HomeMy WebLinkAboutH_5232_S' REVISED FINAL REPORT
STATE OF THE NEWPORT BEACH COAST
Prepared for:
CITY OF NEWPORT BEACH
3300 Newport Boulevard
Newport Beach, CA 92658-8915
Prepared by:
MOFFATT & NICHOL
3780 Kilroy Airport Way, Suite 600
Long Beach, California 90806
Novembe,;,, 2006
M&N File: 5815
, ! Deleted: July 31
EXECUTIVE SUMMARY
Newport Beach is one of the most popular destinations for locals and visitors in the western
United States. It provides an enormous benefit to the state, region and City as a recreational
amenity, and provides protection for urban development and harbor facilities. As such,
preserving and maintaining a high quality beach is a priority.
The beach at Newport has changed significantly over time, varying from a relatively narrow and
low barrier beach along Newport Bay before development, to a wider and higher beach today
mainly due to influences of man. West Newport Beach has experienced severe erosion in the
past, resulting in construction of the groin field and numerous sand nourishment projects. This
beach has remained relatively stable over recent decades. Balboa Peninsula is relatively stable
but appears to be gradually retreating near I 8th Street. Big Corona Beach is also relatively
stable, but is eroding at the east end at Inspiration Point.
The City seeks to better understand the future of its beaches to enable informed management.
This study provides assessment of historic and existing beach conditions, and predicts future
conditions. Conclusions of this study are:
1. Processes acting at Newport's beaches are complex and monitoring should occur to better
understand this coast.
2. West Newport Beach may be losing sand at a maximum rate 15,000 cubic yards of sand
per year (which may increase due to sea level rise the next 100 years and beyond) and
would require nourishment to remain stable.
3. Balboa Peninsula retreats at a rate of at least 9,000 cubic yards of sand per year (which
may increase due to sea level rise) and may actually retreat by a much greater rate of
between 20,000 and 50,000 cubic yards per year. It would also require nourishment to
remain stable.
4. The east end of Big Corona Beach has retreated according to observations and may also
necessitate nourishment.
5. Urbanization, flood control, and navigation works in Southern California have interrupted
natural coastal processes and natural sources of beach quality sand have been
significantly reduced over time. This interruption of the natural processes requires coastal
jurisdictions to have to identify new sources of sand to maintain healthy beaches.
Management suggestions in this report include:
a. Perform beach profile surveys and beach width measurements at established stations to
document the elevation and width of the beaches over time;
b. Reinitiate the Littoral Environmental Observations program to quantify the direction and
magnitude of sediment transport;
Moffa/I & Nichol ES-! July 2006
c. Continue to manage beach berm areas and place the sand at low spots;
d. Backpass sand from near the Santa Ana River to between 30th and 461h Streets;
e. Nourish the beach with sand from outside the City to offset sediment losses at West
Newport and Balboa Peninsula;
f. Directly place available and high quality sand at the foot of the public access ramp at
Inspiration Point at Big Corona Beach whenever possible;
g. Remove and flatten high beach scarps throughout the City when they form;
h. Participate in local, regional, state and federal coastal and watershed planning to preserve
existing sources of sand available for the future.
i. Continue to support and remain involved with the Federal Surfside-Sunset program to
nourish the littoral; and
j. Consider adopting an opportunistic beachfill program to take advantage of potential sand
resources as they become available.
The condition of the ocean coastline at Newport Beach can be maintained and further enhanced
with informed decisions and actions.
Mojfi:rll & Nichol ES-2 .July2006
CONTENTS
EXECUTIVE SUMMARY ...................................................................................................... ES-I
1.0 Introduction ............................................................................................................................... I
I .I Background ........................................................................................................................... I
1.2 Purpose of this Document ..................................................................................................... 6
1.3 Beach Nomenclature .......................................... , .................................................................. 6
2.0 Description of Newport's Beaches ........................................................................................... 9
2.1 West Newport ....................................................................................................................... 9
2.2 Balboa Peninsula ................................................................................................................... 9
2.3 Big Corona .......................................................................................................................... I 0
3.0 History of the Newport Beach Shoreline ................................................................................ 15
3. I History of the Beach ........................................................................................................... 15
3.2 Severe Storms and Coastal Erosion ................................................................................... 19
3.3 Coastal Protection Efforts .................................................................................................. 22
3.3.1 Early Coastal Protection Efforts by Man (Pre-1968) ................................................... 22
1.3.2 Major Beach Erosion Control Activities Initiated in 1968 .......................................... 29
3.3.3 Beach Conditions From 1968 to the Present .............................................................. 35
4.0 Coastal Processes at Newport Beach ...................................................................................... 39
4.1 Geology ............................................................................................................................... 39
4.2 Oceanography .................................................................................................................... 41
4.2.1 Water Levels ............................................................................................................... 41
4.2.2 Waves .......................................................................................................................... 43
4.3 Wind ................................................................................................................................... 49
4.4 Littoral Processes ............................................................................................................... 49
4.4.1 Longshore Transport ................................................................................................... 49
Moffa// & Nichol July 2006
4.4.2 Cross-Shore Transport ................................................................................................. 51
4.5 Dynamic Behavior of the Newport Beach Shoreline ......................................................... 51
4.5. 1 Historic Shoreline Positions ........................................................................................ 51
4.5.2 Historic Beach Widths and Elevations ........................................................................ 52
4.5.3 Historic Aerial Photographs ............................................................................................ 62
4.6 The Newport Beach Sediment Budget.. ............................................................................. 67
4.6.1 Sediment Budget Concept. ............................................................................................... 67
4.6.2 Sediment Budget Prepared by Everts (I 996) .............................................................. 69
4.6.3 Sediment Budget Prepared by the USACE (2002) ..................................................... 70
4.6.4 Conclusions Regarding the Newport Beach Sediment Budget.. ................................. 72
5.0 State of the Newport Beach Coast-Present Problems and Needs ......................................... 74
5. 1 Erosion ................................................................................................................................ 7 4
5. 1. I West Newport Beach .................................................................................................. 74
5.1.2 Balboa Peninsula ......................................................................................................... 74
5. 1.3 Big Corona .................................................................................................................. 75
5.2 Coastal Flooding and Storm Damage ................................................................................. 75
