HomeMy WebLinkAboutJefferson County Sea-Level Rise Study
FINAL
JEFFERSON COUNTY SEA-LEVEL RISE STUDY
Prepared for June 2023
Jefferson County Department of
Community Development
JEFFERSON COUNTY SEA-LEVEL RISE STUDY
Prepared for June 2023
Jefferson County Department of
Community Development
This report was prepared using grant funding from the Washington Department of Ecology’s 2021-2023 Shoreline Master Program Competitive Grant (Grant Agreement No. SEASMPC-
2123-JCDCD-00011)
Services provided pursuant to this Agreement are intended solely for the use and benefit of the Jefferson County Department of Community Development.
No other person or entity shall be entitled to rely on the services, opinions, recommendations, plans or specifications provided pursuant to this agreement without the express written consent of ESA, 575
Market Street, San Francisco CA 94105.
5309 Shilshole Avenue NW Suite 200 Seattle, WA 98107 206.789.9658 esassoc.com
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TABLE OF CONTENTS
Page
1. Introduction .................................................................................................................. 1
2. Existing Conditions ..................................................................................................... 2 2.1 Project Study Area ................................................................................................ 2 2.2 Coastal Flooding Processes and Historic Events ................................................. 3 2.2.1 Tidal Datums and Sea Level Trends .......................................................... 3 2.2.2 Extreme Event Flooding ............................................................................. 4 2.2.3 Historic Erosion .......................................................................................... 6
3. Data Collection and Processing ................................................................................. 8 3.1 Sea-Level Rise Scenarios .................................................................................... 8
3.1.1 Regional Sea-Level Rise Projections ......................................................... 8
3.1.2 Jefferson County Sea-Level Rise Scenarios .............................................. 9 3.2 Existing Studies .................................................................................................. 10 3.2.1 Prioritizing Sea-Level Rise Exposure and Habitat Sensitivity Across Puget Sound ................................................................................ 10 3.2.2 The City of Port Townsend Sea Level Rise and Coastal Flooding Risk Assessment ..................................................................................... 11 3.3 Site Visits ............................................................................................................ 11 3.4 Asset Inventory ................................................................................................... 11 3.5 Community Engagement .................................................................................... 12
4. Future Storm Flooding and Erosion ........................................................................ 14 4.1 Future 100-year Flooding Hazard Zone Development ........................................ 14 4.2 Future Erosion Hazard Zone Development ......................................................... 16
4.3 Exposure Maps ................................................................................................... 17
5. Vulnerability Assessment ......................................................................................... 27 5.1 Methodology ....................................................................................................... 27 5.1.1 Assets ...................................................................................................... 27 5.1.2 Exposure to Hazard and Consequences ................................................. 27 5.1.3 Sensitivity to Hazard and Adaptive Capacity ............................................. 28 5.1.4 Adaptive Capacity of Asset ...................................................................... 29 5.1.5 Vulnerability Summary ............................................................................. 29 5.2 Jefferson County Vulnerabilities .......................................................................... 30 5.3 Summary of County Vulnerabilities ..................................................................... 38
6. Potential Adaptation Strategies ................................................................................ 40 6.1 Existing Adaptation Guidelines ........................................................................... 40 6.1.1 Climate Change Preparedness Plan for the North Olympic Peninsula ................................................................................................. 40
6.1.2 Lessons Learned from Local Governments Incorporating Sea
Level Rise in Shoreline Master Programs ................................................ 41 6.2 General Adaptation Strategies ............................................................................ 41 6.3 Potential Adaptation Strategies for Jefferson County ......................................... 44 6.3.1 Beach and Dune Nourishment ................................................................. 44
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6.3.2 Beach Retention Structures - Groins ....................................................... 45 6.3.3 Beach Retention Structures - Breakwaters .............................................. 46 6.3.4 Beach Retention Structures - Kelp Bed Restoration ................................ 46 6.3.5 Coastal Bluff Erosion Best Management Practices .................................. 46 6.3.6 Shoreline Protection Devices ................................................................... 47 6.3.7 Elevating or Waterproofing Structures and Infrastructure ........................ 49 6.3.8 Elevating Property Grades ....................................................................... 50 6.3.9 Managed Retreat ..................................................................................... 51
7. Next Steps and Recommendations .......................................................................... 53
8. References ................................................................................................................. 54
9. List of Preparers ........................................................................................................ 58
List of Figures
Figure 1 Project Area: Jefferson County ............................................................................. 2 Figure 2 Sea-Level Rise Trend at Port Townsend .............................................................. 4 Figure 3 100-year Still Water Elevations ............................................................................. 5 Figure 4 100-year Total Water Elevations ........................................................................... 6 Figure 5 Historic Bluff Recession Rates.............................................................................. 7 Figure 6 Example of Relative Sea-Level Rise Projections .................................................. 8 Figure 7 Morphological and Hydraulic Response of an Erodible Shoreline to Sea-Level Rise ........................................................................................................ 15 Figure 8 Morphological and Hydraulic Response of an Erosion-Resistant
Shoreline to Sea-Level Rise ............................................................................ 15
Figure 9 Hazard Mapping of Discovery Bay ...................................................................... 18 Figure 10 Hazard Mapping of Beckett Point ....................................................................... 19 Figure 11 Hazard Mapping of Port Ludlow ......................................................................... 20 Figure 12 Hazard Mapping of Port Hadlock ........................................................................ 21 Figure 13 Hazard Mapping of Mystery Bay (Nordland) ....................................................... 22 Figure 14 Hazard Mapping of Squamish Bay ..................................................................... 23 Figure 15 Hazard Mapping of Quilcene .............................................................................. 24 Figure 16 Hazard Mapping of Brinnon ................................................................................ 25 Figure 17 Hazard Mapping of Jefferson County’s West Coast ........................................... 26 Figure 18 Components of Vulnerability ............................................................................... 30 Figure 19 Components of Vulnerability ............................................................................... 32 Figure 20 Sea-Level Rise Adaptation Strategies ................................................................ 42 Figure 21 Protective Adaptation Examples ......................................................................... 43
Figure 22 Accommodation Adaptation Example ................................................................. 43
Figure 23 Retreat Adaptation Example ............................................................................... 44 Figure 24 Cross-Section of Beach Nourishment, Dune Restoration, and Cobble Placement ........................................................................................................ 45 Figure 25 Example Processes Around Groins .................................................................... 46 Figure 26 Example Seawall within Jefferson County .......................................................... 47 Figure 27 Example Revetment within Jefferson County ..................................................... 48 Figure 28 Coastal Squeeze Process Resulting in Beach Loss ........................................... 49
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List of Tables
Table 1 Tidal datums at Port Townsend (#9444900) ......................................................... 3 Table 2 Tidal datums at Quillayute River at La Push (#9442396) ...................................... 4 Table 3 Range of Sea-Level Rise Projections for Jefferson County, Washington ........... 10 Table 4 Sea-Level Rise Projections Used in CGS 2022 .................................................. 10 Table 5 Sea-Level Rise Projections Used in City of Port Townsend and Cascadia Consulting Group 2022 .................................................................................... 11 Table 6 Hazard Exposure Grading .................................................................................. 28 Table 7 Hazard Sensitivity Grading ................................................................................. 28
Table 8 Hazard Adaptive Capacity Grading ..................................................................... 29
Table 9 Jefferson County Vulnerabilities ......................................................................... 30 Table 10 Summary of Vulnerability .................................................................................... 39
Appendices
Appendix A. Site Visit Notes and Photos ...........................................................................A-1 Appendix B. Exposure Tables ...........................................................................................B-1
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1. Introduction
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1. INTRODUCTION
Coastal communities have long been accustomed to responding to hazards such as flooding,
tsunamis, waves, and erosion, among others. As global temperatures continue to warm, melting
polar icecaps and rising sea levels, these hazards will be exacerbated, becoming both more
frequent and intense. Identifying, preparing for, and adapting to the threats posed by sea-level rise
on the social, economic, and environmental systems that depend on the coast, will be one of the
defining challenges of the century.
For Jefferson County, Washington, which has shorelines along both the open coast of the Pacific
Ocean as well as the Puget Sound, planning for sea-level rise is critical. The Jefferson County
Department of Community Development (DCD or County) is tasked with preserving and
enhancing “the quality of life in Jefferson County by promoting a vibrant economy, sound
communities, and a healthy environment.”1 The DCD upholds this mission by drafting and
implementing land use policies and regulations, reviewing and permitting building and land uses,
and coordinating with other County departments, and State and Federal agencies. The DCD is
taking a proactive approach to determining the potential county-wide impacts of sea-level rise
and identifying adaptation strategies and actions in response.
The County contains numerous miles of low-lying marine shoreline with rural development and
steep bluffs along high-energy marine environments, all of which will be affected by sea-level
rise. This study identifies areas of the County that are most vulnerable to sea-level rise, addresses
potential risks, and identifies strategies that may be applicable for addressing these risks.
Community outreach was conducted to solicit input on community priorities. Additionally, a
stakeholder advisory group provided input on the study approach and results. The
recommendations included in this study are consistent with state guidelines and intended to be
incorporated into the County’s current and long-term planning efforts, such as Shoreline Master
Program amendments, Critical Area Ordinance updates, and identification of areas most at risk
during permit application review.
1 https://www.co.jefferson.wa.us/351/About-the-Department
2. Existing Conditions
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2. EXISTING CONDITIONS
This section describes the study area and coastal physical processes along Jefferson County’s
shorelines. This section also discusses the relevant planning context for future coastal hazard
management.
2.1 Project Study Area
Jefferson County is bordered to the north by Clallam County and to the south by Grays Harbor
and Mason Counties and spans the width of the Olympic Peninsula. This results in Jefferson
County having two distinct coastlines – one bordering the open Pacific Ocean and the other
facing Puget Sound – with distinct characteristics and planning and engineering considerations.
Figure 1 illustrates the County boundaries.
SOURCE: City limits: WSDOT, 2023; Federal American Indian Reservations: Esri, 2023; Study area: ESA 2023
Jefferson County SLR Study
Figure 1
Project Study Area and Site Visit Locations
Permitted shoreline uses in Washington State are guided by the state’s Shoreline Management
Act and individual city and county Shoreline Master Programs (SMPs). SMPs are local policies
and regulations that account for varying public and private uses of marine and freshwater
shorelines related to public access (to and along beaches), natural resources, and water-dependent
2. Existing Conditions
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uses (e.g., piers, marinas, ferry terminals, aquaculture, maritime industry, and others). While
hazard mapping was completed for the entire County, the vulnerability assessment was focused
on the eastern marine shoreline defined by Jefferson County’s SMP (see Figure 1), where the
population, extent of development, and permit rates are much higher than on the western
shoreline.
Though within the County’s boundaries, the study does not include an analysis of impacts to Port
Townsend, federally owned land, or tribal reservations (see Figure 1) because they are not within
the County’s SMP. Lastly, the inland extent of the study area was determined based on existing
and projected future hazard zones (as described in Section 4).
2.2 Coastal Flooding Processes and Historic Events
2.2.1 Tidal Datums and Sea Level Trends
Jefferson County experiences mixed semidiurnal tides, or two daily high tides and two daily low
tides of differing elevations. These daily tides also vary with the spring-neap tidal cycles, which
occur approximately twice a month. Tables 1 and 2 present the tidal datums for Port Townsend
(Puget Sound) and Quillayute River at La Push (Pacific Ocean). The tidal gauge on the Quillayute
River falls outside of Jefferson County but is the nearest to the County on the west coast.
The Port Townsend gauge has been recording water level data since 1972. The relative sea level
trend recorded over this period is +1.81 mm/year, which is equivalent to 0.59 feet over 100 years
(Figure 2). The water level record for the Quillayute River gauge dates back to only 2004;
therefore, sea-level rise trend information is not available from NOAA for this gauge. Note, as
discussed in Section 3.1, future sea-level rise is expected to accelerate.
TABLE 1 TIDAL DATUMS AT PORT TOWNSEND (#9444900)
Tidal datum Abbreviation ft. MLLW ft. NAVD
Highest Observed Tide HOT 11.73 10.68
Highest Astronomical Tide HAT 9.99 8.94
Mean Higher High Water MHHW 8.52 7.47
Mean High Water MHW 7.84 6.79
Mean Tide Level MTL 5.17 4.12
Mean Sea Level MSL 5.00 3.95
Mean Low Water MLW 2.50 1.45
North American Vertical Datum of 1988 NAVD 1.05 0.0
Mean Lower Low Water MLLW 0.00 -1.05
NOTES:
The tidal datums listed above are from the most recent tidal epoch: 1983-2001. Datums were converted to from the tide gauge standard
to NAVD using the NOAA’s online Vertical Datum Transformation tool2.
SOURCE: NOAA Tides and Currents, 2003
2 https://vdatum.noaa.gov/vdatumweb/vdatumweb?a=134004720230417
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TABLE 2 TIDAL DATUMS AT QUILLAYUTE RIVER AT LA PUSH (#9442396)
Tidal datum Abbreviation ft. MLLW ft. NAVD
Highest Observed Tide HOT 12.7 11.25
Highest Astronomical Tide HAT 11.11 9.66
Mean Higher High Water MHHW 8.52 7.07
Mean High Water MHW 7.81 6.36
Mean Tide Level MTL 4.60 3.15
Mean Sea Level MSL 4.58 3.13
Mean Low Water MLW 1.38 -0.07
North American Vertical Datum of 1988 NAVD 1.45 0.0
Mean Lower Low Water MLLW 0.0 -1.45
NOTES:
The tidal datums listed above are from the most recent tidal epoch: 1983-2001.
