies to
minimize risks from hazards and to protect coastal resources.
3. Stakeholder and agency coordination – Attend community stakeholder and technical workshops, public hearings, and coastal commission meetings to support the Local Coastal Program and
Zoning Ordinance updates.
This vulnerability assessment will inform the development of sea level rise adaptation strategies, as well as
the update to the city’s Local Coastal Program and Zoning Ordinance.
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3. COASTAL HAZARD MAPPING
This section summarizes how coastal hazards were mapped in this vulnerability assessment. See Attachment A for more detailed information on data inputs, assumptions and limitations.
Carlsbad’s exposure to future rates of sea level rise was determined using preliminary results from the CoSMoS 3.0 model. CoSMoS is a multi-agency effort led by the U.S. Geological Survey (USGS) to make detailed predictions (meter scale) of coastal flooding and erosion based on existing and future climate
scenarios for southern California. The modeling effort depicts coastal flooding, shoreline change and bluff response to a composite, 100-year wave event in combination with various rates of sea level rise and
baseline water levels (i.e., high tide, storm surge, sea level anomaly and river discharge).
The results from four CoSMoS sea level rise scenarios (i.e., 0.5 meters [m], 1.0 m, 1.5 m and 2.0 m) were made available in the preliminary (Phase I) CoSMoS data release in November 2015. The CoSMoS 0.5-m and 2.0-m sea level rise scenarios roughly align with the projected high sea level rise from the 2012 National
Research Council’s report for the 2050 and 2100 planning horizons. Therefore, these sea level rise scenario results were used as the basis for this vulnerability analysis. A comparison of the National Research
Council’s 2012 sea level rise projections for the planning horizons compared to the CoSMoS scenarios used
is shown in Table 1.
TABLE 1: 2012 NATIONAL RESEARCH COUNCIL SEA LEVEL RISE SCENARIO VERSUS COSMOS 3.0 SEA LEVEL RISE SCENARIOS
Year
2012 National Research Council Sea Level Rise Projections CoSMoS 3.0 Sea Level Rise Scenario
Difference (CoSMoS vs. 2012 National Research Council – High SLR) (ft) Projection (ft) Uncertainty (ft, +/-) Low Range (ft) High Range (ft) 2050 0.9 0.3 0.4 2.0 0.5 m (1.6 ft) 0.4
2100 3.1 0.8 1.5 5.5 2.0 m (6.6 ft) 1.1
CoSMoS provides projections of shoreline erosion, coastal flooding and bluff erosion in the city. These results were used to represent inundation, coastal flood and bluff hazard zones. In addition to these hazards,
a fluvial flood hazard zone was developed by Moffatt & Nichol to more accurately depict areas subject to future river floods. The hazard zones used in this analysis are described as follows:
Inundation Hazard Zone – Sea level rise will result in the migration of existing coastal and lagoon
shorelines in the landward direction. The inundation hazard zone is an area that will be subject to daily wetting and drying associated with tides. For beaches, CoSMoS future mean sea level (located at a beach elevation of 2.9 feet, MLLW) shoreline positions were used as a proxy for the future inundation
hazard zone. For the lagoons, an elevation of mean higher high water (5.3 feet, MLLW) was used as a proxy for the future inundation hazard zone.
Bluff Hazard Zone – Rising sea levels may result in the increased erosion of coastal bluffs due to more
frequent exposure to wave attack. CoSMoS bluff erosion projections were used to represent the bluff hazard zone for the two planning horizons.
Flood Hazard Zone – Includes coastal and lagoon zones, described as follows:
Coastal – coastal flooding events are typically short in duration (i.e., hours) and occur episodically in association with extreme wave events (e.g., 100-year return period event). These events, in
combination with high tides represent the coastal flood hazard zone. CoSMoS flooding limits were
used to represent the coastal flood hazard zone for the two planning horizons.
Fluvial (lagoon) – sea level rise has the potential to result in higher water levels in the city’s lagoons
during significant precipitation events (i.e., 100-year return period river flood). Moffatt & Nichol
found that CoSMoS underestimates the potential fluvial flood limits within the city. A revised fluvial flood hazard zone was generated based on the results of existing numerical models of the
lagoons within the city.
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4. VULNERABILITY AND RISK ASSESSMENT METHODS
Methodology for assessing vulnerability and risk were based on the following guidelines developed to assist with adaptation planning efforts aimed at preparing for the effects of climate change and sea level rise:
California Coastal Commission Sea Level Rise Policy Guidance adopted by the California Coastal Commission, August 12, 2015.
Preparing for Climate Change: A Guidebook for Local, Regional, and State Governments, published
by ICLEI-Local Governments for Sustainability (Snover, A.K. et al. 2007).
California Adaptation Planning Guide, Planning for Adaptive Communities prepared by CalEMA, now
known as CalOES, and the California Natural Resources Agency (CalEMA 2012).
A vulnerability assessment was performed to identify impacts that sea level rise and coastal hazards, as described in Section 3, may have on existing resources and assets within the city. Vulnerability was assessed as a function of an asset’s exposure, sensitivity, and adaptive capacity. A numerical rating system was used
to develop an overall vulnerability score for each asset category at the 2050 and 2100 time horizons. The definition of these terms and the rating system used are described in the Table 2. A vulnerability rating of
low (score of 3-4), moderate (score of 5-7), or high (score of 8-9) was assigned for each asset category
based on the sum of ratings for exposure, sensitivity and adaptive capacity.
While the vulnerability assessment was performed to identify impacts from sea level rise, a risk assessment
was performed to evaluate the magnitude of these impacts and likelihood of occurrence. The risk
assessment was performed qualitatively to help the city manage risk related to sea level rise in their planning and decision-making process. Assessment of risk can be subjective and is not intended to establish priorities
for future planning.
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TABLE 2: VULNERABILITY RATING SYSTEM
Exposure is the degree to which an asset or resource is susceptible to coastal hazards such as flooding, inundation and bluff erosion for a given sea level rise scenario. The mapped hazard zones, shown in Section 5 and Attachment B were used to rate the
level of exposure to a given asset or category.
Category Rating Explanation Exposure Low (1) Asset or resource partially exposed to flooding, inundation or bluff erosion.
Moderate (2) Asset or resource moderately exposed to flooding, inundation or bluff erosion.
High (3) The majority of the asset or resource is exposed to flooding, inundation or bluff erosion.
Sensitivity is the degree to which the function of an asset or resource would be impaired (i.e., weakened, compromised or damaged) by the impacts of sea level rise. Example: Carlsbad Boulevard in the vicinity of Tamarack Beach has a high sensitivity to
sea level rise because even minor flooding can cause significant disruption in service.
Category Rating Explanation Sensitivity Low (1) Asset or resource is not affected or minimally affected by coastal hazards at a given sea level rise scenario.
Moderate (2) A moderately sensitive asset or resource may experience minor damage or temporary service
interruption due to coastal hazard impacts, but can recover relatively easily.
High (3) A highly sensitive asset or resource would experience major damage or long-term service interruptions due to coastal hazard impacts, requiring significant effort to restore/rebuild to original condition.
Adaptive capacity is the inherent ability of an asset or resource to adjust to sea level rise impacts without the need for significant intervention or modification. Example: Some wetland habitat has a high adaptive capacity due to their ability to naturally migrate
landward and upward with rising water levels provided adequate space exists.
Category Rating Explanation Adaptive Capacity High (1) Asset or resource can easily be adapted or has the ability and conditions to adapt naturally.
Moderate (2) Asset or resource can be adapted with minor additional effort.
Low (3) Asset or resource has limited ability to adapt without significant changes.
The following vulnerability assessment evaluates exposure, sensitivity, and adaptive capacity for different
asset categories in each of the three planning zones. The assessment includes evaluation of shoreline area vulnerabilities, as well as lagoon vulnerabilities. Sea level rise impacts within the shoreline planning areas
are discussed in terms of inundation (area of future daily tidal influence as a result of beach erosion), flooding (as a result of wave run-up associated with extreme waves), and bluff erosion. Additionally, inland waters at the Buena Vista, Agua Hedionda, and Batiquitos Lagoons were evaluated for inundation
(shoreline position change as a result of daily tidal inundation) and fluvial flooding (from extreme precipitation events) as a result of sea level rise.
In order to assess the vulnerability in each planning zone, assets were sorted into defined categories. These
asset categories and general vulnerability assumptions are described below:
Beaches – The exposure of sandy beaches to sea level rise impacts is high with anticipated erosional impacts with any sea level rise scenario. In a natural setting, beaches can be thought to have a high
adaptive capacity because they will naturally adjust to a rising sea level if adequate sand exists in the system. However, the adaptive capacity of beaches can be low in areas where beaches are backed by
coastal structures or development or where insufficient sand exists in the system. Continuation of sand
bypassing projects, such as the Oceanside Harbor and Agua Hedionda projects, are important in restoring littoral transport of sand to beaches downdrift of these sediment blocking features.
Continuation of episodic beach nourishment projects will also be important to offset regional sediment
deficits.
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Public Access Ways – Public access ways consist of vertical access ways to and lateral access ways along the beach and lagoons. A city GIS data layer was used to identify these vertical and lateral public
access ways.
State Parks – Numerous state park facilities exist along the city’s shoreline and consist of public day-use parking lots and campgrounds. State park facilities are recognized as important assets to the city in
terms of economic and recreation value. The state park facilities also provide an important low cost
visitor-serving amenity with prime access to coastal resources. Though economic impacts to the physical structures (i.e., asphalt paving, restrooms and some utilities) within the affected state parks
would be relatively low, loss of these amenities would be significant since space for these features to
move inland is not available.
Parcels - Parcels evaluated for sea level rise impacts include privately held lots of various land uses or
zoning. Current city zoning data was used to categorize the parcels into their respective zones. Parcels
generally have a low adaptive capacity and high sensitivity though these ratings can be affected by the life expectancy of the development, the permit history and the physical condition of any shoreline
protective device that may exist. Additionally, the adaptive capacity of buildings could potentially be moderate for some parcels with finished floors on an elevated building pad. Note that impacts to parcels may not necessarily represent impacts to the physical buildings on that parcel.
Critical Infrastructure (i.e., water/sewer/electrical utilities) – Critical infrastructure includes facilities necessary to run the city effectively and efficiently since loss of water, sewer or power would significantly disrupt quality of life for residents. This infrastructure typically has a high sensitivity and
low adaptive capacity.
Transportation Infrastructure (roadways, bike/pedestrian paths, trails) – Roadways are generally highly sensitive to flooding hazards as even minor amounts of flooding on roads can cause significant
traffic delays and potentially disrupt emergency service vehicles and evacuation routes. Maintenance and repair requirements may also increase after significant flooding and erosion events (similar to the
bluff erosion repair work occurring along Carlsbad Boulevard at Las Encinas Creek). Roadways
typically have a low adaptive capacity in that significant costs are associated with relocation or raising of these structures.
Environmentally Sensitive Lands – Environmentally sensitive lands include wetlands, riparian areas,
coastal prairies, woodlands and forests, and other natural resources in the coastal zone. These lands can have a high adaptive capacity in areas where adequate space exists for them to naturally shift landward
to a rising sea level. Steep topography and existing development in the coastal zone present challenges
for the landward migration of many of these lands in the City of Carlsbad. Thus, these areas are generally described as having a low adaptive capacity in the city.
A particular asset’s exposure to sea level rise was characterized in terms of hazard type and quantity of assets impacted for each planning horizon.
Some resources impacted by sea level rise are difficult to quantify; thus, a qualitative analysis is provided
below to generally describe how these assets may be affected by sea level rise. These resources include
visual resources, cultural resources, saltwater intrusion into groundwater resources and lifeguard services. These resources are described below:
Visual Resources – Visual resources in the city include views of the beaches, bluffs, and the Pacific Ocean. Sea level rise is not anticipated to affect the existing viewing opportunities of the bluffs and ocean in the city, however, beaches may be impacted as a result of accelerated erosion if no
management actions are taken to mitigate these impacts (e.g., beach nourishment). Without such actions, beaches would become narrower and beach views would be impacted. Views of the ocean
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may also be impacted if coastal structures are built to protect assets from sea level rise or if structures are raised in height to accommodate sea level rise. Design standards in designated scenic areas can be
implemented to protect visual resources while minimizing hazards.
Cultural (historical, archaeological and paleontological) Resources – Exposure of historical sites to coastal hazards can lead to irreplaceable loss of cultural heritage. Identified historical sites in the City
of Carlsbad were determined to not be at risk to sea level rise hazards through year 2100.
Archaeological and paleontological resources in the city may be vulnerable to sea level rise hazards. Maps of these resources are not made publicly available for their protection. New development requires
a site-specific evaluation of potential sea level rise impacts to these resources. Monitoring programs
and plans may be imposed on new development where artifacts may be vulnerable to sea level rise. Additionally, consultation with Native American tribes and State Historic Preservation Officer (SHPO)
would be required if cultural resources are found to be at risk to sea level rise on a new development
site.
Saltwater Intrusion – As sea levels rise, saltwater migrates inland through the soil and underground
pathways into groundwater resources. Research suggests that sea level rise is likely to degrade fresh groundwater resources in certain areas. The degree of impact will vary due to local hydrogeological conditions. Unconfined aquifers are generally found to be the most vulnerable to saltwater intrusion
from sea level rise. Groundwater is not used for potable or irrigation purposes in the City of Carlsbad. Thus, potential saltwater intrusion impacts because of sea level rise is not considered significant.
Lifeguard Services – Most lifeguard facilities in the City of Carlsbad are temporary and seasonal.
Lifeguard services in the city are predominately managed by State Parks. These temporary facilities may be impacted by sea level rise as a result of accelerated beach erosion if no management actions are taken to mitigate these impacts (e.g., beach nourishment). Without such actions, beaches would become
narrower and lifeguard facilities may need to be relocated.
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5. VULNERABILITY AND RISK ASSESSMENT
Results of the vulnerability assessment are discussed by planning zone in this section. Shoreline protective devices were considered in different ways for the various hazard zones in the CoSMoS model. A summary
of how these structures were considered in the modeling is provided below. A more detailed description of these assumptions and limitations is provided in Attachment A.
Inundation Hazard Zone (Coastal) – This zone represents the results from the CoSMoS shoreline
erosion model. This model included coastal structures (rip rap, revetments and seawalls) and coastal infrastructure as a non-erodible layer. Thus, shoreline erosion stops once the beach erodes to the point where it encounters the coastal structure or infrastructure. This assumes the structure serves to protect
upland assets from frequent wave attack, which may not be the case in all areas. Thus, inundation hazards may be understated in some areas where this non-erodible layer was set. A more detailed
analysis of structures approached by this hazard zone may be warranted in some areas.
Inundation Hazard Zone (Lagoon) – Shoreline protection structures are not included in the modeling of this hazard zone. However, since this lagoon area is a tidal system (no wave driven flooding and
erosion), these results are not anticipated to be greatly affected by the lack of these structures.
Bluff Hazard Zone – The CoSMoS model did not include bluff shoreline protection structures in the city. Examples of bluff protection structures that were excluded include coastal structures (seawalls,
revetments, riprap) and bluff stabilization treatments that exist in the community of Terramar. The
CoSMoS model states that coastal structures were not included if the armoring was low enough to be easily overwashed. Determination as to whether armoring was easily overwashed was subjective and
was determined by the USGS. Not accounting for these bluff protection structures in the city likely overestimates bluff erosion hazards in areas.
Flood Hazard Zone (Coastal) – Coastal structures were implicitly captured in the CoSMoS model
when structures were large enough (e.g., revetments in the Village Planning Area) to be captured in the
topographic data set used for the regional study. Small scale features, such as vertical seawalls along Carlsbad Boulevard in the Tamarack Planning Area, were not captured in the model due to the
resolution of the topographic data used. Coastal flooding limits are likely overstated in areas where these small scale coastal structures were not captured. A more detailed analysis of this structure would be needed to more accurately define the flood hazard zone in these areas.
Flood Hazard Zone (Lagoon) – Shoreline protection structures are not included in the modeling of this hazard zone. However, since this a tidal system (no wave driven flooding and erosion), these results
are not anticipated to be greatly affected by the lack of these structures.
Year 2050 and 2100 results are presented and discussed in this section. For simplicity, vulnerability graphics are provided in this section for year 2050 only; vulnerability graphics for year 2100 are included
in Attachment B.
5.1. PLANNING ZONE 1
Planning Zone 1 includes the Village Shoreline and Buena Vista Lagoon planning areas. Assets within this zone are vulnerable to inundation, flooding and bluff erosion in the 2050 and 2100 planning horizons. A
summary of the vulnerability assessment rating is provided in Table 3. A discussion of the vulnerability and risk assessment is also provided for each asset category.
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TABLE 3: PLANNING ZONE 1 VULNERABILITY ASSESSMENT SUMMARY
Asset Category Horizon Hazard
Type
Impacted Assets
Exposure
Rating
Sensitivity
Rating
Adaptive Capacity Rating
Vulnerability Rating (Score)
Beaches
2050 Inundation/ Erosion, Flooding
6 acres (erosion) 3 1 3 Moderate (7)
2100 66 acres (erosion) 3 3 3 High (9)
Public Access Ways
2050 Inundation/ Erosion, Flooding
Vertical – 13 access
points Lateral (trails) - 5,039 linear feet
2 2 1 Moderate (5)
2100 Inundation, Flooding
Vertical – 15 access points Lateral (trails) - 9,626 linear feet
3 2 1 Moderate (6)
Parcels
2050 Flooding 145 parcels 1 2 3 Moderate (6)
2100
Inundation,
Flooding, Bluff Erosion
151 parcels 2 3 3 High (8)
Critical Infrastructure
2050 None N/A N/A N/A N/A N/A
2100 Flooding 1 parcel 2 2 3 Moderate (7)
Transportation (Road, Bike,
Pedestrian)
2050 Flooding /
Bluff Erosion
2,915 linear feet 1 3 3 Moderate (7)
2100 3,857
linear feet 2 3 3 High (8)
Environmentally Sensitive Lands
2050 Flooding 124 acres 0 0 3 Low (3)
2100 Inundation, Flooding 125 acres 2 3 3 High (8)
5.1.1. Beaches
Approximately 6 acres of beach area is projected to be impacted by inundation/erosion by year 2050. Beaches are exposed to any rise in sea levels (high exposure) but will continue to provide recreation and
storm protection benefits during this time horizon (low sensitivity). Beaches are formed by natural processes and have the ability to adapt to rising sea levels, assuming sufficient sand supplies exist and there is adequate space for the beach to migrate landward. However, the adaptive capacity of beaches is low in
areas where beaches are backed by coastal structures or development or where insufficient sand exists in the system. This is the case in this planning area. Development backed beaches are common in southern California and in much of the City of Carlsbad. Thus, the overall vulnerability rating for beaches is moderate
for year 2050. This vulnerability poses a moderate risk to the city because there is a high likelihood of beach loss occurring due to sea level rise, but low consequence to overall beach function based on shoreline
change results from the CoSMoS 3.0 model.
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Vulnerability is rated high for beaches in the 2100 horizon due to the significant erosion expected as the beaches are squeezed between rising sea levels and coastal development. This vulnerability poses a high
risk to the city as increased beach erosion will reduce the natural barrier to storm waves and reduce
opportunity for beach access and recreation. There are also economic costs associated with such impacts; beach visitation from both in-town and out-of-town guests results in economic benefits to city businesses
(e.g., retail, restaurants, hotel).
5.1.2. Public Access Ways
Coastal flooding and erosion has the potential to impact vertical (access to) and lateral (access along) beach
access ways in the city. For example, erosion of the beach may create a large scarp (or drop off) at the end
of a beach access stairway. Wave forces during large surf may also physically damage stairways making them impassable temporarily.
A total of 15 vertical beach access ways exist within Planning Zone 1. Most of these beach access ways
(i.e., 13) were determined to be potentially impacted by coastal flooding by year 2050. All 15 were found to be vulnerable to flooding and erosion by year 2100.
Lateral beach access ways in this planning area include trails in the vicinity of Hosp Grove Park and along Carlsbad Boulevard. Approximately 1 mile of trails were found to be vulnerable by year 2050. Approximately 2 miles of trails were vulnerable by year 2100.
The vulnerability of trails in both planning horizons was found to be moderate, owing mostly to the relatively high adaptive capacity of these assets. Beach access ways can generally accommodate flooding and can typically be repaired relatively easily. Similarly, lagoon trails can accommodate some level of
flooding and can be relocated when maintenance costs become too high.
5.1.3. Parcels
Portions of parcels, where buildings are located, along the northern portion of the Village Planning Area
and Buena Vista Lagoon may be exposed to flooding during an extreme event in year 2050. However, the majority of buildings themselves do not appear flooded in this scenario and are fronted by shore protection
in the form of a revetment or seawall (low exposure). Parcels were assigned a vulnerability rating of
moderate since development is typically sensitive to episodic flooding with little adaptive capacity. This vulnerability poses a moderate risk to parcel owners due to the high consequence of flooding impacts on
parcel usage and value. The likelihood of occurrence of this type of impact is relatively low and would only
be expected during extreme storm events.
Vulnerability of parcels is rated high for the 2100 scenario due to the increased exposure and sensitivity of
parcels to flooding, inundation and bluff erosion during an extreme storm event. This poses a high risk to
parcel owners due to the higher consequence of damage under the storm scenario evaluated for the 2100 planning horizon.
5.1.4. Critical Infrastructure
There were no impacts to parcels identified as critical infrastructure for the 2050 planning horizon. A portion of a sewer pump station parcel was found to be exposed to flooding by the 2100-time horizon. This
asset has sensitive electrical components and could fail should flooding of the facility occur. The pump
station was assigned a moderate vulnerability since the pump station itself was not shown to be exposed to flooding. Thus, the likelihood of flooding is low and may only be expected during extreme storm events
(greater than 100-year return period events). However, the flooding of the pump station has the potential to result in sewer spills and service interruptions.
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5.1.5. Transportation Infrastructure (roadway, bike/pedestrian lanes)
Carlsbad Boulevard provides a vital north-south connection and will be partially exposed to flooding and
bluff erosion during extreme storms in the 2050 planning horizon.
Flooding exposure is localized to the Carlsbad Boulevard crossing of Buena Vista Lagoon in an area that has historically experienced
flooding. Bluff erosion potential is identified along the southern
portion of the Village Planning Area from about Pine Avenue to Tamarack Avenue. The bluff hazard assumes that the seawall in this
area fails or is overwhelmed; thus, allowing erosion to continue
landward of this feature. Although Carlsbad Boulevard is only partially exposed, the asset was assigned a moderate vulnerability
in 2050 because of high sensitivity to flooding (temporary service
interruptions) and low adaptive capacity. This is considered a high vulnerability in 2100 because of the vital north-south connection
provided by Carlsbad Boulevard (high consequence).