5.2.1 West Newport Beach .................................................................................................. 75
5.2.2 Balboa Peninsula ......................................................................................................... 75
5.2.3 Big Corona .................................................................................................................. 76
6.0 State of the Newport Beach Coast -Predicted Future Conditions .......................................... 77
6.1 Scenario One -Future Conditions With Maintenance of Historic Beach Nourishment
Levels ........................................................................................................................................ 77
6.1. I West Newport .............................................................................................................. 77
6.1.2 Balboa Peninsula .......................................................................................................... 78
6. 1.3 Big Corona ................................................................................................................... 78
6.2 Scenario Two -Future Conditions Without Beach Nourishment ...................................... 79
Moffatt & Nichol ES-2 July 2006
6.2.1 West Newport .............................................................................................................. 79
6.2.2 Balboa Peninsula .......................................................................................................... 79
6.2.3 Big Corona ................................................................................................................... 79
7.0 Recommended Future Actions ................................................................................................ 80
7.1 Beach Monitoring and Measurements ................................................................................ 80
7.1.1 Beach and Nearshore Surveys ..................................................................................... 80
7.1.2 Littoral Environmental Observations ........................................................................... 84
7.1.3 Aerial Photography ...................................................................................................... 86
7.1.4 Monitor and Maintain the Groins ................................................................................ 86
7.2 Beach Sand Management. ................................................................................................... 86
7.2.1 Manage the Beach Berm Elevation .............................................................................. 87
7.2.2 Backpass Sand From Excessively Wide Reaches to Narrow Reaches of West Newport
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 87
7.2.3 Beach Nourishment ...................................................................................................... 90
7.2.4 Reduce the Beach Scarp as a Grooming Operation ..................................................... 97
7.3 Watershed-Wide Planning Strategies ............................................................................. 97
7.3.1 Reduce Mining Upstream in the Santa Ana River ....................................................... 97
7.3.2 Management Actions in the Entire Littoral Cell ........................................................ 101
8.0 Conclusions ........................................................................................................................... 102
9.0 References ............................................................................................................................. 104
APPENDICES
A -Significant Events for the Coast of Newport Beach
B - Aerial Photographs
C -Newspaper Accounts of the Southern Swell in August of 1968
Moffatt & Nichol ES-3 July 2006
LIST OF FIGURES
Figure I -300 E. Block of Balboa Boulevard in 1912
Figure 2 -Peninsula Point in 1912
Figure 3 -West Newport on October 10, 1934
Figure 4 -West Newport Beach in Summer 1968
Figure 5 -Emergency Rip Rap Being Placed at West Newport in August of 1968
Figure 6 -Areas of the Littoral Zone
Figure 7 -Map of Newport's Beaches
Figure 8 -The Beach at West Newport
Figure 9 -The Beach Along Balboa Peninsula
Figure 10 -The Beach at Big Corona
Figure 11 ;;:_ 1_875 _1'.opogr_aphic_Map ofN!)wport _Be_ach ______________________________ . • -[ Deleted: -
Figure 12 -1932 Aerial. Photog!l\12h of West Newpprt Beach
Figure 13 -Shoreline Positions from 1904 through 1939
Figure 1:4.,-West Newport BeachNear 47th. Street in 1967
Figure 1.:i,.c-Inst_al_IationofEmergency RockPr_otec_ti_on at w_est_Newport Beach inAugust of 196_8 __
Figure lfi.c-Storm Waves at WestNewport Near 46th_Street in Early Septemberof1968
Figure 17.,:c-Severe Beach Retreatat45th Stre_e_t in w_ est Newport in Early September of 1968
Figure l!l,: Steel Sheetpile Groin at 36thStreet
Figure 19,:c-Dredgingand B_each FiH Plan _ofl934/35 __
Figure :zll.c-Example GroinDesign-48th _Street
Figure 21,:c-ShorelinePo_sitions at \Vest Newport Beach Frnm _1967 Through 1997
Figure 22,,: West Newport on January 18, 1988 at 36th _Street_
Figure 2:J.c-Newport Pi_er Parking LotonJa_nuary 18, 1988 .
Figure 2:1.c-Newport Submarine Canyon
Figure 2.5., :-_V{ ~ve l?xpo_s11re cif __ I\!e_wpo_rt f3~a_ch_
Figure 2i-=--~t?.3:.r~hos~ ~t!:_V5' -~-r~f!sfgr_ll}'!_tiop)~t_!ril!g_ ~Ql!tlJ~r!l _S_~eJl_ .. _______________ _
Figure 2.7,::-__ Nea_rs_h_o_r~ Yfa:v_e_'f_f':1~sfor.~ati_o_n __ Durh~g_W_e_stern ~~~lJ
Figure 21!,::-_Waye Refractio_n_During Southern _S_wells _ _ _ ________ .. _______________ _
Figure 29, -Concept ofLongshore Sediment Transport
figure Nc-_Narrow B_each atWest_Newport Prior_ to_USACE_Proiects, September_ 196_8 __ _
Figure 31,:c-Wide Beach at West Newport After USACEProjects, November1974
Moffa/I & Nichol ES-4 July 2006
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Figure 32,:-FilletFormat.ion For HighNetSedimentTransportRates .
In Two Different Directions
Figure 3J., ~ Fillet __ F_or111ation ;por ]:_,ow _ _Net S_e_di_men_t _'fral)_spor_t __ R_at~s __ I11 B_oth D_ir_e_ctio11s
Figure 3:J. c-Concept ofa SedimentBudget
Figure 31-:-.. The.USACE SedimentBudget for NewportBeach
Figure 3§.-:-Recommended .B.each Profile Location.s
Figure 31..~ __ R.e_c<;H]l~)} ~n_d_eci _B_e':1~h_ Vv_ i_cf tµ __ Iyl_e~s_ur~.lll~_nt _l,_o_~~ti ~n_s _
Figure 3i.=-_~~c.9!_11_11:!~n_d~~ J.Jt_!l?.r~l :§11'::'.i~q_n_~e_nJ:'!l _Q~s~~_a_!i911 J,_9~~tiq_n_s ________________ ~ ,, -
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, -[ Deleted: s Figure 32,-:-West Newport Benn Sand. Recycling Concept
Figure 19.,::-_Balboa_ Penins_ula Ber_m San<i Jlec,y_c.Ji_ng_c_o_no"et_ _________________________ . •• • ·{ Deleted: 39
Figure 4_1,,-SandBackpassing Plan for West Newport ·[ Deleted: o
Figure 42.::-_ Con_cept_ l'jouris_hllle_n! !'\a_n_foi: Y{ eJ! J:-1!''."PQrl ____________________________ . • . ·[ Deleted: 1
Figure 4lc-Typical .Sect.ion of Beach Noudshmentfor West Newport Beach. . -[ Deleted: 2
[ Deleted: 3 Figure 41,::-_Concept_ Nouris_hlllent Plan _for Bal_bo~ _P,11i_n~~l~ __________________________ . •· • :==========='.
[ Deleted: 4 Figure 45,.-:-.. Nears.hore N.ourishment .Plan for Newport Beach
Figure 4§,:,-_Eq_uilibrium B_each Pi:of~l<, pey.,lop111ent _______________________________ _
Figure 47.::-. Scarp Management,Typical Section
LIST OF TABLES
Table 1 -Major Historical Storm Wave Events Affecting Newport Beach
Table 2 -Beach Nourishment at Newport Beach From 1919 Up Through 1967
Table 3 -USACE Projects in the Huntington Beach Littoral Cell
Table 4 -West Newport Groins Information
Table 5 -Nourishment at Newport Beach From 1968 Through 2005
Table 6 -Recorded Water Levels At Newport Harbor (1983-2001 Tidal Epoch
Table 7 -West Newport Beach Widths From USA CE Surveys 1963 Through 1997
Table 8 -Rate of Beach Width Change at West Newport From 1977 Through 1992 Based on
Clancy Data
Table 9 -Rate of Beach Width Change at West Newport From 1989 Through 1998 Based on
Modified Clancy Data
Table 10 -Rate of Beach Width Change at West Newport From 1993 Through 1998 Based on
Modified Clancy Data (Post-Nourishment Period)
ES-5 Jrily2006
-[ Deleted: 5
• ··! Deleted: 6
Table 11 -Rate of Beach Width Change at Balboa Peninsula From 1976 Through 1995 Based on
City Beach Width Data
Table 12 -Rate of Beach Width Change at Balboa Peninsula From 1976 Through 2000 Based on
City Topographic Survey Data
Table 13 -Beach BermEievations 1963 to 2004
Table 14 -Beach Profile Locations
Moffatt & Nichol ES-6 July 2006
1.0 Introduction
Newport Beach possesses some of the most beautiful beaches in the world. In addition to their
aesthetic value, sand beaches are a vital resource, providing opportunities to recreate and relax as
well as a natural form of coastal storm damage reduction. Recognizing this, the City of Newport
Beach initiated this study to better understand the short-and long-term behavior of the sandy
shoreline to anticipate potential erosion, flooding, and changes to the beach for improved
management. The focus of this study was to gather and summarize existing data into a user-
friendly report to serve as both a planning and educational tool for use by decision-makers and
the general public alike.