SOURCE: NOAA Tides and Currents, 2020
SOURCE: NOAA Jefferson County SLR Study
Figure 2 Sea-Level Rise Trend at Port Townsend
2.2.2 Extreme Event Flooding
The Federal Emergency Management Agency (FEMA) provides community assistance before,
during, and after natural disasters, including flooding.3 In fulfilling this mission, FEMA creates
maps, known as Flood Insurance Rate Maps (or FIRMs), that show areas of flood risk under
current conditions (i.e., without sea-level rise). While the maps are meant to provide information
for flood insurance needs and requirements, they also provide useful county-wide storm flooding
information. The flood maps for Jefferson County were last updated in June of 2019.
3 Federal Emergency Management Agency. https://www.fema.gov/about. [Last accessed December 29, 2022].
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The Flood Insurance Study (FIS) for Jefferson County (2019) reports the still water elevation and
base flood elevations (BFE) for 246 coastal locations. The BFE, or total water level, includes the
still water elevation plus wave runup for the 100-year storm (or the storm with a 1% chance of
occurring annually).
Still water elevations throughout Jefferson County for the 100-year event are shown in Figure 3.
Note that the range in water levels across the County only varies from 11.2 to 12.7 feet NAVD.
On the west coast of the County, these elevations ranged from 11.2 to 11.6 feet NAVD, generally
increasing in a northward direction (FEMA, 2019). On the east coast (Puget Sound) side of the
County, still water elevations are generally lowest around Port Townsend (11.5 – 11.6 feet
NAVD) and Discovery (11.3 – 11.5 feet NAVD) Bays, and they are generally highest around
Dabob (12.4 – 12.7 feet NAVD) and Quilcene (12.6 – 12.7 feet NAVD) Bays (FEMA, 2019).
SOURCE: Data from FEMA, 2019 [ft in NAVD88] Jefferson County SLR Study
Note: Figures are clipped to exclude areas outside of the County. Figure 3 100-year Still Water Elevations for Jefferson
County
The BFE (still water elevations + wave runup) for the 100-year event is shown in Figure 4. In
aggregate, the water levels are higher on the open Pacific coast due to storm swell and a longer
wind fetch which results in higher waves. Total water levels range from 11.4 to 31.1 feet NAVD
(FEMA, 2019). On the County’s east coast, total water levels are lower, ranging from 11.5 to 23.5
feet without directional or regional patterns (FEMA, 2019).
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SOURCE: Data from FEMA, 2019 [ft in NAVD88] Jefferson County SLR Study
Note: Figures are clipped to exclude areas outside of the County. Figure 4 100-year Total Water Elevations for Jefferson County
2.2.3 Historic Erosion
The erosion of coastal bluffs—high, steep landforms made of glacial and interglacial sediments—
serves as the primary source of sediment for Puget Sound beaches (Johanessen and MacLennan,
2007). Bluffs make up 42.6% of the Puget Sound shoreline (Coastal Geologic Services [CGS],
2018). Bluffs are dynamic features that may erode slowly over time or in large failures all at once
or over the span of several months to years. Sea-level rise is expected to increase erosion rates,
though site-specific conditions and interventions like beach nourishment and coastal armoring
will affect future erosion rates at local scales...
Historical bluff recession rates in eastern Jefferson County were measured at various locations by
Coastal Geologic Services and are shown in Figure 5. Recession rates range from 0.04 feet/year
to 0.45 feet/year on the mainland, with an average of 0.29 feet/year (CGS, 2018). On nearby
Protection Island, bluff recession was estimated to be much higher, at a minimum rate of 0.98
feet/year due to swell coming from the Strait of Juan de Fuca (CGS, 2018). The Shoreline
Inventory and Characterization Report for the County’s SMP has some description of beach
erosion and geomorphology, however, no rates of erosion are presented.
At the time of this study, information concerning County-wide beach erosion rates and erosion
rates for the Pacific Coast side of the County were unavailable. The Washington Department of
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Ecology has historic erosion rate data for the Pacific Coast4 and future efforts should consider
this data to refine the analysis. Please see Section 4.2 for further details concerning erosion
hazards and mapping.
SOURCE: Data from CGS, 2018 Jefferson County SLR Study
Figure 5
Historic Bluff Recession Rates
4 https://waecy.maps.arcgis.com/apps/View/index.html?appid=389d0a3ce642485db912d4a416a56e25
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3. DATA COLLECTION AND PROCESSING
ESA collected publicly available data on physical processes impacting coastal flooding (e.g., sea-
level rise, erosion) as well as data on coastal assets (i.e., natural or built resources) in Jefferson
County.
3.1 Sea-Level Rise Scenarios
3.1.1 Regional Sea-Level Rise Projections
In 2018, as part of the Washington Coastal Resilience Project (WCRP), the University of
Washington’s Climate Impact Group (UW CIG) prepared an updated assessment of projected
sea-level rise for Washington State (Miller et. al., 2018) based on recent global and regional sea-
level rise projections (Kopp et. al., 2014). The assessment included projections for sea-level rise
at various locations along the Pacific Coast and the Puget Sound shoreline. The UW CIG
developed a website5 that includes interactive sea-level rise data visualizations (e.g., Figure 6) to
illustrate the data from the assessment. The Miller et. al. (2018) report presents different sea-level
rise values based on two global greenhouse gas emissions scenarios:
SOURCE: UW CIG, 2018 Jefferson County SLR Study
Figure 6 Example of Relative Sea-Level Rise Projections
5 UW CIG. https://cig.uw.edu/resources/special-reports/sea-level-rise-in-washington-state-a-2018-assessment/ [last accessed December 19, 2022]
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High Emissions Scenario (Representative Concentration Pathway (RCP) 8.5) – This scenario
represents “business as usual” and assumes a future where there are no significant local or global
efforts to limit or reduce greenhouse gas emissions. This scenario assumes “high population and
relatively slow income growth with modest rates of technological change and energy intensity
improvements, leading in the long-term to high energy demand and greenhouse gas emissions.”
(Riahi et. al 2011).
Low Emissions Scenario (Representative Concentration Pathway (RCP) 4.5) – This scenario
assumes more aggressive emissions reduction actions corresponding to the aspirational goals of
the 2015 Paris Agreement,6 which calls for limiting mean global warming to less than 2 degrees
Celsius and achieving net-zero greenhouse gas emissions in the second half of the century. This
scenario is considered challenging to achieve and would include updated climate policies,
concerted action by all countries, and a shift to a lower emission service and information
economy.
The 2018 assessment also provides a range of probabilities that were specifically included to
inform decision-makers. The probabilities range from “extreme low” (0.1%) to “high” (>83%)
and correspond to the likelihood that a given amount of sea-level rise will be exceeded. For
example, the “extreme low” probabilistic projections correspond to a 0.1% chance of exceedance
(i.e., 99.9% of models predict a lower amount of sea-level rise).
While the UW CIG study provides projections through 2150, it is important to note that sea-level
rise is expected to continue for centuries, because the earth’s climate, cryosphere,7 and ocean
systems will require time to respond to the emissions that have already been released to the
atmosphere.
3.1.2 Jefferson County Sea-Level Rise Scenarios
Figure 6 illustrates an example of the range of sea-level rise projections that are available for each
stretch of the Jefferson County coastline from the UW CIG website. In coordination with the
County and the stakeholder advisory group, ESA used the high emissions scenario (RCP 8.5) and
the 1% likelihood sea-level rise projections to conservatively evaluate the vulnerability of
County-wide assets under a high sea- level rise scenario. This scenario is appropriate as a
precautionary projection that can be used for less adaptive, more vulnerable projects or
populations that will experience medium to high consequences as a result of underestimating sea-
level rise. The range of sea-level rise projections for each stretch of shoreline throughout the
County is summarized in Table 3 below.
The amounts of sea-level rise selected for this study (0, 1, 2, and 5 feet) were intended to
represent averages of the range of sea-level rise that might be expected over the short- (2040),
mid- (2060), and long-term (2100) time horizons. Because there is inherent uncertainty in both
climate science and the sea-level rise projections, the selected sea-level rise amounts represent the
“book ends”, or the lower and higher amounts of sea-level rise, that might be conservatively
6 United Nations. https://www.un.org/en/climatechange/paris-agreement. [last accessed December 30, 2022] 7 The cryosphere is the portion of the Earth’s surface where water is in solid form such as glaciers and ice caps.
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anticipated for Jefferson County over the next century. Using a range of sea-level rise estimates
will support the County in evaluating the potential impacts and adaptation options as both the
climate science and sea-level rise models continue to evolve.
TABLE 3 RANGE OF SEA-LEVEL RISE PROJECTIONS FOR JEFFERSON COUNTY, WASHINGTON
Anticipated Timelinea Likelihood (% Chance of Exceedance) Sea-Level Rise (ft)a,b Sea-Level Rise (ft) Selected for Study
Now N/A 0 0
2040 1% 0.8 – 1.1 1
2060 1% 1.7 – 2.1 2
2100 1% 4.6 – 5.2 5
NOTES:
a The range of sea-level rise projections above are all for the RCP 8.5 (high) emissions and summarize the range of projections for each stretch of shoreline throughout Jefferson County. b The sea-level rise projections account for vertical land movement.
SOURCE: Miller et. al., 2018
3.2 Existing Studies
3.2.1 Prioritizing Sea-Level Rise Exposure and Habitat Sensitivity Across Puget Sound
CGS and Washington Sea Grant prepared a report for the Puget Sound National Estuary Program
in April 2022 that mapped sea-level rise vulnerability at the parcel scale across Puget Sound
(CGS, 2022). The study looked at the 20-year storm (5% chance of annual occurrence) under five
sea-level rise scenarios, using sea-level rise projections from UW CIG (Table 4).
TABLE 4 SEA-LEVEL RISE PROJECTIONS USED IN CGS 2022
Anticipated Timeline Likelihood (% Chance of Occurrence)
Now n/a
2050 50%
2050 1%
2100 50%
2100 1%
NOTE:
The study uses the RCP 8.5 (high) emissions scenario.
A range of scores for habitat sensitivity, infrastructure sensitivity, physical vulnerability, coastal
erosion potential, and coastal flood exposure, among others was used to develop an overall
vulnerability score.
One of the indices used was a Coastal Erosion Potential (CEP) score, which is used in Section 4.2
to develop the erosion hazard zone for this study. The CEP score was developed as a function of
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shore type (e.g., ranging from relatively stable (i.e., bedrock) to highly erodible (i.e., beaches and
feeder bluffs) and wave height. The study assigned a CEP score to each parcel along the
coastline. The highest CEP scores resulted from the more erodible shore types with higher wave
exposure. See Appendix A for further details concerning the assumptions and limitations that
were used in developing the CEP scores.
3.2.2 The City of Port Townsend Sea Level Rise and Coastal
Flooding Risk Assessment
The City of Port Townsend prepared a sea-level rise risk assessment in October 2022 (City of
Port Townsend and Cascadia Consulting Group). This risk assessment used the Miller et. al.
(2018) sea-level rise projections and NOAA 2022 High Projection scenario (Sweet et al. 2022) to
evaluate coastal flooding risks within the City of Port Townsend for 3 feet and 5 feet of sea-level
rise (Table 5). Because the City of Port Townsend has a separate SMP, the area within city limits
is not included in this report; however, the Port Townsend report is mentioned herein for
reference.
TABLE 5 SEA-LEVEL RISE PROJECTIONS USED IN CITY OF PORT TOWNSEND AND CASCADIA CONSULTING GROUP 2022
Anticipated Timeline Likelihood (% Chance of Occurrence) Sea-Level Rise (ft)
Now n/a 0
2100 17% 31
2100 1% 51
2100 n/a 6.522
NOTES: The study uses the RCP 8.5 (high) emissions scenario.
1 Miller et. al., 2018
2 NOAA 2022
3.3 Site Visits
ESA and the County conducted nine site visits on October 27, 2022 (see Figure 1) to assess site
conditions and the potential for sea-level rise impacts to people and existing infrastructure. Sites
were identified using draft hazard mapping. Data were recorded on standardized electronic forms
to ensure comparable information was collected at each site. Data collected at each site included a
description of existing site conditions and identification of existing infrastructure and shoreline
habitats, potential impacts, and potential adaptation strategies. Appendix A includes site visit
notes and photos.
3.4 Asset Inventory
Information concerning critical assets in Jefferson County was obtained from a variety of sources
including the Public Utility District (PUD), the Department of Community Development (DCD),
and Department of Emergency Management (DEM). Some asset information was also obtained
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directly from Jefferson County’s online data portal8 or other publicly available online data
sources. Available data included the following (all data was provided by the County unless
otherwise specified below):
• Building footprints9
• Fire stations
• Gas pipes
• Hospitals
• Hazardous material storage sites
• Permitted septic systems
• Schools
• Seawater intrusion protection zone (SIPZ) wells8
• Sewer drain fields
• Sewer pipes
• Sewer pumps
• Stormwater culverts8
• Stormwater facilities
• Trails
• Water facilities
• Water pipes
3.5 Community Engagement
Two public workshops were held to gather input on existing flood hazards and community
priorities. The first meeting was held virtually on November 10, 2022 and had approximately 5
attendees who were largely from the Port Townsend area. The second meeting was held virtually
on February 21, 2023 and had approximately 19 attendees from various locations throughout the
County. Community concerns and priorities can be summarized by the following topics:
• Availability of local, state, and federal tools to help the County combat the effects of sea-level rise.
– The desire for access to and understanding of ongoing research concerning sea-level rise
projections and geomorphic processes (e.g., erosion) was specifically mentioned.
8 SIPZ wells are freshwater wells that lie within the range of saltwater intrusion. Additional information may be found at the following web address: https://gisdata-jeffcowa.opendata.arcgis.com/. 9 Microsoft Bing. Available: https://www.microsoft.com/en-us/maps/building-footprints. [Last accessed April 18, 2023].
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– A regional king tide and flood warning system was discussed as a possibility of notifying residents of impending floods in real-time.
– Several community members mentioned that they wanted to see what risks the County might experience under extreme sea-level rise projections.
• Damage to public infrastructure and private property:
– Concerns over if and how existing and new transportation infrastructure (e.g., bridges) will adapt to rising sea-levels and increased precipitation.