Vulnerability is considered high for the 2100 planning horizon as the exposure of Carlsbad Boulevard increases. The risk of this impact remains high for the 2100 planning horizon due to service interruptions
or road closures that can result in traffic delays, emergency service delays and loss of evacuation routes. Damage to Carlsbad Boulevard in 2100 would also likely result in higher repair costs.
5.1.6. Environmentally Sensitive Lands
Environmentally sensitive lands (e.g., lagoon, surrounding open lands, etc.) in the Buena Vista Lagoon area are exposed to increased tidal inundation as a result of sea level rise in year 2100 only because of the presence of the inlet weir structure. The weir elevation restricts tidal exchange through year 2050 planning
horizon. Assuming no change to the existing condition, the weir becomes overwhelmed by year 2100 sea levels. Therefore, conditions within the lagoon remain unchanged/unaffected (no exposure and low
sensitivity) by sea levels in the 2050 planning horizon. The vulnerability of environmentally sensitive lands
to sea level rise in 2050 is low.
By 2100, the lagoon would become subject to tides exposing environmentally sensitive lands to daily
inundation (high exposure). These assets are highly sensitive to this exposure as wetland hydrology may be
altered by the rising freshwater-saltwater interface (CalEMA and CNRA 2014) and intertidal and subtidal ecosystems may be affected by changes in water depth and sunlight penetration. Due to the steep
topography and development along the lagoon, the ability for flora and fauna to adapt by migrating
vertically and/or horizontally may be limited (low adaptive capacity). The vulnerability to environmentally sensitive lands in year 2100 is high. The vulnerability poses a high risk to the environmental resources in
the city because impacts to environmentally sensitive lands are likely to occur and may adversely affect the density and diversity of these resources (high consequence). Risk of this vulnerability remains high as the consequence to density and diversity of environmental resources are significant.
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FIGURE 2: VILLAGE SHORELINE HAZARDS IN YEAR 2050 Page 103
FIGURE 3: BUENA VISTA LAGOON HAZARDS IN YEAR 2050 Page 104
5.2. PLANNING ZONE 2
Planning Zone 2 consists of two shoreline planning areas (Tamarack/Warm Water Shoreline and Terramar/
Palomar Shoreline) and the Agua Hedionda Lagoon. Assets within this zone are vulnerable to inundation, coastal flooding and bluff erosion in the 2050 and 2100 planning horizons. A summary of the vulnerability
assessment rating is provided in Table 4. A discussion of the vulnerability and risk assessment is also
provided for each asset category.
TABLE 4: PLANNING ZONE 2 VULNERABILITY ASSESSMENT SUMMARY
Asset Category Horizon Hazard Type Impacted Assets Exposure Rating Sensitivity Rating
Adaptive Capacity Rating
Vulnerability Rating (Score)
Beaches
2050 Inundation/
Erosion, Flooding
7 acres (erosion) 3 1 3 Moderate (7)
2100 26 acres (erosion) 3 3 3 High (9)
Public Access Ways
2050 Inundation/ Erosion,
Flooding
Vertical –
7 access points Lateral
(trails) – 4,036 linear feet
2 2 1 Moderate (5)
2100 Inundation, Flooding
Vertical –
12 access points Lateral
(trails) - 14,941 linear feet
3 2 1 Moderate (6)
State Parks
2050 Flooding / Bluff Erosion
2 parcels 2 1 2 Moderate (5)
2100 2 parcels 3 2 2 Moderate (7)
Parcels
2050 Flooding 370 parcels 2 2 3 Moderate (7)
2100 Inundation, Flooding, Bluff Erosion 451 parcels 3 3 3 High (9)
Critical
Infrastructure
2050 None N/A N/A N/A N/A N/A
2100 Flooding 7 parcels 1 1 3 Moderate (5)
Transportation (Road, Bike, Pedestrian)
2050 Flooding, Bluff Erosion
4,229 linear feet 3 3 3 High (9)
2100 15,326 linear feet 3 3 3 High (9)
Environmentally Sensitive Lands
2050 Inundation, Flooding
392 acres 3 2 3 High (8)
2100 434 acres 3 3 3 High (9)
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5.2.1. Beaches
Approximately seven acres of beach area is projected to be impacted by inundation/erosion in 2050. As stated above, beaches are exposed to any rise in sea levels (high exposure) but will continue to provide recreation and storm protection benefits during this time horizon (low sensitivity). Beaches in this planning
zone are backed by coastal structures and development; thus, have a low adaptive capacity. The overall
vulnerability rating for beaches is moderate for 2050. This impact poses a moderate risk to the city because there is a high likelihood of beach loss occurring due to sea level rise, but low consequence to overall beach
function based on shoreline change results from the CoSMoS 3.0 model.
Vulnerability is rated high for the 2100 horizon due to the significant erosion expected as the beaches are squeezed between rising sea levels and bluffs or coastal structures. This vulnerability poses a high risk to
the city as increased beach erosion will reduce the natural barrier to storm waves and reduce opportunity for beach access and recreation. There are also economic costs associated with such impacts; beach
visitation from both in-town and out-of-town guests results in economic benefits to city businesses (e.g.,
retail, restaurants, hotel).
5.2.2. Public Access Ways
A total of 12 vertical beach access ways exist within Planning Zone 2. A total of seven of these beach access
ways were determined to be potentially impacted by coastal flooding by year 2050. All 12 were found to be vulnerable to flooding and inundation by year 2100.
Lateral beach access ways in this planning area include trails along Agua Hedionda Lagoon and along
Carlsbad Boulevard. Approximately 4,000 feet of trails were found to be vulnerable to flooding by year 2050. Approximately 15,000 feet of trails were vulnerable to flooding by year 2100.
The vulnerability of trails in both planning horizons was found to be moderate, owing mostly to the relatively high adaptive capacity of these assets. Beach access ways can generally accommodate flooding and can typically be repaired relatively easily. Similarly, lagoon trails can accommodate some level of
flooding and can be relocated when maintenance costs become too high.
5.2.3. State Parks
The Tamarack State Beach parking lot becomes partially exposed to flooding during extreme storm events
by 2050. The shoreline position/Inundation Hazard Zone is well seaward of the parking lot (i.e., wide sandy beach) in this scenario. State Park lands in the southern Terramar Planning Area are exposed to bluff erosion in 2050. The sensitivity of State Park lands varies in this planning area. The Tamarack State Beach parking
lot has a low sensitivity and high adaptive capacity since it can tolerate episodic flooding during extreme storms while remaining functional at other times. The overall vulnerability rating for State Park lands is
considered moderate due to the varied levels of sensitivity and adaptive capacity. This vulnerability poses
a relatively low risk in 2050 since the consequence of episodic flooding/erosion during extreme storms will have a limited effect on access and recreational opportunities within the State Park.
Exposure to flooding increases in year 2100 and complete flooding of the Tamarack State Beach parking
lot can be expected during extreme storms events. The shoreline position/Inundation Hazard Zone has eroded to the existing revetment in this area by this time; thus, no beach exists in this scenario. Since
shoreline erosion is projected to stop at the existing revetment line (set as non-erodible in the CoSMoS
model), no erosion of the bluff landward of the parking lot occurs. Exposure to bluff erosion in the southern Terramar planning zone also increases. The overall vulnerability rating for state park lands will increase in
2100 but is still considered moderate. This vulnerability poses a moderate risk in 2100 since the
consequence of more frequent flooding and erosion could result in permanent impacts to recreational opportunities within the state park.
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5.2.4. Parcels
A number of residential parcels in the vicinity of Terramar Point were determined to be exposed to bluff erosion hazards in the 2050 sea level rise scenario. Portions of parcels along the northern shoreline of Agua Hedionda Lagoon may also be exposed to flooding during an extreme event in year 2050 (moderate
exposure). Parcels were assigned a vulnerability rating of moderate since development is typically sensitive
to episodic flooding with little adaptive capacity. This vulnerability poses a moderate risk to parcel owners due to the high consequence of flooding impacts on parcel usage and value. The likelihood of occurrence
of this type of impact is relatively low and would only be expected during extreme storm events.
Vulnerability of parcels is rated high for the 2100 scenario due to the increased exposure and sensitivity of parcels to flooding and bluff erosion during an extreme storm event. Residential parcels along Terramar
Point and the northern shoreline of Agua Hedionda Lagoon were found to be highly exposed to coastal hazards in 2100. The Hubbs Sea World Research Institute, the Carlsbad AquaFarm and the YMCA facility
are also impacted as flood and tidal waters encroach onto these parcels. This poses a high risk to property
owners due to the higher consequence of damage and disruption of operations during the 2100 planning horizon.
5.2.5. Critical Infrastructure
There were no impacts to parcels identified as critical infrastructure for the 2050 planning horizon. The Encina Power Station and the desalination plant parcels were identified as being partially exposed to fluvial
flooding from Agua Hedionda Lagoon as a result of sea level rise in 2100. The Encina Power Station and
the desalination plant appear minimally impacted (low sensitivity) as the flooding does not appear to encroach onto critical facilities. However, confirmation of the future uses of the intake/discharge system
relative to flood risks is needed to fully understand this vulnerability. Note that the Encina Power Station is scheduled to be demolished by 2020; thus, the vulnerability of this existing facility is negligible. The existing power station will be replaced with a new facility (Carlsbad Energy Center Project) that uses peaker
plant technology; the new facility will be located between the railroad and Interstate 5. The Agua Hedionda
Sewer Lift Station and future Carlsbad Energy Center Project (both located between the railroad and Interstate-5) are outside the coastal hazards mapped for the 2050 and 2100 scenarios. However, a project-
specific sea level rise analysis may be warranted for these projects depending on specific components being proposed. Critical infrastructure was assigned a moderate vulnerability due to the low adaptive capacity and uncertainty regarding future uses of the intake/discharge system.
5.2.6. Transportation Infrastructure
Approximately 4,229 linear feet of Carlsbad Boulevard within Planning Zone 2 is exposed to bluff erosion
hazards during the 2050 scenario (high exposure). Carlsbad Boulevard provides a vital north-south linkage
within the city; thus, its sensitivity to sea level rise is high. The adaptive capacity of the road is low since raising or relocating it may be challenging. This is considered a high-risk vulnerability because of the vital
north-south connection provided by Carlsbad Boulevard (high consequence).
Vulnerability remains high for the 2100 planning horizon as 15,326 linear feet of Carlsbad Boulevard are exposed to bluff erosion and flooding during an extreme storm event. The risk of this vulnerability remains
high for the 2100 planning horizon due to service interruptions or road closures that can result in traffic
delays, emergency service delays and loss of evacuation routes. Damage to infrastructure due to hazards identified in 2100 may result in major infrastructure repair or relocation costs.
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5.2.7. Environmentally Sensitive Lands
Environmentally sensitive lands (e.g., lagoon, surrounding open lands, etc.) in the Agua Hedionda Lagoon area are exposed to increased tidal inundation and flooding with any rise in sea levels (high exposure). These assets are moderately sensitive to this exposure as wetland hydrology may be altered by the rising
freshwater-saltwater interface (CalEMA and CNRA 2014) and intertidal and subtidal ecosystems may be
affected by changes in water depth and sunlight penetration. Due to the steep topography and development along the Agua Hedionda Lagoon, the ability for flora and fauna to adapt by migrating vertically and/or
horizontally may be limited (low adaptive capacity). This high vulnerability poses a high risk to the environmental resources in the city because impacts to environmentally sensitive lands are likely to occur and may adversely affect the density and diversity of these resources (high consequence).
A high vulnerability rating was also assigned for the 2100 time horizon as adaptive capacity remains limited. However, despite the large increase in sea level rise between 2050 and 2100, the overall impacted
acreage increased by less than 10%. Risk of this vulnerability remains high as the consequence to density
and diversity of environmental resources are significant.
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FIGURE 4: TAMARACK PLANNING AREA – YEAR 2050 Page 109
FIGURE 5: TERRAMAR / PALOMAR PLANNING AREA – YEAR 2050 Page 110
FIGURE 6: AGUA HEDIONDA LAGOON PLANNING AREA – YEAR 2050 Page 111
5.3. PLANNING ZONE 3
Planning Zone 3 consists of the Southern Shoreline Planning Area and the Batiquitos Lagoon. Assets within
this zone are vulnerable to inundation, coastal flooding and bluff erosion in both planning horizons (2050 and 2100). A summary of the vulnerability assessment rating is provided in Table 5. A discussion of the
vulnerability and risk assessment is also provided for each asset category.
TABLE 5: PLANNING ZONE 3 VULNERABILITY ASSESSMENT SUMMARY
Asset Category Horizon Hazard Type Impacted Assets Exposure Rating Sensitivity Rating
Adaptive Capacity
Rating
Vulnerability Rating (Score)
Beaches
2050
Inundation/
Erosion, Flooding
14 acres (erosion) 3 1 2 Moderate (6)
2100 Inundation/Erosion,
Flooding
54 acres (erosion) 3 2 2 Moderate (7)
Public Access Ways
2050 Inundation,
Flooding
Vertical – 6 access points
Lateral (trails) – 4,791 linear
feet
2 2 1 Moderate (5)
2100 Inundation,
Flooding
Vertical – 10 access points Lateral (trails) - 14,049
linear feet
3 2 1 Moderate (6)
State Parks
2050 Flooding, Bluff
Erosion
4 parcels 2 3 3 High (8)
2100 4 parcels 3 3 3 High (9)
Parcels
2050 Flooding, Bluff
Erosion
49 parcels 1 1 1 Low (3)
2100 55 parcels 1 1 1 Low (3)
Transportation (Road, Bike,
Pedestrian)
2050 Bluff
Erosion
1,383
linear feet 1 3 3 Moderate (7)
2100 Flooding, Bluff
Erosion
11,280
linear feet 2 3 3 High (8)
Environmentally Sensitive Lands
2050 Inundation, Flooding
572 acres 3 2 2 Moderate (7)
2100 606 acres 3 3 3 High (9)
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5.3.1. Beaches
Approximately 14 acres of beach area is projected to be impacted by inundation/erosion in 2050. Beaches are exposed to any rise in sea levels (high exposure) but will continue to provide recreation and storm protection benefits during this time horizon (low sensitivity). Beaches in this planning area are backed by
unarmored coastal bluffs. Sand derived from the natural erosion of the bluff as sea levels rise may be
adequate to sustain beach widths, thus, beaches in this reach were assumed to have a moderate adaptive capacity. The overall vulnerability rating for beaches is moderate for 2050. This impact poses a moderate
risk to the city because there is a moderate likelihood of beach loss occurring due to sea level rise, but low consequence to overall beach function based on shoreline change results from the CoSMoS 3.0 model.
Vulnerability is rated moderate for the 2100 horizon due to the significant amount of erosion expected as
the beaches are squeezed between rising sea levels and bluffs. Assuming the bluffs are unarmored in the future, sand derived from bluff erosion may sustain some level of beaches in this planning area. A complete
loss of beaches poses a high risk to the city as the natural barrier from storm waves is lost as well as a
reduction in beach access, recreation and the economic benefits the beaches provide.
5.3.2. Public Access Ways
A total of 10 vertical beach access ways exist within Planning Zone 3. Six of these beach access ways were
determined to be potentially impacted by coastal flooding by year 2050. All 10 were found to be vulnerable to flooding and inundation by year 2100.
Lateral beach access ways in this planning area include trails along Batiquitos Lagoon and along Carlsbad
Boulevard. Approximately 5,000 feet of trails were found to be vulnerable by year 2050. Approximately 14,000 feet of trails were vulnerable by year 2100.
The vulnerability of trails in both planning horizons was found to be moderate, owing mostly to the relatively high adaptive capacity of these assets. Beach access ways can generally accommodate flooding and can typically be repaired relatively easily. Similarly, lagoon trails can accommodate some level of
flooding and can be relocated when maintenance costs become too high.
5.3.3. State Parks
A majority of the South Carlsbad State Beach day-use facilities and campgrounds (separated into four
parcels) were determined to be exposed to bluff erosion by the 2050 sea level rise scenario (moderate exposure). This resource is considered to have a high sensitivity since bluff erosion could significantly impair usage of the facilities. Though economic impacts to the physical structures within South Carlsbad
State Beach would be relatively low, the loss of this park would be significant since adequate space for the park to move inland is not available (low adaptive capacity). State parks was assigned a high vulnerability
in the 2050 planning horizon. State park facilities are recognized as important assets to the city in terms of
economic and recreation value as well as providing low-cost visitor serving amenities. This vulnerability poses a high risk to coastal access, recreation, and tourism opportunities in this planning area.
In 2100, bluff erosion of South Carlsbad State Beach day-use facilities and campgrounds become more
severe and the South Ponto State Beach day-use area becomes exposed to coastal flooding during extreme events. The sensitivity of the South Ponto day-use area is low because impacts to usage will be temporary
and no major damage to facilities would be anticipated. Vulnerability and risk to State Parks remains high
by 2100 due to the impacts to South Carlsbad State Beach in combination with flooding impacts to South Ponto.
5.3.4. Parcels
Portions of privately held parcels within Batiquitos Lagoon may be exposed to flooding during an extreme event by year 2050 (low exposure). These parcels include undeveloped lands and a golf course on the north
side of the lagoon. No buildings are flooded under this scenario; thus, sensitivity is considered low.
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Adequate space seems to exist to accommodate sea level rise (high adaptive capacity). Overall vulnerability
is considered low. Due to the relatively minor consequence and low likelihood of occurrence the risk of this vulnerability is also low.
A total of 55 parcels were found to be impacted by year 2100. These parcels are open space, planned
communities and transportation corridors. Impacted open space and planned communities are undeveloped
(i.e., buildings not present), thus, vulnerability and risk to these land uses and function are considered low. Impacted transportation corridor parcels are owned by the North County Transit District. The rail line is
elevated on a dike and bridged over the lagoon. Impacts to these parcels are not considered significant.
5.3.5. Transportation Infrastructure
Southbound Carlsbad Boulevard is exposed to bluff erosion in the vicinity of its intersection with Avenida
Encinas and near Las Encinas Creek (low exposure). Bluff erosion recently resulted in emergency shore protection work along Carlsbad Boulevard in the vicinity of Las Encinas Creek. The sensitivity is high
since bluff erosion hazards could significantly impact usage of transportation infrastructure. Right of way
does appear available on the landward side of the southbound roadway at Las Encinas Creek. However, modifying the roadway alignment would result in significant costs (low adaptive capacity). The overall
vulnerability is considered moderate at the 2050 time horizon. Damage to the southbound lanes of Carlsbad
Boulevard poses a high risk due to the potential service interruptions and associated repair costs along this vital north-south connection (high consequence).
Approximately 11,280 linear feet of transportation infrastructure may be exposed to bluff erosion and
flooding by the 2100 scenario. This includes both northbound and southbound lanes of Carlsbad Boulevard in the vicinity of Las Encinas Creek and Batiquitos Lagoon, La Costa Avenue along the south side of
Batiquitos Lagoon, and a private road within North Ponto State Beach Campgrounds. The sensitivity of all roadway segments is high because of the significant disruption to transportation circulation during these events. It is not likely that temporary flooding events will result in the need for major repairs to the roadway,
but repairs due to bluff erosion could be significant. The adaptive capacity of these roadways is low since
raising or relocating them would be costly. Damage to Carlsbad Boulevard from bluff erosion and flooding poses a high risk due to the potential service interruptions and associated repair costs along these routes
(high consequence).
5.3.6. Environmentally Sensitive Lands
Environmentally sensitive lands (e.g., lagoon, surrounding open lands, etc.) in the Batiquitos Lagoon are
exposed to increased tidal inundation with any rise in sea levels (high exposure). These assets are moderately sensitive to this exposure as wetland hydrology may be altered by the rising freshwater-
saltwater interface (CalEMA and CNRA 2014) and intertidal and subtidal ecosystems may be affected by
changes in water depth and sunlight penetration. Due to the topography and development conditions in Batiquitos Lagoon, it is anticipated that most flora and fauna may be able to adapt by migrating vertically
and/or horizontally, keeping pace with the rate of sea level rise up to 2050 (moderate adaptive capacity).
The overall vulnerability of environmentally sensitive lands is moderate in 2050. The vulnerability poses a high risk to the environmental resources in the city because impacts to environmentally sensitive lands are
likely to occur and may adversely affect the density and diversity of these resources (high consequence).
Due to the steep topography and development along the lagoon, the ability for flora and fauna to adapt by migrating vertically and/or horizontally may be limited in 2100 (low adaptive capacity). Thus, a high
vulnerability rating was assigned for the 2100 horizon. Despite the large increase in sea level rise between
2050 and 2100, the overall impacted acreage increased by only 6%. Risk of this vulnerability remains high as the consequence to density and diversity of environmental resources is significant.
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FIGURE 7: SOUTHERN SHORELINE PLANNING AREA – YEAR 2050 Page 115
FIGURE 8: BATIQUITOS LAGOON PLANNING AREA – YEAR 2050 Page 116
6. ADAPTING TO SEA LEVEL RISE
Adaptation to sea level rise, and other results of climate change, involves taking appropriate actions to
prevent or minimize the adverse effects of climate-induced impacts. Adaptation planning involves a range of policies, programmatic measures and specific engineered projects that can be taken in advance of the
potential impacts, or reactively, depending on the degree of preparedness, the willingness to tolerate risk,
financial capacity and political acceptability. Effective adaptation planning will improve community resilience to natural disasters and climate change.
Adaptation strategies, according to Coastal Commission Sea Level Rise Policy guidance (CCC 2015),
generally fall into four main categories: do nothing, protect, accommodate and retreat. These strategies are generally described Section 6.1 below. When considering which strategy (or combination of strategies) is
most appropriate in a particular circumstance, it is important to consider the associated secondary impacts
(e.g., loss of beach resulting from the use of seawalls) and trade-offs (i.e., who/what will benefit and who/what will be adversely impacted?). Sections 6.2 and 6.3 describe the secondary impacts and trade-
offs associated with the various adaptation approaches. The adaptation strategies that may be most effective in Carlsbad are then presented in Section 6.4.
Many of the adaptation strategies described below can be integrated into Local Coastal Program policies
and implemented through zoning regulations.
6.1. ADAPTATION STRATEGIES
6.1.1. The Do Nothing Approach
Choosing to “do nothing” or following a policy of “non-intervention” can be considered an adaptive
response. Doing nothing results in the need to react when sea level rise impacts occur. The reactive approach involves emergency response, attempts to maintain the status-quo and respond to impacts caused
by episodic storm events and other sea level rise impacts. Reactive efforts can be more costly than other adaptation strategies, and the clean-up post disaster is often lacking in vision and leads to reconstruction of the same types of non-resilience strategies.
6.1.2. The Protection Approach
Protection strategies employ some sort of engineered structure or other measure to protect or flood-proof development (or other coastal resources) in its current location without changes to the development or
resources themselves. Protection strategies can be further divided into “hard” and “soft” defensive measures. Examples of a hard approach would be to construct a seawall or revetment, while a soft approach may be to nourish beaches with sand or build sand dunes.