1.1 Background
The City of Newport Beach has a long history of battling coastal erosion and the resulting threat
to infrastructure. Balboa Peninsula experienced coastal flooding in the early l900's on occasions
of high tides and storm waves. Figure 1 shows Balboa Peninsula in 1912 with waves breaking
against a seawall in front of homes; Figure 2 shows "The Point" along the Peninsula with
seawalls being constructed in the same year, West Newport experienced significant erosion and
damage to homes in 1934, 1939, and 1968. Figure 3 shows the beach at West Newport in
October of 1934 retreating landward of homes west of36'h Street where a groin existed at that
time. Figure 4 shows a picture in the Los Angeles Times of,Vest Newport near 43rd Street in
August of 1968; Figure 5 shows rock rip rap being placed with a crane at the same location in
that emergency from the Orange County Register. The most acute problems of documented
erosion have occurred at West Newport.
Newport Beach has been clearly vulnerable in the past to serious beach erosion problems.
Fortunately, the City has experienced relatively reduced coastal erosion and flooding since the
late 1960's due in part to protective actions takell by the Federal government. These actions
have included ongoing beach nourishment at Surfside Colony/Sunset Beach, placing sand at
West Newport and installing groins to retain sand. As a result, upper West Newport (northwest
of 56th Street) has widened and stabilized over the past 40 years. However, lower West Newport
(southeast of 46th Street) remains narrow and recent studies indicate it may still be eroding. The
cause of the erosion is not clearly understood, but can be inferred as related to the complex
interaction of the submarine canyon off Newport Pier, the orientation of the coast relative to
approaching waves, effects of offshore islands on sheltering waves, and other factors. Balboa
Peninsula is documented and observed to be actively eroding at certain areas, as is described in
more detail herein.
Newport Beach has historically relied upon beach nourishment from nearby sources to offset
erosion. An opportunity to nourish the beach became available in 2005 from a major source of
sand from the Santa Ana River. It was declined by the City due to a range of various concerns
including grain size, water quality, impacts to surfing, and impacts to residents. The City was
unable to address these concerns, and they did not have an adequate understanding of the current
erosional or accretional trends of their beaches, so decision-makers unable to confidently accept
the sand. As a result of that experience, the City identified the need to better understand their
coastal system to proactively manage their precious coastal resource and enable optimal
decision-making when needed to mitigate erosional events as have occurred in the past.
Moffa// & Nichol July 2006
<1-__ -·-[ Formatted: Centered
Figure 1 -300 E. Block of Balboa Boulevard in 1912
Figure 2 -Peninsula Point in 1912
(Images courtesy of the City Public Works Department)
Moffa!/ & Nichol 2 July 2006
Mojji:ill & Nichol
Figure 3 • West Newport on October 10, 1934
(Source: U.S. Army Corps of Engineers, 2002)
3 July 20()6
Figure 4-West Newport Beach in Summer 1968
4 July 2006
Figure 5 -Emergency Rip Rap Being Placed at West Newport in August of 1968
Mojfbtt & Nichol 5 July 2006
1.2 Purpose of this Document
The purpose of this document is to serve as a State of the Newport Beach Coast report that
summarizes the condition of the City's coast and recommends management actions in a way that
can be understood by the general public and used by decision-makers. Emphasis has been placed
on creating a user-friendly document that presents relevant information in relatively simple, non-
technical terms, yet allows the user to "drill down" into more technical concepts and data sources
if desired. Graphic illustrations are used to convey important concepts and easy-to-read tables
to convey information concisely. It will serve as a "livingH document that the City can update
and modify over time as new information becomes available or as the local shoreline evolves.
1.3 Beach Nomenclature
Figure 6 provides a schematic illustration of the key elements within the coastal zone that are
relevant to the focus of this report. Terms commonly used in coastal studies and throughout this
report are defined below.
• Backshore: The upper part of the active beach above the normal reach of the tides and
wave run-up (high water), but occasionally affected by high waves occurring during a
spring high tide.
• Beach: That portion of land and seabed above Mean Lower Low Water (MLLW).
Includes the foreshore and backshore areas.
• Beach Profile: A cross-section through the beach perpendicular to the beach slope; it may
include a dune face or sea wall, extend across the beach, and seaward into the nearshore
zone to the closure depth (see below).
• Berm: A near-level area of the beach above the reach of the water that provides necessary
sandy area of the backshore.
• Closure Depth The maximum depth of average seasonal cross-shore sand movement.
This depth represents the seaward end of the beach profile, and essentially remains
unchanged on average over the long term. Sand that moves beyond the depth of closure
in a seaward direction is typically lost to the littoral cell and not available for natural
seasonal beach recovery. The actual closure depth is typically approximately -30 feet
MLL W in Southern California and -40 feet MLL W or deeper in Northern California.
• Compatibility: When the range of grain sizes of a potential sand material source lies
within the range (envelope) of natural grain sizes existing at the receiver site, with certain
allowances for exceedances of coarse and fine-grained sediments.
• Fine-grained Materials (or Fines): Clays and silts, passing the #200 soil grain size sieve,
or less than 0.074 millimeters in diameter.
Mujfall & Nic}wf 6 July 2006
• Foreshore: In general terms, the sloping beach face between approximately Mean Higher
High Water and Mean Lower Low Water, This is the zone of wave run up and run down
(or swash). It is actively under the influence of the waves and tides, and is therefore the
zone of active sand movement along the shore called longshore sediment transport.
Waves also seasonally pull sand from the foreshore and store it in a bar just offshore, and
push it back onshore again.
• Beach Nourishment Material: Material that is generally compatible in grain size with
sand at the dry beach and with sand at the nearshore portion (between MLL Wand the
closure depth) of the receiver site. The fines fraction should be within 10% of that of the
existing nearshore sediments that exist along a profile. Typically, the percent fines of the
nearshore portion ofa beach profile in California can range from 5% to 35% fines.
• Littoral Cell: A reach, or compartment, of the shoreline in which all sediment transport is
bounded. In theory, it has zero longshore sediment transport beyond its updrift and
downdrift boundaries. It will likely contain sand sources (rivers), storage areas
(beaches), and sinks (canyons).
• Longshore Sediment Transport: Sediment transport along the shore under the influence of
currents driven primarily by waves.
• Nearshore: The seafloor along a coast between the closure depth (typically near -30 feet
MLL W) and Mean Lower Low Water (MLL W).
• Offshore: That part of the seabed below the depth of closure.
• Receiver Site: The entire related system of coastal environments that would receive beach
nourishment materials, including the beach, nearshore and offshore regions.
Moffa// & Nichol 7 July 2006
Figure 6 -Areas of the Littoral Zone
Moffatt & Nichol 8 July 2006
2.0 Description of Newport's Beaches
The Newport Beach shoreline can be subdivided into three general regions referred to, from west
to east, as West Newport, Balboa Peninsula, and Big Corona. Locations are illustrated in Figure
7. Each beach region is described below.
2.1 West Newport
West Newport Beach is delineated by the mouth of the Santa Ana River to the west and the
Newport Submarine Canyon to the east. As a result of this juxtaposition between two high
influential geologic features, it demonstrates a dynamic behavior that is unique. Key features
include an erosional "hot spot" that is the narrowest beach in Newport and the focus of historic
shore protection efforts. Lower West Newport (southeast of 46th Street) is sufficiently narrow to
be vulnerable to direct wave action and potential damage during extreme storm wave events.
This beach is significantly influenced by effects of the Newport submarine canyon on
approaching waves and resulting currents due to its position and orientation relative to the
canyon. It is typified by a greater range of change than other City beaches.
