HomeMy WebLinkAboutPA2021-308_20211222_Coastal Hazards_7-15-21Geotechnical C Geologic C Coastal C Environmental
5741 Palmer Way C Carlsbad, California 92010 C (760) 438-3155 C FAX (760) 931-0915 C www.geosoilsinc.com
July 15, 2021
Mr. Jack Langson
c/o PMR Construction
2026 West Balboa Blvd. Suite D
Newport Beach, CA 92663
SUBJECT: Coastal Hazard and Sea Level Rise Discussion for New Residence, 2676
Bayshore Drive, Newport Beach, Orange County, California.
Dear Mr. Langson:
In accordance with the request and authorization, GeoSoils, Inc. (GSI) is pleased to
provide this discussion regarding the potential coastal hazards, including the impact of
future sea level rise (SLR), on the proposed new residence at 2676 Bayshore Drive in
Newport Beach, California. The purpose of this report is to provide the hazard information
for your permit application typically requested by the City of Newport Beach and the
California Coastal Commission (CCC). Our scope of work includes a review of the State
of California Sea-Level Rise (SLR) Policy Guidance document (March 2018), CCC SLR
Guidance (November 2018), a review of City of Newport Beach Municipal Code (NBMC)
21.30.15.E.2 and 21.30.15.E.3, a review of the proposed plans, and preparation of this
letter report.
INTRODUCTION
The proposed project is new single-family residence and associated improvements, in the
City of Newport Beach. The site is fronted by a concrete bulkhead, a boat dock, and a
large navigation channel within Newport Bay. The project will include either reinforcing the
existing bulkhead and raising the top of the bulkhead to elevation +10.9 feet NAVD88, or
replacement with a new bulkhead to a minimum height of 10.9 feet NAVD88. The
proposed finished first floor (FF) of the residence is ~+12.4 feet NAVD88. The surface
drainage flow line on Bayshore Drive is at about elevation +11.0 feet NAVD88. Figure 1,
downloaded from Google Maps (Bird’s Eye View), shows the site in relation to the adjacent
properties and the navigation channel. The site is currently mapped by FEMA (FIRM Panel
06059C0381K) to be in the Shaded X Zone with no base flood elevation (BFE). The
bulkhead and adjacent navigation channel are in the FEMA AE Zone with a BFE of +8 feet
NAVD88.
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Figure 1. Subject site, 2676 Bayshore Drive, adjacent properties, and navigation
channel within Newport Bay.
DATA & DATUM
The datum used in this report is NAVD88, which is about 2.62 feet below the mean tide
level (MTL). The units of measurement in this report are feet (ft), pounds force (lbs), and
seconds (sec). Site elevations were taken from a topographic map prepared by
CivilScapes Engineering. Preliminary development plans were discussed with Scott
Shaffer and PMR Construction. A site reconnaissance was performed on March 23, 2021.
There is no beach or shoreline fronting the site.
HAZARD ANALYSIS
There are three different potential shoreline hazards for ocean and waterfront
development: shoreline movement/erosion, waves and wave runup, and flooding. For
ease of review, each of these hazards will be analyzed and discussed separately, followed
by a summary of the analysis including conclusions and recommendations, as necessary.
Shoreline Erosion Hazard
There is no actual beach or shoreline at the site proper. The elevation of the mudline at
the bulkhead is below the lowest bay water elevation.
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Waves and Wave Runup
The potential surface gravity waves (ocean swell) to arrive at this site is nil. Boat wakes
are the only possible waves that can reach the bulkhead fronting the site. However, boat
wakes are typically small due to speed restriction within the channel. Anticipated wave
runup and overtopping of the bulkhead at the site was calculated using the USACOE
Automated Coastal Engineering System, ACES. ACES is an interactive computer-based
design and analysis system in the field of coastal engineering. The methods to calculate
wave runup and overtopping implemented within this ACES application are discussed in
greater detail in the 2004 Coastal Engineering Manual. A 0.75-foot high wave was used
in the ACES wave runup and overtopping analysis with a current maximum historical water
level of +7.7 feet NAVD88 (no future SLR). This combination of wave and water level
represents an approximate 100-year recurrence interval oceanographic condition under
current sea level. Table I below is the computed output from the ACES program for the
wave runup analysis.