Although the California Coastal Act allows for potential protection strategies for “existing development” (i.e., development that was in existence when the Coastal Act was enacted in 1976), it also directs that new
development (i.e., development after 1976) be sited and designed to avoid hazards and not require future
protection that may alter a natural shoreline. When issuing a permit to allow a hard protective structure, such as a seawall, for the purpose of protecting a building or other improvement, the Coastal Commission
has imposed conditions that identify when a building/improvement no longer requires protection or
encroaches onto state tidelands, then the hard protective structure must be removed.
Currently, much of the coastline of Carlsbad is armored with seawalls, revetment or rip rap. Documenting
the age, height, condition, and permit conditions of both protective structures and the development they
were built to protect will be important to determine the remaining life expectancy of protective structures, and the longer-term viability of maintaining these structures in a regulatory sense. Additional engineering
work, including increasing the elevation of existing protective devices, and maintenance will likely be
required in the future to ensure the structure effectively protects against the impacts of sea level rise.
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When evaluating whether or not the protection approach is an appropriate adaptation strategy, it is important
to evaluate the long-term viability of protective structures and any potential impacts to coastal resources that could result if protective structures are maintained in place (see Section 6.2 for more information related to secondary impacts). It is critical to also understand the possible impacts to coastal resources that could
manifest over time if protective structures are maintained in place. Passive erosion of the beach as a result
of a coastal structure is one of the most significant to consider. Understanding how fast these impacts could occur, the magnitude of those impacts, and the efficacy of any measures that could mitigate those impacts
is critical for determining whether – and for how long – the protection approach is appropriate for use in the city and, therefore, what policy and development standards should be included in the Local Coastal Program.
Given the negative impacts of hard protective structures (as described in Section 6.2), more attention is being focused on the implementation and resulting effectiveness of soft solutions. Soft options, sometimes
called living shorelines or natural infrastructure, include sediment management to reduce erosion by
building wider beaches (beach nourishment) and higher sand dunes, as well as cobble placement. These soft solutions tend to mimic natural processes and can help lessen erosion and flooding while also providing
habitat, water filtration and recreational opportunities. The effectiveness of soft solutions to mitigate the
impacts of sea level rise is the topic of ongoing research and pilot projects. Generally, these solutions are found to be effective for shoreline protection when applied at appropriate areas. More study would be
needed to determine the effectiveness of soft solutions to address sea level rise vulnerabilities in Carlsbad.
6.1.3. The Accommodation Approach
Accommodation strategies employ methods that modify existing or design new developments or
infrastructure in a manner that decreases hazard risks and, therefore, increases the resiliency of the development/infrastructure to the impacts of sea level rise.
On an individual project scale, these accommodation strategies include actions such as elevating structures,
retrofitting or using materials to increase the strength of development/infrastructure such as: the ability to
handle additional wave impacts; building structures that can easily be moved and relocated; or using additional setback distances to account for acceleration of erosion.
On a community scale, accommodation strategies include appropriate land use designations, zoning regulations or other measures that require the above types of actions; as well as strategies such as clustering development in less vulnerable areas or requiring mitigation actions to protect natural areas.
6.1.4. The Retreat Approach
Retreat strategies relocate or remove existing development out of hazard areas and limit the construction of
new development in vulnerable areas. These strategies include creating land use policies and zoning
regulations that encourage building in less hazardous areas and the gradual removal and relocation of existing development as it becomes threatened or damaged. There are a variety of mechanisms to implement
this approach including: acquisition and buy-out programs, transfer of development rights programs and
removal of structures where the right to protection was waived (i.e., via permit condition). Other retreat strategies include use of conservation easements or rolling easements that limit or prohibit development in
order to allow coastal erosion processes to occur into upland property; as well as hazard overlay zones that
require all properties within the zone assume the risk of being in a hazardous environment, and identify triggers indicating when development needs to be relocated.
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6.2. SECONDARY IMPACTS
Almost all adaptation strategies have secondary impacts associated with them. Some of these are minor
issues, such as short-term habitat impacts following removal of infrastructure or undergrounding of overhead power lines. Other strategies can be difficult and expensive, such as the burial of beaches under
rocks following construction of revetments, or a retrofit to a critical infrastructure component. Another
example of secondary impacts is the potential impacts to visual resources associated with adaptation strategies that elevate buildings or armor coastal bluffs to protect against elevated levels of flooding. The
following information describes some of common secondary impacts that may result from sea level rise
adaptation strategies.
6.2.1. Secondary Impacts of Doing Nothing
Doing nothing can be thought of an adaptive response and one that can result in secondary impacts. Initial
costs are low for this strategy; however, the long-term costs of maintenance of existing coastal structures and emergency repair of vulnerable coastal infrastructure (i.e., roadways) can be costly. Therefore, an
analysis of long-term maintenance and emergency repair of existing and future vulnerable areas should be
considered. Note that this analysis should include more frequent maintenance and emergency repairs over time to account for sea level rise.
Coastal resources can also be impacted by doing nothing as a result of beaches and environmentally sensitive lands being squeezed between rising water levels and coastal infrastructure. Areas where these resources will change significantly or be lost by doing nothing should be considered in the long-term.
6.2.2. Secondary Impacts of Protection Strategies
6.2.2.1. Soft Protection Strategies
The impacts of soft protection solutions, such as sediment management through beach nourishment and
sand dunes, are generally limited to cost, as the maintenance costs of soft protection solutions can be higher than hard protective solutions. Sediment management can be costly, and ongoing sand supplies for large
projects have become scarcer, which has resulted in high construction costs. Secondary impacts from
sediment management vary depending on the volume, frequency and method of placing, but typically include impacts to sandy beach ecosystems, temporary recreational impacts and rocky intertidal habitat
impacts.
6.2.2.2. Hard Protection Strategies
The inevitable impacts associated with hard protective solutions are commonly described within the context
of the following impact categories:
Placement loss – Wherever a hard structure is built, there is a footprint of the structure. The footprint of this structure results in a loss of coastal area known as placement loss. This inevitable impact can
reduce the usable beach for recreation or habitat purposes. For example, a 10-foot high revetment
constructed at a 2:1 slope can occupy 20 feet of usable beach for only the sloping portion of the structure. A vertical seawall or sheet pile groin typically has a smaller placement loss than a revetment
or rubble mound groin.
Passive erosion – Wherever a hard structure is built along a shoreline undergoing long-term net erosion, the shoreline will eventually migrate landward to (and potentially beyond) the structure. The effect of
this migration will be the gradual loss of beach in front of the seawall or revetment as the water deepens and the shore face moves landward. While structures may be temporarily saved, the public beach is
lost. This process of passive erosion is a generally agreed-upon result of fixing the position of the
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shoreline on an otherwise eroding stretch of coast, and is independent of the type of seawall constructed.
Passive erosion will eventually destroy the recreational and habitat beach area unless this area is continually replenished. Excessive passive erosion may impact the beach profile such that shallow areas required to create breaking waves for surfing are lost.
Limits on beach access – Depending on the type of structure, impacts to beach access vary. Typically,
vertical beach access (ability to get to the beach) can be impacted unless there are special features integrated into the engineering design; however, as passive erosion occurs (see above), lateral (along)
beach access is usually impacted.
Active erosion – Refers to the interrelationship between wall and beach whereby, due to wave reflection, wave scouring, "end effects" and other coastal processes, the wall may increase the rate of
loss of beach in front of the structure, and escalate the erosion rates along adjacent unarmored sections of the coast. Active erosion is typically site-specific and dependent on sand input, wave climate, specific
design characteristics and other local factors.
Ecological impacts – Scientific studies have documented a loss of ecosystem services, loss of habitat and reduction in biodiversity when seawall-impacted beaches were compared to natural beaches.
As described above, hard protective solutions can adversely affect a wide range of coastal resources and
uses, and by doing so, may conflict with the policies of the California Coastal Act, as follows:
Hard protective solutions can impede or degrade public access and recreation along the shoreline by
occupying beach area or tidelands and by reducing shoreline sand supply. Protecting the back of the
beach with a protective structure, such as a seawall, ultimately leads to the loss of the beach as coastal erosion from sea level rise continues on adjacent unarmored sections.
Hard protective solutions can also fill coastal waters or tidelands and harm marine resources and biological productivity.
Hard protective solutions can prevent the inland migration of intertidal and beach species during large
wave events. This disruption will prevent intertidal habitats, saltmarshes, beaches and other low-lying
habitats from advancing landward as sea levels rise over the long-term.
Hard protective solutions can degrade the scenic quality of coastal areas and alter natural landforms.
The visual impact of hard protective structures and the aesthetic degradation that results from the loss of beach can have adverse economic and fiscal impacts on the local economy tied to reduced tourism and community character changes.
Recent trends in coastal armoring permitting by the Coastal Commission have been to tie the coastal armoring to the structure it is required to protect, and identifying when that subject structure either no longer
requires the protection or encroaches onto State tidelands. At which time, the coastal armoring is to be
removed.
6.2.3. Secondary Impacts of Accommodation Strategies
The primary secondary impact associated with the accommodation strategy is that it can result in impacts
to visual resources and community character. Raising a building to allow for a floodable first floor can result in ocean and beach views from other portions of the city being lost. Similarly, raising coastal
infrastructure or a coastal structure can impact visual resources to the public and eventually result in a
change in the character of a city.
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Accommodation alone is not always protective of evolving coastal resources. For example, a coastal
building that is raised to avoid being damaged by a future coastal storm does not protect the sandy beach. The beach will erode as sea levels rise underneath the coastal building. The beach condition underneath the building has limited function recreationally and ecologically at this state. Thus, the fate of adjacent coastal
resources should be considered when considering accommodation strategies.
6.2.4. Secondary Impacts of Retreat Strategies
Many communities have relied on setbacks in an effort to reduce hazard risk, and some are currently
experimenting with establishing setback lines that are based on modeled predictions of the future coastline location. Setbacks alone are potentially insufficient protection and create a false sense of security because they may eventually lead to structures being at risk due to the uncertainty in the modeled predictions of the
future coastline. Therefore, to be most effective at minimizing hazard risks, it is important to consider other elements of retreat, such as requiring movable foundations or identifying locations for transfer of
development. Further, establishing clear triggers for action, such as relocation of development, could work
in conjunction with regulatory setback policies. Finally, development located in hazardous areas should assume the risk of being located in a hazardous environment, and waive the right to any future shoreline
armoring.
Another example of secondary impacts from retreat strategies is cost; for example, the use of public acquisition and buy-out programs can be very costly for local, state and/or federal agencies. However, these
costs should be compared against the construction and maintenance of hard engineered solutions and other
adaptation approaches over the long-term.
6.2.5. Maladaptation
Adaptation measures that reduce the ability of people and communities to deal with and respond to climate change over time are called maladaptation. Maladaptation has several characteristics that help identify when it is occurring: 1) It creates a more rigid system that lead property owners and communities into a false
sense of security (i.e., should one of these strategies fail, the consequences could be severe); 2) it increases
greenhouse gas emissions; and 3) it reduces incentives to adapt.
6.3. UNDERSTANDING TRADEOFFS
There are trade-offs associated with the various adaptation strategies, particularly in terms of “who” benefits
from the adaptation strategy. For example, with hard protection strategies, like seawalls, the private property owner takes the greatest benefit through protection of their existing structures; however, as
described in Section 6.2, hard protective solutions have negative impacts. The Coastal Commission has
addressed these negative impacts through the use of in-lieu fees assessed for the loss of recreational beach area and sand supply. The Coastal Commission is also attempting to develop a means to calculate the
replacement value of the sandy beach ecosystem.
For any segment of eroding shoreline, the choice of which adaptation option to implement is affected by multiple interested parties, advisers and decision-makers, such as:
Property owners;
The public (i.e., community members and visitors of the beach);
Experts and consultants (such as civil engineers and geologists);
Government regulators, permitting and compliance officials;
Special interest groups such as chambers of commerce, or non-government organizations (e.g.,
environmental groups, social justice); and
Policy-makers or lawmakers.
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The motivations and constraints of the different interested parties, advisers and decision-makers vary
depending on their relation to the property, their knowledge of different types of shoreline protection options, their stewardship responsibilities, their professional interests, regulatory framework, legal precedence, and local preferences. Thus, often the choice of adaptation strategy involves conflict and
tension between private versus public benefits.
For example, proponents of shoreline protection are usually property owners driven by a desire to preserve upland area and value or by a desire to protect, create, or restore recreational opportunities that a beach may
provide. They seek an outcome that will protect and maximize their uses of the shoreline and their investment. Also, the existence of shoreline protection may reduce property insurance costs, which is another reason property owners may support construction of shoreline protection structures.
Regarding private interests, a key consideration is the Public Trust Doctrine (“public trust”). Public trust ensures that the government holds title to resources for public use, such as coastal shoreline areas between
the high and low tide lines (tidelands). The government is the trustee of tidelands and nearshore waters for
the benefit of the public and maintains this stewardship responsibility even though some of these areas may be privately owned.
The public trust has implications for all decisions regarding shoreline erosion control options that inevitably
produce an impact on public trust lands. The options to benefit public trust interests vary and may also conflict. For example, some erosion control options, such as wetland creation and “living shorelines,” may
impede the public trust interest of navigation while enhancing other public interests such as environmental
quality and fishery habitat. Other erosion control options, such as breakwaters and jetties, may degrade the quality of nearshore environments (e.g., reduce their quality as fish habitat), but maintain navigation. If
protecting natural shorelines, wetlands, and beaches is a priority in an area, then some erosion control options, such as vertical seawalls, may not be feasible. In other areas, protection of private or public infrastructure interests might be paramount and lead to erosion control options that conflict with
conservation of natural areas.
An additional issue that often complicates the subject of trade-offs is public access. Not only does common law recognize the riparian right of access to navigable waters, it also guarantees the public’s right to
navigate on waters. This latter concept may create obstacles for adaptation strategies that interfere unreasonably with the public’s access to navigable waters, as well as the public navigation interest. Erosion control options, such as beach creation, may also create new opportunities for public access to the fringes
of navigable waters.
Sea level rise adaptation strategies may also result in conflicts and trade-offs when applying the Coastal
Act to a proposed adaptation strategy. Coastal Act Section 30235 allows for the construction of shoreline
protection, such as a seawall, when it is necessary to protect “existing structures” (i.e., existing when the Coastal Act was enacted in 1976) or public beaches from erosion. However, the construction of shoreline
armoring may cause impacts that are inconsistent with other Coastal Act requirements; for example, Coastal
Act Section 30253 prohibits new development from in any way requiring “the construction of protective devices that would substantially alter natural landforms along bluffs and cliffs.” Shoreline protective
devices can also conflict with other coastal resources and uses that the Coastal Act protects, such as public
access and recreation along the shoreline.
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6.4. POTENTIAL ADAPTATION STRATEGIES FOR CARLSBAD
6.4.1. Adaptation Policy Strategies
Chapter 7 of the Coastal Commission’s Sea Level Rise Policy Guidance describes many sea level rise adaptation alternatives. Of those, the following list represents adaptation strategies that can be considered
in Carlsbad, but does not specify if a particular strategy should be applied or when and where a strategy
could be implemented. As part of the city’s Local Coastal Program update, policies and regulations will be created to implement adaptation strategies that address the vulnerabilities identified in this study. When
developing policies and regulations, and when determining the appropriate adaptation to implement in a
given circumstance/point in time, consideration should be given to the long-term effectiveness of a particular adaptation strategy, as well as and the economic, ecological, and other potential costs/impacts.
Additionally, some projects will be subject to additional analysis of potential sea level rise and coastal
hazard impacts. Based on the findings of this study, it is recommended that the city consider the following adaptation policy strategies:
1. Continue to participate in regional beach nourishment projects. Beach nourishment has been
found to be an adequate approach to keep pace with low levels of sea level rise (Flick and Ewing 2009). Beach nourishment requires placement of sand from a source outside of the littoral zone;
thus, providing a new source of sand to the system. Beach nourishment opportunities should continue to be pursued within Carlsbad. Continued participation and coordination with the SANDAG regional beach nourishment program should be included, as regional actions tend to
provide for larger project opportunities.
2. Continue existing sand bypassing program. The beaches in Carlsbad, especially those adjacent
to infrastructure (such as portions of Carlsbad Boulevard) and/or residential development, have a
low adaptive capacity. Continued sand bypassing and beach nourishment projects improve the adaptive capacity rating of these beaches. Continuation of sand bypassing activities from Oceanside
Harbor, which presently occur annually, is important. The city should support the continuation of
this dredge bypass program.
3. Continue to implement local opportunistic sand management plan. Presently, the city has
multiple sources of beach quality sand and other sediments available from local sources. It is
suggested that the city continue to implement its opportunistic sand use program that identifies appropriate sediment characteristics and locations for placing the sediment to achieve the maximum
benefit to recreational resources and coastal dependent uses along the city waterfront. Currently
there are two routine sources of sediment in the city - Agua Hedionda Lagoon that produces 200 - 400 thousand cubic yards, on a 2-3 year cycle and Batiquitos Lagoon - that produce 50-100
thousand cubic yards, on a 4-5-year cycle. In addition, future development or restoration projects may produce additional sediment, such as the Buena Vista Lagoon restoration project.
4. Consider constructing winter berm or dune system. Residential properties in the Village
Planning Area may consider a winter berm or dune system fronting their properties to provide protection during extreme events. A winter berm would protect the homes from wave run-up vulnerabilities from winter storms and could be lowered in the summer to allow for unimpeded
recreational uses. A dune would be a more persistent, year-round feature that would offer similar protection. Further analysis would be needed to determine if adequate space exists and to properly
size this feature. Assuming a winter berm or dune system were technically feasible and could be
approved consistent with the Coastal Act on the beach fronting the Village Planning Area, a beach-wide approach would be more appropriate than implementing these on a private, per parcel basis. A geologic hazard abatement district could be established as a potential funding mechanism. The
percentage share could be based on the proportional contributions made by each landowner to the
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construction costs. The costs could be shared based on the proportion of land frontage, or some
other arrangement agreed by the landowners submitting the development application.
5. Consider landward relocation of public assets. Consideration should be given to landward relocation of development or infrastructure in areas where adequate space exists. Carlsbad
Boulevard in the vicinity of Las Encinas Creek is an example of a potential landward relocation
opportunity. Consideration of landward relocation should take place at the time of planned capital improvements or after repetitive emergency repairs. The landward relocation analysis should
consider the cost to maintain or protect the asset and the associated secondary impacts of doing so, versus the cost to relocate over the asset’s design life. The analysis should also consider the coastal resource and economic impact as well as the potential value of added recreational opportunities
that could result from such relocation.
6. Adopt hazard overlay zones. This strategy would identify areas that are vulnerable to a set of
specific hazards. Within each hazard zone, there could be a restriction on the types of development
(e.g., residential), a basis for setback lines, or triggers for site-specific technical analyses or studies (e.g., geologic report triggers, slope stability analysis).
7. Require site-specific coastal hazard reports. For properties located in a coastal hazard overlay
zone, this strategy would require a coastal development permit application to include a site-specific coastal hazard investigation that evaluates the exposure of the property to existing and future
coastal hazards.
8. Management of prioritized existing revetments. This strategy would employ hard protection only if allowable and if no feasible less damaging alternative exists. In some cases, caissons and
pilings may also be considered hard shoreline protective devices. Under current law, shoreline protection for existing structures in danger from erosion may be allowed if coastal resource impacts are avoided or minimized and fully mitigated where unavoidable. On intensely developed,
urbanized shorelines, if the removal of armoring would put existing development at risk and not
otherwise result in significant protection or enhancement of coastal resources, it may be appropriate to allow properly designed shoreline armoring to remain for the foreseeable future, subject to
conditions that provide for potential future removal in coordination with surrounding development.
9. Real estate disclosures for coastal hazards. This strategy would require that upon any real estate transaction, buyers of properties in a coastal hazard overlay zone are made aware of the potential
hazards to their property. This disclosure informs buyers that they may face such hazards as erosion, coastal flooding, inundation, wildfire, or flooding as a result of climate-induced impacts, such as
sea level rise. It is important to note that disclosures for earthquake hazards and creek flooding
already exists if a property is required to carry flood insurance.
10. Building and zoning code revisions. This approach would involve incorporating flexibility into
development codes to help adapt to changes in climate. This could include limiting development in
flood-prone areas, increasing building heights, using movable foundations, or requiring materials and foundations that are resistant to hazards such as fires or extreme wind. Updating height
restrictions by freeboard elevation (i.e., difference in elevation between the water surface and the
crest or floor of a structure), which would allow buildings to be raised for flood protection purposes, and revising the grading ordinance to reflect sea level rise projections are two examples. Structural
adaptation is the modification of the design, construction, and placement of structures sited in or
near coastal hazardous areas to improve their durability and/or facilitate their eventual retreat, relocation, or removal. This is often done through the elevation of structures, specific site
placement, and innovative foundation construction.
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11. Develop rolling easements along the oceanfront bluff edge. The term “rolling easement” refers
to a policy or policies intended to allow coastal lands and habitats, including beaches and wetlands, to migrate landward over time as the mean high tide line and public trust boundary moves inland with sea level rise. Such policies often restrict the use of shoreline protective structures, limit new
development, and encourage the removal of structures that are seaward (or become seaward over
time) of a designated boundary. This boundary may be designated based on such variables as the mean high tide line, dune vegetation line, bluff edge, or other dynamic line or legal requirement.
In some cases, implementation of this can be through a permit condition (such as the “no future seawall” limitation) or purchased (such as purchasing the land between the MHW boundary and the dune vegetation line plus 5 additional feet in the landward direction so the easement can adjust
with sea level rise).
12. Fee simple acquisition. This approach is the purchase of vacant or developed land in order to
prevent or remove property from the danger of coastal hazards such as erosion or flooding. One
such example of this adaptation strategy is to purchase properties at risk and to demolish structures and restore habitats and physical processes, as has been done in Pacifica, California. A hybridized
version of this adaptation strategy may be a public acquisition program in which an entity purchases
the hazardous property and then leases the land back to the previous landowner with the deed restriction and understanding that when the structure or parcel is damaged that the lease may expire.
13. Require special considerations for critical infrastructure and facilities. Addressing sea level
rise impacts to critical facilities and infrastructure (e.g., roads, bridges, water, sewer facilities, etc.) will likely be more complex than for other resources and may require greater amounts of planning
time, impacts analyses, public input, and funding. To address these complexities, the city could establish measures that require continued function of critical infrastructure, or the basic facilities, service, networks, and systems needed for the functioning of a community. Programs and measures
within a Local Coastal Program could include identification of critical infrastructure that is
vulnerable to sea level rise hazards, establishment of a plan for managed relocation of at-risk facilities, and/or other measures to ensure functional continuity of the critical services provided by
infrastructure at risk from sea level rise and extreme storms. Repair and maintenance, elevation or spot-repair of key components, or fortification of structures where consistent with the California Coastal Act may be implemented through coastal development permits.