An aerial photograph showing the key features of West Newport is shown in Figure 8. A field of
eight rubblemound groins exists at the beach from 28th Street to 56th Street. The beach is widest
at the northwest end near the Santa Ana River and narrowest at 44th Street, and remaining
relatively narrow toward Newport Pier. The beach immediately adjacent to the Pier is very
narrow. West Newport faces southwest and is exposed to ocean swell from west through south.
This beach serves as a "pass through" for sand moving to adjacent beaches on either side but is
less able to retain sand itself and thus is concave-shaped when viewed from the air. It is one of
the most intensely-used beaches in the City and is a dense surfing area.
2.2 Balboa Peninsula
Balboa Peninsula is located between Newport Pier to the west and the Newport Harbor entrance
channel to the east. The shoreline along Balboa Peninsula is wider than West Newport due to
historic beach nourishment from Newport Bay and the existence of lower wave energy under
most conditions. Despite its currently wide condition, analysis of long-term shoreline behavior
indicates a slight erosional trend landward toward the homes. Erosion has also been documented
over time by the City Marine Safety staff(Jim Turner and Eric Bauer, Personal Communication,
2005). Structures are not presently vulnerable to direct impacts from waves and not in imminent
danger. However, this beach exhibits low elevations along the back portion of the beach
between 15th Street and Island Street resulting in ponding on the berm during storm conditions,
and the beach at E Street that has flooded in the past during high storm waves and high tides (Jim
Turner, Eric Bauer, and Tom Anderson, Personal Communication, 2005).
Figure 9 shows an aerial view of the Balboa Peninsula. The peninsula is the remnant of a
historic sand spit formed by sand from the Santa Ana River and trapped by the West Jetty to the
Harbor entrance. The Peninsula faces predominantly south and is exposed mainly to ocean
swells and storms from the south, with some exposure to waves from the west. This beach is
also influenced by effects of the Newport submarine canyon, but those effects do not lead to the
Mof/i:ill & Nichol 9 July 2006
degree of change experienced at West Newport due the location and orientation of this beach
relative to the canyon. It serves as an important recreational area. Due to its expansive area and
location farther from the major highways, the beach is typically less intensely-used than other
City beaches, with the exceptions of areas near available parking. Surfing occurs along the
Peninsula at various sites such as "The Point" on the west end and "The Wedge" at the east end,
and at certain locations in between depending on conditions.
2.3 Big Corona
Big Corona is a "pocket" beach that lies directly east of the east Harbor entrance channel and
west of the rocky outcrop at Inspiration Point in Corona Del \1ar. The beach is stabilized by the
east Harbor Jetty and the rock headland at Inspiration Point. Sand does not move significantly
out of the pocket and as a result the beach is relatively wide. However, City staff has indicated
anecdotal evidence of beach retreat toward the east end of the beach over time. Less threat of
erosion exists at Big Corona Beach.
Figure 10 shows Big Corona Beach. The site faces due south and is only exposed to ocean waves
from that direction. It is an intensely-used recreation area, but does not present a frequent
surfing opportunity. Surfing only occurs there under conditions of high southern swell and
mainly during lower tides. It is a fairly stable beach with fewer problems than other City
beaches, with the exception of the most eastern end of the beach. The east end of Big Corona
Beach has been observed to have become narrower over time with the ocean encroaching on a
concrete public access ramp (Jim Turner, Personal Communication, July 18, 2006). The City has
placed rock rip-rap along the base of the ramp to protect it from coastal erosion, but high tide
appears to reach the bottom of the ramp under average tide and wave conditions as observed by
Moffatt & Nichol on July 19, 2006. High tides combined with high waves could potentially
damage the access infrastructure.
Mnjfa/1 & Nichol 10 J11ly 2006
Figure 7 -Map of Newport's Beaches
Moffatt & Nichol 11 July 2006
Figure 8 -The Beach at West Newport
~ffe,,&N-, ~1t12 r flt,,, July 2006
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Figure 9 -The Beach Along Balboa fJiiiinsiil~j
Moffa/I & Nichol 13 July 2006
Figure 10 -The Beach at Big Corona
Moffa/I & Nichol 14 July 2006
3.0 History of the Newport Beach Shoreline
3.1 History of the Beach
A chronology of historic events at Newport Beach is presented in timeline fashion as Appendix ◄
A. Also included as Appendix B is an aerial photographic record to help illustrate the evolution
of the beaches of Newport Beach,S_ollle_ ~f;the key eve_nts_ rele_va~t t_o _tll, llisto_l')' of the_ b_each ar_e __ ....
summarized in the following paragraphs:
Newport Beach benefited significantly by a major shift in the course of the Santa Ana River in
1884. Originally near Bolsa Chica, the course change shifted the river mouth south of
Huntington Beach mesa relatively close to its present location (USACE, 2002). The Santa Ana
River has historically been a major source of beach sand for all of Newport Beach. West
Newport Beach and Balboa Peninsula originally formed as a sand spit from sand delivered from
the Santa Ana River, Newport Bay, and the San Gabriel and Los Angeles Rivers to the north
over time. Historically, these rivers discharged much higher quantities of sand than they do now.
Flood control projects including construction of darns and paving of flood charmels greatly
reduced the delivery of sediment to the shoreline. Construction of navigation projects such as
harbor entrances, breakwaters, and jetties severely limited the transport of these river-borne
sediments along the shoreline. As a result, the sand spit along Newport is no longer accreting.
The Santa Ana River mouth was stabilized in its present location in 1916 (USACE, 2002).
The Newport Beach coast was historically narrow, consisting of a long sand spit from near the
Santa Ana River mouth to the inlet at Newport Bay. This configuration is illustrated in an 1875
map of the coast shown in Figure 11. The shoreline planforrn was likely in an ''equilibrium"
condition resulting from a balance of sediment supply, sediment loss, and wave energy.
Sediment was supplied from the Los Angeles River, San Gabriel River, Santa Ana River, and
San Diego Creek. Relatively large quantities of sediment were naturally delivered to Newport
Beach prior to the construction of the offshore breakwaters at Los Angeles/Long Beach Harhors,
jetties at the Anaheim Bay entrance channel, and flood control structures on each of these rivers.
This sediment fed the seU1d spit and allowed it to persist naturally, although evidence suggests it
was still relatively narrow and subject to periodic overwash by high tides and waves (Beach
Erosion Control Board, 1938). Figure 12 shows the narrow spit beach at West Newport in 1932.
Richard Patterson, former City Public Works Director from 1928 to 1946, described in an
interview that the beach was narrow in 1916 after a destructive storm (Orange County Register,
1968) (see Appendix C for complete news article). According to the article:
Dredging of the harbor in 1918 and 1919 resulted in sand placed between the Harbor
entrance and Balboa Pier creating a wider beach that protected from erosion. However,
houses at 38th St. were washed out to sea in 1934 by a severe storm wave event.
lhe relatively narrow conditionofthe City 'scoast changed dramatically inl 934:35with
the addition of up to 7. 5 million cubic yards along the entire City beach. The public
constructed homes on the newly widened beach in locations that were formerly not
available, so development encroached farther seaward along all areas of West Newport
and the Peninsula.
Mojfhtt & Nichol 15 July 2006
Formatted: Space Before: O pt,
After: O pt
·I Deleted: 11
.. ·1 Deleted: ,i
West Newport received 1.9 million cubic yards of sand to 4811' St. The City also installed
a steel groin at 36'' St. Groins from 3d" to 46'' St and shore protection were planned but
not constructed due to lack of local fonds. This project caused disequilibrium along the
shoreline as the beach was artificially widened far beyond its natural condition. People
were lulled into a false sense of security and a severe storm in 1939 overwashed all of
Balboa Peninsula from F St to I 5th St. Newport Pier was totally destroyed and piles were
found north to Anaheim Bay.
The beach.filled back in and this artificially-widened condition persisted for a period of
time and withstood a significant storm wave even in 1952 when the boardwalk and many
houses were undermined up to 36th St.