TABLE I
The calculated maximum wave runup under the current 100-year recurrence interval water
level conditions is about 0.84 feet above the 100-year water level or about elevation +8.5
feet NAVD88. This is currently below the proposed minimum elevation of the
reconditioned or replaced bulkhead. With the proposed minimum bulkhead elevation
+10.9 feet NAVD88 and SLR of 2.3 feet (+8.5 NAVD88 + 2.3 feet SLR = 10.8 NAVD88),
waves/wakes will not overtop the bulkhead. Any wake/wave runup waters that reach near
this elevation will have a low velocity, no energy, and no erosion capacity. It should be
noted that under higher future SLR conditions the height of the bulkhead can be increased
to prevent overtopping.
ACES I Mode: Single Case I Functional Area: Wave -Structure Interaction
App I icat ion: Wave Runup and Overtopping on Impermeable Structures
Item Unit Ualue Smooth Slope
Runup and
Incident Wave Height Hi: ft 0 .750 Overtopping
Wave Period T: sec 3 .500
COTAN of Nearshore Slope COTC!II): 20.000 2676 Bayshore Water Depth at Structure Toe ds: ft 7.200 Drive COTAN of Structure Slope COTC8): 0.000
Structure Height Above Toe hs: ft 8.500 No SLR
Bulkhead Wave Runup R: ft 0 .838 Overtopping Onshore Wind Velocity u: ft/sec 8.439
Deepwater Wave Height H0: ft 0 .813
Relative Height ds/H0: 8 .860
Wave Steepness H0/CgT"2): 0.002062
Overtopping Coefficient 0:: 0.070000
Overtopping Coefficient Qstar0: 0.070000
Overtopping Rate Q: ftA3/s-ft 0 .000
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Current Flooding Hazard
The National Oceanographic and Atmospheric (NOAA) National Ocean Survey tidal data
station closest to the site with a long tidal record (Everest International Consultants Inc.
(EICI), 2011) is located at Los Angeles Harbor (Station 94106600). The tidal datum
elevations are as follows:
Mean High Water 4.55 feet
Mean Tide Level (MSL) 2.62 feet
Mean Low Water 0.74 feet
NAVD88 0.0 feet
Mean Lower Low Water -0.2 feet
The historical highest ocean water elevation at the Los Angeles Harbor Tide station is
+7.72 feet NAVD88 on January 10, 2005. In addition, EICI reported that the elevation of
7.71 feet NAVD88 is the 1% water elevation. For this analysis the historical highest water
elevation will be +7.7 feet NAVD88.
Future Tide Levels Due to Sea Level Rise
The California Coastal Commission (CCC) SLR Guidance document recommends that a
project designer determine the range of SLR using the “best available science.” The
California Ocean Protection Council (COPC) adopted an update to the State’s Sea-Level
Rise Guidance in March 2018. These new estimates are based upon a 2014 report
entitled “Probabilistic 21st and 22nd century sea-level projections at a global network of
tide-gauge sites” (Kopp et al., 2014). This update included SLR estimates and probabilities
for Los Angeles Harbor the closest SLR estimates to Newport Bay. These SLR likelihood
estimates are provided below in Figure 2 taken from the Kopp et al., 2014 report. The
report provides SLR estimates based upon various carbon emission scenarios known as
a “representative concentration pathway” or RCP. Figure 2 provides the March 2018
COPC data (from the Kopp et al., 2014 report) with the latest SLR adopted estimates (in
feet) and the probabilities of those estimate to meet or exceed the 1991-2009 mean, based
upon the best available science.
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Figure 2. Table from Kopp et al., (2014) and COPC 2018, providing current SLR estimates
and probabilities for the Los Angeles Harbor tide station.
This table illustrates that SLR in the year 2100 for the likely range, and considering the
most onerous RCP (8.5), is 1.3 feet to 3.2 feet above the 1991-2009 mean. The City of
Newport Beach currently requires the use of a lower probability SLR estimate. The design
historical water elevation at the for Newport Bay is elevation +7.7 feet NAVD88 (1% water
elevation). Interpolating the above table, the very low probability SLR (0.5%) for the year
2096, low emissions, SLR is ~5.0 feet, and the high emissions, SLR is 6 feet. Based upon
this table there is a much lower probability (0.5%) of SLR of about 6.0 feet. This SLR
would account for future extreme bay water level of 13.7 feet NAVD88 (7.7 feet NAVD88
+ 6 feet SLR). As stated before, the present maximum (1%) historical water elevation at
the site, including El Niño effects, is +7.7 feet NAVD88. Based upon the elevation of the
modified or replaced bulkhead (10.9 feet NAVD88), the extreme Newport Bay water level
will exceed the height of the bulkhead when SLR is 3.2 feet or greater.