14. Limit redevelopment or upgrades to existing legal non-conforming structures in at-risk locations. The city could develop and enforce policies and regulations that define non-conforming
development in coastal hazard zones and place limits on expansion, redevelopment, or upgrades to
legal non-conforming structures. These may require redevelopment proposals to comply with requirements for new development, including regulations that minimize sea level rise hazards; also,
deed restrictions or other mechanisms could be required to notify existing and future property
owners about such limitations.
15. Continue to monitor beaches. The city’s existing beach monitoring program provides a long-term
record of beach width change in Carlsbad. It is recommended that this program be continued into
the future to track local beach response to sea level rise. As part of this program, it is also recommended that storm events be documented through photographs and field notes. This
documentation will assist in validation of the numerical modeling results and to track the frequency
of these events.
16. Periodically update this Sea Level Rise Vulnerability Assessment. Update this assessment when
significant changes in climate science or coastal hazard mapping methods occur. Addenda to this
document could be an approach to capture these updates.
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17. Develop a coastal armoring database and action plan. The city could create a database of the
status and condition of existing armoring in the city. The database can build off the GIS database developed for this study and should be compatible with the redesigned coastal armoring database developed by the California Coastal Commission. A coastal armoring database will provide the city
to with an inventory of the age, type and condition of coastal structures in the city as well as similar
information about the structure or asset the armoring serves to protect. This data is important for future decision making and implementation of future Local Coastal Program policies related to sea
level rise adaptation.
18. Revise development setbacks. Existing building setback requirements should be revised to account for accelerated erosion caused by increasing sea levels and hours of wave attack, as well
as a factor of safety distance that is related to the erosion mechanism (e.g., dune erosion versus cliff erosion). The setback should factor in the life expectancy of the proposed development or
redevelopment. For example, in a bluff-backed shoreline, where historic failures have shown to be
capable of a 30-foot failure, the setback should include accelerated erosion rates in addition to a failure distance that could occur at the end of the development’s life expectancy.
19. Develop a repetitive loss program. One way to implement managed retreat would be to develop
a repetitive loss program that could include the following strategies in response to requests to repair property damaged by sea level rise related storm damage: 1) permit the first request to repair storm
damage; 2) when a property is damaged a second time, permit the repairs and apply zoning
limitations or a zone change that precludes future development/improvements on the property or the portion of the property that is vulnerable to sea level rise impacts; and 3) when a property is
damaged a third time, repairs would not be permitted unless it is demonstrated that the repairs will remove the structure/property from future hazard.
20. Identify triggers to shift implementation to different adaptation strategies. Over time, the city
may implement all or most of the potential adaptation strategies, likely in the following order:
protect, accommodate, and retreat. Given the uncertainty in timing and severity of impacts, it is important to identify triggers, which once reached, will commence planning and implementation
actions for the next set of adaptation strategies. Triggers can vary widely, but generally fall into four categories:
a. By sea level rise elevation or rate of sea level rise observable at tide gages.
b. By time, such as upon closure of the once through cooling power plants.
c. By exposure, such as how frequently Carlsbad Boulevard is closed to travel due to wave
action.
d. By damages, such as a structure needs to be removed once it is damaged by more than 50% or has multiple insurance claims for flood damages.
To be effective, these triggers should be implemented through specific measurable metrics with
clear direction on what should happen once a threshold is triggered.
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6.4.2. Adaptation Project Strategies
This section generally describes the types of adaptation projects that would be effective in minimizing coastal hazards within geographic areas that are vulnerable to sea level rise, which include Carlsbad’s low-lying beaches, low-lying estuaries, and the bluff-backed shoreline segments.
6.4.2.1. Low-Lying Beaches
Low-lying beaches are exposed to coastal hazards related to wave flooding, coastal erosion, stormwater coastal confluences (rainfall runoff trapped by high tides and sea level rise), and eventually tidal inundation.
Carlsbad’s low-lying beaches are predominately within the northern portion of the Village Planning Area. To adapt to these coastal hazards, the following types of adaptation projects are likely to be most effective and are listed in order of soft strategies to hard strategies:
Managed retreat (soft)
Dune restoration (soft)
Beach nourishment (soft)
Sand retention with nourishment (soft)
Elevating structures (hard)
Coastal armoring (hard)
6.4.2.2. Low-Lying Estuaries
Low-lying estuaries are exposed to coastal hazards of stormwater confluences (rainfall runoff trapped by
high tides and sea level rise) and increasing tidal inundation. These areas include Buena Vista Lagoon, Aqua Hedionda Lagoon and Batiquitos Lagoon. To adapt to these coastal hazards, the following types of
projects are likely to be most effective and are listed in order of soft strategies to hard strategies:
Managed retreat (soft)
Dune or wetland restoration (soft) Elevating structures (hard)
Coastal armoring (hard)
6.4.2.3. Bluff-Backed Shoreline
Most of the Carlsbad shoreline is bluff-backed, which includes much of Terramar and the Southern
Planning Areas. In bluff-backed shoreline reaches, the physical processes causing the vulnerabilities are
largely due to wave velocity, erosion of the bluffs, some minor coastal flooding along low lying bluffs, and acceleration of bluff erosion in the future as sea levels rise. Of particular concern, bluff-backed shoreline
segments provide public access, as well as state park campgrounds. To adapt to the coastal hazards in the bluff-backed shoreline reaches, the following types of projects are likely to be the most effective and are listed in order of soft strategies to hard strategies:
Managed retreat (soft)
Movable foundation (soft/hard hybrid)
Coastal armoring (hard)
6.4.3. Adaptation Strategy Costs
The costs associated with the various adaptation strategies should be considered when developing
adaptation policies and regulations. The cost to construct and maintain hard protective structures can be significant, and consideration of the initial construction and periodic maintenance costs should be evaluated
over time to develop life-cycle cost of a coastal armoring strategy. When planning for sea level rise, the
life-cycle cost to protect should be compared to the cost of the asset being protected or cost to relocate that asset. As an example, the rough order of magnitude costs (in 2017 dollars) of common protection strategies
are provided in Table 6 below.
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TABLE 6. ROUGH ORDER OF MAGNITUDE COSTS FOR COASTAL PROTECTION STRATEGIES
Protection Strategy
Approx. Initial Construction Cost ($/unit)
Approx. Maintenance
Costs ($ every 5 years)* Assumptions
Revetment $2,500/linear foot $150/linear foot Revetment of 3- to 5-ton stone with a crest elevation of +18 ft MLLW.
Seawall $5,000/linear foot $50/linear foot
Sheet pile or gravity wall seawall fronted with rip rap for
scour protection. Seawall crest constructed to +22 ft MLLW.
Beach Nourishment $40/CY $50/CY Assumes 100,000 CY nourishment project constructed
via offshore dredge methods.
*Assumes inflated cost of 5% of initial construction costs every 5 years.
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7. CONCLUSIONS AND RECOMMENDATIONS
The purpose of this vulnerability assessment was to identify assets and planning areas at risk to future rates
of sea level rise within Carlsbad. The study considered vulnerabilities to flooding, inundation and bluff erosion as a result of two sea level rise scenarios (2050 and 2100) as predicted by preliminary results from
CoSMoS 3.0 and supplemental fluvial flooding zones generated by Moffatt & Nichol. The results of the vulnerability assessment are summarized in Table 7.
TABLE 7. CITY-WIDE SEA LEVEL RISE VULNERABILITY SUMMARY
Asset Category Horizon Impacted Assets Overall Vulnerability Rating (Low - High)
Beaches 2050 27 acres Moderate
2100 146 acres High
Public Access Ways 2050 26 beach access ways 2.6 miles of lateral access ways Moderate
2100 37 beach access ways 7.3 miles of lateral access ways Moderate
State Parks 2050 6 Parcels Moderate - High
2100 6 Parcels Moderate - High
Parcels 2050 564 Parcels Moderate
2100 657 Parcels High
Critical Infrastructure 2050 0 Parcels Low
2100 8 Parcels Moderate
Transportation (Road, Bike, Pedestrian)
2050 1.6 miles High
2100 5.8 miles High
Environmentally Sensitive Lands
2050 1,088 acres Moderate
2100 1,164 acres High
The results of the vulnerability assessment, as based on the USGS CoSMoS 3.0 modeling outputs, are described by asset type below:
Beaches – Beach erosion impacts do not appear significant until year 2100. Carlsbad beaches were found to lose 146 acres of shoreline by this time horizon. The loss of beach results in numerous adverse
impacts, including reduction of beach “towel space” or recreational area for visitors and residents,
reduction of coastal public access, loss of coastal habitat and ecological value, and impacts to the beach’s ability to function as a natural storm buffer. In addition, the loss of beaches has been found to
result in direct and indirect economic impacts; direct impacts are a byproduct of the protection that they
provide to coastal infrastructure; and indirect impacts are a result of a reduction in visitation from residents and visitors, which would then impact visitor-serving businesses. The overall vulnerability of
beaches by year 2050 is considered moderate.
Public Access Ways – Coastal flooding and erosion has the potential to impact vertical (access to) and lateral (access along) beach access ways in the city. A total of 37 vertical beach access ways exist in
the city. All of these access ways were determined to be vulnerable to flooding and inundation by year 2100. About three quarters of these access ways were vulnerable to flooding during the 2050 time horizon.
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About 7 miles of lateral access ways (trails) were found to be vulnerable by year 2100. The public
access ways exist along the beach and lagoons in the city. About 2.5 miles of trails are vulnerable to flooding in the 2050 time horizon. The overall vulnerability of public access ways in year 2050
was determined to be moderate.
State Parks – Though state parks are not owned or operated by the city, they provide a valuable asset to the city by providing recreation and a low-cost visitor serving amenity. State parks are most at risk
in Planning Zones 2 and 3 where beaches, campgrounds (South Carlsbad and Ponto) and day-use
parking facilities are within coastal hazard zones. The primary coastal hazard is bluff erosion, which may result in the loss or partial loss of campsites and day use facilities. The overall vulnerability to this
asset by year 2050 is considered moderate-high.
Parcels – The majority of the parcels at risk are in Planning Zones 1 and 2, where 515 parcels were found to be impacted by the 2050 sea level rise scenario. The parcels that are at risk to flooding and
bluff erosion are located on coastal and lagoon-front properties in these planning zones. The most
parcels at risk are in Planning Zone 2, where 451 parcels were found to be at risk by 2100. The overall vulnerability to this asset by year 2050 is considered moderate.
Critical Infrastructure – Critical infrastructure was found to be at risk to sea level rise in Planning
Zones 1 and 2. Critical infrastructure was limited to sewer pump stations and the commercial uses adjacent to the Agua Hedionda Lagoon. The overall vulnerability to these assets by year 2100 is
considered moderate. The overall vulnerability to this asset by year 2050 is considered low due to no parcels being impacted.
Transportation – Transportation infrastructure in all planning zones was found to be at risk to flooding
and bluff erosion by year 2050. Carlsbad Boulevard was determined to be the most vulnerable due to the critical north-south linkage it provides; however, La Costa Avenue, Jefferson Street, and private
roads within state parks campgrounds were also found to be vulnerable. The overall vulnerability to
this asset by year 2050 is considered high.
Environmentally Sensitive Lands – Environmentally sensitive lands include wetlands, riparian areas,
coastal prairies, woodlands and forests, and other natural resources in the coastal zone. Planning Zone
3 had the most environmentally sensitive lands at risk to flooding with a total of 606 acres at risk by year 2100. Due to the steep topography and development along much of the lagoon shorelines in
Carlsbad, the ability for flora and fauna to naturally adapt by migrating vertically and/or horizontally
may be limited. The overall vulnerability to this asset by year 2050 is considered moderate.
To address identified vulnerabilities, the adaptation measures described in this report provide a range of
available options for the city to consider in the development of its Local Coastal Program update. These
potential adaptation options are as follows:
Continue to participate in Regional Beach Nourishment Projects
Continuation of Sand Bypassing Program
Continue to implement local opportunistic sand management plan
Construct winter berm or dune system
Landward relocation of public assets
Adopt Hazard Overlay Zones
Require site-specific coastal hazard reports
Management of prioritized existing revetments
Real estate disclosures for coastal hazards
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Building and zone code revisions
Develop rolling easements along the oceanfront bluff edge
Fee simple acquisition of vulnerable properties
Require special considerations for critical infrastructure and facilities
Limit redevelopment or upgrades to existing legal non-conforming structures in at-risk locations
Continue to monitor beaches
Periodically update Vulnerability Assessment
Develop a coastal armoring database and action plan
Revise development setbacks
Develop a repetitive loss program
Identify triggers to shift implementation to different adaptation strategies. Triggers may include sea level elevation, time, exposure or damage.
Generally, the shoreline areas in Carlsbad that are vulnerable to sea level rise include: low lying beaches,
low lying estuaries, and bluff-backed shoreline. Current and future coastal hazard vulnerabilities to these shoreline segments vary and, likewise, the most effective adaptation responses differ. The following types
of adaptation responses are the most effective for the respective shoreline type and are listed in order of
“soft” to “hard” strategies:
Low lying beaches
Managed retreat
Dune restoration
Beach nourishment
Sand retention with nourishment
Elevating structures
Coastal armoring
Low lying estuaries
Managed retreat
Dune or wetland restoration
Elevating structures
Coastal armoring
Bluff-backed shoreline
Managed retreat
Movable foundation
Coastal armoring
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8. REFERENCES
California Coastal Commission, 2015. California Coastal Commission Sea Level Rise Policy Guidance.
Adopted August 12, 2015.
California Emergency Management Agency and the California Natural Resources Agency (CalEMA &
CNRA). 2012. California Adaptation Planning Guide, Planning for Adaptive Communities California Natural Resources Agency (CNRA). 2014. Safeguarding California: Reducing Climate Risk.
Coastal and Ocean Working Group of the California Climate Action Team (CO-CAT). 2013. State of
California Sea-Level Rise Guidance Document, March 2013 Update.
U.S. Geological Survey. Coastal Storm Modeling System (CoSMoS) 3.0 Southern California. https://walrus.wr.usgs.gov/coastal_processes/cosmos/socal3.0/index.html.
Flick, R.E. and L.C. Ewing. 2009. Sand Volume Needs of southern California beaches as a function of future sea-level rise rates. Shore and Beach Vol. 77, No. 4. Fall 2009.
Snover, A.K., L. Whitely Binder, J. Lopez, E. Willmott, J. Kay, D. Howell, and J. Simmonds. 2007.
Preparing for Climate Change: A Guidebook for Local, Regional, and State Governments. In association with and published by ICLEI – Local Governments for Sustainability, Oakland, CA.
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Attachment A:
Sea Level Rise Science & Coastal Hazard Mapping Assumptions
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This attachment presents technical information on sea level rise science, the City of Carlsbad’s (City) coastal setting and limitations and assumptions related to coastal hazard mapping.
1. SEA LEVEL RISE SCIENCE AND PROJECTIONS
Sea levels are projected to rise in the coming decades as a result of increased global temperatures associated with climate change (Intergovernmental Panel on Climate Change 2013). When discussing sea level rise
(and when reviewing sea level rise projections), it is important to distinguish the differences between global
and local sea level rise rates. Global sea level rise rates disregard local effects such as tectonics (i.e., land uplift/subsidence), water temperatures, and wind stress patterns that can act to subdue or amplify the global sea level rise rates. Local (or relative) sea level rise refers to the observed changes in sea level relative to
the shoreline in a specific region and takes into account these local factors.
It should be noted that guidance related to sea level rise evolves as new science is released. The most
relevant science and guidance from the international, federal, and state levels at the time of this report is
summarized in this section.
1.1. STATE GUIDANCE
The 2012 National Research Council report titled “Sea-Level Rise for the Coasts of California, Oregon,
and Washington: Past, Present, and Future,” is considered the best available science for California (CCC 2015, CO-CAT 2013). Thus, both state guidance documents utilize the sea level rise projections from the National Research Council’s report. The National Research Council is a conglomerate of scientists and
research organizations that act as an advisory group for government agencies.
1.1.1. California Coastal Commission Sea Level Rise Policy Guidance (CCC 2015)
The document states that the best available science should be utilized when incorporating sea level rise into
planning documents or when applying for a coastal development permit. As stated above, the 2012 National Research Council’s report is generally considered as the best available science for the region at the time of
this report. The 2012 National Research Council’s report predicts a 0.9-ft increase of relative sea level rise
(i.e., relative rise of the ocean water level compared to land) by 2050 and a 3.1-ft increase by 2100 in the City (Table 1). These projections are described as being applicable to all areas south of Cape Mendocino
in the study. The sea level rise projection values in Table 1 indicate the mean and uncertainty (i.e., standard deviation) for a specific IPCC future greenhouse gas emission scenarios (i.e., A1B). The A1B scenario represents a world of rapid economic growth and a balanced use of fossil and non-fossil energy sources.
The sea level rise ranges in Table 1 represent the means for the B1 (low greenhouse gas emission scenario)
and A1FI (high greenhouse gas emission scenario). Note that the certainty in projections decrease with time, as indicated by the increasing uncertainty values.
TABLE 1: SEA LEVEL RISE PROJECTIONS FOR LOS ANGELES REGION
Year Projected Sea Level Rise (ft.)
Projection
Uncertainty
(ft., +/-)
Low Range (ft.) High Range (ft.)
2030 0.5 0.2 0.2 1.0
2050 0.9 0.3 0.4 2.0
2100 3.1 0.8 1.5 5.5
(Source: National Research Council 2012)
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1.1.2. State of California Sea-level Rise Guidance Document (CO-CAT 2013)
A state sea level rise guidance document, titled “State of California Sea-Level Rise Guidance Document
(Interim Guidance)” (CO-CAT 2013), was originally released in October 2010 and re-released/updated in March 2013 to provide guidance to state agencies for incorporation of sea level rise projections into project
planning and decision making. The document recommended use of the ranges of sea level rise presented in
the 2012 National Research Council’s report as a starting place. CO-CAT recommends that specific project design sea level rise scenario ranges should then be based on agency- and context-specific considerations
of risk tolerance and adaptive capacity of the affected assets.
2. COASTAL SETTING
2.1. WATER LEVELS
The nearest, long-term sea level record in proximity to the study area is the La Jolla tide gage (Station
9410230) operated by the National Oceanic and Atmospheric Administration (NOAA). The gage is located on the Scripps Pier, which has been collecting data since 1924. These data are applicable to the San Diego region open-ocean coastline and are summarized in Table 2.
TABLE 2: WATER LEVELS IN LA JOLLA (1983-2001 TIDAL EPOCH)
Description Datum Elevation (ft MLLW) Highest Observed Water Level
(1/11/2005 5:00:00 PM) Maximum 7.66
Highest Astronomical Tide HAT 7.14
Mean Higher-High Water MHHW 5.32
Mean High Water MHW 4.60
Mean Sea Level MSL 2.73
Mean Low Water MLW 0.90
Mean Lower-Low Water MLLW 0.00
North American Vertical Datum of 1988 NAVD88 0.19 Lowest Astronomical Tide LAT -1.88
Lowest Observed Water Level
(12/17/1933 11:36:00 PM) Minimum -2.87
(Source: NOAA 2015)
2.2. LITTORAL PROCESSES
A littoral cell is a segment of shoreline in which sand is bounded or contained. The City is located within
the Oceanside Littoral Cell, which extends from Dana Point Harbor to La Jolla, a distance of approximately
50 miles (Patsch and Griggs 2007). The cell’s shoreline consists of a narrow beach that is backed by seacliffs, bluffs, and mouths of coastal streams and rivers. Inputs to the Oceanside Littoral Cell include:
fluvial sources (rivers), bluff erosion, gully and terrace erosion, and anthropogenic sources (i.e., beach
nourishment). Natural sand loss occurs at sand sinks, which include the La Jolla and Scripps submarine canyons, lagoons, and offshore bars (Patsch and Griggs 2007).
Human intervention has significantly influenced the coastal processes in the Oceanside Littoral Cell. The
construction of coastal structures (i.e., jetties, seawalls, etc.) and inland flood control structures (i.e., dams) have reduced the amount of sand traveling along the coast and being delivered to the coast, respectively. In
particular, the Oceanside Harbor jetty system effectively traps sand from naturally traveling from north to
south. The harbor captures sand, which is dredged and placed on downdrift beaches. This is approximately equal to the net littoral drift from Oceanside Harbor to Scripps Submarine Canyon (Patsch and Griggs
2007).
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The City currently monitors the beaches by measuring beach profiles throughout the city at historic beach profile locations. Beaches have been monitored at 12 sites for 20 years. Data from the monitoring indicate
that Carlsbad beaches are relatively stable, with seasonal shifts in beach width and gains associated with
beach nourishment or bypassing projects. Specifically, North Carlsbad Beach is relatively stable due to the effects of periodic nourishment from the Regional Beach Sand Projects (RBSPs), and from more regular
nourishment from maintenance dredging and bypassing in and around Agua Hedionda Lagoon. Beaches
south of the Agua Hedionda Lagoon mouth (middle beach) vary, with stability from sand placed as part of the lagoon maintenance dredge material placed between the inlet jetties. Beaches south of Terramar Point
through the Southern Planning Area are actively eroding, with periodic widening from San Diego
Association of Governments (SANDAG) sand replenishment projects (see Section 2.4, below) followed by narrowing. Farthest to the south, the beaches on both sides of the Batiquitos Lagoon mouth are relatively
wide due to the sand retention effects of the lagoon mouth jetties, from benefits of nourishment from initial 1995 lagoon restoration, and from on-going maintenance dredging of the lagoon since approximately 2005.
2.3. WAVES
Waves act to carry sand in both the cross-shore and longshore directions and can also cause short-duration
flooding events by causing dynamic increases in water levels. Thus, the wave climate (or long-term exposure of a coastline to incoming waves) and extreme wave events are important in understanding future
sea level rise vulnerabilities.
Offshore wave data was analyzed for Carlsbad from Wave Information Studies (WIS) Station 83105 from 1980 to 2011 (Figure 1). WIS, developed by the USACE, is an online database of estimated nearshore wave
conditions covering U.S. coasts. The wave information is derived based on a database of collected wind measurements (a process known as wave “hindcasting”) and is calibrated by offshore wave buoys. The hindcast data provides a valuable source of decades-long nearshore wave data for coastlines in the U.S.
FIGURE 1: LOCATION OF WIS STATION 83105
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2.3.1. Wave Climate
The largest percentage (36%) of the waves approaching Carlsbad are from the west (270 degrees). The most
frequent wave height is 1.5 to 3 ft., as shown in Figure 2. Wave periods were between 12 and 16 seconds
with 14 to 15 seconds occurring the most frequently (Figure 3).
2.3.2. Extreme Waves
The 50- and 100-year return period wave heights in Carlsbad are approximately 19.6 and 22 ft, respectively
(Figure 3). The largest waves occur in the winter when northern hemisphere cyclonic storms generate powerful, long period waves. These waves can result in coastal erosion, flooding and bluff failures.