By the mid-1960's, the beaches had narrowed again with West Newport becoming the narrowest.
Severe storm wave events between 1965 and 1968 essentially denuded West Newport of its sand
beach. In the summer of 1968, waves were directly impacting homes in the 43rd block of
Seashore Drive (43'' Street).
In response, the USACE constructed a major beach nourishment project from 1968 through 1973
and added another 1.9 million cubic yards of sand, and subsequently added another 1.5 million
cubic yards to the nearshore zone off West Newport in 1992. This reach of beach has therefore
been artificially widened since the summer of 1968 with the cumulative addition of3.5 million
cubic yards of sand. The beach has stabilized in position with minor retreat throughout these
episodes. Retreat will likely increase and continue into the future if nourishment does not
continue. Although it is wide in 2006 at certain areas, the beach between 30"' Street and 46th
Street may eventually retreat back toward the homes if not periodically nourished.
MujfUII & Nichol 16 July21W6
◄ _ • ·[ Formatted: Centered
Moffa/I & Nichol
Figure 11 -1875 Topographic Map of Newport Beach
(Source: United States Geological Survey)
17 July 2006
Moffa/I & Nichol
Figure 12 -1932 Aerial Photograph of West Newport Beach
(Source: The First American Corporation Historical CoJlection)
18
J Formatted: Centered
July 2006
3.2 Severe Storms and Coastal Erosion
Historic major storm wave events are summarized in Table 1. These events are associated with
winter storms with waves generated in the North Pacific, and storms occurring near the South
Pole in our summer with waves approaching shore from the south. Erosion at West Newport
Beach has mainly been associated with southern swell due to effects of the submarine canyon
and the orientation of the coast. Years of significant southern swell within this grouping of
storm events that caused erosion at Newport Beach were 1905, 1916, 1934, 1939, 1952, and
1965-1968. There has not been a significant severe storm wave event with waves from the south
since summer of 1968.
. ., ··( Deleted: 2 The shoreline episodically retreated to near the house line in the! 930's, Figure !;),shows historic , .
shoreline positions from the early 1900's through the 1939 from federal surveys. The 1904
shoreline may represent the most natural condition prior to man's influence. The beach was
rela~y narrow throygh_out West Ne"YJ)ort, even near the mouth of the Santa Ana River. The
shoreline in 1939 was landward of Seashore Drive between 36th and 56th Streets, and was
landward of the first row of homes from 36th Street to Prospect Street. The most significant
event causing erosion was the southern swell from a hurricane in 1939. According to former
City Engineer Richard Patterson, this storm wave event consisted of ... waves up to 25 feet high
that seriously damaged Newport Pier and completely eroded the beach from 36' street to 43°"
Street (Daily Pilot, 1968). This storm seriously damaged the original groin at 36th Street to
where it became ineffective.
The Cooperative Beach Erosion Study was completed for Orange County (1938) and
summarized beach changes caused by storms. The report recommended a shore protection
project of groins along West Newport Beach. A subsequent report by the United States Beach
Erosion Board ( 1940) explains the problems at West Newport and called for remedial action,
although it concluded that no federal action was warranted and local agencies would be
responsible for the projects. Remedial actions included construction ofa bulkhead and a series
of nine groins, including repair and extension of the damaged 36th Street groin. The local
governments were unable to fund implementation and no projects were constructed. Patterson
also indicated that significant erosion occurred during the summer of 1952 during a large
southern swell event.
Moffat/ & Nichol 19 July 2006
MnjJaJl & Nichol
Figure lJ..-Shoreline Positions fromJ_9_o_t !l!i:_o)!gh_ !~J~ _
(Source: City of Newport Beach Public Works Department)
20
,1 Deleted::2
July 2006
Table 1 • Major Historical Storm Wave Events Affecting Newport Beach
Year or Period and Storm General Direction of Wave Relative Extent of Damage at
Event Approach Newport Beach
1905 (Unlmown) South Extensive
1916 (Unknown) South Extensive
1926 West Not Extensive
1931 West Not Extensive
1934 (Unknown) South Extensive
1939 (Unnamed Hurricane) South Very Extensive
1941 West Not Extensive
1952-53 South Not Extensive
1965-68 (Hurriane Liza) South Extensive
1969 West Not Extensive
1979-80 West Not Extensive
1982-83 West Not Extensive
1988 (January 18 Storm) West Moderately Extensive
1997-98 West Not Extensive
2005 West Not Extensive
By 1967, the shoreline had retreated at West Newport to the point of threatening homes as shown
in Figure 1.1,. Likelythe most acute _and pubjicizederosion event _occurr_edin late August of
1968. Hurricane Liza generated southern swells up to 10 feet along Newport Beach. West
Newport Beach was eroded and the beach retreated under the rear patios of several homes at 43 rd
Street, resulting in collapse of many of the patio structures. Newspaper accounts of the event are
included in Appendix C. The USACE mobilized a contractor to initiate emergency placement of
up to approximately 250,000 cubic yards of sand taken from near the Santa Ana River Mouth at
Moffa/I &-Nichol 21 Mal'ch 2006
-·1 Deleted: 3
West Newport near 43 rd Street. Rip-rap was also placed as emergency revetment along the reach
of West Newport adjacent to 43'' Street. Figures 111§,,and!J.showphotographsofthe event ..
from newspaper accounts.
3.3 Coastal Protection Efforts
This report summarizes coastal protection efforts separated into the three key periods:
• Pre-summer of 1968
• Summerof 1968
• Post-summer of 1968 to the present
The reason for this separation is that the USA CE initiated Stage 2 of the Surfside/Sunset Federal
Project to restore beaches from Anaheim Bay to Newport Pier in summer of 1968. As described
in more detail in subsequent sections of this report, construction of harbor jetties at Anaheim Bay
in 1941 and flood control projects on the Santa Ana River interrupted the supply of sand from
major rivers and beaches upcoast and caused severe erosion from Surfside through Newport. As
a result, conditions of the beach at Newport progressively deteriorated through the summer of
1968, and were substantially mitigated and improved after that time.
3.3.1 Early Coastal Protection Efforts by Man (Pre-1968)
36th Street Groin
The City of Newport Beach constructed a steel sheetpile groin at 36th Street in the 1930 to
stabilize the beach. Figure l!!,shows the groinin fall of 1934andthe sa_ndbeach retained east of
it toward Newport Pier. Groins function as "sand blocking" structures and tend to retain sand on
their "updrift" side. If poorly planned, they can also result in erosion on their "downdrifi" :sidt-.
In the case of the 36th Street groin, summer wave conditions caused sand to move to the
northwest (toward Surfside) and thus build-up sand on its east (updrift) side. Correspondingly, a
shortage of sand resulted on its west ( downdrift) side and the beach to the west retreated under
homes resulting in major damage. This groin remained in effect until 1939 when it was
destroyed in a major storm wave event along with the seaward end of Newport Pier.
Beach Nourishment
The City periodically dredged Lower Newport Bay and entrance channel and placed the material
on the beach several times between 1919 and 1946. The total volume of material placed along
Newport Beach during the period was 2.1 million cubic yards, with 850,000 cubic yards being
placed on Balboa Peninsula and 175,000 cubic yards being placed at West Newport.
The USACE performed a joint project with dredging of the Lower Bay and nourishment of the
City's beaches in 1934/1935 shown in Figure 19, Approximately8.2 lllillioncubicyards of.