– Susceptibility of wastewater treatment plants to future hazards.
– Risks to critical infrastructure (e.g., hospitals, community centers, etc.) or potentially hazardous material sites (septic systems, gas stations, etc.).
– Availability and prioritization of limited funding and resources to address impacts at a County-wide level.
• Effects on tribal and cultural resources.
• Effects to natural resources such as water quality and fish spawning habitat.
• Risks to public health and safety:
– Emergency preparedness (food, shelter, and access) before, during, and after extreme flood events.
– Desire to build or adjust infrastructure to withstand projected future hazards (e.g., making specific buildings tsunami and flood-ready).
• Impacts to the local economy:
– Tourism (housing and businesses).
– Maritime industry (boating, ports, etc.).
– Degradation of recreational resources.
– Reduced beach access (both to and along beaches).
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4. FUTURE STORM FLOODING AND
EROSION
Future sea-level rise is expected to create a permanent rise in ocean water levels that would shift
the water’s edge landward. Higher water levels will increase erosion of beaches and bluffs,
causing a loss of sand, and resulting in narrower distances between assets and the water, if no
action is taken. Additionally, the combination of higher ocean water levels and erosion will mean
that coastal storms will potentially cause greater flooding and damage, because a reduced beach
width is less effective at reducing wave energy, and waves positioned at a higher elevation allow
for a deeper reach landward. This section identifies two future hazard zones that constitute storm
flooding and erosion impacts associated with projected sea-level rise, the underlying data sets and
assumptions associated with coastal processes for each zone, and methods used to map each zone.
4.1 Future 100-year Flooding Hazard Zone
Development
ESA used FEMA’s 2016 Technical Methods Manual (TMM) “Relating Future Coastal
Conditions to Existing FEMA Flood Hazard Maps” (Battalio et. al., 2016), which was written
with the Pacific Coast’s wave climate (or wave characteristics) in mind, to create future flood
maps with sea-level rise. The TMM provides four levels of application that entail a range of effort
and information. The lower levels are simpler to apply while the higher levels require more
information, but more accurately relate future and existing hazards. Based on data availability,
this study uses the Level 2a application, which recommends adding sea-level rise to the coastal
FEMA BFE, or total water level (TWL), and considering a morphology factor adjustment. Sea-
level rise will result in a change to the shore due to waves dissipating their power at higher
elevations and this morphology response can lead to lateral (inland) shore migration several
orders of magnitude greater than sea-level rise alone. As a result, the following equation is
recommended where F is the morphology factor:
TWL_future = TWL_existing + SLR * F
The TMM recommends a range of morphological factors from 1 to 4, with the lower factors
representing the more erodible shorelines and higher factors representing the less erodible
shorelines. For the purposes of this study, morphological factors of 1 and 3 were applied for
Jefferson County’s beaches and bluffs, respectively. These values were chosen because, as sea
levels rise, it is anticipated that non-armored sandy shorelines will migrate inland and upwards
and adjust to the higher water levels in a way that does not increase TWLs.
Bluff-backed or armored shorelines are less likely (depending on soil composition) to migrate as
far inland, so higher water levels result in increased wave runup due to the generally steeper
slopes and erosion-resistant composition, thus requiring a higher morphological factor to account
for the increased TWL (Figures 7 and 8). It should also be noted that this study focuses on
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coastal flood hazards and did not include compound flood modeling (i.e., modeling of
simultaneous riverine and coastal flooding, which may exacerbate future flood conditions).
SOURCE: Battalio et. al., 2016 Jefferson County SLR Study
Figure 7 Morphological and Hydraulic Response of an Erodible Shoreline to Sea-Level Rise
SOURCE: Battalio et. al., 2016 Jefferson County SLR Study
Figure 8 Morphological and Hydraulic Response of an Erosion-Resistant Shoreline to Sea-Level Rise
The beaches and bluffs were delineated using FEMA’s modeling transects and adjustments based
on review of aerial imagery.
It is important to note that the flooding hazard zones modeled in this study are not intended to
provide site-specific analysis, but rather to provide a planning-level tool to estimate the potential
county-wide scale of impact due to flooding.
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4.2 Future Erosion Hazard Zone Development
ESA used the CEP data from CGS 2022 to identify the stretches of Jefferson County shoreline
along Puget Sound with the highest erosion potential. The CGS report identified the top 10% of
shorelines throughout the Sound with the highest CEP scores and ESA used these high-erosion-
potential parcels extracted for Jefferson County. Future erosion along the Pacific Coast shoreline
was not modeled due to the lack of historic erosion rate data at the time of this study. As noted in
Section 2.2.3, data is now available from the Washington Department of Ecology and future
efforts should consider this data (see Section 7 for recommended next steps).
Future erosion of the eastern County shorelines was projected inland for the high erosion
shorelines based on available historic bluff erosion data along Puget Sound. The average historic
erosion rate from the CGS 2018 dataset was 0.25 feet per year, though Protection Island had a
much higher rate of erosion (0.98 feet per year) than any other sample location, likely due to the
island’s composition and exposure. ESA selected a rate higher than average historical erosion
rates (0.25 ft/yr) to generally represent the increase in coastal erosion anticipated with accelerated
sea level rise. A rate of 0.5 ft/yr was selected using engineering judgment and applied to all
shores except Protection Island which is already seeing higher rates of erosion. While
approximate, ESA’s judgment is that an approximate erosion rate greater than historical erosion is
preferred over explicitly or implicitly ignoring the potentially significant hazards associated with
coastal erosion. The selected erosion rates were applied to the shorelines with the top 10% highest
CEP scores.
Using these rates, a total amount of erosion was calculated for 2040, 2060, and 2100 (10, 20, and
40 feet for the mainland and coast side of the County, and 18, 37, and 76 feet for Protection
Island). For the identified erosive shoreline, an erosion zone was developed by buffering the
existing shoreline inland by the amount of erosion for each scenario. Actual future erosion may
exceed these amounts, which are not intended for uses other than a high-level risk assessment by
the County. More detailed analysis is recommended for assets in close proximity to these erosion
hazards.
It should be acknowledged that due to data limitations, the erosion hazard zone should be used as
a planning-level tool to provide the County with a high-level estimate of the potential scale of
impact due to erosion. Localized rates of erosion were not available and beach and bluff erosion
rates typically differ from one another. Note, that beach erosion data was not available, so the
historic bluff erosion rates were applied to beaches as well in order to develop a rough estimate of
potential erosion. Additionally, erosion rates are highly variable from one location to another and
over time. In addition, while an erosion hazard zone is only depicted for those areas that fell
within the CGS’s top 10 percent CEP score, areas not mapped within an erosion hazard zone may
still be subject to erosion hazards. Future efforts should consider development of a beach and
bluff erosion monitoring program to better determine future erosion hazards. Additionally, sea-
level rise is expected to increase erosion rates and future studies should refine estimates to
consider how much rates will change. As a result, the erosion hazard zone should be considered a
planning-level tool and should not be used for site-specific analyses.
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4.3 Exposure Maps
For the purposes of this report, ESA developed exposure maps for several key areas to
demonstrate the results of the County-wide hazard mapping . GIS hazard and asset data for the
full SMP shoreline has been provided to the County and is included in the vulnerability
assessment in Section 5. Figures 9–17 below include the following areas on the eastern side of
the County: Discovery Bay, Beckett Point, Port Hadlock, Mystery Bay, Port Ludlow, Squamish
Harbor, Quilcene, and Brinnon. For the western portion of the County, ESA selected a stretch of
coastline mid-County where Highway 101 is particularly exposed to potential future flood
hazards.
As might be expected, the greatest potential flood inundation was observed in low-lying areas
with connections to freshwater tributaries (please note, future increases in riverine flooding due to
climate change were not modeled as a part of this study). The remaining sections of Jefferson
County’s shorelines are composed of bluff-backed shoreline, for which erosion is the primary
hazard.
For the bluff-backed shorelines, asset exposure to erosion appeared to be greatest along the
northern portion of the County’s east coast, likely due to its greater exposure to swells that travel
in from the Pacific Ocean through the Strait of Juan de Fuca. Several sections of the County’s
west coast also exhibited areas with high asset exposure to flooding. In particular, numerous
sections of Highway 101 were within close proximity to the flood hazard zone (see Figure 17
below).
Highway101Highway101Path: U:\GIS\GIS\Projects\2022xxx\D202200495_JeffersonCo_SLR\03_MXDs_Projects\JeffersonCoSLR\JeffersonCoSLR.aprx Exposure-Coast-Hwy 101, LSheehan 6/10/2023Roads
Building Footprints
Flood Hazard Zone
0 ft SLR
1 ft SLR
2 ft SLR
5 ft SLR
N 0 100
Feet
Pacific Ocean
SOURCE: Data from CGS and Jefferson County; Hazard Mapping by ESA Jefferson County SLR Study
Figure 17
Hazard Mapping of Jefferson County's West Coast
Quinault
Reservation
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5. VULNERABILITY ASSESSMENT
This section uses the future hazard zones described in Section 4 to identify the assets potentially
at risk from sea-level rise (e.g., homes, roads, utilities). These places or assets, as described in
Section 3.4, are categorized into the following asset categories based on purpose/function:
emergency response facilities, schools, buildings, wastewater infrastructure, water infrastructure,
transportation, recreation, natural resources, hazardous material storage sites, and social.
Vulnerability is the “extent to which an individual or community will be adversely affected when
experiencing a climate-related hazard.” (UW CIG, 2018) As the definition implies, vulnerability
is a function of exposure, sensitivity, and adaptive capacity to a given hazard or stressor.
Exposure is whether, when, and how often an asset is or will be exposed to a given hazard (e.g.,
flooding, erosion). Sensitivity relates to the consequences to the asset once it has been exposed to
said hazard. Adaptive capacity is how easily an asset can bounce back after exposure to a hazard.
Vulnerability assessments are intended to help planners identify what is vulnerable as well as
what is not vulnerable and identify priorities for future planning and project efforts.
5.1 Methodology
Assets within the study area (Figure 1) were analyzed to determine the potential exposure to the
different hazard areas and consequences, and the sensitivity and adaptive capacity of the assets to
the potential hazard. Sensitivity and adaptive capacity scoring were developed generally for asset
categories based on ESA’s judgement with input from the County and stakeholder advisory
group. The results of this analysis are summarized in tables provided in Section 5.2 for each asset
category and Figures 9–17. The following sections describe in further detail the information
contained within each of these tables.
5.1.1 Assets
The first row of each table describes the type of assets in a particular category and provides
details relevant to Jefferson County. For example, in the transportation category, major
transportation corridors are identified.
5.1.2 Exposure to Hazard and Consequences
To assess exposure to hazards, the assets in different categories were intersected in GIS with each
potential future hazard zone. Point assets (like fire stations) in each potential future hazard zone
were counted, linear assets (like roads and pipelines) were measured by mile, and planar assets
(like building footprints) were measured by acre. A summary of these results is reported in the
second row of the table sections. The full set of results is provided in tabular form in Appendix
B. If an asset was identified as at risk for both flooding and erosion, it was counted under the
erosion column in Appendix B since it is presumed that erosion generally causes more damage
than flooding and is therefore the more extreme hazard.
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To further characterize an asset’s exposure to hazards, a hazard exposure grade of Low, Medium,
or High was assigned. This grade was assigned after quantifying the asset’s exposure and is
dependent on both timeframe (e.g., if an asset could potentially flood in the near-term it would
have a higher hazard exposure grade than one that could flood in the long-term) and the potential
level of severity posed by the type of hazard zone (i.e., erosion versus long-term effects of
infrequent flooding). For example, future erosion by 2040 is considered “high” exposure because
it would cause significant damage to structures and infrastructure in the near-term, while
exposure to erosion in 2060 is considered “medium” exposure and erosion by 2100 is considered
“low” exposure because the risk is later in the century. Exposure to 100-year flooding by 2040 is
considered “medium” exposure because while the risk is a near-term risk, it is still a low-
likelihood event (i.e., 1% annual chance of occurrence annually).
The hazard exposure grading scheme is provided in Table 6 below.
TABLE 6 HAZARD EXPOSURE GRADING
Timeframe/ Amount of Sea-Level Rise (ft)/Erosion Future Erosion Future 100-year Coastal Flooding
Existing Conditions High High
Short-term/ 1 ft of SLR/2040 High Medium
Mid-term/ 2 ft of SLR/2060 Medium Low
Long-term/ 5 ft of SLR/2100 Low Low
5.1.3 Sensitivity to Hazard and Adaptive Capacity
In the third row of each table section (for those asset categories within the study area (Figure 1)
that exhibited exposure), an asset’s sensitivity, or the asset’s level of impairment if flooded or
affected by erosion or waves, is discussed. In general, assets that are highly sensitive would lose
their primary function if exposed to any degree of flood or erosion whatsoever. If assets can
maintain their primary function(s) during inundation, they would have low sensitivity. If assets
would lose only part of their function, it is considered, for the purposes of this assessment,
moderately sensitive. For example, one of the sensitivities of impacts to major transportation
corridors is the disruption of vehicular access critical for the provision of emergency services,
which would mean the asset has a high sensitivity.
Similar to the hazard exposure grades, a hazard sensitivity grade is determined for each asset.
Table 7 presents the grading scheme.
TABLE 7 HAZARD SENSITIVITY GRADING
Score Considerations
Low The given hazard would have no or a low impact on the asset, and the primary function of the asset could be maintained.
Medium The given hazard would cause minor damage or disruption.
High The given hazard would cause major damage or disruption.
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5.1.4 Adaptive Capacity of Asset
In the fourth row of each table (for those asset categories that exhibited exposure), an asset’s
adaptive capacity is discussed. For the purposes of this study, adaptive capacity is defined as the
asset’s ability to cope with and recover from impacts. In general, assets that have low adaptive
capacity would take a long time or be unable to recover if exposed to any degree of flood or
erosion whatsoever. If assets are operational as soon as waters recede, they would have high
adaptive capacity. For example, in many cases once waters recede off roads, vehicular access is
restored with little damage to the roadway itself, which would mean the asset has a high adaptive
capacity. Note, adaptive capacity is inversely correlated with vulnerability (i.e., low adaptive
capacity leads to higher vulnerability).