For the likely COPC SLR estimate range (high emissions) the site is safe from flooding until
beyond the year 2090. For the 0.5% SLR case, this may occur after the year 2070. It
should be noted that, if SLR is higher, flooding at the site will not occur constantly but
rather only a few times a month, at the full moon and new moon, for a period of about 1
hour. With the proposed FF at elevation ~12.4 feet NAVD88, the structure will be safe
from flooding from offsite sources until about the year 2085 for the 0.5% SLR. For the 5%
COPC SLR estimate range (high emissions) the structure is safe from flooding until beyond
the year 2110.
LOW Medium -High Extreme Risk
Aversion Risk Aversion Risk Aversion
High emissions 2030 0 .3 0.2 0.5 0.6 0.7 1.0
2040 0.5 0.4 0.7 0.9 1.2 1.7
2050 0.7 0.5 1.0 1.2 1.8 2.6
Low emissions 2060 0 .8 0.5 1.1 1.4 22
High emissions 2060 1.0 0.7 1.3 1.7 2.5 3.7
Low emissions 2070 0.9 0.6 1.3 1.8 2.9
High emissions 2070 1.2 0.8 1.7 2.2 3.3 5.0
Low emissions 2080 1.0 0.6 1.6 2.1 3.6
High emissions 2080 1.5 1.0 2.2 2.8 4.3 6.4
Low emissions 2090 1.2 0.7 1.8 2.5 4.5
High emissions 2090 1.8 1.2 2.7 3.4 5.3 8.0
Low emissions 2100 1.3 0.7 2.1 3.0 5.4
High emissions 2100 22 1.3 3.2 4.1 6.7 9.9
Low emissions 2110· 1.4 0.9 2.2 3.1 6.0
High emissions 2110· 2.3 1.6 3.3 4.3 7.1 11.S
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The Kopp et al. paper used 2009 to 2012 SLR modeling for the probability analysis, which
means the “best available science” as determined by the CCC is almost 10 years old. The
CCC SLR Guidance requires the use of the “best available science.” Dr. Reinhard Flick
from the Scripps Institution of Oceanography has provided information that global sea level
from 1992 to 2018 has resulted in 8.32 centimeters of relatively uniform SLR in the past
26 years. This information is shown on Figure 3 taken from the CCC SLR Guidance
(2015). This current measurement shows that SLR is tracking more on the intermediate
SLR prediction curves, which is more like a 50% (median) probability SLR in the year 2100,
as shown in Figure 3.
Figure 3. Current global SLR plotted on SLR prediction curves (graphic taken from
TerraCosta Consulting).
The recent global SLR measurement provided in Figure 3 shows that the current SLR
trend, is not following the higher SLR estimate curves. It is GSI’s professional opinion that
the methodology and SLR estimates suggested by the CCC SLR Guidance, based upon
current SLR trends, are an overestimate of SLR over the project design life of 75 years.
The City of Newport Beach has recognized that in the future there will be a need to raise
the elevation of the boardwalks and bulkheads around the Newport Bay. The City of
Newport Beach Building Department (CNBBD) has a standard drawing, and a regional plan
for rehabilitating and raising the bulkheads. Flooding from the bay and from the beach will
result in flooding of the public roads in the area. Recent action by the City Council has
raised the minimum bulkhead elevation for new development to be 10.9 feet NAVD88.
i ~
t 0 i e ~ s ii
'W • . .., .. rZ
C
i
ii ..Q .2 0
~---------------------------~2.13m (7.011.)
200 Observed
160
12()
80
4()
0
1 ..
3.2 mm/year J
-40
1900 1950 2000
Ye■r
S<:enanos
8.32 cm
I C0 2050 a "'
Higheot • 2.0 m
1.37 m (4.511.)
Jntormadlato-H,gh • 1.2 m
tntermediat•Low • 0.5 m
Lowest -0.2 m
2100
Modified from Figure 5 of the California Coastal Commission Sea Level Rise Policy Guidance
document adopted August 12, 2015.
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Tsunami
Tsunami are waves generated by submarine earthquakes, landslides, or volcanic action.