Moffa/I & Nichol 22 March 2006
Deleted: 4
-Deleted: 5
' Deleted: 6
-·j Deleted: 7
-[ Deleted: 8
Figure l:!.c: '\Ve_s! Ne~p_ort BeacANe~r_ 47th Street i_n_l9_6'7 ___________ . • ••
, 1 Deleted: J
(Photograph Courtesy of Newport Beach Public Works Department)
Moffa/I & Nichol 23 March 2006
Figure lj--, lnstaHatio.n ofE:111~rgencr RockPro!e.ction.at West l'ie'l'port Beach in. {\~gust
of 1968
Moffatt & Nichol 24 March 2006
,. , -( Deleted: 4
Figure lfJ. :-_S_torm _Waves_ at_West_ Newport _Near_ 4611'_ Street _in _Ea_rly_ Sep_tem_b_e~ _or l ~(j8 __
j Deleted: 5
Mof(alt & Nichol 25 March 2006
Figure 1,Z.:-__ Sey~r_e_ ~4:'.~.c~--~~t_r~~t __ a_t __ 4_5~_h __ ~tt~e_t,_,i~ _W ~s_t .. N: ~'\.'.P._O_f'.t J~ ~_a_rly __ ~ep_~~J11!J~r_ ()f
1968
M()/fall & Nichol 26 March 2006
-[ Deleted: 6
sandy sediment was dredged from all of Lower Newport Bay south of Pacific Coast Highway.
Approximately 7.5 million cubic yards of the sand was placed on the beaches, with the
remainder placed along the south side of the present alignment of Pacific Coast Highway from
56'h Street to Newport Boulevard. The majority of the beach fill was placed along Balboa
Peninsula (5.6 million cubic yards), a large quantity was also placed at West Newport (1.9
million cubic yards), and the balance was placed at Big Corona (450,000 cubic yards). This
project benefited Balboa Peninsula up to the present-day. It also benefited West Newport for
three decades until the mid-1960's. The severe storm wave event of 1939 eroded the beach and
damaged structures, but so much sand had been placed within the coastal system that West
Newport recovered after that and was sustained until 1968.
Moffa/I & Nichol
Figure 1§,, Steel SheetpHe Groin at 361h Street
(Image courtesy of the City Public Works Department
27 March 2006
. , -[ Deleted: 7 J
Figure 1.?,-:: D_redgin_g_ and Beach Fill Pla.n of 1934/35 ___ _ . i Deleted: 8
Moffatt & Nichol 28 March 2006
Table 2 shows a summary of specific beach nourishment locations, quantities, and dates for
Newport Beach from 1919 through 1967. It is important to note that, based on available records,
no beach nourishment took place for the 20 year period from 1946 until 1965.
Notable activities during the period include:
• By the end of!967, approximately 2.5 million cubic yards of sand had been placed at West
Newport to halt erosion, with more than ten percent of that sand coming from the beach at
Balboa Peninsula.
• Balboa Peninsula beach received up to 7.4 million cubic yards of sand during the period,
with the entire amount coming from Newport Harbor. Sand that was removed from the
Peninsula and placed at West Newport in the mid-1960's formed a low area along the back
beach knovm. as "peanut pond" that ponds during rains and wave overwash ( Jim Turner and
Eric Bauer, Personal Communication, December 8, 2005).
• Big Corona received 450,000 cubic yard from Newport Bay.
• A total of 10 million cubic yards of sand was placed on Newport's beaches prior to 1968.
An average annual rate of 52,000 cubic yards of sand per year was placed at West Newport;
149,000 cubic yards of sand per year was placed at Balboa Peninsula (net volume
accounting for transfer of sand to West Newport); and 9,000 cubic yards of sand per year
was placed at Big Corona. Even with the relatively generous nourishment occurring at the
beach during this period, the beach was still actively eroding resulting in undermining of
homes in 1967 and 1968 as shown in previous figures.
3.3.2 Major Beach Erosion Control Activities Initiated in 1968
The U.S. Army Corps of Engineers (USACE) initiated their involvement with a health of Orange
County's beaches in 1954 with a shore protection project at Surfside-Sunset Beach authorized by
Public Law 780, 83'd Congress. The 1962 a document titled Report on Beach Erosion Control
was prepared for the Orange County area. The report recommended modification of the
authorized project at Surfside-Sunset project to provide for construction of a 2,600-foot-long
offshore breakwater just west (updrift) of Newport Pier, adjacent to the mouth of the Santa Ana
River, That project was not constructed.
Projects benefiting Newport Beach that were constructed included Stages 1 through 5 of the
Surfside-Sunset Beach project. Stage I of the Surfside-Sunset Beach project consisted of beach
nourishment at the northwest (updrift) end of the littoral cell to feed all areas downdrift, include
Newport Beach. Stages 2, 3 and 5 were projects specifically in West Newport Beach. They
included both beach nourishment and construction of groin structures to retain sand. The various
projects are summarized below and are summarized in Table 3.
Mo,[(a/1 & Nichol 29 March 2006
Table 2 -Beacb Nourishment at Newport Beach (1919 Through 1967)
=acn
Beach Fills at Beach Fills Mining at Beach Fill
West Newport at Balboa Balboa ! atBig Total Beach Beach Peninsula Peninsula Corona Nourishment ...,uan ·-• uua ..... .,
Quantity {CUbic I (Cubic
Year (Cubic Yards) Source Year Yards) Source Year Quantity CY! Source YM, Yards) Source (Cubic Yards)
I 1921 80,000 County, SAR 1919 170,000 City, Lower Bay 1965 -124,000INotAppllcable 1934-35 450,000 USAGE & OC, Bay
I 1930 50,000 City, Lower Bay 1920-22 934,300 County, Lower Bay 1966 -60,00 Not Applicable
1934-35 1,900,000 USAGE & OC, Bay 1923 65.000 Cfty, Lower Bay 1967 -150,00 0 Not Applicable
1938 13,000 City, Lower Bay 1928 40,000 City, Harbor Entrance
1939 14,400 City, Unknown 1929 21,000 City, Harbor Entrance
1942 30,500 Cit,,, Lower Bay 1930 530,000 City, Harbor Entrance
1946 67,300 City, Lower Bay 1931 28,000 Crly, Lower Bay
1965 124,000 Balboa Peninsula 1934-35 5,600,000 USAGE & OC, Bay
1966 60,000 Balboa Peninsula
GRAND
1967 150,000 Balboa Peninsula TOTAL
TOTAL 2,489,200 7,388,300 -334,000
Source:
{Net Nourishment)
450,000 9,993,500
Patterson, 1961
Moffatt & Nichol 30 March2006
Table 3 -USACE Projects in the Huntington Beach Littoral Cell
Stage Year Components
Beach Nourishment Structures
1 1964 4,000,000 cubic yards None
at Surfside-Sunset
Beach
2 1968 740,000 cubic yards at Exferimental groins at
West Newport 481 , 40th, and 44th
Streets
3 1969 875,000 cubic yards at Groins at 361\ 52nd,
West Newport and 56th Streets,
extension of 48th
Street groin
4 1971 2,300,000 cubic yards None
at Surfside-Sunset
Beach
5 1973 360,000 cubic yards at Groins at 32nd and 23th
West Newport Streets, extensions of
groins at 44th and 40111
Streets
6 Not Applicable None None
7 1979 1,600,000 cubic yards None
at Surfside-Sunset
8 1983 550,000 cubic yards at None
Surfside-Sunset Beach
9 1990 1,800,000 cubic yards None
at Surfside-Sunset
Beach
10 1997 1,600,000 cubic yards None
at Surfside-Sunset
Beach and 140,000 at
West Newport
Mo,tfiJII & Nichol 31 March 2006
Groin Field
As part of the Surfside-Sunset Beach project by the USACE, eight groins were constructed at
West Newport between 56th and 28th Streets between 1968 and 1973. The purpose of the groin
construction was to halt the persistent net retreat of the shoreline. Their specifications are shown
in Table 4 below
Table 4 -West Newport Groins Information
Groin Location Year Constructed Length and Material
48th Street 1968 200 Feet; Steel Sheetpile
40th Street 1968 258 Feet; Steel Sheetpile
44th Street 1968 191 Feet; Steel Sheetpile
48th Street 1968 340 Feet; Sheetpile Encased in
Rock
36th Street 1969 508 Feet; Rock
52"' Street 1969 345 Feet; Rock
56th Street 1969 575 Feet; Rock
44th Street 1973 Extended to 470 Feet; Rock
Encasement
40th Street 1973 Extended to 480 Feet; Rock
Encasement
32nd Street 1973 540 Feet; Rock
28th Street 1973 600 Feet; Rock
A typical design of the groins is shown for the 48th Street groin in Figure m.,.