FIGURE 2: ANNUAL SIGNIFICANT WAVE HEIGHT AND DIRECTION (WIS STA. 83105)
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FIGURE 3: WAVE RETURN PERIODS, WIS STATION 83105
2.4. SHORELINE MANAGEMENT
In addition to dredging projects along the Oceanside Littoral Cell coast, periodic beach nourishment projects have added to the sediment budget. The City of Carlsbad has actively participated in the Shoreline
Preservation Working Group within SANDAG since its inception as the Shoreline Erosion Committee in 1991. SANDAG issued its Shoreline Preservation Strategy in the early 1990s that called for pilot beach nourishment projects to restore the region’s beaches (SANDAG 1993). The two RBSPs in the city were
implemented as RBSP I in 2001 and RBSP II in 2012 that included sand placed at two beach locations along Carlsbad’s coastline.
The city’s other sand management activities include coordinating with the sand bypassing by Encina Power
Station at Agua Hedionda Lagoon. At the request of the city, the sand from the lagoon entrance is placed on the beach both north and south of the jetties. City leaders work through an appointed Beach Preservation
Committee that makes recommendations regarding sand management.
As mentioned above, the city has also participated in two RBSPs. One of the sites was located at North Carlsbad Beach, just south of the Buena Vista Lagoon mouth, and the other site was located at South
Carlsbad North just north of the mouth of Las Encinas Creek. Sand from other placement sites adjacent to
Carlsbad (i.e., Oceanside and Encinitas) also moved both up and down the coast to benefit the city.
2.5. SHORELINE ARMORING
Shoreline armoring exists along much of the city’s coastline, though is concentrated along the north
coastline. Armoring consists of seawalls, revetments, and rip rap, as shown in Figure 4. A shoreline armoring GIS shapefile was created for the city to inventory the presence and type of shoreline structures. This file was based on a prior shoreline armoring database created by the Coastal Commission in 2005
(Dare 2005). The database was revised to include proper structure type (where applicable) and improved to be spatially explicit. The Dare 2005 database was previously set to an arbitrary, straight offshore line in the
city. This line was revised to represent the approximate location of coastal structures in the city. The
legality, age, and state of repair of the structure was not detailed as part of this effort.
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FIGURE 4: SHORELINE ARMORING IN CARLSBAD
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3. COASTAL HAZARD MODELING AND MAPPING
Carlsbad’s exposure to future rates of sea level rise was determined using preliminary results from the CoSMoS 3.0 model. CoSMoS is a multi-agency effort led by the U.S. Geological Survey (USGS) to make
detailed predictions (meter scale) of coastal flooding and erosion based on existing and future climate scenarios for Southern California. The modeling effort depicts coastal flooding, shoreline change and bluff
response to a composite, 100-year wave event in combination with various rates of sea level rise and
baseline water levels (i.e., high tide, storm surge, sea level anomaly and river discharge).
Details on the sea level rise scenarios selected and how the respective coastal hazards were mapped are provided in this section.
3.1. SEA LEVEL RISE SCENARIOS
Years 2050 and 2100 were selected as planning horizons for this vulnerability assessment. The CoSMoS 0.5 m and 2 m sea level rise scenarios roughly align with the projected high sea level rise from the 2012
National Research Council’s report for the 2050 and 2100 planning horizons. Therefore, these sea level rise scenario results were used as the basis for this vulnerability analysis. The National Research Council’s high range projection is slightly higher (0.3 ft.) for year 2050 and slightly lower (1.1 ft.) for year 2100 compared
to CoSMoS projections. Thus, the hazards predicted by CoSMoS projection for 2050 will be marginally less than hazards resulting from the National Research Council’s projection and the hazards for 2100 will be greater as predicted by CoSMoS projections compared to the National Research Council projections. A
comparison of the National Research Council’s 2012 sea level rise projections for the planning horizons compared to the CoSMoS scenarios used is shown in Table 3.
TABLE 3: 2012 NATIONAL RESEARCH COUNCIL SEA LEVEL RISE SCENARIO VERSUS
COSMOS 3.0 SEA LEVEL RISE SCENARIOS
Year
2012 National Research Council Sea Level Rise Projections CoSMoS 3.0 Sea Level Rise Scenario
Difference (CoSMoS vs. 2012National Research Council) (ft.)
Projection
(ft.)
Uncertainty Low Range
(ft.)
High Range
(ft.) (ft., +/-)
2050 0.9 0.3 0.4 2 0.5 m (1.7 ft.) 0.3
2100 3.1 0.8 1.5 5.5 2.0 m (6.6 ft.) 1.1
3.2. BLUFF EROSION
Projections of coastal cliff-retreat rates (or cliff erosion rates) and positions for future sea level rise scenarios were made using numerical and statistical models based on field observations such as historical cliff retreat
rate, submarine slope, coastal cliff height, and mean annual wave power (CoSMoS 2015). Bluff profile evolution models relate breaking-wave height and period to bluff erosion, and distribute erosion vertically over a tidal cycle.
The above modeling approach was run assuming a bluff edge baseline established from the 2010 digital elevation model. Determining the bluff edge is a subjective process and spatial projections will depend on
the interpretation of the bluff edge. The bluff hazard zone for each projection year was shown as the area
between the baseline bluff positon and the projected bluff position for the 0.5 m and 2.0 m sea level rise scenarios. Bluff erosion rates are based on historical rates from the USGS National Assessment of Shoreline
Change and assume that sea level rise does not accelerate erosion. Figure 5 provides a schematic depicting
the projected CoSMoS 3.0 bluff erosion results for various sea level rise scenarios (shown as blue to red polylines) and uncertainty limits for the 2.0 m scenario (shown as a light grey).
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FIGURE 5: COSMOS BLUFF EROSION PROJECTIONS BY 2100
(CoSMoS-COAST 2015)
3.3. COASTAL FLOODING
The CoSMoS model is comprised of three tiers that transform the offshore wave climate to the shoreline
and inland. Tier I contains two models: a hydrodynamics (motions and forces of fluids) flow model (Delft 3D) that computes tides, water level variations, flows, and currents; and a wave generation and propagation
model (SWAN). Tier II refines the resolution of the model by segmenting the Southern California Bight (coastline from Point Conception to San Diego) area into 11 sections and incorporating fluvial discharge through the FLOW model to simulate flooding from elevated water (coastal and river) levels. Tier III uses
the XBeach model to run hydrostatic, morphodynamic (water and beach interaction and resulting adjustments and changes) simulations.
The resulting projected flood hazards mapped are areas vulnerable to coastal flooding due to storm surge,
sea-level anomalies (e.g., higher water levels due to warm water temperatures or low atmospheric pressure), tide elevation, and wave run-up during the 2100 storm simulation in combinations with the maximum elevation of still-water level.
3.4. SHORELINE EROSION
Projections of shoreline change as a result of future sea level rise scenarios were made using CoSMoS-COAST model (Figure 6). This shoreline model uses a series of global-to-local nested wave models (such
as WaveWatch III and SWAN) forced with Global Climate Model (GCM) derived wind fields. Historical
and projected time series of daily maximum wave height and corresponding wave period and direction from 1990 to 2100 force the shoreline model (CoSMoS-COAST 2015).
Additionally, the CoSMoS-COAST model incorporates the following relevant processes in sediment transport: longshore transport and shoreline equilibrium equations; wave-driven cross-shore transport and resulting equilibrium beach profiles; and long-term beach profile changes due to sea level rise. Light
detection and ranging (LIDAR) data is then used to adjust the model parameters in an effort to estimate the effects of unresolved processes, such as natural and anthropogenic (beach nourishment and bypassing)
sediment supply.
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FIGURE 6: COSMOS SHORELINE EROSION PROJECTIONS BY 2100
3.5. MODEL LIMITATIONS
The preliminary CoSMoS 3.0 release is a useful dataset for the first-order identification of future at-risk
areas. The data is preliminary; therefore, is subject to revision prior to being finalized in 2017. However, even when the final CoSMoS product is released, due to the regional nature of the modeling exercise, city-
scale details can be lost. Other limitations of the CoSMoS 3.0 data set are discussed in this section.
3.5.1. Topographic / Bathymetric Model Resolutions
CoSMoS developed a seamless, topo-bathymetric digital elevation model combining land based
topographic elevation data with below water bathymetric elevation data, which was based on bare-earth LIDAR data collected in 2009-2011 for the California Coastal Conservancy LIDAR Project, bathymetric LIDAR from 2009-2010 as well as acoustic multi- and single-beam data collected primarily between 2001
and 2013. Though this data was the best-available to the study team, some local-scale details in the city were lost in this data set (e.g., vertical seawalls).
3.5.2. Bluff Erosion (Bluff Hazard Zone)
The CoSMoS model makes regional assumptions using a uniform bluff substrate, meaning that the bluff is assumed to be made up entirely of the same sediment; thus, oversimplifies many bluffs in San Diego County
that consist of multiple sediment layers of varying erosive tendencies, the degree of prediction provided by
these assumptions is unknown. The modelers cited a sparsity of data on bluff substrate as the reason for this assumption. The model used the USGS National Shoreline Assessment study for data on historical bluff
retreat. This study analyzed bluff change from about 1933 to 1998 and found that bluffs within the
Oceanside region, which captures the City of Carlsbad, are retreating at an average rate of 0.7 ft. per year.
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The accuracy of these bluff erosion predictions is dependent on the deviation from the uniform bluff
substrate assumed at each bluff location. These historic erosion rates which do not account for acceleration due to sea level rise may underestimate the effects of sea level rise on erosion.
The model did not include shoreline protection structures in the city. Examples of bluff protection structures
that were excluded include coastal structures (seawalls, revetments, riprap) and bluff stabilization treatments that exist in the community of Terramar. The model states that coastal structures were not
included if the armoring was low enough to be easily overwashed. Determination as to whether armoring
was easily overwashed was subjective and was determined by the USGS. Not accounting for these bluff protection structures in the city likely overestimates bluff erosion hazards in certain areas.
3.5.3. Shoreline Erosion (Inundation Hazard Zone)
The shoreline model includes a variable for long-term beach accretion or erosion based on an analysis of historical shoreline change. This variable represents sediment contributions from beach nourishment, bluff
erosion and fluvial (river) contributions and was calculated through analysis of historical shoreline change dataset from 1970s to present. Based on coordination with the USGS, the long-term shoreline change variable included in the shoreline model for the city is 0.5 ft of shoreline gain per year on average.
Historical averages of beach or bluff erosion does not account for accelerated erosion due to sea level rise. Fluvial conditions may also differ from historical norms as a result of climate change. Past rates of beach nourishment may not accurately represent beach management practices in the future. Beach nourishment
rates and volumes have been decreasing over time in many areas in southern California because of funding and regulatory constraints for these types of projects.
The shoreline model included coastal structures (rip rap, revetments and seawalls) and coastal
infrastructure. Thus, shoreline erosion model results become invalid as the beach becomes fully eroded and possibly undermines coastal structures and infrastructure. Therefore, shoreline erosion is understated where
the projected shoreline encounters a coastal structure or infrastructure.
3.5.4. Coastal Flooding (Flood Hazard Zone - Shoreline)
Coastal flooding results were de-coupled with future shoreline position data. Thus, the coastal flooding
results shown are based on today’s shoreline position instead of an eroded, future condition. This likely
understates the flooding results and was recognized as a limitation in the preliminary data release. The future coastal flooding data will utilize the future shoreline position to then generate coastal flooding limits.
Flooding limits are anticipated to be greater and extend more landward with the coupling of these analyses
in the future release.
The landward extent of coastal flood limits was based on the USGS, bare-earth DEM. Topographic features
captured in this DEM effected the landward propagation of flooding. Coastal structures were implicitly captured in these results when these structures were large enough (revetments in the Village Planning Area). Small scale features, such as seawalls along Carlsbad Boulevard in the Tamarack Planning Area, were not
captured in the DEM. Thus, coastal flooding limits are likely overstated in areas where small scale coastal
structures were excluded from the modeling domain.
3.5.5. Lagoon Inundation (Inundation Hazard Zone)
Areas in the lagoons subject to future daily tides were mapped using a DEM provided by city GIS staff. A mean higher high water vertical elevation of 5.3 feet (MLLW) was used to represent future, daily-high still water tidal elevations in the lagoons. The mean higher high water elevation was added to the projected sea
level rise for each planning year (i.e., 2050 and 2100). Since the weir at Buena Vista Lagoon has a crest elevation of 7.89 feet (MLLW), it was found that this lagoon would only experience tidal inundation during
the 2.0 m, year 2100 scenario.
Page 143
3.5.6. Lagoon Flooding (Flood Hazard Zone - Lagoons)
Moffatt & Nichol conducted a review of the CoSMoS model outputs with existing fluvial (river) models of
the three lagoons in the city. Existing fluvial models of these lagoons were performed in connection with
the North Coast Corridor project being led by SANDAG. Based on this review, Moffatt & Nichol found the following deficiencies in the CoSMoS 3.0 lagoon flooding model outputs:
Coastal lagoons are included in the Tier II high resolution CoSMoS models; however, the lagoon
bathymetry is derived from topo LIDAR. Thus, the lagoon area below the water surface is a simple flat surface that may not correctly represent the effects of tides and storms within the lagoon, this
can lead to both under estimation and over estimation of hazards.
CoSMoS is intended to model the 100-year storm from ocean conditions. The hydrograph (graphical representation of storm flow) is idealized and the peak flow included in the model is
based on atmospheric pressure conditions that are produced during the coastal storms. The peak flow rate of the CoSMoS storm is about 10% of the FEMA 100-year fluvial discharge. The small storm used in the CoSMoS model underestimates the hazards that could exist during a 100-year
fluvial storm with sea level rise conditions.
Culverts or other manmade and natural underground pathways between coastal waters and land are not considered. This likely underestimates flooding hazards that may occur in areas connected to
coastal waters by culverts and other manmade and natural conduits.
Based on these deficiencies, Moffatt & Nichol developed a new data layer showing the limits of these lagoon flood hazards. Inundation hazard zones (areas subject to daily tides) were also mapped to show the
migration of the lagoon shoreline landward. More detailed assessment of each of the findings per lagoon is provided in this section.
Page 144
3.5.6.1. BATIQUITOS LAGOON
At Batiquitos Lagoon, CoSMoS results provide an adequate prediction scenario for a 100-year coastal storm
and should be used for the nearshore area outside of the lagoon. The impacts of a 100-year fluvial storm are not included in the CoSMoS model, the small fluvial storm used in CoSMoS does not represent the
effects of a 100-year fluvial storm in the lagoon during sea level rise conditions. The Moffatt & Nichol
RMA-2 model results provide an adequate prediction scenario for the 100-year fluvial storm with sea level rise and should be used in the lagoon area for planning purposes. Batiquitos Lagoon and referenced basins
are shown in Figure 7. A comparison of water surface elevations for the models reviewed are summarized
in Table 4.
FIGURE 7: BATIQUITOS LAGOON TABLE 4: COMPARISON OF WATER SURFACE ELEVATIONS FOR BATIQUITOS LAGOON
Water Surface Elevation ft, NAVD 88
Model Sea Level Rise Year
Sea Level Rise, ft. (m) Fluvial Storm, cfs (cms) Return Frequency Beach West Basin Central Basin East Basin
FEMA Current 0 15,700 (444.6) 100-Yr 10 - - -
COSMOS
Current 0 1,646 (46.6) N/A *12 7 7 7
2050 1.6 (0.5) 1,646 (46.6) N/A *14 8.5 8.5 8.5
2100 6.6 (2.0) 1,646 (46.6) N/A *17 14 14 14
Moffatt &
Nichol
Current 0 1,646 (46.6) N/A 7.1 7.1 7.1 7.2
2050 1.6 (0.5) 1,646 (46.6) N/A 8.7 8.7 8.8 8.8
2100 6.6 (2.0) 1,646 (46.6) N/A 13.7 13.7 13.7 13.7
Current 0 16,560 (468.9) 100-Yr 7.1 *7.9 *8.7 *10.2
2050 1.6 (0.5) 16,560 (468.9) 100-Yr 8.7 *9.3 *9.9 *11.3
2100 6.6 (2.0) 16,560 (468.9) 100-Yr 13.7 *14.0 *14.4 *15.2
* Results used for planning purposes
Note: Cosmos water surface elevations estimated from shapefiles
FEMA flood elevations are not established for the lagoon
Page 145
3.5.6.2. AGUA HEDIONDA LAGOON
At Agua Hedionda, CoSMoS results provide an adequate prediction scenario for a 100-year coastal storm
and should be used for the nearshore coastal area outside of the lagoon. The impacts of a 100-year fluvial storm are not included in the CoSMoS model, the small fluvial storm used in CoSMoS does not represent
the effects of a 100-year fluvial storm in the lagoon during sea level rise condition. The Chang Hydraulic
and Scour Studies for Proposed Interstate 5 Bridge Widening across Three Lagoons HEC-RAS model results adjusted by Moffatt & Nichol to account for sea level rise conditions under the 100-year fluvial
storm provide a conservative prediction scenario and should be used in the lagoon area for planning
purposes, additional fluvial modeling study is recommended if accurate results similar to that for Batiquitos Lagoon are desired. A comparison of model water surface elevations is shown in Table 5. Agua Hedionda
Lagoon and referenced basins are shown in Figure 8.
FIGURE 8: AGUA HEDIONDA TABLE 5: COMPARISON OF WATER SURFACE ELEVATIONS FOR AGUA HEDIONDA LAGOON
Water Surface Elevation ft, NAVD 88
Model Sea Level Rise Year
Sea Level Rise, ft. (m) Fluvial Storm, cfs (cms) Return Frequency Beach West Basin Central Basin East Basin
FEMA Current 0 9,850 (278.9) 100-Yr 11 - - -
COSMOS
Current 0 918 (26) N/A *11 7 7 5.5
2050 1.6 (0.5) 918 (26) N/A *13 9 8 5.5
2100 6.6 (2.0) 918 (26) N/A *18 14 13 8
CHANG Current 0 10,500 (297.3) 100-Yr - *6.9 *7.8 *9.9
Moffatt & Nichol **
2050 1.6 (0.5) 10,500 (297.3) 100-Yr - *8.5 *9.4 *11.5
2100 6.6 (2.0) 10,500 (297.3) 100-Yr - *13.5 *14.4 *16.5
* Results used for planning purposes
Note: Cosmos water surface elevations estimated from shapefiles
FEMA flood elevations are not established for the lagoon
**WATER SURFACE ELEVATIONS ARE ESTIMATED BASED ON CHANG CONSULTANTS STUDY AND MOFFATT & NICHOL
INTERPRETATIONS FOR SEA LEVEL RISE
Page 146
3.5.6.3. BUENA VISTA LAGOON
CoSMoS results provide an adequate prediction scenario for a 100-year coastal storm and should be used for the nearshore area outside of the lagoon. The impacts of a 100-year fluvial storm are not included in the
CoSMoS model, the small fluvial storm used in CoSMoS does not represent the effects of a 100-year fluvial
storm in the lagoon during sea level rise conditions. The two-dimensional Everest model results for current lagoon conditions from the Buena Vista Lagoon Enhancement Project DEIR provide an adequate prediction
of water surface elevations for current sea level conditions with a 100-year fluvial storm and estimates for sea level rise conditions under the 100-year fluvial storm, these results should be used in the lagoon area for planning purposes.
FIGURE 9: BUENA VISTA LAGOON
TABLE 6: COMPARISON OF WATER SURFACE ELEVATIONS FOR BUENA VISTA LAGOON
Water Surface Elevation ft, NAVD 88
Model Sea Level Rise Year Sea Level Rise, ft (m) Fluvial Storm, cfs (cms) Return Frequency Beach Weir Basin Railroad Basin Coast Hwy Basin I-5 Basin
FEMA Current 0 8,500 (240.7) 100-Yr 11 - - -
COSMOS
Current 0 671 (19) N/A *11 9 8 8 14
2050 1.6 (0.5) 671 (19) N/A *15 9 8 8 14
2100 6.6 (2.0) 671 (19) N/A *23 16 12 12 14
EVEREST
Current 0 8,500 (240.7) 100-Yr - *14.2 *14.2 *14.2 *17.9
2050 1.6 (0.5) 8,500 (240.7) 100-Yr - *14.8 *14.9 *15 *19
2100 6.6 (2.0) 8,500 (240.7) 100-Yr - *15.2 *15.3 *15.4 *19.1
* Results used for planning purposes
NOTE: COSMOS water surface elevations estimated from shapefiles
FEMA flood elevations are not established for the lagoon
Page 147
3.5.7. Culverts and Storm Drain Systems
The CoSMoS model currently does not include culverts, storm drain systems or other manmade and natural
underground pathways between coastal waters and land. Thus, flooding limits may be understated in some
areas. Increased water levels due to sea level rise, fluvial storms, coastal storms, high tides, and wave run-up can back into these conduits and result in flooding of upland areas into which these conduits drain. The
potential for flooding of drainage areas connected to these systems is dependent on topography, conveyance
invert elevations, slopes, backwater conditions, drainage structures, and other hydraulic factors. Increased tail water levels at the outlet of storm drain systems may cause flooding of low lying areas connected to
these systems and flooding due to reduced drainage capacity of the system. Culverts intended to provide
drainage during storm events could cause backwater flooding if the tail water levels are higher than the invert of the these structures.
Culverts and storm drain systems that outlet into coastal lagoons or beach areas that could have potential backwater flow problems were identified using the city’s storm drain GIS database. Note that backwater flooding should not be expected for storm drains having functional flapgates. This data was not available
at the time of this study.
Storm water vulnerabilities as a result of tail water from future rates of sea level rise are summarized in Table 7 through Table 11. Culverts and storm drain systems could result in additional flooding not predicted
by the CoSMoS model and additional study is recommended to validate the vulnerability of these storm drains.