An adaptive capacity grade is determined for each asset. Table 8 presents the grading scheme.
TABLE 8 HAZARD ADAPTIVE CAPACITY GRADING
Score Considerations
High The asset would be able to rebound from the impact quickly (e.g., high adaptive capacity).
Medium The given hazard would cause temporary operational interruption.
Low The given hazard would cause long-term operational interruption. The asset would require a significant effort to rebound from the impact (e.g., low adaptive capacity).
5.1.5 Vulnerability Summary
The last row of each table section identifies the overall vulnerability of the asset categories to
potential future flooding and erosion as determined by the analysis. The overall vulnerability was
determined based on the combination of an asset’s vulnerability components (Figure 18).
Vulnerability = (Exposure + Sensitivity) – Adaptive Capacity
The vulnerability summaries are indications of the degree of potential vulnerability, not rankings
or priorities.
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SOURCE: ESA 2023 Jefferson County SLR Study
Figure 18
Components of Vulnerability
5.2 Jefferson County Vulnerabilities
TABLE 9 JEFFERSON COUNTY VULNERABILITIES
Emergency Response Facilities
Asset Several types of emergency response buildings and infrastructure exist in Jefferson County (e.g., hospitals, fire stations, police stations, emergency shelter sites). ESA obtained geospatial information for the following assets:
• Fire stations
• Hospitals
Exposure to Hazard and Consequences Based on available asset data, no emergency response facilities fall within the potential future flooding or erosion hazard zones. Note, Brinnon and Port Ludlow are within close proximity to the flood hazard zone with 5ft of sea-level rise
Schools
Asset Available asset data for schools included 11 elementary, middle, secondary, and combined schools within Jefferson County.
Exposure to Hazard and Consequences Based on the available asset data, no schools are located in the potential future flooding or erosion hazard zones.
• Quilcene School: recreational and sports facilities on the east side of the school are within close proximity to the flood hazard zone with 5ft of sea-level rise. Brinnon Elementary School: is not mapped within a hazard zone but may be subject to flooding with 5ft of sea-level rise.
Buildings
Asset Building footprints were obtained from Microsoft Bing Maps (2020)10. The available data does not include building type and therefore the analysis could not be subdivided accordingly.
10 https://github.com/Microsoft/USBuildingFootprints
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Exposure to Hazard and Consequences The GIS analysis shows that the following building assets could be impacted by current or potential future flooding and erosion over the short- to long-term time horizons:
• Under existing conditions, 1,000 buildings are at risk of flooding during the 100-yr event
• Short-Term:
o 100-yr Flooding: 1,770 buildings with 1ft of SLR
o Erosion: 33 buildings by 2040
• Mid-Term:
o 100-yr Flooding: 2,430 buildings with 2ft of SLR
o Erosion: 117 buildings by 2060
• Long-Term:
o 100-yr Flooding: 3,080 buildings with 5ft of SLR
o Erosion: 277 buildings by 2100
Hazard exposure grade:
• Buildings: High (1,033), Medium (887), Low (1,437)
Sensitivity to Hazard • Increased frequency of flooding of buildings leading to water damage and other flood-related damages.
• Disrupted access to and from buildings.
• Buildings within highly erosive coastline stretches may be subject to gradual or significant immediate damage, depending on the rate and mechanism of erosion, whether armoring is present, and whether other adaptive approaches (e.g., beach nourishment) have been initiated.
Sensitivity grade: Medium
Adaptive Capacity of Asset • Long-term operational interruption if flooding or mechanical and plumbing systems are present on the ground floor and are subject to damage.
• Structures in areas where roads and other infrastructure will flood will have lower adaptive capacity than other areas because it will be challenging to rebuild.
Adaptive capacity grade: Medium
Vulnerability Summary Medium-High (1,033), Medium (1,887), Medium-Low (1,437)
Wastewater Infrastructure
Asset In the coastal zone, available geo-spatially referenced wastewater system infrastructure data includes sewer pipes, septic systems, and sewer drain fields.
Exposure to Hazard and Consequences The GIS analysis shows that the following wastewater assets may be impacted by flooding and/or erosion over the short- to long-term time horizons:
• Sewer pipes
o Flooding: 4 miles of pipeline are currently at risk of exposure to the 100-yr flood, 5.3 miles would be exposed with 1 ft of SLR, 5.9 miles would be exposed with 2 ft of SLR, and 6.4 miles would be exposed with 5ft of SLR.
o Erosion: 0.3 mile of pipeline would be exposed to erosion by 2040, 0.6 mile by 2060, and 0.66 mile by 2100.
• Septic systems
o Flooding: 520 septic systems are currently at risk of exposure to the 100-yr flood, 701 would be exposed with 1 ft of SLR, 796 would be exposed with 2 ft of SLR, and 1,053 would be exposed with 5 ft of SLR.
o Erosion: 1 septic system would be exposed to erosion by 2040, 6 septic systems by 2060, and 78 by 2100.
• Sewer drain fields
o Flooding: there are no sewer drain fields mapped within the flood hazard zone.
o Erosion: there are no sewer drain fields mapped within the erosion hazard zone.
Hazard exposure grade:
• Sewer pipes: Low to High depending on individual asset
• Septic systems: Low to High depending on individual asset
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• Sewer drain fields: n/a; not expected to flood under the 100-year event with 5 ft of SLR
Sensitivity to Hazard • Rising surface waters may limit access to facilities and pipelines for maintenance and operations.
• Rising groundwater levels may place unanticipated buoyancy forces on buried pipelines, potentially leading to leaks and/or pipe failure. However, pressurized pipes are not expected to be very sensitive to infrequent flooding.
• Inundation of septic systems would cause system failure and may cause impacts to water quality.
Sensitivity grade:
• Sewer pipes: Low
• Septic systems: High
Adaptive Capacity of Asset • Pressurized pipes would likely be operational once water levels recede and maintenance access is restored.
• Septic systems could potentially need to be replaced depending on the level of inundation of the system. If inundation becomes more frequent, the septic system will not function (see Figure 19). Additionally, systems are usually managed by individual homeowners, so the burden of repair would fall on individuals.
Adaptive capacity grade:
• Sewer pipes: High
• Septic systems: Low
Vulnerability Summary • Sewer pipes: Medium-Low
• Septic systems: Medium-High
SOURCE: ESA 2023 Jefferson County SLR Study
Figure 19 Components of Septic Tank Vulnerability to Groundwater with Sea-Level Rise
TABLE 9 JEFFERSON COUNTY VULNERABILITIES (CONT.)
Water Infrastructure
Asset Available geospatially-referenced data for water infrastructure included the following:
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• Water pipes
• Water facilities (including reservoirs, wells, pump stations, etc.)
• 751 Seawater Intrusion Protection Zone (SIPZ) monitoring wells
Exposure to Hazard and Consequences GIS analysis shows that the following assets may be impacted by flooding and/or erosion over the short- to long-term time horizons:
• Water pipes
o Flooding: 6 miles of pipeline are currently at risk of exposure to the 100-yr flood, 8 miles would be exposed with 1 ft of SLR, 9 miles would be exposed with 2 ft of SLR, and 11.3 miles would be exposed with 5 ft of SLR.
o Erosion: 0.1 mile of pipeline would be exposed by 2040 and 0.2 mile by 2060.
• Water facilities
o Flooding: 3 water facilities (1 well and 2 hose hydrants) would be exposed to flooding with 5ft of SLR.
o Erosion: no exposure to erosion hazards.
• SIPZ wells
o Flooding: 34 wells are currently at risk of exposure to the 100-yr flood, 39 wells would be exposed with 1 ft of SLR, 48 wells would be exposed with 2 ft of SLR, and 65 wells would be exposed with 5 ft of SLR.
o Erosion: 3 wells would be exposed to erosion by 2100.
Hazard exposure grade:
• Water pipes: Low to High depending on individual asset
• Wells: Low (1)
• Fire hydrants: Low (2)
• SIPZ wells: High (37), Medium (14), Low (17)
Sensitivity to Hazard • Rising surface waters may limit access to facilities and pipelines for maintenance and operations.
• Rising groundwater levels may place unanticipated buoyancy forces on buried pipelines, potentially leading to leaks and/or pipe failure. However, pressurized pipes are not expected to be very sensitive to infrequent flooding.
• Inundation of wells with salt water would make the water undrinkable.
• Flooding may disrupt access pathways critical for emergency services (such as access to fire hydrants)
• Flooding of SIPZ wells would not cause much damage to the wells themselves but would likely be representative of greater impacts to individual homeowner drinking water wells.
Sensitivity grade:
• Water pipes: Low
• Wells: High
• Fire hydrants: Medium
• SIPZ wells: Low
Adaptive Capacity of Asset • Pressurized pipes and fire hydrants would likely be operational once water levels recede and maintenance access is restored.
• Drinking wells would be contaminated if inundated with salt water
• SIPZ wells would likely show an expanding seawater intrusion zone, indicative of impacts to drinking wells.
Adaptive capacity grade:
• Water pipes: High
• Wells: Low
• Fire hydrants: High
• SIPZ wells: High
Vulnerability Summary • Water pipes: Medium-Low
• Wells: Medium-High (1)
• Fire hydrants: Medium-Low (2)
• SIPZ wells: Medium-Low (42), Low (17)
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Transportation
Asset Available transportation data for Jefferson County11 includes highways, primary, secondary, and tertiary roadways, service roads, and residential roads. There are many smaller surface streets in the area, which provide access to local businesses, residences, and the coast. The major thoroughfares within the County that provide critical access are as follows:
• U.S. Highway 101 (coast and Puget Sound)
• State Route 116 (connection to Indian and Marrowstone Islands)
• State Route 20 (connects Discovery Bay and Port Townsend)
Exposure to Hazard and Consequences The GIS analysis shows that the following length (in miles) of roadways could be impacted by current or potential future flooding and erosion over the short- to long-term time horizons:
• Under existing conditions, 24 miles of road are at risk of flooding during the 100-year event
• Short-Term:
o Flooding: 9 miles of road with 1ft of SLR (24 miles under current conditions)
o Erosion: 0.2 mile of road by 2040
• Mid-Term:
o Flooding: 16 miles of road with 2ft of SLR
o Erosion: 0.46 mile of road by 2060
• Long-Term:
o Flooding: 30 miles of road with 5ft of SLR
o Erosion: 0.96 mile of road by 2100
Of the major thoroughfares, the following show sections of exposure to sea-level rise:
• U.S. Highway 101: Exposure to 100-yr flooding under current conditions along numerous stretches of the coast and Puget Sound waterways.
• State Route 116: Exposure to 100-yr flooding under current conditions near Mystery Bay and Nordland near the crossings between Marrowstone Island, Indian Island, and the mainland and near Indian Island park.
• State Route 20: Exposure to 100-yr flooding under current conditions at the confluence with Highway 101 towards the southern extent of Discovery Bay.
Hazard exposure grade:
• U.S. Highway 101: High
• State Route 116: High
• State Route 20: High
• Other Roads: Low to High depending on road
Sensitivity to Hazard • Disrupt access pathways critical for emergency services.
• Disrupt transportation links to local businesses, residences, and municipal infrastructure.
• Damage to existing roadways and related infrastructure due to scour and erosion of embankments, footings, and other structural/geotechnical elements.
Sensitivity grade:
• Major Transportation Corridors: High
• Other Roads: Medium
Adaptive Capacity of Asset Once water recedes, roads are likely to be operational fairly quickly. Roads that are impacted by erosion will require repair or rerouting.
Adaptive capacity grade:
• U.S. Highway 101: High
• State Route 116: High
• State Route 20: High
• Flooded Roads: High
• Eroded Roads: Medium
11 OpenStreetMap. Last accessed on November 23, 2022 via http://download.geofabrik.de/north-america/us/washington-latest-free.shp.zip
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Vulnerability Summary • U.S. Highway 101: Medium-High
• State Route 116: Medium-High
• State Route 20: Medium-High
• Other roads: Medium-Low to Medium-High
Recreation (Trails)
Asset Recreation and visitor-serving assets in Jefferson County’s coastal zone include the following: parks, bicycle routes, trails, beach access points and beaches, hotels and lodging, and recreational buildings. GIS analysis was performed solely for trails because it was the only geospatially-referenced available data.
Exposure to Hazard and Consequences The GIS analysis shows that the following length (in miles) of trail systems could be impacted by current or potential future flooding and erosion over the short- to long-term time horizons:
• Under existing conditions, 24 miles of trail are at risk to a 100-year event
• Short-Term:
o Flooding: 0.64 mile of trails with 1ft of SLR
o Erosion: 0.91 mile of road by 2040
• Mid-Term:
o Flooding: 1.09 miles of trails with 2ft of SLR
o Erosion: 1.19 miles of trails by 2060
• Long-Term:
o Flooding: 1.92 miles of trails with 5ft of SLR
o Erosion: no additional miles of trails are projected to erode by 2100
Of these trails, the most exposed areas include the entire stretch of the western coastline, portions of the Olympic Discovery Trail at the confluence of Discovery Bay, and the Portage and Lagoon Trails that rim the southwestern portion of Indian Island Park.
Hazard exposure grade: Low to High depending on individual asset
Sensitivity to Hazard • Increased frequency of flooding and erosion leading to water damage and other flood related damages.
• Loss of coastal access due to inundation of coastal access ways.
• Loss of access to recreational amenities.
• Loss of mobility for pedestrian and bicyclists within the coastal zone due to inundation of segments of existing and planned trails.