Beach Nourishment
Since 1968, all beach nourishment at West Newport Beach has been performed by USA CE
projects. Their work has mainly been part of the Surfside-Sunset Project. Comprising eleven
stages since its inception, four of those stages involved beach nourishment directly at West
Moffa// & Nichol 32 March 2006
, , ,[ Deleted: 19
Figure 20 -Example Groin ]}esign -48th Street
-------..,,,..,,...,....,,.,,-_.I
Mojfhtl & Nichol 33 March 2006
Deleted: <sp>
•1(1 ---
Deleted:
Deleted: 19
'I [' ri ,,
I\
' 1
Newport Beach. Nourishment at West Newport occurred in Stages 2, 3, 5 and 10 from 1968 to
1997. A total of3.5 million cubic yards of sand was placed at West Newport during that period.
Since the last stage of the Surfside-Sunset beach nourishment project in 1997, the most recent
beach nourishment effort was a relatively small project of90,000 cubic yards in 2005 as part of
the Santa Ana River Mainstem Maintenance project. That project was intended to be a 400,000
cubic yard project but was reduced because of both public opposition and severe environmental
conditions that existed that winter which constrained the construction. The winter of2004/2005
was the second wettest winter in recorded history in Southern California and the Santa Ana River
remained at high stages for extended periods of time precluding the ability to dredge and pump
material to the nearshore. The initial plan was for clearing the river in the dry and trucking sand
to the beach at West Newport, but the City declined to participate in the project due to
uncertainties of environmental effects and citizen opposition.
Table 5 summarizes the beach nourishment activities at Newport Beach since the summer of
1968. A total of3.5 million cubic yards of sand has been placed at West Newport, for an
average rate of approximately 92,000 cubic yards per year. A total of 82,000 cubic yards of sand
was placed at Big Corona Beach for an average rate of2,000 cubic yards per year.
Table 5 -Nourishment at Newport Beach From 1968 Through 2005
Year Quantity (Cubic Source Placement Site
Yards)
1968 495,000 Balboa Peninsula West Newport
1968 246,000 Santa Ana River West Newport
1969 750,000 Santa Ana River West Newport
1970 124,000 Santa Ana River West Newport
1973 358,000 Santa Ana River West Newport
1981 82,000 Newport Harbor Big Corona
1992* 1,300,000 Santa Ana River West Newport
1997 140,000 Santa Ana River West Newport
2005 90,000 Santa Ana River West Newport
TOTAL 3,585,000 Not Applicable
* The material in 1992 was placed in the nearshore as a mound rather than on the beach.
Moffa/I & Nichol 34 March 2006
3.3.3 Beach Conditions From 1968 to the Present
The relatively high rate ofnourishment at West Newport, together with the sand retention effects
of the groins, held the shoreline position seaward of development. Shoreline positions recorded
in eleven different years between 1968 and 1997 are shown in Figure 21, The shorelinewestof
Prospect Street toward the Santa Ana River advanced significantly seaward throughout the
period, and the shoreline in the lower groin field below 46th Street remained constant in width.
Comn..ared with the more "natural" shoreline condition· of 1904 as shown in Figure 1:.whe beach
is wider throughout West Newport, particularly near the Santa Ana River. The recent position of
the beach as shmvn in Figure 21 and in recent aerial photographs indicates that the condition of
West Ne)Vport Ls now signific~mtly influenced by the effects of man.
Severe storm wave events can still result in coastal flooding and damage to the first row of
homes as evidenced in Figures 2:1,and2;J, .. The figmes iHustr~tecoastalflooding near 36th .street
and the Newport Pier parking lot during a severe storm on January 18, 1998. This extremely
severe coastal storm was considered an event that occurs once every 200 years (Seymour, 1989).
West Newport is relatively narrow from 30th Street to 46th Street. The area to the west is wider
near the Santa Ana River, and areas to the southeast are also wider along Balboa Peninsula.
Balboa Peninsula is relatively wide and less prone to flooding, but the low area of previous sand
mining presents a ponding problem during certain high water conditions. Big Corona Beach is
relatively stable along its western end and not prone to erosion or damage even under extreme
conditions. The east end of Big Corona Beach has apparently eroded over time per observations
by City staff and may pose a problem for future maintenance (Jim Turner, Personal
Communication, May 2, 2006).
Observations by local agency staff indicate that erosion of the beaches along Newport is more
episodic than gradual, meaning that most of it occurs over very short time periods during severe
storms. Balboa Peninsula can lose up to 10 to 20 feet of beach per day under conditions of
southern hemisphere swells (Jim Turner, Personal Communication, May 2, 2006). The Peninsula
near the lifeguard headquarters building at Nev,rport Pier can also lose more sand than that during
pre-frontal seas from approaching winter storm with southwest winds (Jim Turner, Personal
Communication, December 14, 2005). Clusters of storms can also cause major sand losses over
a season, and Catalina Eddy conditions in spring and summer can also move away sand quickly
(Tom Rossmiller, Personal Communication, May 2, 2006). This episodic change in the beaches
may be sand shifting from one area of the City beach to another, rather than true losses,
according to staffs observations.
Mofji:111 & Nichol 35 March 2006
·[ Deleted: o
·: _ -_: "l Deleted: I
-Deleted: 2
Figure 2J. :-'.. ~~~ri;.~e. P!,Jsifi.o_llS_ ~(~ t,!li _N e_l!P!l!'t !3~~ _F):_o_~ _l.?.~7 .. '!!J.!'~~gl_l _1_9.?7 ..
. ·! Deleted: 0
Source: USACE, Coastal of California Storm and Tidal Wave Study, 2002.
Moffett & Nichol 36 July 2006
Moffa// & Nichol
Figures 2,1,, WestNewport onJanuary 18, 1988.at 36thStreet
(Image courtesy of the City Public Works Department)
37
. , ,[ Deleted: I
July 2006
Moffatt & Nichol
Figures 22,-N"e,vport PierParkin_g Lot on January18, 1988
(Image courtesy of the City Public Works Department)
38
-( Deleted: 2
July 2()(16
4.0 Coastal Processes at Newport Beach
The beach and nearshore zone ofa coast is the region where the forces of the sea react against
the land. The physical setting within this region is influenced primarily of the motion of the sea,
which supplies energy to the system, and the shore, which absorbs this energy. Because the
shoreline is the intersection of the air, land, and water, the physical interactions which occur in
this region are unique and very complex. This section first provides a simplified description of
the various coastal processes along the Newport Beach shoreline (Sections 4.1 through 4.4),
followed by an in-depth look at how the Newport Beach shoreline has historically responded to
these complex coastal processes. More detailed information can be found in a regional report by
the USACE titled the Coast of California Storm and Tidal Waves Study-Orange Coast Region
(2002).