TABLE 7: STORM DRAIN SYSTEMS OUTLET TO BATIQUITOS LAGOON – PLANNING ZONE 3
Object ID Facility ID Type Size Downstream Invert Upstream Invert Vulnerable Year
7571 SDC6092 RCP 18 0 0 current
7570 SDC6091 RCP 24 0 0 current
7569 SDC6090 RCP 24 0 0 current
5658 SDC3342 RCP 24 0 0 current
6354 SDC3341 RCP 24 0 0 current
8669 SDC9741 PVC 18 0 0 current
8668 SDC9740 PVC 18 0 0 current
13194 SDP100860 RCP 30 0 0 current
5661 SDC3345 RCP 30 0 0 current
7796 SDC7560 RCP 10 0 0 current
6411 SDC3376 RCP 18 0 0 current
12876 SDC3374 RCP 24 0 0 current
7886 SDC7769 RCP 24 0 0 current
8723 SDC10072 RCP 60 0 0 current
8702 SDC10041 RCP 24 0 0 current
8688 SDC9914 CMP 24 0 0 current
13090 SDP100755 RCP 24 0 0 current
13091 SDP100756 RCP 24 0 0 current
7155 SDC4379 RCP 36 6.27 0 current
6308 SDC4296 RCP 18 6.27 6.4 current
Page 148
Object ID Facility ID Type Size Downstream Invert Upstream Invert Vulnerable Year
6925 SDC4313 CMP 36 0 0 current
8710 SDC10048 RCP 30 0 0 current
7156 SDC4380 RCP 36 3.3 0 current
6647 SDC3730 RCP 72 3.3 20.76 current
6644 SDC3727 RCP 48 5.4 0 current
6645 SDC3728 RCP 48 5.4 5.6 current
6519 SDC3509 RCP 60 8.8 9 2050
6517 SDC3507 RCP 36 1.35 14.03 current
6512 SDC3502 RCP 18 13.5 35.67 2100
7045 SDC4227 RCP 72 0 0 current
6374 SDC3583 RCP 42 10 11.76 current
6618 SDC3700 RCP 72 11.6 14.12 2100
6583 SDC3664 RCP 72 0 0 current
6412 SDC3378 CMP 36 6.53 10.26 current
13616 SDP101287 RCP 30 2.81 3.06 current
5662 SDC3348 RCP 18 0 0 current
Note: Invert elevations with a zero value may be due to missing data
TABLE 8: STORM DRAIN SYSTEMS OUTLET TO SHORELINE BETWEEN AGUA HEDIONDA LAGOON AND BATIQUITOS LAGOON – SHORELINE PLANNING AREAS 2 AND 3
Object ID Facility ID Type Size Downstream Invert Upstream Invert Vulnerable Year
7179 SDC4407 RCP 18 13.47 33.75 2100
7215 SDC4447 RCP 24 0 0 current
8335 SDC8550 RCP 18 0 0 current
7944 SDC7949 RCB 9X20 0 0 current
7914 SDC7904 CMP 18 0 0 current
7943 SDC7948 RCP 18 0 0 current
6337 SDC3237 CMP 12 0 0 current
6335 SDC2924 CMP 18 0 0 current
2963 SDC1250 RCP 18 0 0 current
2436 SDC2925 CMP 18 0 0 current
12776 SDC1308 RCP 18 0 0 current
1743 SDC1332 RCP 18 12.4 33.67 2050
Note: Invert elevations with a zero value may be due to missing data
Page 149
TABLE 9: STORM DRAIN SYSTEMS OUTLET TO AGUA HEDIONDA LAGOON – PLANNING ZONE 2
Object ID Facility ID Type Size Downstream
Invert
Upstream
Invert
Vulnerable
Year
1753 SDC1342 RCP 48 4.25 4.6 current
12698 SDC1351 RCP 18 0 0 current
12696 SDC1349 RCP 18 0 0 current
12694 SDC1347 RCP 18 0 0 current
12692 SDC1345 RCP 18 0 0 current
1754 SDC1343 RCP 18 0 0 current
2844 SDC9833 RCP 96 0 0 current
2933 SDC10009 RCP 24 0 0 current
1536 SDC684 RCP 24 0 0 current
10554 SDC683 RCP 36 0 0 current
11575 SDC949 RCP 36 4.1 5 current
764 SDC1719 RCP 36 5.4 0 current
11671 SDC3246 RCP 60 -1.47 -0.55 current
11686 SDC951 RCP 18 3.8 5.13 current
3142 SDC11611 PVC 6 0 0 current
3143 SDC11618 PVC 6 7.5 9.35 current
3146 SDC11621 PVC 6 7.5 9.35 current
11674 SDC9283 RCP 24 0 7.9 current
13078 SDP100743 RCP 18 8.03 16.39 current
12293 SDC1245 CMP 12 0 0 current
12301 SDC1427 CMP 12 0 0 current
12291 SDC1426 CMP 21 6 21 current
14029 SDP101710 CMP 48 0 0 current
2838 SDC9775 RCP 24 0 0 current
2440 SDC2934 RCP 84 8 13.82 2050
1766 SDC1382 CMP 15 5.75 37.52 current
12691 SDC1380 RCP 48 0 0 current
Note: Invert elevations with a zero value may be due to missing data
Page 150
TABLE 10: STORM DRAIN SYSTEMS OUTLET TO THE VILLAGE SHORELINE – PLANNING ZONE 1
Object ID Facility ID Type Size Downstream
Invert
Upstream
Invert
Vulnerable
Year
1893 SDC1617 RCP 24 17 46 2100
2072 SDC1889 PVC 6 0 0 current
2073 SDC1890 PVC 6 0 0 current
10968 SDC2530 RCP 24 0 35.67 current
12403 SDP100471 RCP 18 10.51 22.59 current
11034 SDC1833 PVC 18 11.4 20.5 2050
Note: Invert elevations with a zero value may be due to missing data
TABLE 11: STORM DRAIN SYSTEMS OUTLET TO BUENA VISTA LAGOON – PLANNING ZONE 1
Object ID Facility ID Type Size Downstream Invert Upstream Invert Vulnerable Year
2036 SDC1834 PVC 12 0 0 current
13651 SDP101322 PVC 18 12 12.29 current
13573 SDP101243 RCP 24 17.3 19.04 2100
13767 SDP101440 RCP 18 9.5 11.04 current
12721 SDC1867 RCP 66 0 20.5 current
13772 SDP101445 RCP 48 8 18 current
13972 SDP101653 RCP 10 0 0 current
2032 SDC1825 RCP 18 11 32.37 current
2901 SDC9969 RCP 48 0 0 current
2309 SDC2519 CMP 24 0 0 current
13516 SDP101185 CMP 24 0 0 current
2670 SDC10535 PVC 18 0 0 current
2311 SDC2522 CMP 18 0 0 current
13515 SDP101184 RCP 24 0 0 current
2266 SDC2457 CMP 18 0 0 current
2268 SDC2460 RCP 18 0 0 current
3044 SDC11256 RCP 18 9 10 current
2285 SDC2479 RCP 72 0 4.4 current
2407 SDC2859 RCP 24 0 0 current
2310 SDC2521 PVC 12 0 0 current
2482 SDC3253 CMP 36 0 0 current
Note: Invert elevations with a zero value may be due to missing data
Page 151
4. REFERENCES
California Coastal Commission, 2015. California Coastal Commission Sea Level Rise Policy Guidance. Adopted August 12, 2015.
Chang Consultants, 2010. Hydraulic and Scour Studies for Proposed Interstate 5 Bridge Widening across
Three Lagoons.
Coastal and Ocean Working Group of the California Climate Action Team (CO-CAT). 2013. State of
California Sea-Level Rise Guidance Document, March 2013 Update
U.S. Geological Survey. Coastal Storm Modeling System (CoSMoS) 3.0 Southern California. https://walrus.wr.usgs.gov/coastal_processes/cosmos/socal3.0/index.html.
Everest International Consultants. 2004. Buena Vista Lagoon Restoration Feasibility Analysis.
Everest International Consultants. 2014. Buena Vista Lagoon Enhancement Project Fluvial and Tidal Hydraulics Analyses.
Inter-governmental Panel on Climate Change (IPCC). 2013. Working Group I Contribution to the
Intergovernmental Panel on Climate Change Fifth Assessment Report, Climate Change 2013: The Physical Science Basis, Summary for Policymakers. September 27th.
Marine Physical Laboratory (MPL), 2010. Hydrodynamic Approach to Wetland Restoration by
Optimization of Bridge Waterways
Moffatt & Nichol. 2015. Bridge Hydraulics Study for I-5 Bridge over Batiquitos Lagoon. Final Hydraulics
Report at 90% Design, prepared for SANDAG and Caltrans District 11. December 2015.
National Research Council of the National Academies. 2012. Sea Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future.
Patsch, Kiki and Gary Griggs. 2007. Development of Sand Budgets for California’s Major Littoral Cells. Institute of Marine Sciences. University of California, Santa Cruz.
San Diego Association of Governments. 1993. Shoreline Preservation Strategy. July 1993.
Stockdon, H.F., R.A. Holman, P.A. Howd, and A.H. Sallenger. 2006. Empirical Parameterization of Setup, Swash, and Run-up. Coastal Engineering 53: 573–88.Trenhail. 2000
Trenhaile, A. 2000. “Modeling the development of wave-cut shore platforms.” Marine Geology, 166, 163-
178.
Trenhaile, A. 2011. “Predicting the response of hard and soft rock coasts to changes in sea level and wave height.” Climatic Change, 109, 599-615.
U.S. Army Corps of Engineers. 1991a. State of the Coast Report, San Diego Region. Volume I Main Report, Final, Coast of California Storm and Tidal Wave Study. U.S. Army Corps of Engineers, Los Angeles
District, Los Angeles, CA.
U.S. Army Corps of Engineers. 1991b. State of the Coast Report, San Diego Region. Volume II Appendices, Final, Coast of California Storm and Tidal Wave Study. U.S. Army Corps of Engineers,
Los Angeles District, Los Angeles, CA.
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Walkden, M.J.A., and Hall, J. 2005. “A predictive mesoscale model of the erosion and profile development
of soft rock shores.” Coastal Engineering, 52, 535-563.
Walkden, M.J.A., and Hall, J. 2011. “A mesoscale predictive model of the evolution and management of a
soft-rock coast.” Journal of Coastal Research, 27(3), 529-543.
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ATTACHMENT B: YEAR 2100 SEA LEVEL RISE HAZARD MAPS
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! ! !!!!Trails
Stormdrains
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Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
EXHIBIT B2Page 156
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Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
EXHIBIT B3Page 157
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Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
EXHIBIT B4Page 158
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Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
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EXHIBIT B5Page 159
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ASSETS
%Lifeguard Towers
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Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
EXHIBIT B6Page 160
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POTENTIALLY VULNERABLE
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Open Space
Planned Community
Transportation Corridor
ASSETS
%Lifeguard Towers
Eù Beach Access Points
^_Sewer Pump Station
! ! !!!!Trails
Stormdrains
Roads
Data Sources:• CoSMoS 3.0 (USGS, Feb 2016), City of Carlsbad, Moffatt & Nichol
05/12/16
EXHIBIT B7Page 161
Sea Level Rise Vulnerability Assessment
Community Participation
EXHIBIT 2
Preparation of the City of Carlsbad Sea Level Rise Vulnerability Assessment included numerous efforts to
inform community members about the projected impacts of future sea level rise. Community members
were also asked to provide input regarding their concerns about sea level rise and their own experiences
with coastal flooding and erosion. The following is a summary of community participation during the
preparation of the Sea Level Rise Vulnerability Assessment.
A. Public Review of Draft Sea Level Rise Vulnerability Assessment
The first draft of the Sea Level Rise Vulnerability Assessment was released for public review and comment
in June 2016. Ten comment letters were received over the 30-day public review period. In general, the
comments received pertain to the time frames chosen to study sea level rise (i.e. years 2050 and 2100),
the choice of consultant team, the state campground at South Carlsbad State Beach, and specific concerns
related to coastal impacts resulting from more recent storm events.
The public comments were reviewed and considered during preparation of the final draft of the Sea Level
Rise Vulnerability Assessment. The public review comment letters are attached in the order in which they
were received.
B. Two Public Workshops
In May and October 2016, public workshops were conducted as summarized below.
Public Workshop May 19, 2016 -The Future of Carlsbad's Coast and Lagoons
The city hosted a panel discussion and community meeting about the future of Carlsbad's coast and
lagoons. The panel included city staff, coastal scientists and the lead project consultant. The workshop
was designed to provide the community with a background on sea level rise science, the regional
perspective on sea level rise and also how sea level rise may affect Carlsbad specifically. Attendees
provided valuable input by filling out public comment and question cards. The workshop was well
attended, with more than 125 attendees, including Carlsbad residents, community members, elected
officials, city staff and interested stakeholders.
Public Workshop October 12, 2016 -Adapting to a Rising Sea Level Along our Coast and Lagoons
The city hosted a panel discussion and community meeting about adapting to a rising sea level along our
coast and lagoons. The panel included members of the project team, including coastal scientists and the
lead project consultant. The workshop was designed to provide an update on the project up to that point
and then a presentation and discussion of sea level rise adaptation strategies and how they may be applied
in Carlsbad. The workshop was attended by about 60 residents, community members, city staff and
interested stakeholders.
Page 162
The public workshop presentations may be viewed on the city Local Coastal Program and Zone Code
Update page under the heading community meetings at:
http://www.carlsbadca.gov/services/depts/planning/sea level rise meeting.asp
C. Presentations to Community Groups
Following the release of the Draft Sea Level Rise Vulnerability Assessment for public review, staff
presentations to various groups were requested by the community or scheduled by the project team.
These presentations enabled city staff to educate residents and stakeholders regarding sea level rise
science and the results of the Draft Sea Level Rise Vulnerability Assessment, and to receive early feedback.
In addition, the presentations were an opportunity to further the regional dialogue on sea level rise in San
Diego. The majority of presentations occurred between mid-2016 and early 2017. Presentations were
given by city staff and members of the consultant team, depending on the type of meeting and expertise
needed to present the information and answer questions.
Presentations were given to:
• Carlsbad Beach Preservation Committee
• Carlsbad High Noon Rotary Club
• Carlsbad Southwest Homeowners Association Group
• City staff from various departments
• SAN DAG Shoreline Preservation Group
• San Diego Climate Collaborative
• Emerging Leaders in Environmental and Energy Policy Network
• The Center for Ocean Solutions
Presentations occurred at regular meetings ofthe groups or in some cases the city hosted meetings. The
project team in attendance at these meetings provided an overview of the city's draft vulnerability
assessment, listened to concerns of the community and interested stakeholders, and responded to
questions.
D. Targeted Outreach to Affected Property Owners and Interest Groups
The Sea Level Rise Vulnerability Assessment identifies the parcels of land along the coast and lagoons that
are vulnerable to sea level rise. To help inform the preparation of the Sea Level Rise Vulnerability
Assessment, city staff and consultants wanted to know what specific concerns those property owners and
interest groups have regarding sea level rise, how their properties have been impacted by recent storm
events, what specific infrastructure and assets are of concern, and do property owners have any plans to
respond to sea level rise. To obtain this information, stakeholder interviews were held with interest
groups and non-residential property owners {i.e., public agencies, utilities, and non-profit groups), and a
survey was mailed to all owners of residentially developed/designated property.
Page 163
Stakeholder Interviews
In June 2016, stakeholder Interviews were conducted with various public agencies, utilities, non-profit
groups and special interest groups, including:
• Agua Hedionda Lagoon Foundation
• Batiquitos Lagoon Foundation
• Buena Vista Lagoon Foundation
• California State Parks
• Caltrans
• City Staff
• Encina Wastewater Authority
• Leucadia Wastewater District
• North County Association of Realtors
• North County Transit District
• NRG
• Poseidon
• Preserve Calavera
• SDG&E
• Sierra Club
• Surfrider
• Vista Irrigation District
Survey of Residential Property Owners
In September 2016, a survey was mailed to approximately 700 owners of residentially
developed/designated property, which is identified as being vulnerable to sea level rise. The survey was
also available on the city's website. In total, 250 completed surveys were returned (including both mail
and on line), resulting in an excellent response rate of 35 percent (a typical community survey response
rate is close to 10 percent).
The survey results are attached.
Page 164
Comments on Draft Carlsbad Sea Level Rise Vulnerability Assessment June -July 2016 (10 total received)
1. June 25, 2016: Terry Van de Kamp, terryvdek@gmail.com
Hi Carl,
If you're concerned about erosion, your immediate focus should be the current problem with rodents -
(squirrels, rabbits and rats). They are consuming the new plants and burrowing into the slope causing
erosion with every rain and even irrigation. Look into it.
Carlsbad resident since 1979.
Terry Van de Kamp
2. July 4, 2016: Donna Suarez, sagebrushd@gmail.com
Hi,
My husband and I have been living in Carlsbad since 1987. I read the Carlsbad Sea Level Rise Vulnerability
Assessment and have a couple of comments.
First, I expect that sea level rise of .5 meter in 2050 and 2 meters in 2100 is probably pretty conservative.
These number come from a 2012 report which should have been updated by now I expect. And no
estimate for 2030?
Second, after reading the report, I fail to understand how the city could have possibly wanted to build a
shopping mall on the Agua Hedionda Lagoon. Don't you think it would have made sense to release this
assessment before proposing the mall? Clearly, a mall at that site makes no sense with the inevitable
flooding that will occur around the lagoon.
I'm looking forward to the final version of the report with a bit more realistic sea level rise estimates.
Thanks,
Donna Suarez
3984 Syme Drive
Carlsbad, CA 92008
Page 165
July 18, 2016: Amanda Mascia, amandamascia77@gmail.com (and attachment)
Mr. Stiehl,
The attached PDF includes my full public comment for the SLR Draft Vulnerability Assessment. Below is
my introduction/overview.
Thank You for your communications and including the public in this very important assessment.
-Amanda
Public Comment Regarding: SEA LEVEL RISE VULNERABILITY ASSESSMENT Draft (June 2016)
Attn: Carl Stiehl
Thank You for the chance to submit public comment on the Sea Level Rise Vulnerability Assessment.
My comments first cover a series of questions, including:
1. Why does Carlsbad predict in a 50 Year Intervals, rather than 20 year Intervals?
2. How much of the SLR Vulnerability Assessment was conducted/supported and signed off on by
Revell Coastal?
3. What went into the decision making process to hire Michael Baker International, an engineering
firm that has done less than sufficient work for Carlsbad in the near past, to be the contractor for
the SLR?
I have also outlined my belief that the projected "moderate" effects of Sea Level Rise in Zones 1,2 and 3
are understated for the year 2050, as "moderate" effects are happening in the years 2011-2016 (through
present day).
Lastly, I suggest that there IS a potential to keep the Carlsbad State Beach Campgrounds viable, as they
can move east on the "old 101 parcel" by finishing a land swap w ith the City of Carlsbad.
Sincerely,
Amanda Mascia July 18, 2016
Page 166
3. July 18, 2016: Rich Breyer, rpbreyer@gmail.com
Attn: Carl Stiehl
Thank You for the chance to submit public comment on the Sea Level Rise Vulnerability Assessment. As
an avid surfer (almost daily} for the past 50 years and a Licenses Civil Engineer in California, I have great
concerns of the rise in sea levels and the effects it is having on our coastline. I have watched Carlsbad
coastal cliffs erode over the past 32 years living in Carlsbad. The rate has increased greatly in the past 5
years. The tie-back retaining wall at Terramar Cove that was built originally without a coastal permit now
has a large void at the north end of the wall created just this past few months. The fence along the top of
cliff on the State own property at Terramar has been relocated at least twice in 30 years due to the sea
cliff eroding and being undermined and cut back for the ocean waves.
My comments first cover a series of questions, including:
1. Why does Carlsbad predict in a 50 Year Intervals, rather than 20 year Intervals?
2. How much of the SLR Vulnerability Assessment was conducted/supported and signed off on by
Revell Coastal?
3. The Campgrounds need to be preserved. My family and friends use and enjoy this special area
for years. I feel that the old piece of 101 needs to be protected and potentially used to move the
campgrounds back away from the eroding cliffs if SLR keeps cutting buck the cliffs as it has done
and predicted to increase in the future.
I have also outlined my belief that the projected "moderate" effects of Sea Level Rise in Zones 1,2 and 3
are understated for the year 2050, as "moderate" effects are happening in the years 2011-2016 (through
present day}.
Sincerely,
Richard Breyer July 18, 2016
4. July 18, 2016: Vickey Syage, vickey.syage@roadrunner.com
Dear Mr. Stiehl,
I have two comments regarding the City's Sea Level Rise Assessment.
First, it is of utmost importance to me as a resident and taxpayer that the City of Carlsbad do everything
in its power to preserve and protect Carlsbad State Beach campgrounds from the impact of erosion. At
one point there was discussion of deeding the old 101 strip of the state in exchange for some other State
property. That seems like a wonderful idea as it would allow the campgrounds to move east. The
campground needs to remain viable as a highest priority.
Secondly, how was Michael Baker chosen to conduct this study for the City? Who were the other
companies that were vetted? Michael Baker was the author of the 9212 Report associated with Measure
A (85/15 Plan} and was a vitally flawed piece of work in multiple areas. I as a taxpayer do not have
confidence in this firm's competence and ability to be unbiased in this Sea Level Rise Assessment.
Thank you.
Vickey Syage
Page 167
5. July 18, 2016: Wesley Marx, wmarx33@sbcglobal.net
Comments-SLR Vulnerability Assessment
Wesley Marx wmarx33@sbcglobal.net July 18. 2016
2995 Ocean St., Carlsbad
Introduction. Planning Zone 1, Village Shoreline
Is the description "low lying" accurate? Many homes are sited on the upper part of a bluff that is
approximately 30 feet above the sandy beach. Re "transitions to high relief", the difference between the
bluff height to the north -the low lying area --and the bluff to the south is approximately 10 to IS feet.
Re "primarily armored", a significant reach from Carlsbad Village Drive to Pine Ave. a distance of over
1,000 feet -is not armored. The beach here tends to be wider than the beach to the north were shore
protection devices can narrow the beach.
Planning Zone 2 Tamarack/Warm Waters Shoreline
Re last sentence "the entire shoreline along this reach is armored ... ", the beach roughly parallel to the
power plant site and which ends at Terramar is not armored. The beach here tend to be wider then
adjacent armored beaches .
Planning Zone 3, Southern Shoreline
Re second sentence "narrow sandy beach", the beaches here, with the exception of the armored segment
adjacent to Encinas Bridge, are as wide or wider then beaches to the north, which are not cited as narrow.
For a narrow beach, see the armored Terra mar beachfront.
5.1.3 Parcels, second sentence," ... fronted by shoreline protection devices."
The study in Attachment A, 2.5 states that the legality, age and state of repairs of such devices is unknown.
Should this be acknowledged here to avoid inference of actual protection?
5.2.4 Is subsidence in developed areas sited on landfill taken into account in evaluating vulnerability?
6.5 Secondary impacts, last paragraph -Sediment management
In the wake of the 2012 regional sand nourishment project, the beach along Ocean Street became
inverted with the berm higher than the backshore. This has resulted in periodic backshore flooding, an
event Dr. Sarah Giddings alluded to in her presentation at the SLR meeting. The nourishment project used
a more coarse sand than prior projects. This coarse sand can result in a steep beach profile that can be a
hazard to bathers and require more lifeguard patrol and rescue resources. Dr. Giddings discussed how
sand accretion in lagoons can lower oxygen levels and damage ecosystems. Should these issues be
addressed as secondary impacts that impact Carlsbad?
6.7 Dams can trap sand that once supplied beaches. Should removal of dams that lose their storage
capacity be considered a policy option to restore sand supply? Another policy option --Support programs
to cut greenhouse emissions that cause se level rise and the ensuing threat to our shoreline.
Page 168
6.7.3 Where does the sand for building up the dunes/berm come from? The existing beach? Imported?
Attachment A, 2.1 The table here appears to be 15 years out of date. The current 2016 tide tables for
southern California cite extreme high tides of 7.4 feet.