Sensitivity grade: Low
Adaptive Capacity of Asset Trails are generally more adaptive given their usage and sometimes less-developed form (e.g., dirt or gravel trails). Once water recedes, trails are likely to be operational fairly quickly.
Adaptive capacity grade: High
Vulnerability Summary Low to Medium-Low
Natural Resources
Asset Coastal and nearshore habitats in Jefferson County include kelp and eelgrass beds, intertidal mudflats, beaches, bluffs, wetlands, and freshwater streams.
Exposure to Hazard and Consequences Sea level rise will reduce the extent of sandy and rocky beaches, and nearshore and intertidal habitats that are critical for anadromous fish (e.g., chum, coho, steelhead, cutthroat), forage fish (e.g., surf smelt, sand lance, Pacific herring), shellfish (e.g., Dungeness crab, Pacific geoduck, Olympia oyster), shorebirds and seabirds, and some marine mammals as feeding, breeding, and migration sites (Krueger et al. 2011; Miller et al. 2013; Smith and Liedtke 2022). Feeder bluffs will likely experience increased erosion, which may cause sedimentation of hard- and soft-bottom habitats in the area (Miller et al. 2013). Increased water depths may alter light availability for algae and benthic plants and reduce eelgrass growth rates (Shaughnessy et al. 2012; Miller et al. 2013).
Hazard exposure grade: Medium
Sensitivity to Hazard and Some coastal and nearshore habitats may be able to shift inland as sea levels rise in areas where shoreline armoring or other coastal development (e.g., roads) does not prevent this landward migration (Krueger et al. 2011; Mauger et al. 2015). This is more unlikely in more populated or developed areas along Puget Sound shorelines, such as Beckett Point, Port
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Adaptive Capacity of Asset Hadlock/Irondale, and Port Ludlow. Areas of potential inland or upland habitat migration include areas south of Port Ludlow, such as Quilcene Bay, Dosewallips Estuary, Duckabush Estuary, McDonald Cove, and Triton Cove, and areas along the Olympic Coast.(e.g., undeveloped areas of land within the Oly National Forest and sections of coastline uninhibited from migrating inland of Highway 101 (i.e., between Ruby Beach and northern Queets)).
Sensitivity grade: High
Adaptive capacity grade: Low
Note, these grades may vary depending on habitat type, but determining these distinctions requires further analysis beyond the scope of this study (see recommended next steps in Section 7).
Vulnerability Summary Medium-High
Hazardous Material Storage Sites
Asset There are 16 hazardous materials storage sites within Jefferson County. These sites store a variety of potentially hazardous materials and include paper plants, quarries, gas stations, and substations.
Exposure to Hazard and Consequences The GIS analysis indicates that there are 2 hazardous material storage sites within the erosion and flood hazard zones:
• Mats Mats quarry (Port Ludlow)
o Flooding: subject to flooding under current conditions during the 100-yr event (0 ft SLR)
• Port Townsend paper mill
o Flooding: subject to flooding under current conditions (0ft SLR)
o Erosion: located along a highly erosive stretch of shoreline
Hazard exposure grade:
• Mats Mats quarry: High
• Port Townsend paper mill: High
Sensitivity to Hazard Increased flood risk may increase the likelihood of an accidental hazardous material release, depending on the storage facility location, material type, and storage configuration. Hazardous materials that are water-soluble or that react with water, materials that are stored in non-waterproof containers, and materials that are stored in buildings that have an elevated risk of flood damage are expected to have the greatest risk of accidental release during a flood event.
An accidental release of hazardous materials may lead to the following:
• Mobilization of hazardous materials in surface water.
• Mobilization of hazardous materials in groundwater.
• Airborne/aerosol release of hazardous materials.
• Contamination of soils.
Such a release may expose humans, wildlife, and habitats to toxic, corrosive, or otherwise harmful materials. The consequences of exposure can vary greatly depending on the type of hazardous material and the mode, duration, and amount of exposure.
Sensitivity grade: High
Adaptive Capacity of Asset If a hazardous materials storage site is inundated, it would likely require extensive effort to respond to a hazardous material release.
Adaptive capacity grade: Low
Vulnerability Summary High
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Social Vulnerability
Populations Evaluated Over 22,370 people live in the coastal communities of Jefferson County (excluding Port Townsend).
• Age: In Jefferson County, the median age of residents is 59.5 years with approximately 12% under the age of 18 and 37% over the age of 65 (U.S. Census Bureau 2021a-g).
• Disability: About 18% of individuals in the county’s coastal areas report having a disability. Of those individuals, 1% are under 18 years, 33% are between 18-64 years old, and 66% are 65 years and over (U.S. Census Bureau 2021a-g).
• Income: The median household income in the county’s coastal communities is $62,929, per capita income is $37,176, and the poverty rate is 14% (U.S. Census Bureau 2021a-g).
• Housing occupancy and type: In Jefferson County, there are approximately 12,964 housing units, 79% of which are occupied by either owners (86%) or renters (14%). These structures include single units (79%), multi-housing units (4%), mobile homes (15%), and other types (e.g., boat, van, RV; 2%) (U.S. Census Bureau 2021a-g).
• Computer/internet access: Of occupied housing in the coastal areas, approximately 73% of units have a computer and 69% have a broadband Internet connection (U.S. Census Bureau 2021a-g).
Exposure to Hazard and Consequences GIS exposure analysis was not performed for social assets due to the lack of geospatially-referenced information for the County.
Sensitivity to Hazard and Adaptive Capacity of Population
Sea level rise will create health, safety, and housing challenges for the people living in the coastal communities of Jefferson County. For example, increased coastal flooding may cause temporary or permanent displacement of residents and disruption to transportation routes for medical, food, and other services and supplies. Existing social and economic factors (e.g., age, disability, income, housing, access to information) may amplify a community’s sensitivity and challenge the ability to cope with or recover from sea level rise impacts. For example:
• Age: Children and seniors are typically more sensitive to sea level rise and flooding given existing health conditions, dependence on others for support, and reliance on critical services and infrastructure such as medical support, schools and daycares, and nursing homes or assisted living facilities
• Disability: Residents with disabilities may have a harder time evacuating or accessing critical services due to disruptions to critical transportation routes.
• Income: Low-income residents are more at risk of displacement given resource constraints. Limited access to expendable income restricts the ability of these residents to rebuild and/or recover.
• Housing occupancy and type: Renters are typically more at risk of displacement than homeowners. Manufactured and mobile homes may be more susceptible to flood damage.
• Computer/internet access: Limited access to internet services can affect a resident’s ability to effectively access emergency alerts and apply to and receive funding from recovery programs.
Sensitivity grade: Medium to High
Vulnerability Summary Fleming and Regan (2022) conducted a social vulnerability assessment as part of a larger sea level rise study for Puget Sound. This study created a composite index of multiple social and economic indicators (e.g., income, age, housing, access to services, etc.) to create a social vulnerability index score. The coastal areas of Puget Sound within Jefferson County received overall vulnerability rankings of:
• Medium for the Port Hadlock/Irondale area;
• Low-medium for the area from Discovery Bay east to Port Ludlow; and
• Low for Port Ludlow south to Triton Cove State Park at the southern extent of the county line.
Higher vulnerability ratings were associated with factors such as age, income, and access to services.
NOTES:
Exposure counts are cumulative (e.g., if 100 assets are currently exposed, and 50 new assets become exposed in 2060, there are a total of 150 assets that would be exposed by 2060).
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Asset exposure was counted separately for flooding and erosion hazard zones. If an asset is located in both the flood and erosion hazard zones, it was counted in the erosion hazard category because erosion is assumed to be more permanent and cause the greatest amount of damage over a potentially short duration.
Total exposure counts noted in this table include assets within the projected hazard zones of the identified study area (see Figure 1 for further details).
SOURCE: ESA, 2023
5.3 Summary of County Vulnerabilities
With anticipated sea-level rise, Jefferson County’s current vulnerabilities to coastal flooding and
erosion are projected to increase in frequency, intensity, and extent. There are many currently at-
risk assets in the coastal zone that may experience increased exposure to hazards. There are also
many assets that are not currently subject to flooding or erosion but may be subject to these
hazards under projected future conditions. Table 10 summarizes the grades for each asset
category’s exposure to hazards, sensitivity to hazards, adaptive capacity, and overall
vulnerability.
Compared to some communities, Jefferson County is unique because the analysis did not show
any one concentrated area of high vulnerability, but rather many small pockets of areas with high
vulnerability. Based on the exposure analysis, the following are assets most vulnerable to sea-
level rise hazards (i.e., received an overall vulnerability ranking of high or medium) and may
merit more site-specific vulnerability analyses in the future:
• Mats Mats quarry and Port Townsend Paper Mill
• Coastal buildings (public and private assets)
• Coastal septic systems (private asset)
• Coastal drinking wells (private asset)
• Transportation infrastructure in low-lying areas:
– Highway 101: the highway is most at risk to flooding near Kalaloch, at the mouth of Discovery Bay (Figure 9), through Brinnon (Figure 16) and near the Duckabush River, and near North Triton Cove.
– State Route 116: This state route is most susceptible to flooding near Mystery Bay and Nordland (Figure 13), near the crossings between Marrowstone Island, Indian Island, and the mainland, and near Indian Island Park.
– State Route 20: This state route is most at risk of flooding near the confluence of SR20 and Hwy101 at the mouth of Discovery Bay.
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TABLE 10 SUMMARY OF VULNERABILITY
Asset Category Asset Subcategory
Potential Exposure to Future Hazards Sensitivity to Hazards
Adaptive
Capacitya Vulnerability
Buildings Homes/Businesses High (1,033) Medium Medium Medium-High
Medium (887) Medium Medium Medium
Low (1,437) Medium-Low
Wastewater Infrastructure Sewer pipes Low to High Low High Medium-Low
Septic systems Low to High High Low Medium-High
Water Infrastructure Water pipes Low to High Low High Medium-Low
Well Low (1) High Low Medium-High
Fire Hydrant Low (2) Medium High Medium-Low
SIPZ wells
High (37) Low High Medium-Low
Medium (5) Medium-Low
Low (17) Low
Transportation Hwy 101 High High High Medium-High
State Route 116 High High High Medium-High
State Route 20 (near Port Townsend and Discovery Bay)
High High High Medium-High
Other roads Low to High Medium Medium to High Medium
Recreation Trails Low to High Low High Low to Medium-Low
Hazardous Material Storage Sites
Mats Mats quarry and
Port Townsend paper mill
High High Low High
NOTE:
a Adaptive capacity is inversely correlated with vulnerability (i.e., low adaptive capacity leads to higher vulnerability).
This table does not include vulnerability scores for emergency response facilities, schools, natural resources, and social assets either because the assets were not exposed to flooding or erosion hazards or because a geospatial analysis was not performed for them.
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6. POTENTIAL ADAPTATION STRATEGIES
Adaptation strategies are implementation projects or policies that help reduce the County’s
vulnerability to sea-level rise. Some of these strategies may require revisions to existing County
policy, regulatory, and procedural tools (e.g., the SMP, which specifies the regulatory framework
for shoreline modifications); creation of new tools and programs; identification of funding
sources; and project-level planning, design, and construction. This section identifies potential
adaptation strategies so that the County may begin planning how to implement different options.
These strategies have not been analyzed for feasibility or environmental effects, which should be
considered as part of an overall Adaptation Plan (see recommended next steps in Section 7).
6.1 Existing Adaptation Guidelines
6.1.1 Climate Change Preparedness Plan for the North
Olympic Peninsula
In August of 2015, multiple stakeholders, including Jefferson County, participated in the Climate
Change Preparedness Plan for the North Olympic Peninsula (Petersen et. al, 2015). This plan
formulated adaptation strategies for both Jefferson and Clallam Counties in the following
categories: ecosystems, water supplies, and critical infrastructure. Sea-level rise-related excerpts
from each of the three adaptation categories are listed below:
1. Strategies for Ecosystems:
a. Incorporate climate change more explicitly into comprehensive plans and Shoreline Master Programs (SMPs)
b. Encourage FEMA to incorporate climate change in rate maps and guidance
c. Develop graphic tools to illustrate climate impacts
d. Update financing policies for development in high risk areas
e. Utilize low cost citizen science monitoring and analysis approaches and technologies
2. Strategies for Water Supplies:
a. Research or develop models to assess sea-level rise and saltwater intrusion to
groundwater
3. Strategies for Critical Infrastructure:
a. Update emergency management and response planning to include climate change where
needed
b. Reduce inflow and infiltration to wastewater systems
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c. Update planning documents for sea-level rise and flooding where needed
d. Do outreach and education on climate adaptation to build community support
e. Create critical area flood mapping beyond FEMA’s historical flood data
f. Encourage soft defenses for shoreline infrastructure
g. Improve on-site stormwater management practices
h. Participate in FEMA’s Community Rating System
6.1.2 Lessons Learned from Local Governments
Incorporating Sea Level Rise in Shoreline Master Programs
The Washington State Department of Ecology (Ecology) released a guidance document in July of
2021 that included sea-level rise case studies, success strategies, challenges, needs, and
opportunities for local governments to incorporate sea-level rise in their SMPs (Ecology, 2021).
Jefferson County has already taken the suggested step of performing a vulnerability assessment
(i.e., this report), which will be used to advance sea-level rise considerations in its SMP. Future
adaptation planning efforts should look to this document as well as the Washington Coastal
Hazards Resilience Network (WSG and WSDE, 2022).12 for further guidance and adaptation
planning resources.
6.2 General Adaptation Strategies
This section identifies general adaptation strategies based on industry best practices and state
guidance. Different types of strategies (illustrated in Figure 20) will be appropriate in different
locations, and, in some cases, a hybrid approach with strategies from multiple categories may be
the best option. Additionally, the suite of strategies chosen may need to change over time as
conditions change and previous areas of uncertainty and unknown variables become more certain.