Lander, et al. (1993) discusses the frequency and magnitude of recorded or observed
tsunami in the southern California area. James Houston (1980) predicts a tsunami of less
than 5 feet for a 500-year recurrence interval for this area. Legg, et al. (2002) examined
the potential tsunami wave runup in southern California. While this study is not specific to
the site, it provides a first order analysis for the area. The Legg, et al. (2002) report
determined a maximum open ocean tsunami height of less than 2 meters. The maximum
tsunami runup in the Newport Beach open coast area is less than 1 meters in height. Any
wave, including a tsunami, that approaches the site in will be refracted, modified, and
reduced in height by the Newport jetties, and as it travels into the bay. Due to the
infrequent nature and the relatively low 500-year recurrence interval tsunami wave height,
and the elevation of the proposed improvements, the site is reasonably safe from tsunami
hazards.
It should be noted that the site is mapped within the limits of the California Office of
Emergency Services tsunami innundation map, Newport Beach Quadrangle (State of
California, 2009). The tsunami inundation maps are very specific as to their use. Their use
is for evacuation planning only. The limitation on the use of the maps is clearly stated in
the PURPOSE OF THIS MAP on every quadrangle of California coastline. In addition, the
following paragraph is taken from the CalOES Local Planning Guidance on Tsunami
Response concerning the use of the tsunami inundation maps.
Inundation projections and resulting planning maps are to be used for emergency
planning purposes only. They are not based on a specific earthquake and tsunami.
Areas actually inundated by a specific tsunami can vary from those predicted. The
inundation maps are not a prediction of the performance, in an earthquake or
tsunami, of any structure within or outside of the projected inundation area.
The City of Newport Beach and County of Orange have clearly marked tsunami evacuation
routes for the entire Newport Beach/Bay area.
CITY OF NEWPORT BEACH INFORMATION
Coastal Hazards Report (NBMC 21.30.15.E.2):
i. A statement of the preparer’s qualifications;
Mr. Skelly is Vice President and Principal Engineer for GeoSoils, Inc. (GSI). He has
worked with GSI for several decades on numerous land development projects
throughout California. Mr. Skelly has over 40 years experience in coastal
engineering. Prior to joining the GSI team, he worked as a research engineer at the
Center for Coastal Studies at Scripps Institution of Oceanography for 17 years.
During his tenure at Scripps, Mr. Skelly worked on coastal erosion problems
throughout the world. He has written numerous technical reports and published
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papers on these projects. He was a co-author of a major Coast of California Storm
and Tidal Wave Study report. He has extensive experience with coastal processes
in southern California. Mr. Skelly also performs wave shoring and uprush analysis
for coastal development, and analyzes coastal processes, wave forces, water
elevation, longshore transport of sand, and coastal erosion.
ii. Identification of costal hazards affecting the site;
As stated in this hazard analysis, the typical coastal hazards to consider
are shoreline erosion, flooding, and wave/wake impacts. There is no beach at, or
near, the site. Boat wakes and wind waves are too small, even with sea level rise
(SLR), to potentially flood the proposed residence provided the bulkheads in the
area are maintained to mitigate SLR impacts. The City of Newport Beach has
recognized that in the future there will be a need to raise the elevation of the
boardwalks and bulkheads on Balboa Island (and other areas), and as such the City
of Newport Beach has a standard drawing(s), and a regional plan for rehabilitating
and raising the bulkheads. There is no potential coastal hazard of flooding of the
development provided adaptation strategies such as waterproofing the structure to
above the potential flood elevation, and increasing the height of the bulkhead are
implemented, if required, in the future.
iii. An analysis of the following conditions:
1. A seasonally eroded beach combined with long-term (75 year)
erosion factoring in sea level rise;
There is no beach at, or near, the site.
2. High tide conditions, combined with long-term (75 year) projections
for sea level rise;
Using the likely CCC SLR estimate over the project 75-year design life, the
SLR in the year ~2096 is 2.9 feet. There is a 0.5% probability that SLR could
be 6 feet in the next 75 years. This is the design sea level rise range (2.9 feet
to 6 feet) for the proposed project. This SLR would account for future
extreme bay water level of 10.6 feet NAVD88 to 13.7 feet NAVD88.
3. Storm waves from a one hundred year event or storm that compares
to the 1982/83 El Nino event;
No ocean waves can reach the site.
4. An analysis of bluff stability; a quantitative slope stability analysis
that shows either that the bluff currently possesses a factor of safety
against sliding of all least 1.5 under static conditions, and 1.1 under
seismic (pseudostatic conditions); or the distance from the bluff edge
needed to achieve these factors of safety; and
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There is no bluff fronting the site. This condition does not occur at the site.