Attachment A, 2.2 Is Carlsbad Submarine Canyon considered a sand sink?
6. July 18, 2016: California Coastal Commission, Erin Prahler, erin.prahler@coastal.ca.gov
California Coastal Commission: As requested, specific comments on Sections 6 and 7 of the June 2016
Draft Sea Level Rise Vulnerability Assessment are described below. Commission staff did not review other
sections of the June 2016 Draft because we understand that the City and consultants are still working
through our previous comments provided on April 8, 2016. We look forward to reviewing the next draft
incorporating all of our comments.
6. Adaptation Strategies
Comment 1: The discussion of maladaptation in the second paragraph feels out of place. Perhaps it is
better suited to the Secondary Impacts discussion in Section 6.5.
6.2 The Protection Approach
Comment 1: In our April 8, 2016 comments we noted that this section should more specifically discuss
passive erosion and resulting impacts to recreation and habitat associated with hard solutions. We
suggest adding a short sentence that references the discussion of these issues in Section 6.5 Secondary
Impacts. It should also address questions re: effectiveness of soft solutions. These issues are not
discussed in this section.
Comment 2: The fourth sentence of this section notes that the Coastal Act allows protective devices for
"existing development." This section should describe "existing development" as development that was
in existence when the Coastal Act was passed. See Chapter 8 (pg. 165) of the Commission's Sea Level Rise
Guidance for a detailed discussion.
Comment 3: This section points out that most of the Carlsbad shoreline is currently armored, and that
understanding the permit history, life expectancy, etc., of these structures is important. To reinforce this
issue and explain how it relates to LCP planning, we suggest adding the following: "As explained in Section
6.5 Secondary Impacts, it is critical to also understand the possible impacts to coastal resources that could
manifest overtime if protective structures are maintained in place. Understanding how fast these impacts
could occur, the magnitude of those impacts, and the efficacy of any measures that could mitigate those
impacts is critical for determining whether-and for how long-the protection approach is appropriate for
use in Carlsbad and. therefore. what policy and development standards should be included in the LCP."
Comment 4: This section should link the lifespan of protective devices to the development they were built
to protect. For example, the second to last sentence could be revised to read: "Documenting the age,
height, condition, and permit conditions of both protective structures and the development they were
built to protect will be important to determine the remaining life expectancy of protective structures, and
the longer term viability of maintaining these structures in a regulatory sense."
Page 169
Comment 5: The final sentence of this section should more clearly describe the "additional engineering
work" that existing protective devices will likely need as sea level rises: "Additional engineering work,
including increasing the elevation of existing protective devices, and maintenance will likely be required
to combat future threats from sea level rise in the f1:1t1:1re; however, such analysis is beyond the scope of
this study."
6.4 The Retreat Approach
Comment 1: Clarify the last sentence. For example, "Other more novel approaches to retreat contain a
va-ri-ety include use of conservation easements or rolling easements which p1:1rchase or reg1:1late the right
e-f..limit or prohibit development in order to allow coastal erosion processes to occur into upland property.
Hazard overlay zones could include triggers that identify when development would need to be relocated,
and require that all properties within the zone assume the risk of being in a hazardous environment."
6.5 Secondary Impacts
Comment 1: Revise the second paragraph to clarify why setbacks can be insufficient and to remove the
idea that an acquisition program could eliminate the need for setbacks. Buy-out programs can and should
work in conjunction with setbacks: "Setbacks alone could be considered potentially rnaladaptive
insufficient because they may eventually lead to structures being at risk due to uncertainty in modeling.
Therefore, to be most effective at minimizing hazard risks, it is important to consider elements of retreat,
such as requiring movable foundations or identifying locations for transfer of development. Further,
setting clear triggers for action, such as relocation of development thro1:1gh p1:1blic acq1:1isition, should take
the place of or work in conjunction with regulatory setback policies. Finally, development located in
hazardous areas should assume the risk of being located in a hazardous environment, and waive the right
to any future shoreline armoring."
Comment 2: The third paragraph could be recast as a discussion of short vs. long term costs associated
with failure to take adaptive action. The FEMA funding for severe repetitive loss properties is available
because the long term costs of repetitive losses exceed the costs for doing something about these
developments now. The FEMA funding is available for multiple types of mitigation projects, including
acquisition. This cost analysis issue is not specific to acquisition programs -it could apply to any number
of adaptation strategies, including armoring projects. In areas where the FEMA funding may not be
applicable or not considered due to SLR, similar repetitive loss programs could be implemented within a
Hazard Overlay Zone as a trigger to identify when a development would need to be relocated.
Comment 3: A paragraph should be added under the fourth paragraph (list of impacts from shoreline
protection devices) to describe aesthetic degradation and community character changes that would be
associated with the loss of a beach. This should also be tied to the economic and fiscal impacts that
changes to tourism may have on the local economy.
Comment 4: The second to last paragraph on pg. 28 includes "no usable beach area for 12 months" as a
trigger the Commission has used to identify when coastal armoring should be removed. We are not
familiar with this trigger. Instead, recent approaches have been to tie the coastal armoring to the
structure it is required to protect, and identify that when that subject structure either no longer requires
the protection or encroaches onto State tidelands, then the armoring must be removed.
Page 170
6.6 Understanding Tradeoffs
Comment 1: Revise the first paragraph to read: "The Coastal Commission has Often these are addressed
these adverse impacts through the use of in-lieu fees that req1:1ire additional fees assessed for the loss of
recreational beach area and sand supply. Ongoing 11,rork in the State The Coastal Commission is also
attempting to develop a means to calculate the replacement value of the cost of the sandy beach
ecosystem."
Comment 2: This section appears to be depicting the tension between private versus public benefits, but
that point could be made more explicit.
Comment 3: This section currently lists four classes of decision makers who affect the choice of adaptation
approaches for an eroding shoreline. "The public" should be added as a fifth. The public, including people
who don't live at the shoreline but instead visit it to recreate, have a large interest in these adaptation
strategies. The use of a shoreline among the wider public constitutes the access and recreation concerns
that must be addressed in the LCP.
Comment 4: This section should also describe "existing development" as development that was in
existence when the Coastal Act was passed. See Chapter 8 of the Commission's Sea Level Rise Guidance
for a detailed discussion of this.
6.7 Potential Adaptation Strategies for Carlsbad
Comment 1: The intro to this section could be more concise. Something like: "This vulnerability
assessment is one of the first steps in the City's ongoing Local Coastal Program and Zoning Ordinance
update. The update will include policies and regulations that address the vulnerabilities presented in this
study. Chapter 7 of the CCC's Sea Level Rise Policy Guidance describes many alternative adaptation
strategies. Of those, the following list represent strategies the City will examine more closely in the next
phase of this update project: ... "
Comment 2: Describe why a coastal armoring database would be useful on page 32 (Item 15).
Comment 3: As discussed between Carlsbad and Coastal Commission staff, the City intends to complete
additional work to identify the adaptation measures and strategies to be implemented. The beginning of
Section 6.7 should include language along the lines of: "This section provides a list of potential adaptation
strategies that can be considered in Carlsbad, but does not describe if they should be applied nor detail
about when and where they could be implemented. Importantly, the City intends to undertake additional
work to identify and prioritize adaptation strategies to address the specific vulnerabilities identified in this
Sea Level Rise Vulnerability Assessment. Those adaptation strategies will then be formalized and
implemented through appropriate LCP updates."
Comment 4: Adaptation strategies #1 and #2 should state that the City should consider how long
nourishment and/or sand bypassing could remain effective against SLR, and how to mitigate the
associated economic, ecological, and/or other costs/impacts.
Comment 5: The last sentence in #4 should read, "The landward relocation analysis should consider the
cost to maintain or protect the asset, along with the associated coastal resource and economic impacts
(also called secondary impacts, as discussed in Section 6.5), versus the cost to relocate over the asset's
design life.
Page 171
Comment 6: In #12, please clarify that when a legal non-conforming structure is redeveloped, it should
come into conformance with existing provisions in the LCP for new development. Those provisions should
include the City's updated policies and standards that address SLR concerns, including the minimization
of hazards related to SLR.
7. Conclusions and Recommendations
Comment 1: In our April 8, 2016 comment letter, we noted that the summary of findings for Beaches
states that reduction in beach area will also result in loss of recreational area for beach visitors. Loss of
other beach values should be acknowledged, including public access, habitat/ecological values, and the
function of a beach as a natural storm buffer. These other beach values are still not acknowledged in this
section.
Comment 2: The second to last sentence in the summary of findings for Critical Infrastructure incorrectly
states that "The overall vulnerability to this asset by year 2050 is considered high." It should say "2100."
Comment 3: "Develop coastal armoring database" is listed twice (pages 34 and 35).
7. July 18, 2016: Patricia Amador, amadorap@gmail.com
Mr. Stiehl,
With reference to the Seal Level Rise Meeting of May 19, 2016, I am writing to state my concern for the
California coast line and in particular, the City of Carlsbad, California coastal region. I believe experts
testified during the SLR meeting with more information and emphasis than I can possible convey by email,
regarding the pending or looming destruction that can occur along our coastal region. Carlsbad, California
will potentially experience "increased frequency of (climate) events= increased risks" as stated by Sarah
Giddings, PhD, Scripps UCSD during her presentation at the meeting.
Driving South from Carlsbad through Terramar area, I can see for myself the potential for a cave-in
alongside the roadway on the bluff just South of Cerezo Street. The bluff area will now be permanently
fenced off with no local access for residents or guests due to the potential for the bluff/cave to collapse.
This action along the bluff is the first of many to come as long as humans walk along the bluff or build
houses there. Permanent closure of this area is strongly suggested. I have watched people climb under
the fence at the North fence area and WALK ALONG THE BLUFF TOPS OR SCRAMBLE DOWN THE SIDE OF
THE BLUFF TO THE OCEAN.
Further along the road heading South, just before the campground, the road has already collapsed on the
Western most lane and that lane has been closed to traffic for the last 6 or 7 months. Rocks have been
dumped there to try to stem the pounding by the ocean and I surmise that the ocean will eventually win
that battle.
Clearly, none of us can ignore the warning signs Mother Nature has vividly provided to us, residents of
Carlsbad and visitors. The Agua Hedionda Lagoon has likewise been impacted "by hypoxia" that has
impacted the estuary's ability to oxygenate itself and maintain life.
Page 172
Experts have spoken. We must heed the warnings and make every attempt to reduce activities on the
bluffs to further prevent human-enabled erosion. Climate action groups have formed and strongly
encourage the City to join in their preventative actions, eliminate construction of any type along the
coastal zone and especially alongside roadways near bluffs and coast line.
Another concern is for the campground South of Terramar whose existence is in jeopardy and suggest
they have the option of moving across the roadway to the "old 101 parcel" before the bluffs collapse.
Option: limit human activity in the area.
Thank you for your consideration of these comments. I look forward to reading the City of Carlsbad
Climate Action Plan/Sea Level Rise.
Patricia Amador
Mobile: 858 205 8557
8. July 18, 2016: Jan Bandich, jbandich@att.net
I am responding to the opportunity to provide comments and feedback on the Sea Level Rise Vulnerability
Assessment.
I think most people could relate to 20-year prediction intervals better than 50 years; they don't feel like it
applies to them, let someone else worry about it.
The projected "moderate" effects of Sea Level Rise in Zones 1, 2 and 3 seem to be understated for the
year 2050, as "moderate" effects have been happening from 2011 to present day.
As a resident along the Agua Hedionda Lagoon, I am especially concerned about Zone 2. SLR report, page
15, states "Planning Zone 2 consists of two shoreline planning areas (Tamarack/Warm Water Shoreline
and Terramar/Palomar Shoreline) and the Agua Hedionda Lagoon. Asset$ within this zone are vulnerable
to shoreline erosion, inundation, coastal flooding and bluff erosion in the 2050 and 2100 planning
horizons." This prediction seems to play down the real effects that are already being experienced along
the coast by residents, scientists, visitors and city staff in Planning Zone 2. We saw the highest and lowest
tides ever, up to 7', this year. Can't help but wonder whether dredging would help.
The popular Carlsbad State Beach Campgrounds can remain viable, just move the Campgrounds east on
the "old 101 parcel" by managing a land swap with the City of Carlsbad.
Jan Bandich
May you always have: Love to share, Friends who care, and Health to spare.
Page 173
9. July 19, 2016: Michael Schertzer, mcshertzer@yahoo.com
Dear Carl Stiehl,
Has the Sea Level Rise Study thoroughly addressed potential issues regarding the geological integrity of
the earth and soils below the power plant during and after demolition and what effects Sea Level Rise and
more intense wave action might have on the outer lagoon, the ocean bluffs and other adjacent sensitive
locations? And it should be noted that the last three years have seen the bluffs across from the Power
Plant face uncharacteristic landslides with significant dangers to beach goers and pedestrians alike.
Unstable soil in this area may forewarn other serious problems as well.
Will there be comprehensive testing of the soils deep below the power plant foundation so that potential
toxic pollutants can be factored into the comprehensive Sea Lever Rise analysis?
Nobody knows the extent that leaks, spills and leaching may have had below the Power Plant and other
adjacent locations such as the entire "outer lagoon" section and the base of the coastal bluffs. Could
there be leaked fuel oil that has run from old tanks through very old and corroded pipes to fuel the boilers
for over 60 years? What about solvents, antifreeze, grease, paints, thinners, lead and copper etc.?
The existing Power Plant was originally placed very deep into the lagoon so that ocean water cooling
would be available. Now we are facing a once in a lifetime reconfiguration of this large area which entails
the "Hedionda Lagoon-Pacific Ocean Marine Environment", adjacent surface topography, below surface
geology, the coast highway, coastal bluffs, beaches and the ocean itself.
I urge that no final action be taken regarding the Sea Level Rise Study until the issues above have been
fully and satisfactorily addressed. Failure to do so may result in a multitude of undesirable outcomes that
could have been addressed proactively. The risks caused by failing to address foreseeable conditions far
exceed any problems that may be caused by exercising caution with further scientific study.
Thank You
Michael Schertzer
Carlsbad Ca.
7/18/2016
Page 174
Amanda Mascia
July 18, 2016
Public Comment Regarding: SEA LEVEL RISE VULNERABILITY
ASSESSMENT Draft (June 2016)
Attn: Carl Stiehl
Associate Planner
Community and Economic Development Department
Planning Division
1635 Faraday Ave. Carlsbad, CA 92008
www.carlsbadca.gov
760-602-4605 I carl.stiehl@carlsbadca.gov
Thank You for the chance to submit public comment on the Sea Level Rise
Vulnerability Assessment.
My comments first cover a series of questions, including:
1. Why does Carlsbad predict in a 50 Year Intervals, rather than 20 year
Intervals?
2. How much of the SLR Vulnerability Assessment was conducted/supported and
signed off on by Revell Coastal?
3. What went into the decision making process to hire Michael Baker
International, an engineering firm that has done less than sufficient work for
Carlsbad in the near past, to be the contractor for the SLR?
I have also outlined my belief that the projected "moderate" effects of Sea Level
Rise in Zones 1,2 and 3 are understated for the year 2050, as "moderate" effects
are happening in the years 2011-2016 (through present day).
Lastly, I suggest that there IS a potential to keep the Carlsbad State Beach
Campgrounds viable, as they can move east on the "old 101 parcel" by finishing
a land swap with the City of Carlsbad.
Sincerely,
Amanda Mascia
July 18, 2016
Page 175
Questions:
Amanda Mascia
July 18, 2016
1. Why does Carlsbad predict in a 50 Year Intervals, rather than 20 year
Intervals?
Carlsbad chose to date sea level rise scenarios in 2050 and 2100 (50 year
intervals), whereas other cities that completed SLR's conducted projections every
20 (2030, 2050, 2070, 2100). What was the rationale for not providing a more
detailed breakdown, as seems to be the norm?
2. How much of the SLR Vulnerability Assessment was conducted/
supported and signed off on by Revell Coastal?
3. What went into the decision making process to hire Michael Baker
International, an engineering firm, to be the contractor for the SLR? Have
they conducted SLRs in the past?
There is reason not to fully buy into their viability to assess the entire
Carlsbad coastline, considering the lack of validity found in their previous
Carlsbad work. Carlsbad had contracted Michael Baker International in
2015 for another project, the 9212 Report, on the Agua Hedionda South
Shore Specific Plan.
"The city of Carlsbad commissioned Michael Baker International, an independent
consulting firm, to review Caruso Affiliated's 4,000-page report. The city's
consultant's reports were compiled into the 9212 report"
(Source: http://www. thecoastnews.com/2016/02/15/if-mall-passes-developer-
will-mitigate-more-than-their-impact/)
The work done by Michael Baker International in the 9212 report was
considered by many citizens to not be sufficient:
"Tell that to the long line of residents attending the August 25 meeting, waiting to
explain the shortcomings of the 9212 Report"
(Source: http://sandiegofreepress.org/2016/03/carlsbad-city-council-very-
u nfamil iar-with-lagoon-mal I-review-process/)
"We were very disappointed in the 9212 report. A key concern is that it failed to
identify all of the constraints they were operating under, constraints that call to
question the ability to make any accurate conclusions about the truel impacts of
the project. -Diane Nygaard."
(Source: http://www.osidenews.com/2015/08/11/carlsbad-initiative-report/)
Page 176
Amanda Mascia
July 18, 2016
One issue that gravely concerned many residents, was that the 9212 report
did not include 1-5 or the 101 in the traffic analysis for a project that projected to
bring 24,000 car trips a day to the coastline, and for which many reasonably
deduced would greatly restrict access to the beach. The 9212 traffic assessment
"In short, the 9212 report states traffic will be better at all intersections including
the aforementioned eight, in all three scenarios analyzed" infuriated residents.
(Source; http://www.thecoastnews.com/2016/02/15/if-mall-passes-developer-will-
mitigate-more-than-thei r-i m pact/)
"The report also used out of date standards for evaluating the impacts of
toxaphene contamination in the soil on the project site.
The environmental assessment report:
Lacks the detail necessary to support the recommendations and conclusions
presented, and does not provide sufficient detail for the development of an
actionable Phase II analysis.
Fails to call for detailed sampling and analysis of those parts of post-
agricultural land slated for hiking and biking trails, picnic areas and other
passive recreational activities (P-OS areas) that contain elevated levels of
toxaphene.
Fails to discuss the potential release of hazardous materials in the P-OS
areas, and fails to discuss potential soil remediation efforts.
Fails to discuss the potential impact on hazards if contaminated soil would be
removed from the project site."
(Source:http://www.citizensfornorthcounty.org/soil-contamination.html )
In short, the approved contractor, Michael Baker International has not proven to
be a reliable or trusted contractor for the Citizens of Carlsbad and North County.
2. Zones are vastly under-predicted for effects of
coastal erosion, flooding and for beach impact in the
SLR vulnerability assessment. 2050/2100 predictions
are already happening, now.
Zone 1
SLR report, page 1 O states "Planning Zone 1 includes the Village Shoreline
and Buena Vista Lagoon planning areas. Assets within this zone are vulnerable
to shoreline erosion, inundation, coastal flooding and bluff erosion in the 2050
and 2100 planning horizons."
Page 177
Amanda Mascia
July 18, 2016
Reports from the 2016 storm, seem to indicate that flooding is already happening
on roadways in Planning Zone 1 "Rick Anderson of Carlsbad attested to the
flooding. "I can say that mid afternoon as I drove north on Coast Hwy the bridge
over Buena Vista Lagoon was under water and once past the monument at State
& Carlsbad Blvd there was nowhere to go but forward and hope none of us in
bumper to bumper traffic stalled." (Source: http://patch.com/california/oceanside-
camppendleton/when-it-floods-oceanside-alternative-transport-de-rigueur).
While the SLR refers often to the "100 year storm" as a benchmark for causing
coastal flooding, a report by Everett International Consultants in 2012 for a
Bridge Study at the Buena Vista Lagoon states "The results indicate that the
pattern of impacts for these minor storm events is similar to the pattern of
impacts predicted for the 100-year storm."
(Source: http://www.dot.ca.gov/dist11/Env docs/5NCSupplemental/
1-5 bridge study buena vista lagoon may 2012.pdf)
In short, Planning Zone 1 is experiencing flooding and minimal storm
events can cause it, not just the 100 year storm. We need to be better
prepared.
Zone 2
SLR report, page 15, states "Planning Zone 2 consists of two shoreline
planning areas (Tamarack/Warm Water Shoreline and Terramar/ Palomar
Shoreline) and the Agua Hediona Lagoon. Assets within this zone are vulnerable
to shoreline erosion, inundation, coastal flooding and bluff erosion in the 2050
and 2100 planning horizons." This prediction seems to play down the real
effects that are already being experienced along the coast by residents,
scientists, visitors and city staff in Planning Zone 2:
El Nino preparations in Zone 2:
As recently as 2015, during a year predicted to expect an El Nino storm system,
city official Pat Thomas explained to the Coast News in an article dated
November 12, 2015 that mudslides were a possibility, as well as flooding of the
Agua Hedionda Lagoon.
(Source: http://www.thecoastnews.com/2015/11/12/carlsbad-continues-to-brace-
for-el-nino/)
It's important to review how the city braces for El Nino, because as Sarah
Giddings (Scripps Institution on Oceanography UCSD) detailed in a May 19
Carlsbad Forum on Sea Level Change, El Nino could be a window into the
future. Ms. Giddings outlined the following scenarios as predictions "more
extreme water level event and "larger storms with waves and flooding."
Page 178
Existing erosion, caves and flooding:
Amanda Mascia
July 18, 2016
December of 2015, there was infrastructure damage to the Encinitas Creek
Bridge and Roadway flooding on the seawall at Carlsbad Blvd and Tamarack.
(Source: Scripps Report, May 19)
February 18, 2016. "significant accretion/flooding" at Batiquitos Lagoon and the
Agua Hedionda Lagoon (Source: Scripps Report, May 19)
March 26, 2016 (Seaside Courier) "It's been at least a month since a huge chunk
of cliff in Carlsbad fell into the sea during a winter El Nino storm, but the city of
Carlsbad is still trying to figure out what to do about it. The pounding storm holed
out a 15-foot-deep sea cave that caused the bluff top to collapse. The cave is
close to 30 feet wide and about the same distance high."
March 29, 2016 (LA Times)" A huge sea cave that has opened beneath a
Carlsbad bluff is the latest danger looming along San Diego County's coastline,
which has been battered this winter by high tides and big waves. The cave -
south of Cannon Road in the city's Terramar area -is about 25 feet wide, 25
feet tall and 15 feet deep, and it has prompted authorities to post warning signs
and cordon off the top of the bluff about 50 feet from its edge. "We're all running
from emergency to emergency," said Robin Greene, superintendent of the San
Diego office of the California Department of Parks and Recreation.State parks
officials are considering a number of ideas to deal with the hazard in Carlsbad,
Greene said, including using explosives, cables, inflatable wedge bags or high-
pressure hoses to tear down the cave before it collapses."