12 https://wacoastalnetwork.com/
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SOURCE: Modified from California Coastal Commission Sea Level Rise Policy Guidance, 2018 Jefferson County SLR Study
Figure 20 Sea-Level Rise Adaptation Strategies
Adaptation strategies are typically organized within the following categories: protection (Figure
21), accommodation (Figure 22), retreat (Figure 23), and hybrid. Each category is further
defined below.
• Protection strategies, which employ some sort of engineered structure or other measure to defend development (or resources) in its current location without changes to the development itself. Examples include: shoreline protective devices such as seawalls, revetments, groins,
and breakwaters, which defend against coastal hazards like wave impacts, erosion, and flooding; natural or “green” methods like dynamic cobble revetments and artificial oyster reefs to buffer coastal areas; and hybrid approaches using both artificial and natural
infrastructure.
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SOURCE: San Francisco SLR Action Plan Jefferson County SLR Study
Figure 21 Protective Adaptation Examples
• Accommodation strategies, which modify existing development or design new development in a way that decreases hazard risks and increases the resiliency of development. Examples include elevating and/or retrofitting structures and using materials that increase the strength
of development. In Jefferson County, this could include floodproofing the first floor of buildings to accommodate high-water-level events or designing new development with first floors above the future base flood elevation.
SOURCE: San Francisco SLR Action Plan Jefferson County SLR Study
Figure 22 Accommodation Adaptation Example
• Retreat strategies, which relocate existing development, limit substantial redevelopment, and/or limit the construction of new development in vulnerable areas. Development setbacks are an example of a retreat strategy.
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SOURCE: San Francisco SLR Action Plan Jefferson County SLR Study
Figure 23 Retreat Adaptation Example
• Hybrid strategies, which may employ a combination of one or more of the aforementioned strategies. For example, maybe coastal armoring is installed to buy time for a community to retreat.
6.3 Potential Adaptation Strategies for Jefferson
County
This section expands upon the general adaptation strategies mentioned above and provides tools
for the County to consider. The following subsections describe a variety of typical adaptation
strategies, their potential benefits, and their potential challenges.
6.3.1 Beach and Dune Nourishment
Though not a common geomorphic shore type on the Puget Sound side of the County, beaches
and dunes may be found along the Pacific Coast side and in a few locations on the east side of the
County. Beach nourishment is an adaptation strategy that provides protection against coastal
storm erosion while maintaining the natural condition, beach habitat, and processes (such as the
ability of the beach to erode in response to winter coastal storms and build up sand in response to
summer wave conditions). Beach nourishment refers to placement of sand or cobble to widen a
beach, which can be accomplished by placing a sediment-water slurry directly on the beach or
mechanical placement of sediment with construction equipment. Impacts to beach species can
occur during construction but are expected to be temporary. Sediment can be obtained from
inland sources (e.g., construction projects, quarries) and can be dredged from offshore, however,
it can be difficult to find sediment supplies of the right quality (e.g., size, color, shape) for beach
nourishment.
In addition to beach nourishment, dune restoration is recognized as a natural way of mitigating
backshore erosion as well as maintaining a wider beach through sacrificial erosion of the dunes.
Dune construction along the open coast would include placing sand, grading, and planting to form
“living” back beach dunes. Dune restoration can provide aesthetic, ecological, and recreational
benefits. A variant includes burying or placing a layer of cobble provides a “backstop” that is
more erosion resistant and dissipates waves to a greater degree (Figure 24).
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While beach nourishment initially reduces the risk of flooding and erosion along the beach, the
beach width is expected to diminish with time, requiring an ongoing cycle of “re-nourishment” to
maintain the beach. Additionally, while a wider beach reduces wave energy that reaches the
shore, nourishment may not protect against flooding during high water level events. During large
coastal storm events, sediment can be transported off the beach rapidly, reducing or eliminating
the benefit of the nourishment. Additionally, the sediment can be transported into estuaries).
Restored dunes can provide coastal storm protection but can also be eroded and washed out
during storm events, exposing landward areas to flood risks.
SOURCE: ESA Jefferson County SLR Study
Figure 24 Cross-Section of Beach Nourishment, Dune Restoration, and Cobble Placement
6.3.2 Beach Retention Structures - Groins
Groins extend perpendicular to a beach and trap sediment from drifting downcoast (Figure 25).
Where wave conditions are ideal, groins have been successfully used in Washington and other
locations to maintain a wider beach. In other cases, groins can induce and/or accelerate erosion
downcoast of the groin, as shown in Figure 25. Groins are generally considered along stretches
of coast with high net longshore sediment transport. In application, groins segment the beach
and nourishment efforts into compartments, where sediment is mostly limited to the
compartment it is in.
Public access across or over groins has the potential to negatively affect lateral access along the
beach. Constructing rock groins and other rock structures on the beach and/or in the ocean would
alter the character of the natural shoreline and offshore habitats and have biological impacts to
beach species. When first constructed, groins can significantly reduce the amount of sand
transported down-current to neighboring beach areas as sand is trapped up-current of the groin.
This impact can be somewhat mitigated if the area up-current of the groin is partially filled with
sand as part of construction. This can require significant amounts of imported sediment.
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SOURCE: ESA Jefferson County SLR Study
Figure 25 Example Processes Around Groins
6.3.3 Beach Retention Structures - Breakwaters
Breakwaters are offshore structures made of cement, riprap, and in some instances natural
materials (e.g., oyster reefs) that are constructed parallel to a beach to reduce wave action.
Typically built out of rock, breakwaters extend from the ocean floor to above the ocean level,
thereby acting as a wall that blocks waves by causing them to break farther offshore. Breakwaters
dissipate incident wave energy shoreward of the breakwater and change the pattern of sediment
transport in their lee (i.e., wave shadow), thereby reducing the transport of sediment. These
structures are generally applicable where there is a firm seabed and the need to create a calm area
free from wave energy.
Breakwaters have been used to shelter shorelines and harbors, have been built in shorter segments
to encourage sediment accumulation behind the breakwater segments, and in some instances can
provide access and recreation. However, when first constructed they can starve down-current
areas of sediment as sediment accumulates in front of the breakwater. Breakwaters can also
displace and change ocean habitats.
6.3.4 Beach Retention Structures - Kelp Bed Restoration
Offshore kelp beds may dissipate waves to some extent but would not be very effective at
maintaining sediment on the beach. Restoration of existing kelp beds can provide habitat benefits
with some reduction in sediment movement downcoast. Restoring kelp beds requires a rock
substrate and can be accomplished in areas with existing submerged rock or by placing rock
offshore. With a focus on restoration of habitat, permitting of this strategy would likely be less
complex than other sediment retention structures.
6.3.5 Coastal Bluff Erosion Best Management Practices
Best management practices (BMPs) for reducing coastal bluff erosion include management of
surface drainage as well as shallow subsurface groundwater drainage to the bluff’s edge and face
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to control local erosion and slope failure due to drainage. The goal of these practices is to control
surface runoff and avoid concentrated flow down the bluffs, reducing shallow groundwater flow
that saturates upper soils and facilitates erosion, and to facilitate management of groundwater
daylighting (i.e., reaching the surface) at geologic layers.
6.3.6 Shoreline Protection Devices
Shoreline protection devices, such as seawalls and rock revetments, are structures along the coast
that provide flood and erosion protection for properties by absorbing or dissipating wave energy.
Seawalls are vertical structures along a beach or coastal bluff used to protect structures and
property from wave action (see example in Figure 26). A seawall works by absorbing or
dissipating wave energy. They may be either gravity- or pile-supported structures and are
normally constructed of stone or concrete.
SOURCE: ESA Jefferson County SLR Study
Figure 26 Example Seawall within Jefferson County
Revetments provide protection to slopes and are constructed of sturdy materials, such as stone
(see example in Figure 27). Similar in purpose to a seawall, revetments work by absorbing or
dissipating wave energy. Revetments are made up of an armor layer (e.g., rock rip-rap piled up or
a carefully placed assortment of interlocking material, which forms a geometric pattern), a filter
layer (which provides for drainage and retains the soil that lies beneath), and a buried toe (which
adds stability at the bottom of the structure).
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SOURCE: ESA Jefferson County SLR Study
Figure 27 Example Revetment within Jefferson County
While seawalls and revetments provide protection to existing shoreline development behind them,
these structures can contribute to erosion and accelerate beach loss, which has significant
implications for valuable nearshore habitat. The structures prevent the shoreline and bluffs from
naturally eroding. Normally, waves lose momentum and energy as they run up a gently sloping
shoreline, and sediment is deposited to form beaches. Many shoreline protection devices make it
so that there is a hard back-stop to the shoreline. Waves hit the devices and reflect backward,
rather than dissipating, often causing increased sand erosion in front of the device. They can also
increase beach and bluff erosion on either side of the device and impact down-shore sediment
supplies. With ongoing beach erosion and sea-level rise and without any other mitigating
measures, fixing the shoreline location with a seawall or revetment will eventually lead to the loss
of the beach seaward of the structure (Figure 28).
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SOURCE: California Coastal Commission, 2018 Figure 28 Coastal Squeeze Process Resulting in Beach Loss
Seawalls and rock revetments, in some cases, can have significant impacts on lateral acccess
along the beach due to their displacement of beach area when they are constructed and the beach
loss that can occur in front of and adjacent to these devices. In some cases they may also affect
vertical access to the beach. Paths of access can be provided over and along the top of seawalls
and revetments. It is more difficult, however, to climb one of these structures than to simply walk
on the beach. Seawalls and rock revetments also can displace and change beach habitats.
Additionally, using seawalls or rock revetments to “hold the line” on an eroding shoreline with
sea-level rise may not be sustainable due to increasing wave action and overtopping associated
with the loss of the fronting beach. However, in some locations beach nourishment could be
implemented in conjunction with a seawall or revetment to at least partially offset this process for
some time. Additionally, sea-level rise will require more frequent maintenance or reconstruction
of these structures, which can be costly. Over time, the rocks of a revetment can move around and
get washed onto the beach, reducing the effectiveness of the revetment and causing increased
impacts to beach access.
Note that shoreline protection devices are designed to protect and withstand coastal storm events
up to a certain severity, such as the “100-year storm event.” Storm events that are more severe
than the design events can cause flooding and damage.
6.3.7 Elevating or Waterproofing Structures and Infrastructure
Raising structures such as buildings, roads, and utilities is a measure that can shift infrastructure
above coastal flooding elevations. Elevating structures can include raising buildings on pile
foundations to allow for some limited migration and persistence of a fronting beach in the near-
term. Raising roads and utilities could include replacing at-grade roads with pile-supported
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causeways. Associated utilities such as power, sewer, water, and electrical connections also need
to be raised or waterproofed to avoid damage. Properties located in mapped flood hazard zones
(pursuant to the FEMA Flood Insurance Rate Maps) are currently required to elevate the first
floor above the base flood elevation. However, FEMA Flood Insurance Rate Maps do not account
for the projected increases in flooding associated with sea-level rise or potential for increased
flooding hazards in the future from changes in rainfall patterns as a result of climate change. In
addition, many old buildings may not conform to current FEMA standards.
Raising buildings to address flooding as a result of less frequent coastal or riverine storm events
allows use of the buildings in between storm events. However, as sea levels rise and areas
become more inundated from regular high tides or more frequent small coastal storm events,
raising buildings on piles becomes ineffective as an adaptation strategy by itself because access to
the structures would be restricted due to flooding of surrounding streets. Additionally, it could
become hard to maintain services (e.g., water, wastewater, and electricity) to the structures. If
measures such as beach nourishment and retention are not taken, the shoreline could continue to
migrate past structures and potentially damage roads, infrastructure, and even the buildings if the
pilings are undermined. In order to raise buildings in some areas, it may also be necessary to
change height restrictions and other municipal code requirements. For beachfront properties
where retaining a beach is a priority, raising buildings could be preferable to installing seawalls or
revetments as it allows for the retention of structures for some time while still maintaining some
beach area.
Building designs can also be modified so that the second floor is above the target flood level and
contains all flood-sensitive features, while the first floor is used for parking and/or storage and is
designed to be durable and resilient to flood damage. Abandoning the lowest floor or elevating
the lowest habitable floor are effective strategies to reduce damage to the buildings from coastal
or riverine storm events and is often employed to meet FEMA base flood-elevation minimums.
Roads could be raised to avoid flood hazards. Infrastructure such as water and wastewater
pipelines could be redesigned to be waterproofed.
6.3.8 Elevating Property Grades
Raising buildings or roads could also be accomplished by placing fill to rebuild the grades at
higher elevations. Utilities such as sewer pipelines and storm drains that are vulnerable to
flooding, erosion, or increased groundwater levels can also be raised, so long as gravity flow is
maintained or pumps are installed. However, if one road is raised, all connecting roads, trails, and
utilities would have to be rebuilt to slope up to the new grade. Elevating grades requires
significant amounts of fill and, therefore, may only be feasible for areas of limited size.
Additionally, filling an area changes the hydrology of both the area filled and the way rainfall
runoff flows to neighboring areas. Stormwater would have to be managed effectively from the
filled areas so as to not increase flood risks elsewhere.
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6.3.9 Managed Retreat
Managed retreat strategies are those strategies that relocate or remove existing development out
of hazard areas and limit the construction of new development in vulnerable areas. As buildings,
utilities, and other infrastructure are increasingly at risk along beaches, coastal bluffs, or tidally
inundated areas, removal or relocation to a less hazardous area is an effective adaptation strategy.
Relocation requires sufficient and appropriate space. In some cases, this could require land
acquisition. Removal or relocation can also be phased to maintain at least some temporary use of
the development or infrastructure as sea levels rise.
When considering removal or relocation of infrastructure and roads, a key consideration is how
this would affect service and access to public and private properties remaining in hazard areas. If
it becomes infeasible or uneconomical to maintain public services to private properties in hazard
areas, many significant issues would need to be considered, including impacts to property owners,
underserved, place-based, and low-income communities, and public safety.