5. Demonstration that development will be sited such that it maintains
a factor of safety against sliding of at least 1.5 under static conditions
and 1.1 under seismic (pseudostatic) conditions for its economic life
(generally 75 years). This generally means that the setback necessary
to achieve a factor of safety of 1.5 (static) and 1.1 (pseudostatic) today
must be added to the expected amount of bluff erosion over the
economic life of the development (generally 75 years);
There is no bluff fronting the site. There is no potential for sliding. This
condition does not occur at the site.
iv. On sites with an existing bulkhead, a determination as to whether the
existing bulkhead can be removed and/or the existing or a replacement
bulkhead is required to protect existing principal structures and adjacent
development or public facilities on the site or in the surrounding areas; and
There is a bulkhead on the site. It is our understanding that the project
includes the raising of the bulkhead up to elevation 10.9 feet NAVD88 or
replacement of the bulkhead to a minimum elevation of 10.9 feet NAVD88.
Another engineering consultant, PMA Consulting Inc., has been retained for
this phase of the project.
v. Identification of necessary mitigation measures to address current
hazardous conditions such as siting development away from hazardous areas
and elevating the finished floor of structures to be at or above the base floor
elevation including measures that may be required in the future to address
increased erosion and flooding due to sea level rise such as waterproofing,
flood shields, watertight doors, moveable floodwalls, partitions, water-
resistive sealant devices, sandbagging and other similar flood-proofing
techniques.
The project is safe from the coastal hazard of flooding by the proposed
addition to the bulkhead height (or bulkhead replacement), the finished floor
elevation, and the ability to waterproof the building, if necessary. It is
important to point out that SLR will not impact this area alone. It will impact
all of the Newport Bay low lying areas. The public streets throughout the
Newport Beach coastal area, including the Lido Island, Balboa Peninsula and
Balboa Island, will flood with lower SLR well before the residence floods. It
is very likely that the entire community will soon adopt some of the SLR
adaptation strategies that are currently being considered by the City of
Newport Beach. The City recently raised the minimum bulkhead elevation
to 10.9 feet NAVD88. These strategies involve raising, or adding/replacing
the bulkheads, beaches and walkways that surround the bay, and
waterproofing of residences. These are a site specific adaptation strategies.
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The project includes the raising of the height of the bulkhead or replacement of the
bulkhead without any new bayward encroachment. The engineer of record for this
phase of the project, PMA Consulting inc., will provide additional assessment of the
bulkhead, as warranted. The following is provided as GSI’s preliminary
assessment of the existing bulkhead.
Bulkhead condition report shall include (NBMC 21.30.15.E.3):
i. A statement of the preparer’s qualifications;
Mr. Skelly is Vice President and Principal Engineer for GeoSoils, Inc. (GSI). He has
worked with GSI for several decades on numerous land development projects
throughout California. Mr. Skelly has over 40 years experience in coastal
engineering. Prior to joining the GSI team, he worked as a research engineer at the
Center for Coastal Studies at Scripps Institution of Oceanography for 17 years. Mr.
Skelly has extensive experience in shoreline erosion, bluff erosion, soils
engineering, and the design, permitting, and construction of shore protection
devices. Projects include levee engineering and design in San Francisco Bay,
seawall and marina engineering in Baja California Sur, coastal boardwalk design
and protection in Pacifica, and seawall projects throughout southern California.
ii. An analysis of the condition of any existing bulkhead including whether the
top elevation meets current City standards, the conditions of the sheetpiles
or panels, the condition of existing tiebacks and/or deadmen or similar, and
any other relevant conditions;
The bulkhead was visually inspected and is in reasonably good condition. There is
some spalling of the concrete cap that does not impact the performance of the
bulkhead at this time. The bulkhead, with the top at elevation ~+8 feet NAVD88,
does not meet the current City’s top of bulkhead elevation requirement of +10.9 feet
NAVD88. It should be noted that very few bulkheads in the Newport Bay area meet
this newer elevation requirement. Based upon our visual observations and general
knowledge of bulkhead design, it is GSI’s opinion that the bulkhead height can be
increased without any bayward encroachment. However, the condition of the
tieback rods that restrain the wall is unknown and should be investigated before any
increase in height. Additional inspection and opinion will be provided by the
bulkhead engineer, PMA Consulting Inc. (PMACI).
iii. Recommendations regarding the need for repair, augmentation or
replacement of the bulkhead or any parts thereof;
Augmentation or replacement of the bulkhead will be necessary to meet the current
City height requirement, and to protect site and general area regardless of the
proposed development at the site. The increase in height or replacement of the
bulkhead is an SLR adaptation strategy. Recommendations for the augmentation
will be provided by the bulkhead engineer, PMACI.