(Source: http://www.latimes.com/local/california/la-me-el-nino-caves-
danger-20160329-story.html)
Erosion in this area is not new, in fact it goes back to 2011, as reported by
Surfrider "Goetz Seawall in Carlsbad A seawall was erected under an
emergency permit at Terramar Beach. The City of Carlsbad approved a permit
after the emergency." (Source: https://sandiego.surfrider.org/2011/10/25/
breaking-waves-on-developed-shores/)
The SLR only outlines "moderate" vulnerability for flooding by 2050 in
Planning Zone 2's beaches. This seems drastically innacurate and
optismistic, considering Planning Zone 2 in the years 2011-2016 is already
experiencing moderate effects.
Page 179
Zone 3
Amanda Mascia
July 18, 2016
SLR report, page 21, states" Planning Zone 3 consists of the Southern
Shoreline Planning Area and the Batiquitos Lagoon. Assets within this zone are
vulnerable to coastal flooding and bluff erosion in both planning horizons (2050
and 2100). Approximately 14 acres of beach area is projected to be impacted by
erosion in 2050. Beaches are exposed to any rise in sea levels (high exposure)
but will continue to provide recreation and storm protection benefits during this
time horizon (low sensitivity). "
"State Park I Planning Zone 3
Southern Shoreline -Approximately 2.4 miles of shoreline from Encinas Creek to
the southern city boundary at South Carlsbad State Beach. The shoreline
generally consists of narrow sandy beaches backed by moderate to high relief
bluffs. The bluff tops are developed with camping facilities owned and operated
by the State of California Department of Parks and Recreation. This portion of
shoreline also includes the mouth of the Batiquitos Lagoon, which is controlled by
a jetty system."
The Scripps report also shows the real effects of erosion and flooding over the
last year during winter storm season in Planning Zone 3:
~ Carlsbad State Beach in October 2015, in which the beach is very
narrow and there is "back shore flooding and minimal sand."
~ February 18, 2016. "significant accretion/flooding" at Batiquitos
Lagoon and the Agua Hedionda Lagoon
• (Source: http://www.carlsbadca.gov/civicax/filebank/
blobdload .aspx?BloblD=30791 )
Suggestion: "Old 101 parcel" should be traded to the
State to protect Campgrounds and affordable coastal
access
Section 5.3.3. of the SLR states "A majority of the South Carlsbad State Beach
day-use facilities and campgrounds (separated into four parcels) were
determined to be exposed to bluff erosion by the 2050 sea level rise scenario
(moderate exposure). This resource is considered to have a high sensitivity
since bluff erosion could significantly impair usage of the facilities. Though
economic impacts to the physical structures within South Carlsbad State Beach
would be relatively low, the loss of this park would be significant since
adequate space for the park to move inland is not available (low adaptive
Page 180
Amanda Mascia
July 18, 2016
capacity). State parks was assigned a high vulnerability in the 2050 planning
horizon. State park facilities are recognized as important assets to the City in
terms of economic and recreation value as well as providing low-cost visitor
serving amenities. This vulnerability poses a high risk to coastal access,
recreation, and tourism opportunities in this planning area."
I would like to kindly refute the suggestion that land is not available for the State
Park Campground to move inland, there is, it is the old 101 parcel. A few years
ago there was active discussion between California State Parks and The City of
Carlsbad in regards to a "land swap." The City of Carlsbad owns a parcel
referred to as "the old 101" (running on the western side of the 101, from
Breakwater Road to Ponto Road). California State Parks owns an inland parcel
of land ( around Palomar Airport Road) that they use for storage and consider
non-essential. The two entities had been in negotiations to swap the parcels so
that the campgrounds could remain viable for camping and affordable recreation
by moving east, when coastal erosion took precious camping area. The
negotiations were abandoned in 2012-2013, despite the State Parks investing
significant money (estimated $100,000) in researching the viability of the land
swap. California State Parks is still interested in the parcel, and by all means
necessary it should be obtained to ensure camping for generations to come.
Private Email from State Parks District Superintendant, Robin Greene, to
Amanda Mascia in which I explained about the SLR and the opportunity to lobby
to obtain the parcel as part of the SLR Assessment:
"I am really interested in the specific parcel you are talking about. The property
right outside the campground? That is the most important parcel to the State as it
would allow retreat from the bluff as it erodes through the years. Did the
commission assign an analyst to the proposal?" -May 16, 2016
-Amanda Mascia
July 18, 2016
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on lagoon
Buena Vista
near a lagoon
on laggon with dock
Buena Vista Jefferson St 2525 L
Agua Hedionda
Buena Vista Lagoon
Bristol Cove Channel
Near Lagoon
Next to Buena vista Lagoon
Bristol Cove on the Lagoon
Bristol Cove off Agua Hedionda Lagoon
ON THE LAGOON
NEAR A LAGOON
NEAR A LAGOON
NEAR A LAGOON
condo on the lagoon
near a lagoon
near a lagoon
near a lagoon
Juniper and Carlsbad Blvd.
Agua Hedindia
Hedionda
On Agua Hedonia Bet Power Plant/Tamarack
Agua Hedionda
In the new Summerhouse development just south of San Malo
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Responses
and slightly concerned
If your property sustained
damage, please explain (provide as much
detail as possible regarding the location
and extent of damage, or email photos of
the damage to carl.stiehl@carlsbadca.gov).
We checked the tidal wave map and we should be ok.
Carpeting got wet near patio sliding door and furniture moved.
The huge boulders that surround the left side of the building have had to be replaced and replenished recently due to
the water rising and especially to storms. This project was recently completed however, the recent storm carried many
of the rocks/boulders out and down the lagoon.
damage 25 plus years ago
In the very bad storm of 83-84 (approx.) we lost half our stairway to the beach and water came up to the lowest
cottage. There was erosion of the beach below the cottage because of the storm, five of us on Ocean St. were
allowed to push in boulders to protect our properties.
Waves have damaged granite (sp?) sea wall that protects our bluff and concrete stair leading to beach. Several
thousands in repair and replacements over last five years. We have owned property for more than 30 years and
frequency of high creef (sp?) levels appear to be increasing.
I have walked the beach for 63 years, haven't seen any change. 83/84 elenor (sp?) storm high tides and wind storm at
same time. Some bluff damage. I've been told by Dr. Patrick Boldl (sp?) of Red Doluod (sp?) that our coastal plates
are actually rising? Hope we get some facts.
We are living @ summer house since 2/16. We have no knowledge of any floor issues prior to that time.
Somewhat concerned about our property, extremely concerned regarding sea level rise in general
Our sea wall and entry stairs get battered by high tides and surf. They are deteriorating and in need of costly repairs.
We live at Seaslope on the lower level. Many years ago, before we purchased, a storm did break windows and glass
doors, and there was water damage to the interior. No problems since, although the winter of 2015-26 had water come
to the bottom of the deck which is about 5 feet above the sand. Believe it to be a combination of loss of sand on beach
and strong tides.
Dredging of canal in Bristol Cove. Reposition/repcitce rip/rap on lagoon side of condo complex
Rain did water damage, du to the fact our 3 story building is over 30 years old and porches on 3rd floor are rotting the
wood, from rain over the years. 4513 Cove Drive
Concern that time share developers will impact the beauty of the lagoon.
There is a granite walking path above Agua Hedionda Lagoon, in front of our 42 unit Bayshore townhouses. It ends @
Tucasa. Over the last 6 years since we have lived here, the rain causes further erosion down the path to the lagoon
beach. Also the high tides then add to the erosion. Getting very close to some backyards here @ Bayshore.
No significant data shows this. Data does show that history repeats some.
High waves in Jan/Feb. formed sand on the ice plant at the base of the private beach. Nothing much that time.
Previous owner reports that there was major damage during storms in the early ?O's. She had photos. I do not have
those at this time. The house that is being constructed is 30ft (+/-) east of location or original house. Recent damage
has only been wind related.
Just purchased condo at 2387 Ocean St.
Change of address. we still own the condo at 3430 Carlsbad Blvd. 92008. We are renting at 2769 Glasoow Dr.
Carlsbad 92010
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Water damage due to heavy rain and very strong winds which required replacement on hardwood floors in southeast
facing room. The water came in through the below the door frame. This was probably a combination construction and
weather issue but the type of storm was definitely a major factor.
Nothing since the 1980's. Seawall was installed at base of bluff. No damage since.
We have had significant erosion of our shoreline in front of our condo on Hedionda lagoon. We moved here in 201 O
Stairs to beach eroding Railing needed repair Large rocks moving greatly
No damage, rising water table noticeable in gardens.
Rip rap height lowered-undermined by sand removal, C. A. Smith
Stupid waste of$. DO not buy into tree hugger confiscation of tax $$
Due to high tides and rising sea levels damage was done to landscaping closest to the water. Further damage was
incurred due to Lifeguard vehicles driving on landscape on private property.
No damage and no coastal beachfront erosion/denegration of rock rip rap revetment at 5015 Tierra Del Oro
High waves over rock rip rap cause damage to steps to beach. Dangerous to get to water now. Need additional rip rap
to protectfrom additional damage and repair steps. Thank you, Jim Milstrap, 5067 Shore Dr., 760-431-6900
Backshore flooding can block beach access.
We have gunite fortunately but it has damaged it and we are repairing as soon as tide is down enough. Tide has taken
out our handrail down to the beach.
I am on 3rd Floor
Never property though
Wave damage 30 years ago
No change in the last 9 years
I live on the beach and every high tide in the past the water has caused damage to our beach front property
Mostly Coastal erosion of sand. I have a sea wall, however I would like to work with the city/ccc to shore up the sand.
Best, Donna Bower
No damage
Our sea wall has experienced some erosion due to coastal waves. We typically will have to redo these walls every few
years.
We have a gate and up to 12 steps heading from our property onto the beach. At the present time, all stairs are
covered with sand and the sand comes to the bottom of the gate. If the san rises any higher we will not be able to get
the gate open.
1983 El Nino storms removed the backyard
Years ago during an El Nino, underground water caused our bank on the lagoon to start sliding. Don't know if it is still
happening.
Around Easter 1976 the ocean came into our lower floor condo unit (Seaslope #6) In January 1988 the ocean again
broke into our condo unit #6
When it rains with offshore winds, sometimes water comes into the home
This is the second time I've received this.
N/A
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Our house is not on the immediate shorefrontand is on the rise of the bluff top, beyond the hazard zones shown on
the map.
The sea wall is deteriorating due to tides and waves. As it goes, the bluffs/slope will disappear. That will cause the
house to wash into the ocean.
none
see 5
Concerned about conversionof fresh water to salt in B.V. lagoon
Yard
Sea rising could reach 1st floor of the building
none
no
Lower deck @private beaches
Lagoon roadside errosion
Large breake water rocks brought in by the Owalevs in the 20's.
no
revetment
Condo right on ocean. As long as curretn sand level is maintained, I don't think there will be a problem unless a major
tsunami occurs.
N/A
no
Patio cover, Flooding of street
If sea rises in Buena Vista lagoonit could innvade our property@ 2399 Jefferson St.
Bristol cove rip rap and surrounding
N/A
Bluffs continue to erode due to tides and people climbing down.
very close to the water on the lagoon
Bluff and sewall maintenance is imperative. Any change in curretn allowed maintenance will result in ultimate loss of
property.
Stairs and slope eroding, large rocks moving
any erosionunder lower patio
Not unless significant rise
none
I live at Laguna Delos Palos, 2525 Jefferson St. My unit (B) is right on Jefferson St. but other units are on a bluff
directly above Buena Vista Lagoon. Don't know if my unit would be in danger but other units right above the lagoon
ceratinly might be in danger.
Rip Rap
none
Steps/stairs adn landscaping, with repeatewd high tides, especially during winter storms, steps/stairs and handrialsto
the beach are at risk for being washed away
NA
none
no
none
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no
no
Deck
N/A
Condo (First floor, Ground level)
Pools
Boat dock, patio & pool area: lower floor of my condo. Jacuzzi, Garage
BLUFFS AT THE OCEAN
DOCK
none
Drainage
none
none
Underground parking structure and small patio 3
none
I think there is potential for a sink hole out in front of building @817 Kalpati Circle, Carlsbad
None
Beach side of condo complex-deck
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We must repair the wall and keep the stairs in good repair. We depend on SAN DAG for sand replenishment.
Sand replenishment was extreme success. We have been on Ocean St. since '65.
HOA plans a special assesment to replace
none
Dredging of Agua Hedionda Lagoon. City should be a part of NOAA Float Program. Carlsbad is th eonly beach city in
SD County and Orange not in the program
none
no
maintenance of existing revetment, if possible
Property is townhome so HOA governed. Not sure o fprocedures on this aspect.
Do not no. The slopes are protected you can not do anyhting. That is my understanding.
Grade for flooding, modify gutter to larger size
I did repair the construction issue mentioned above but live in a condo so options are limited.
Sand replenishment is crucial.
Boulders in front of bluff
Bluff is currently covered with shotcrete. Owner contracts for regular maintenance.
Noway
none
NA
none
Drainage system is complete and functioning
no
no
concern-seawalls/secondary imputs-narrow beach, loss of storm buffer, recreation
no
Plant ice plant
N/A
RISK IS LOW. NO REAL PLANS. REQUIRED TO HAVE FLOOD INSURANCE.
NONE
unknown
Not necessary!
no
none
none
Rocks along embankment
would be important to keep up with
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Live in a condo, association members/delegates determine steps to take, if necessary
sea walls completed 30 years ago
none
No plans
No
None
Decision is based on homeowners association since it is a condo
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What other information would you like
us to know?
We need an annual ongoing sand replenishment program.
Residents within 1 /4 mile of lagoons, ocean should be receiving data. I had to attend a meeting just to find out of this
survey. City needs to be better at informing public with data/websites.
I live at the Bristol Anchorage Complex off of Park Drive which is situated off an inlet on the lagoon (Agua Hedionda).
In my opinion it would have to be high tide and the sea level would have to raise drastically for this to affect my
property. However, I'm interested in the outcome of your study.
New resident. Have little experience on how rains, flooding affect the area
Our property is at the end of the Bristol Cove inlet and well above high tide time--not a high risk area.
Permits are an issue. Coastal commission too much control.
Our building was built in 1979 and we have never had any flooding or water issues from the lagoon.
When they built the marina and Oceanside Harbor they unnaturally blocked the flow of sand. That has harmed the
beaches of sand replenishment. Then they damaged the San Louis Rey River all hurting sand replenishment It's all
the government's fault for no natural sand replenishment. Fix those and we will have plenty of sand in Carlsbad
beaches.
I am probably more interested in its effect, than concerned. Have studied sea level rise for many years. Have worked
with David Cannon on the effect of sea level rise on the BVL. I hope you have read his analysis--It shows the effect
on the lagoon and especially St. Malo (sp?) as a result of the state of California mandated sea level rise of 66 inches
by 2100.
There are multiple issues. As sea level rises, public access to the beach is diminished. Homeowners facing the coast
will push for bigger sea walls, which in turn diminish public access. I support the proposal to expand open space
around the existing Terramar private access, because it will allow continued public engagement of the coast. It should
be public, not private.
Uniform sand replenishment could work for future. 1. saves structures 2. better beach for tourists 3. has lasted well
Need testing protocol for De-Sal Environmental Impact please!
We have a concern ... on the lagoon there is an entrance to the lagoon. Large numbers of people use this for paddle
boarding, walking the dogs or sunbathing. There are no bathrooms. The city needs to close this to dogs. If you ran a
health check of the area you would find it highly contaminated.
City should have Evaporation signs. Training like CERT, flooding, control surge from growth etc.
Keep Buena Vista fresh water!
Draining of changing the regime of Buena Vista Lagoon will not improve any. Negative affect of any perceived sea
level rise or fall. 75 Years from now, residents of Carlsbad may be populating "Islands" built off our coast.
Our complex is next to marina units
Even though our Summerhouse Condominiem is not at risk for damage from rising sea levels, we are extremely
concerned because of the global impact.
Stop allowing development on the lagoon! Too many people, far more dangerous!
I would like to know all the information available about the rise of the ocean. I have always loved the ocean since my
childhood. 3820Carlsbad Blvd. Apt D Carlsbad CA 92008-4004 phone: 760-729-5350
I'm glad to see your concern about this.
Beach sand provides first line of defense. Oceanside harbor prevented migration of sand to Carlsbad. Federal Court
should provide funds to remiediate all Carlsbad beaches.
We live in a town home community-so it's decisions come frorn the "board" after input from us homeowners.
Address 2445 Ocean St.
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Sea Level Rise Survey of Residential Property Owners September 2016
Looks gradual. Neighboring Associations noticeable erosion.
Do not waste tax payer$$ on bogus junk science.
I would like to respectively request that city/state officials not drive on my private property, as this causes plant
damage, making it easier for further erosion.
I think fear of climate change is without basis.
I have not noticed any global warming/sea level rising issues with our oceanfront property.
Get rid of homeless people on beach who invade private property
support reduction of green house gas emmisions, responsible for SLR. electric/hybrid vehicles, urban forests,
renewable energy
Why are you doing a survey like this?
On Bristol Cove Channel
Lagoon resoration needed as a matter of priority.
I took out flood insurance!
AHLF replaced Seawall. Thank you. I'm moderately concerned. There is a public easement that gets washed away
and it would be nice if sand were there.
We live on Agua Hedionda Lagoon. The Desalinization plant has created major issues for us and the marine life and
plants with devastating effects. Increased salinity, sea kep eradication, and decrease of sea life in the the water, along
the shore, and the air .... fish, crabs, birds, etc. In the decades to come Global Warming will create a rise in sea levels.
I'm not sure if before we purchased the property if the city was more involved in the construction and maintenance of
the sea walls. It would be nice to have a consistent solution to ensuring the integrity of these walls.
Garbage cans placed on beach will be spilled due to water. There should be NO garbage cans on beach level.
No concerns during my lifetime
Since the bluff is eroding on Carlsbad Blvd between Cerezo and the state park, I would like to see some sort of a plan
to put in a sea-wall to reoke future erosion
Carlsbad is an awesome place:)
When are you going to do something about the BV lagoon? Overgrowth of plants and disappearing water, soon to be
desert!
My concern is dog poop, oil, trash running into ocean and lagoon.
We sit about 10-151 above lagoon.
Keep Buena Vista Lagoon Fresh Water!
I just bought the house in May and have not thought about the rising ocean threat.
The beach sand has all but disappeared in the last few decades due to redirection of the water by the state that used
to bring sand into the beaches. This used to protect the houses from exposure. Now the coastal commission puts all
the burden and restrictions on the homeowners, they need to have the state fix the original problem!
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Overview of Sea Level Rise
Vulnerability Assessment
DEV 15-061
Carl Stiehl
Gabe Buhr
Laura Engeman
Richard Beck
Sea Level Rise
Vulnerability Assessment
How did we get here?
•Local Coastal Program (LCP) Update
•California Coastal Commission
•LCP Grant for Sea Level Rise Assessment and
LCP Update
•Assessment informs LCP Update
Who has been involved?
•Consultant Team
Michael Baker International
Moffatt & Nichol
Revell Coastal
•California Coastal Commission
•Interested Residents and Stakeholders
•San Diego Climate Collaborative
Coastal Act = State + Local
Local Coastal Programs (LCPs)
•Land Use Plan & Zoning Ordinance
•Delegates permit authority to local government
Santa Monica Beach
Photo Credit: Coastal Commission staff
California Coastal Trail, San Francisco
Photo Credit: Coastal Commission staff
SLR Guidance Contents
1. Introduction
2. Guiding Principles
3. Sea Level Rise Science
4. Consequences of SLR
5. Addressing SLR in LCPs
6. Addressing SLR in CDPs
7. Adaptation Strategies
8. Legal Context
9. Next Steps
Chapters
A. Sea Level Rise Science
B. Local Hazard Conditions
C. Resources
D. LCP Amendment
E. Funding Opportunities
F. Coastal Act Policies
G. CCC Contact Info
Appendices
Adaptation Planning & LCP Updates
•Sea Level Rise Guidance provides a library of adaptation strategies
•Applicable to either LCPs or individual projects
•Organized by Coastal Act resource, then planning goal
Grants for LCP Updates
Round 1: 2013
$1,000,000 to 11 jurisdictions
Round 2: 2014
$1,000,000 to 13 jurisdictions
Round 3: 2016
$3,000,000 to 14 jurisdictions
Regional Coastal Sea Level Rise
•Oceanside
•Carlsbad
•Encinitas
•County
•Solana Beach
•Del Mar
•San Diego
•SDG&E
•Navy
•Port of
San Diego
•Imperial Beach
•Tijuana Estuary
NOAA Regional Coastal Resilience
Project
Regional Working Group
40
Scientific Advisory Committee
Local Coastal Planning Tools
Living Shorelines
Outreach
Regional & State Resources
•Coastal Commission SLR Policy Guidance
•State SLR Guidance (currently being updated)
•CoSMoS Coastal Storm Modeling
•Navy: Climate Change Adaptation Strategies
for Military Coastal Installations
•Other City examples
•FEMA Hazard Mitigation Programs
How Is Carlsbad Planning
for Sea Level Rise?
2015/16 El Nino Provided
“a glimpse into the future”
Las Encinas Bridge, Carlsbad Blvd.
Photo Credit: San Diego Union Tribune
Modeling Assumptions
•Inputs
•100 year storm
(waves and rain)
•Extreme water levels
•Outputs
•Future Bluff Position
•Future Shoreline Position
•Future Flooding Limits
•Uncertainty bands
Carlsbad Planning Areas
Modeling Analysis and Mapping
Stakeholder Outreach
•Public/City Workshops
•May 19, 2016
•October 12, 2016
•February 14, 2017
Stakeholder Outreach
•18 Stakeholder
Interviews
•Residents
•Local Agencies
•State Agencies
•Non-Profits
•Coastal Resident
Survey
•Dedicated Website
Survey Questionnaires
•250 Respondents
•60% Near Lagoon
•30% North Carlsbad
•15% Terramar
•14% of respondents had past coastal
damage.
•At risk, 55% properties with bluffs or
slopes.
Noted Vulnerabilities
•Beaches
•State Parks
•Buildings
•Critical Infrastructure
•Transportation
•Environmentally Sensitive Lands
Adaptation Strategies
Do Nothing Accommodate
Protect Inland
Relocation
Hybrid
Adaptation Strategies
Adaptation Examples
•Monitoring and Triggers
•Nourishment Projects
•Relocation of assets
•Building/Zoning Code Revisions
•Rolling Easements
•Fee Acquisition
•Armoring, Setbacks, Elevating CCC Coastal SLR
Guidance 2015
Next steps:
Planning, Development and Approval
•Continued use of data
•Continued coordination with coastal staff
•Development of specific coastal policies
•Complete draft LCP/Zoning
•Public Hearings
Sea Level Rise
Vulnerability Assessment
City Council Input:
•Key areas of concern to
inform LCP Update
•Thoughts on adaptation
strategies
•Important considerations
on our coast