Hazard avoidance can also be facilitated through development restrictions that are consistent with
state statutes and state and federal constitutions. Note, undeveloped parcels were not assess in the
vulnerability assessment but may be key to understanding risks to future development.
Programs and policy options for removal or retreat of private property might include:
• Acquisition and buyout programs
• Conservation easements (e.g., setting aside low-lying land for conservation and habitat migration purposes as the sea level rises)
• Rolling easements
• Transfer of development right programs
Application of managed retreat to developed property may give rise to significant legal issues,
including the potential for inverse condemnation liability. Implementation measures for managed
retreat will require careful evaluation prior to adoption.
Throughout the United States, there are some examples of development removal and/or relocation
programs sponsored by the FEMA. As part of the Hazard Mitigation Grant Program Acquisition
Project, FEMA provides funds for local governments to purchase properties based on the
principle of fair compensation from a willing, voluntary seller that have a structure that may or
may not have been damaged or destroyed as a result of a hazard event. There is no readily
available information regarding the effectiveness of this program and the extent to which it has
already been applied. However, communities in Jefferson County could seek funding under this
program following a Presidential Major Disaster declaration (the mechanism that unlocks Hazard
Mitigation Grant Program funds).
Other issues that will need to be further considered in the future relating to retreat programs
include existing federal and state laws concerning property ownership and takings of property. It
is also unclear, based on current case law, how exactly property ownership boundaries (e.g., the
location of state tidelands) could move as the shoreline erodes and the mean high tide moves
6. Potential Adaptation Strategies
Jefferson County Sea-Level Rise Study 52 ESA / D202200495.00
June 2023
inland from sea-level rise. The current state and federal laws governing property ownership,
takings, and use of the coast were not written with consideration for large-scale changes such as
sea-level rise. How these laws will be implemented and interpreted by the courts in the face of
accelerated sea-level rise in the coming years is unknown. It is also possible that some of these
laws will be amended in the future to address the issues caused by sea-level rise and other climate
change hazards.
Additional federal and state-wide policy, legal guidance, and information on funding mechanisms
for managed retreat programs are likely needed to support the establishment of a private
development removal program in Jefferson County. In upcoming years, the County could follow
legal cases, legislative actions, and the development of removal or managed retreat programs in
other jurisdictions throughout the United States and pursue studies of how such programs could
be implemented in Jefferson County as more information becomes available.
7. Next Steps and Recommendations
Jefferson County Sea-Level Rise Study 53 ESA / D202200495.00
June 2023
7. NEXT STEPS AND RECOMMENDATIONS
This study presented the results of a County-wide sea-level rise analysis that is intended to
provide the basis for future site-specific assessments and broader adaptation planning. Based on
the findings of this study, ESA recommends the following next steps:
1. Develop a full Adaptation Plan: This could include identification of monitoring priorities and adaptation triggers. The County should continue to work with stakeholders, community
members, and tribes to develop coastal planning goals and adaptation planning priorities. Additional outreach plans may need to be developed in order to reach the broad range of community members throughout Jefferson County.
2. Develop an erosion monitoring plan and Pacific coast erosion analysis: Though ESA was able to obtain historic bluff erosion data for several places throughout the east side of the County, data was not available for the outer Pacific coastline nor beach/dune erosion at the time of the study. However, the Washington Department of Ecology has historic erosion rate data for the Pacific Coast and future efforts should consider this data to develop a coastal erosion hazard zone for the western county.
3. Develop a coastal armoring geodatabase: Information about the location, extent, and type of shoreline armoring is a key piece of information when assessing erosion and flooding because
armoring alters natural shoreline sediment processes and may exacerbate flooding or erosion in some locations. Since armoring is an adaptation strategy that the County or landowners may seek to implement, gathering existing data can be helpful to inform a County-wide
Adaptation Plan.
4. Conduct habitat evolution modeling: To better understand how coastal habitats will be impacted with sea-level rise, the County could analyze habitat evolution. This type of
modeling could help identify areas to preserve for future restoration and areas most at risk of drowning out.
8. References
Jefferson County Sea-Level Rise Study 54 ESA / D202200495.00
June 2023
8. REFERENCES
Battalio, R.T., P. D. Bromirski, D. R. Cayan, L. A. White, 2016. Relating Future Coastal
Conditions to Existing FEMA Flood Hazard Maps: Technical Methods Manual. Prepared for California Department of Water Resources and California Ocean Science Trust, Prepared by Environmental Science Associates (ESA), pp. 114.
City of Port Townsend, October 2022. The City of Port Townsend’s Sea Level Rise and Coastal Flooding Risk Assessment. Prepared by the City of Port Townsend and Cascadia Consulting Group.
Coastal Geologic Services (CGS), 2018. Coastal erosion data.
Coastal Geologic Services (CGS), Maverick, A., Johannessen, J., Miller, I.M., 2022. Prioritizing Sea Level Rise Exposure and Habitat Sensitivity Across Puget Sound Final Technical
Report. Prepared for EPA’s National Estuary Program in support of Near-Term Action 2018-0685, 46p., Bellingham, WA. Available: https://wacoastalnetwork.com/wp-content/uploads/2022/12/Prioritizing-Sea-Level-Rise-Exposure-and-Habitat-Sensitivity-
Across-Puget-Sound.pdf.
Federal Emergency Management Agency (FEMA). 2019. Flood Insurance Study (FIS) for Jefferson County, Washington and Incorporated Areas. June, 2019.
Fleming, C.S., S.D. Regan. 2022. A complementary social vulnerability assessment to support sea level rise planning in the Puget Sound region of Washington State. NOAA Technical Memorandum NOS NCCOS 302. Silver Spring, MD. 48 pp. DOI: 10.25923/rs2x-yk25
Johannesen, J. and A. MacLennan, 2007. Beaches and Bluffs of Puget Sound. Puget Sound Nearshore Partnership Report No. 2007-04. Published by Seattle District, US Army Corps
of Engineers, Seattle, Washington. Available: https://wdfw.wa.gov/sites/default/files/publications/02194/wdfw02194.pdf.
Kopp, R. E., Horton, R. M., Little, C. M., Mitrovica, J. X., Oppenheimer, M., Rasmussen, D. J.,
Strauss, B.H., and Tebaldi, C. 2014. Probabilistic 21st and 22nd century sea-level projections at a global network of tide-gauge sites. Earth’s Future, 2(8), 383-406. https://doi.org/10.1002/2014EF000239
Krueger, K.L., K.B. Pierce, T. Quinn, and D.E. Penttila. 2011. Anticipated Effects of Sea Level Rise in Puget Sound on Two Beach-Spawning Fishes. Puget Sound Shorelines and the Impacts of Armoring—Proceedings of a State of the Science Workshop.
https://wdfw.wa.gov/sites/default/files/publications/01210/wdfw01210.pdf
Mauger, G.S., J.H. Casola, H.A. Morgan, R.L. Strauch, B. Jones, B. Curry, T.M. Busch Isaksen, L. Whitely Binder, M.B. Krosby, A.K. Snover, 2015. State of knowledge report: Climate change in Puget Sound. Report prepared for the Puget Sound Partnership and the National Oceanic and Atmospheric Administration. Climate Impacts Group, University of Washington, Seattle, WA.
8. References
Jefferson County Sea-Level Rise Study 55 ESA / D202200495.00
June 2023
Miller, I.M., C. Shishido, L. Antrim, and C.E. Bowlby, 2013. Climate Change and the Olympic Coast National Marine Sanctuary: Interpreting Potential Futures. Marine Sanctuaries
Conservation Series ONMS-13-01. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Office of National Marine Sanctuaries, Silver Spring, MD. 238 pp.
Miller, I.M., Morgan, H., Mauger, G., Newton, T., Weldon, R., Schmidt, D., Welch, M., Grossman, E., 2018. Projected Sea Level Rise for Washington State – A 2018 Assessment. A collaboration of Washington Sea Grant, University of Washington Climate Impacts
Group, University of Oregon, University of Washington, and US Geological Survey. Prepared for the Washington Coastal Resilience Project, updated 07/2019. Available: https://cig.uw.edu/resources/special-reports/sea-level-rise-in-washington-state-a-2018-assessment/ [last accessed December 19, 2022]
National Oceanic and Atmospheric Administration (NOAA), 2003. Datums for 9444900, Port Townsend, WA. Available: https://tidesandcurrents.noaa.gov/datums.html?id=9444900.
NOAA, 2020. Datums for 9442396, La Push, Quillayute River WA. Available: https://tidesandcurrents.noaa.gov/datums.html?id=9442396.
Petersen, S., Bell, J., Miller, I., Jayne, C., Dean, K., Fougerat, M. 2015. Climate Change Preparedness Plan for the North Olympic Peninsula. A Project of the North Olympic Peninsula Resource Conservation & Development Council and the Washington Department
of Commerce, funded by the Environmental Protection Agency. Available: www.noprcd.org
Riahi, K., Rao, S., Krey, V. et al., 2011. RCP 8.5 – A scenario of comparatively high greenhouse
gas emissions. Climate Change 109, 33. https://doi.org/10.1007/s10584-011-0149-y https://link.springer.com/article/10.1007/s10584-011-0149-y#citeas [last accessed December 19, 2022]
Shaughnessy, F.J., W. Gilkerson, J.M. Black, D.H. Ward, and M. Petrie, 2012. Predicted Eelgrass Response to Sea Level Rise and its Availability to Foraging Black Brant in Pacific Coast Estuaries. Ecological Applications 22 (6): 1743-1761. doi: 10.1890/11-1083.1.
Smith, C.D., and T.L. Liedtke, 2022. Potential effects of sea level rise on nearshore habitat availability for surf smelt (Hypomesus pretiosus) and eelgrass (Zostera marina), Puget Sound, Washington: U.S. Geological Survey Open-File Report 2022–1054, 17 p., https://doi.org/10.3133/ofr20221054.
Sweet, W.V., Hamlington, B.D., Kopp, R.E., Weaver, C.P., Barnard, P.L., Bekaert, D., Brooks, W., Craghan, M., Dusek, G., Frederikse, T., Garner, G., Genz, A.S., Krasting, J.P., Larour, E., Marcy, D., Marra, J.J., Obeysekera, J., Osler, M., Pendleton, M., Roman, D., Schmied, L., Veatch, W., White, K.D., and Zuzak, C, 2022. Global and Regional Sea Level Rise
Scenarios for the United States: Up- dated Mean Projections and Extreme Water Level Probabilities Along U.S. Coastlines. NOAA Technical Report NOS 01. National Oceanic and Atmospheric Administration, National Ocean Service, Silver Spring, MD, 111 pp.
https://oceanservice.noaa.gov/hazards/sealevelrise/noaa-nos- techrpt01-global-regional-SLR-scenarios-US.pdf.
8. References
Jefferson County Sea-Level Rise Study 56 ESA / D202200495.00
June 2023
University of Washington Climate Impacts Group (UW CIG), 2018. Interactive Sea Level Rise Data Visualizations. Climate Impacts Group, University of Washington.
https://cig.uw.edu/projects/interactive-sea-level-rise-data-visualizations/
University of Washington Climate Impacts Group (UW CIG), UW Department of Environmental and Occupational Health Sciences, Front and Centered, and Urban@UW. 2018. An Unfair
Share: Exploring the disproportionate risks from climate change facing Washington state communities. A report prepared for Seattle Foundation. University of Washington, Seattle. URL: https://cig.uw.edu/wp-
content/uploads/sites/2/2018/08/AnUnfairShare_WashingtonState_August2018.pdf
U.S. Census Bureau. 2021a. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9503.01, Jefferson, WA https://censusreporter.org/profiles/14000US53031950301-census-tract-950301-jefferson-wa
U.S. Census Bureau. 2021b. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9503.02, Jefferson, WA https://censusreporter.org/profiles/14000US53031950302-census-tract-950302-jefferson-
wa/
U.S. Census Bureau. 2021c. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9504, Jefferson, WA
https://censusreporter.org/profiles/14000US53031950400-census-tract-9504-jefferson-wa/
U.S. Census Bureau. 2021d. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9505.01, Jefferson, WA
https://censusreporter.org/profiles/14000US53031950501-census-tract-950501-jefferson-wa/
U.S. Census Bureau. 2021e. American Community Survey 5-year estimates. Retrieved from
Census Reporter Profile page for Census Tract 9505.02, Jefferson, WA https://censusreporter.org/profiles/14000US53031950502-census-tract-950502-jefferson-wa/
U.S. Census Bureau. 2021f. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9505.02, Jefferson, WA https://censusreporter.org/profiles/14000US53031950202-census-tract-950202-jefferson-wa/
U.S. Census Bureau. 2021g. American Community Survey 5-year estimates. Retrieved from Census Reporter Profile page for Census Tract 9507.02, Jefferson, WA https://censusreporter.org/profiles/14000US53031950702-census-tract-950702-jefferson-wa/
Washington State Department of Ecology (Ecology), Shorelands and Environmental Assistance Program, 2021. Lessons Learned from Local Governments Incorporating Sea Level Rise in Shoreline Master Programs: A Compilation of Success Strategies, Challenges, Needs, and
Opportunities. Publication 21-06-014. Available: https://apps.ecology.wa.gov/publications/documents/2106014.pdf.
8. References
Jefferson County Sea-Level Rise Study 57 ESA / D202200495.00
June 2023
Washington Sea Grant (WSG) and Washington State Department of Ecology (WSDE), 2022. Washington Coastal Hazards Resilience Network. https://wacoastalnetwork.com/
9. List of Preparers
Jefferson County Sea-Level Rise Study 58 ESA / D202200495.00
June 2023
9. LIST OF PREPARERS
The following ESA staff contributed to the work described in this report:
Meagan Flier, EIT
Lindsey Sheehan, P.E.
Rachel Gregg
Alicia Juang, EIT
Bob Battalio, P.E.
We acknowledge the review and guidance of the Jefferson County Department of Community
Development staff during site visits, meetings, and virtual workshops.