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iv. If augmentation or replacement in the existing alignment is necessary,
recommendations that will avoid seaward encroachment of the bulkhead;
The augmented or replacement bulkhead can be located within the current
bulkhead footprint.
v. If replacement is necessary and the existing bulkhead is not in alignment
with adjacent bulkheads, recommended alternatives that will relocate the
bulkhead in as much in alignment with adjacent bulkheads and as far
landward, as possible.
The site bulkhead, even with the augmentation in height or replacement, can remain
aligned with the adjacent bulkheads.
CONCLUSIONS
• The proposed residential structure, with a FF of +12.4 feet NAVD88, is reasonably
safe from the unlikely 0.5% SLR hazards until about the year 2085. The design is
such that implementation of additional SLR adaptation strategies (design for future
water proofing to above elevation +13.7 feet NAVD88 and the future protection of
area by adoption of a resiliency plan by the community) will not be adversely
impacted by potential coastal hazards including a 6 feet sea level rise or more over
the next minimum 75 years. The site will be part of a community wide response to
mitigate SLR hazards.
• An augmented bulkhead (or replacement bulkhead) is proposed at this time to meet
the current City standard height of +10.9 feet NAVD88. This height increase can
be accomplished without further bayward encroachment of the bulkhead. Plans for
the increase in height have been prepared by PMACI and are provided as part of
the project application package.
• For the most part, in the entire Newport Beach coastal and bay areas, including the
Balboa Peninsula, and other developed islands within the bay, flooding with a lower
SLR is likely to occur. Such flooding will occur well before any part of the proposed
residence will flood.
• Provided the recommendations of this report are implemented during the project
construction, no additional site specific protective devices will be necessary to
protect the proposed development from any existing or anticipated future coastal
hazards for the next 75 years or more.
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RECOMMENDATIONS
Based upon the analysis and discussion herein, the proposed development is reasonably
safe from coastal hazards for the next 75 years including shoreline movement, waves and
wave runup, and flooding with future SLR for the next 75 years. It should be noted that
future flooding hazards due to SLR are shared by all development around Newport Bay.
The public roads for access to the area will be impassable due to ocean flooding long
before the flood water level approaches the FF elevation of the development. SLR impacts
will be a regional problem and only solved by a regional management plan. The proposed
City of Newport Beach bulkhead modification/replacement plan will likely mitigate any SLR
impacts on the project. The proposed development will neither create nor contribute
significantly to erosion, geologic instability, or destruction of the site or adjacent area.
The opportunity to be of service is sincerely appreciated. If you should have any
questions, please do not hesitate to contact me.
Respectfully submitted,
GeoSoils, Inc.
David W. Skelly MS, PE
RCE#47857
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REFERENCES
Everest International Consultants, Inc., 2011, Assessment of seawall structure integrity and
potential for seawall over-topping for Balboa Island and Little Balboa Island, main report,
No Project No., dated April 21.
Kopp, Robert E., Radley M. Horton Christopher M. Little Jerry X. Mitrovica Michael
Oppenheimer D. J. Rasmussen Benjamin H. Strauss Claudia Tebaldi Radley M. Horton
Christopher M. Little Jerry X. Mitrovica Michael Oppenheimer D. J. Rasmussen Benjamin
H. Strauss Claudia Tebaldi “Probabilistic 21st and 22nd century sea-level projections at
a global network of tide-gauge sites” First published: 13 June 2014
Newport Beach, “Waterfront Project Guidelines and Standards, Harbor Design Criteria
Commercial & Residential Facilities,” March 23, 2021.
NOAA, 2020, Web Site, Maps http://anchor.ncd.noaa.gov/states/ca.htm Tidal Datums
http://www.opsd.nos.noaa.gov/cgi-bin/websql/ftp/query_new.pl
State of California, County of Orange, 2009, “Tsunami Inundation Map for Emergency
Planning, Newport Beach Quadrangle,” 1:24,000 scale, dated June 1.
State of California Sea Level Rise Guidance 2018 Update, by Ocean Protection Council,
dated in March 2018.
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