Jefferson County Sea-Level Rise Study A-1 ESA / D202200495.00
[Type of Document] June 2023
Preliminary − Subject to Revision
Appendix A.
Site Visit Notes and Photos
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 16:33:02 UTC by SEA IPAD12
Updated 2022-12-15 18:31:26 UTC by SEA IPAD12
Location 48.0446021492, -122.768344609
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 587–599 E Moore St
Irondale, WA 98339
Location Irondale beach park
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Sandy beach, intertidal non-wetland habitat up to vegetated bluff north of the parking
lot. Some wetland with a drainage south of lot then more intertidal non-wetland
Describe at risk asset, infrastructure, shoreline
habitat:
Several houses, beach access, park amenities, parking lot
Identify potential impacts to people, existing
structures, and the shoreline environment:
Storms inundating park
Describe potential strategies to mitigate risk and
adaption strategies:
Walk around park, allow beach to migrate inland north and south of parking lot
Photo Log
sandy beach
Irondale beach park, 2022-10-27Irondale beach park, 2022-10-27
Page: 1 of 5
sandy beach with houses behind
parking lot
Page: 2 of 5
beach to the south
beach to the south
Page: 3 of 5
drainage from marshy area south of parking lot
marshy area south of parking lot
Page: 4 of 5
beach to the south
Page: 5 of 5
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 16:59:07 UTC by SEA IPAD12
Updated 2022-12-15 18:29:45 UTC by SEA IPAD12
Location 48.033189266, -122.752623512
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 163–199 Lower Hadlock Rd
Irondale, WA 98339
Location Water front Hadlock
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Beach slope south along road, sandy w/ rocks, north is developed with riprap and
maybe filled in places. Bluff to the west of the road.
Describe at risk asset, infrastructure, shoreline
habitat:
Star marine inc, NW school of wooden boat building, several homes (tiny houses
associated with the school?), roads, several homes to the north at higher elevations.
Ajax cafe is popular quirky spot. Aquaculture, oysters and seaweed proposed at south
end of road. Septic field on inland side of road.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Already ponding from rainfall- not good drainage. Buildings are over water so probably
already experience flooding and waves during storms. Septic system along road
Describe potential strategies to mitigate risk and
adaption strategies:
Could raise buildings that are already on piers, raise road but houses behind would be
(are already) lower.
Photo Log
marsh behind road
Water front Hadlock, 2022-10-27Water front Hadlock, 2022-10-27
Page: 1 of 9
dead end road
sandy beach
Page: 2 of 9
buildings over water
docks
Page: 3 of 9
docks
popular restaurant/local spot
Page: 4 of 9
building over water
building over water
Page: 5 of 9
heavy riprap
homes behind road- low-lying
Page: 6 of 9
riprap between over-water buildings
homes behind road- low-lying, ponding
Page: 7 of 9
septic system very close to water
marsh behind road
Page: 8 of 9
marsh behind road
Page: 9 of 9
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 17:42:23 UTC by SEA IPAD12
Updated 2022-12-15 18:26:54 UTC by SEA IPAD12
Location 48.0568534022, -122.684110506
Date 2022-10-27
Field Staff Lindsey Sheehan
Address E Beach Park Rd
Nordland, WA 98358
Location East beach park on marrowstone island
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Sandy beach, 2-ft wall maybe for wind blown sand. Big waves, large exposure.
Describe at risk asset, infrastructure, shoreline
habitat:
Parking lot, structure over picnic tables. Can see bluff-top homes in the distance. Little
to no other infrastructure.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Loss of park
Describe potential strategies to mitigate risk and
adaption strategies:
Larger wall to protect parking lot or allow for beach migration and eventual loss of part
of all of parking lot.
Photo Log
short wall protecting parking lot
East beach park on marrowstone island, 2022-10-27East beach park on marrowstone island, 2022-10-27
Page: 1 of 4
beach with marsh behind
BBQ cabana
Page: 2 of 4
bluffs further north
picnic tables
Page: 3 of 4
sandy beach
Page: 4 of 4
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 18:36:44 UTC by SEA IPAD12
Updated 2022-12-15 18:25:19 UTC by SEA IPAD12
Location 47.9587404578, -122.692563348
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 160–398 Bayshore Dr
Nordland, WA 98365
Location Bay shore drive
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Rocky shore, small beach
Describe at risk asset, infrastructure, shoreline
habitat:
Road has low spot maybe 300 ft. Small drainage culvert at lowest point in road
Identify potential impacts to people, existing
structures, and the shoreline environment:
Erosion of road edge, overtopping.
Describe potential strategies to mitigate risk and
adaption strategies:
Investigate alternative access routes for residences. Raise road at lowest point.
Photo Log
road dips down near water
Bay shore drive, 2022-10-27Bay shore drive, 2022-10-27
Page: 1 of 1
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 18:53:20 UTC by SEA IPAD12
Updated 2022-12-15 18:24:44 UTC by SEA IPAD12
Location 47.914171057, -122.688214189
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 175 Lagoon Ln
Port Ludlow, WA 98365
Location Lagoon lane
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Private road, drop in road coming in. Lagoon and tidal marsh behind homes, shore in
front. Calmer water so likely more protected - exposed mostly to northerly storms.
Describe at risk asset, infrastructure, shoreline
habitat:
Flooding from both sides
Identify potential impacts to people, existing
structures, and the shoreline environment:
Several private houses could lose access or be flooded. Risk of habitat change in the
lagoon (transition from salt marsh to mudflat or open water)
Describe potential strategies to mitigate risk and
adaption strategies:
Sea wall or managed retreat. Seawall would be difficult to protect from flooding on all
sides - road would need to be raised as well
Lagoon lane, 2022-10-27Lagoon lane, 2022-10-27
Page: 1 of 2
Photo Log
homes backed by marsh
homes close to bay
Page: 2 of 2
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 17:34:12 UTC by SEA IPAD12
Updated 2022-12-15 18:23:37 UTC by SEA IPAD12
Location 48.0490625622, -122.691068284
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 7040–7058 Flagler Rd
Nordland, WA 98358
Location Flagler Rd low spot
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Road probably ~6 ft above water level. Maybe 2 ft above high water mark. Little to no
wave exposure
Describe at risk asset, infrastructure, shoreline
habitat:
State road. Two private driveways connect to Flagler Road and span the southern end
of Mystery bay.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Emergency access, but there is west road for alternative access.
Describe potential strategies to mitigate risk and
adaption strategies:
Could raise low spot or add berm along the length of the road (potentially concern with
shoulder safety if berm added).
Additional Comments South end of Mystery Bay
Photo Log
high water line ~2 ft down from road
Flagler Rd low spot, 2022-10-27Flagler Rd low spot, 2022-10-27
Page: 1 of 3
high water line ~2 ft down from road
culvert and road to homes
Page: 2 of 3
homes across from road
homes across from road
Page: 3 of 3
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 18:10:36 UTC by SEA IPAD12
Updated 2022-12-15 18:22:11 UTC by SEA IPAD12
Location 48.0209896574, -122.731016055
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 181 Portage Way
Nordland, WA 98339
Location Portage bay and hiller rd
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Road already has large riprap along length at Oak Bay Campground and campground
access road. Homes are slightly more protected from waves with more beach and
vegetated berm. Some homes have 2-3 ft sea wall with veg in front. Waves already
causing spay and likely overtopping of road.
Describe at risk asset, infrastructure, shoreline
habitat:
Parking lot for county camp ground, vault toilet, road, homes
Identify potential impacts to people, existing
structures, and the shoreline environment:
Already wave overtopping, septic systems near shore. Some septic systems have been
moved uphill already.
Describe potential strategies to mitigate risk and
adaption strategies:
Raise road, higher sea wall for houses or remove. Consider seasonal management of
campground access road, and long term move campground and remove
infrastructure.
Photo Log
heavy riprap along road
Portage bay and hiller rd, 2022-10-27Portage bay and hiller rd, 2022-10-27
Page: 1 of 4
heavy riprap along road
some beach in front of homes
Page: 2 of 4
some beach in front of homes
small seawall protecting homes
Page: 3 of 4
road experiencing wave overtopping
Page: 4 of 4
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 19:19:09 UTC by SEA IPAD12
Updated 2022-12-15 18:20:46 UTC by SEA IPAD12
Location 47.8695872566, -122.691279128
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 295 Margaret St
Port Ludlow, WA 98365
Location Margaret St
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Cobble beach with substantial sea wall. Eastern houses most exposed, sea wall
decreases going west where there is a lagoon. High Tide Line is part way up seawall.
Describe at risk asset, infrastructure, shoreline
habitat:
Several houses, road turns to private. Road is set back a bit from the shoreline, private
homes are most at risk. Unknown septic/utilities.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Overtopping of seawall and gravel/log transport into homes causing damage. Potential
undermining and failure of seawall, though walls appear to be in good condition
currently. If septic fields, likely at risk.
Describe potential strategies to mitigate risk and
adaption strategies:
Short term - consider cobble/gravel nourishment prior to seawalls getting undermined
Photo Log
seawalls protecting homes to the east
Margaret St, 2022-10-27Margaret St, 2022-10-27
Page: 1 of 3
to the west, more bluff and homes set back more
gravel shore
Page: 2 of 3
small bluff, homes set back
Page: 3 of 3
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 20:11:10 UTC by SEA IPAD12
Updated 2022-12-15 18:19:18 UTC by SEA IPAD12
Location 47.8281589913, -122.857645687
Date 2022-10-27
Field Staff Lindsey Sheehan
Address E Quilcene Rd
Quilcene, WA 98376
Location E Quilcene Rd
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Road w bridge over little quilcene river. Low part is actually west side of bridge and
bridge raises up. Bridge spans Donovan Creek, and has riprap armoring in good
condition.
Describe at risk asset, infrastructure, shoreline
habitat:
Wetland habitat, access, small lot on east of bridge. Flooding issues exist in lowest
reach of Little Quilcene River - county has built small berm parallel to E Quilcene Road
to reduce fluvial flooding. Inland agricultural and residential parcels to the north are
low in elevation.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Road limits natural habitat transition over time
E Quilcene Rd, 2022-10-27E Quilcene Rd, 2022-10-27
Page: 1 of 2
Photo Log
wetland
wetland
Page: 2 of 2
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 20:23:38 UTC by SEA IPAD12
Updated 2022-12-15 18:14:50 UTC by SEA IPAD12
Location 47.8034886998, -122.868320514
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 1511 Linger Longer Rd
Quilcene, WA 98376
Location Quilcene linger longer rd
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Yacht club, row of houses w riprap, Herb Beck Marina, Pacific Seafoods company.
Pacific Seafoods buildings partially over water. Shallow bay, relatively low wave
exposure.
Describe at risk asset, infrastructure, shoreline
habitat:
Many houses have riprap revetment plus a small berm. Linger Longer Road itself is set
back and a bit higher along most of the length.
Identify potential impacts to people, existing
structures, and the shoreline environment:
Loss of only marina in area, large shellfish employer, loss of residences
Describe potential strategies to mitigate risk and
adaption strategies:
Add or enhance berms in front of residences and along road. Consider options for
adjustable trestle access to marina facilities
Photo Log
homes to the north
Quilcene linger longer rd , 2022-10-27Quilcene linger longer rd , 2022-10-27
Page: 1 of 3
ponding in parking lot
heavy rock riprap
Page: 2 of 3
heavy rock riprap
Page: 3 of 3
Project D202200495 - Jefferson County SLR Study
Created 2022-10-27 21:00:08 UTC by SEA IPAD12
Updated 2022-12-15 18:12:44 UTC by SEA IPAD12
Location 47.6935670717, -122.89752497
Date 2022-10-27
Field Staff Lindsey Sheehan
Address 22 Sylopash Ln
Brinnon, WA 98320
Location Brinnon
Describe existing site conditions(shoreline
protection devices, shore slope, beach or bluff,
grain size, etc.):
Low wide marsh plain in front of row of houses. Private road (gravel). Low energy wave
environment.
Describe at risk asset, infrastructure, shoreline
habitat:
Several homes. Likely septic fields
Identify potential impacts to people, existing
structures, and the shoreline environment:
Already flooding all the way to fire station - some of this may be associated with fluvial
or estuarine flooding
Describe potential strategies to mitigate risk and
adaption strategies:
Add berm or seawall in front of houses. Evaluate estuarine flooding risk.
Photo Log
extensive marsh in front of homes, but flat
Brinnon, 2022-10-27Brinnon, 2022-10-27
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extensive marsh in front of homes, but flat
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Jefferson County Sea-Level Rise Study B-1 ESA / D202200495.00
[Type of Document] June 2023
Preliminary − Subject to Revision
Appendix B.
Exposure Tables
Asset Unit (Count or Miles) Current Sea LevelFuture Sea Level with 1ft of SLRFuture 2040 ShorelineFuture Sea Level with 2ft of SLRFuture 2060 ShorelineFuture Sea Level with 5ft of SLRFuture 2100 ShorelineHospitalsCount0000000Fire StationsCount 0 0 0 0 0 0 0SchoolsCount 0 0 0 0 0 0 0BuildingsCount 1151 1,920 33 2,577 117 3,226 277Sewer PipesMiles 4.1 5.4 0.03 6.0 0.06 6.4 0.12Septic SystemsCount 520 701 1 796 6 1053 78Sewer Drain FieldsCount 0 0 0 0 0 0 0Water PipesMiles 3.3 3.8 0.1 4.4 0.2 6.2 0.2Water Facilities (Wells and Fire Hydrants)Count 0 0 0 0 0 3 0Seawater Intrusion Protection Zone (SIPZ) WellsCount 34 39 1 48 2 65 3RoadsMiles 24 34 0.2 41 0.5 54 1.0TrailsMiles 23 24 0.9 24 1.2 25 2.1Hazardous Material Storage SitesCount 2 2 1.0 2 1 2 1Short‐Term (2040) Mid‐Term (2060) Long‐Term (2100)