4.1 Geology
General
Relative to other coastal locations throughout the world, coastal lands along the Pacific Coast of
North America are generally well above sea level because of tectonic uplift of the coast
(National Research Council, 1995). Mountains are typically near the shore, and rivers tend to be
short and discharge directly into the ocean with few large estuaries or embayments. Dunes are
rare, and barrier forms are limited to an occasional large spit. The continental shelf is quite
narrow, as evident at the head of Newport Submarine Canyon. Newport Beach is low-lying
because it occupies one of these large spits and surrounds an estuary. Higher relief encroaches
up to the north City boundary along Newport Mesa and the San Joaquin Hills. The local Santa
Ana River discharges directly into the ocean.
Sand sources are predominantly rivers and seacliff erosion, with only a small contribution from
shells or other sources. Newport's natural sand source is the Santa Ana River. Harbors at Los
Angeles/Long Beach, Anaheim Bay, and Newport Beach contribute to sand trapping, and the
additional human contributions to coastal erosion stem from flood control measures that trap
sand in the Santa Ana River basin, and mining sand from the basins. Construction of jetties and
groins retards the alongshore movement of sand and can also cause erosion, but those at Newport
do not adversely affect the beach.
Bathymetry
Bathymetry is defined as the submarine topography of the sea floor. Most sandy coastal
locations, such as Newport Beach, exhibit bathymetry that slopes from the beach out into the sea
at a fairly constant slope. Exceptions are rocky coasts with more variable bathymetry depending
on geology, wave exposure, and possibly other factors. Newport Beach is exceptional compared
to other sandy coasts of the region due to the major submarine canyon off Newport Pier as
shown in Figure 21, _ T~~ :t,J~~p2r_t _Sp!J~~i!_l~ ~_!l!?-:Y~l!_ ~ff~c.!~ ~~y~s_ '!PP~~a.9~~ng_tQ.~ ~l!o!~ !f! ~ __ .... ·[ Deleted: 3 ~---------way that causes them to change direction as they propagate toward the shore. The net effect of
the canyon is that it causes approaching wave crests to "refract" or bend along the contours of
the canyon rim and assume a more exaggerated angle of approach to shore than would otherwise
M()ffall & Nichol 39 July 2006
occur. Essentially, wave refraction at the canyon causes waves to approach West Newport at a
greater angle to shore than at other local
Moffatt & Nichol
Figure 2:1,,c Newport Submarine .. Canyon
(USACE, 2002)
40 July 2006
_, •( Deleted: J
beaches. This affects wave-induced currents and sand transport along West Newport that are not
experienced by any other beach in the area, rendering it a unique feature and subject to unusual
conditions.
4.2 Oceanography
4.2.1 Water Levels
Ocean water levels are dictated primarily by tides and sea level as described below. Storm
surges and El Nino conditions can also affect sea levels on a short-term basis.
Tides
Tides at Newport Beach are similar to those of most Southern California coastal areas. They are
mixed with generally two high tides and two low tides each day. The tide range range (elevation
difference between low and high tide) varies from approximately nine feet during spring tide
conditions to three feet for neap tide conditions. Spring tides present conditions of the highest
tidal elevations and the greatest ranges, and occur during periods when the earth and moon are in
alignment with the sun (full moon and new moon). Neap tides present conditions of the lower
tides and narrowest ranges, and occur when the earth and moon are aligned at 90 degrees to the
sun (quarter moons). The highest spring tides occur in both summer and winter, with the highest
tidal elevations in January and July.
Mean side level (MSL) is approximately 2.8 feet above mean lower low water (MLLW). Water
level statistics for Newport Harbor are summarized in Table 6. More information about tides can
be found at http://co-ops.nos.noaa.gov/data res.html.
Severe beach erosion events typically occur when higher than average tides are coupled with
higher than average waves. Large tide ranges associated with spring tides affect a wider band of
the shore and cause sediment transport from along broader zone, thus leading to increased
erosion compared to milder tidal conditions. Also, the higher tide levels bring the dynamic surf
zone closer to adjacent residential, municipal and commercial development.
Sea Level Rise
Sea level is slowly rising throughout the world. Sea level has varied dramatically over historic
time and the current trend is a gradual rise. Sea level is rising as the result of general global
warming that melts ice caps and expands the water column through heating. Sea level dictates
the position of the water relative to the beach and backshore areas.
Sea level rise is estimated to be gradual but significant, with a 90% probability that sea levels at
Newport Beach will rise by 2.6 inches by 2025, 4.5 inches by 2050, and 9.0 inches by 2100
(California Coastal Commission, 2001). The primary effect of sea level rise on the beach is that
the position of the shoreline will retreat landward and result in waves reaching farther toward
developed areas. For example, Newport's beaches have a slope of approximately 10:1
(horizontal:vertical), so each inch of sea level rise would result in 10 inches of beach retreat.
Moffatt & Nichol 41 July 2006
Horizontal beach retreat would therefore be approximately two feet by 2025, four feet by 2050,
and approximately eight feet by 2100.
Table 6 -Recorded Water Levels At Newport Harbor (1983-2001 Tidal Epoch)
Description Elevation
(feet, M LLW)
Extreme High Water (1/27/83) +7.66
Mean Higher High Water (MHHW) +5.41
Mean High Water (MHW) +4.67
Mean Sea Level (MSL) +2.77
Mean Low Water (ML W) +0.92
North America Vertical Datum-1988 +0.18
(NAVD)
Mean Lower Low Water (MLL W) 0.00
Extreme Low Water (12/17/33) -2.35
Sea level rise could have a considerable effect on Newport Beach and Everts (1996) indicates
that it could effectively cause retreat of the shore equal to loss ofup to 6,000 cubic yards per year
at West Newport and up to 4,000 cubic yards per year at Balboa Peninsula.
Storm Surge
Per the USA CE (2002), storm surge is the super elevation of the water level that results from
reduced barometric pressure and high wind stress on the ocean surface during storm events.
Storm surges on the Southern California coast are comparatively small (less than one foot) when
compared with tidal fluctuations, and wave-related water level increases are more important to
this area. For example, the winter storm of January 17 and 18, 1988 produced the lowest
recorded barometric pressure in the area. The measured water level at the NOAA Los Angeles
Harbor gauge during this event was 0.7 feet above predicted astronomical levels.
The El Nino-Southern Oscillation causes global-scale climatic variations that extend for one to
more years. They are characterized by a decrease in atmospheric pressure in the eastern tropical
Pacific Ocean, a reduction in easterly tra.de winds, and an increase in sea level on the west coast
of North and South America. Monthly mean sea levels in the Southern California Bight were
increased by up to one foot) during the major ENSO event during 1997-1998 (Flick, 1998).
Mo,ffa/1 & Nichol 42 July 2006
Land Subsidence
Subsidence of the land surface also results in retreat of the shoreline and results in a relative rise
in sea level compared to land. The USACE (2002) notes subsidence has occurred throughout the
Huntington Beach Littoral Cell, including within Newport Beach from oil extraction activities.
Their estimates are than land subsides very slowly, but causes retreat of the shoreline equal to
loss ofup to 7,000 cubic yards per year at West Newport and up to 13,000 cubic yards per year
along Balboa Peninsula.
4.2.2 Waves
Offshore Wave Climate
Waves are the primary force that transports sand along the beach of Southern California. Ocean
waves off the coast of Southern California can be classified into four main categories: northern
hemisphere swell, tropical swell (Chubascos), southern hemisphere swell and seas generated by
local winds.
1. Northern hemisphere swell generally represents the category of the most severe waves
reaching the California coast. Deepwater significant wave heights rarely exceed 10 feet,
with wave periods ranging from 12 to 18 seconds. However, during extreme northern
hemisphere storm events, wave heights may exceed 20 feet with periods ranging from 18
to 22 seconds. Newport is somewhat sheltered from waves from this source, although
they do still occur and influence that coast.
2. Tropical cyclones develop off the west coast of Mexico during the summer and early fall.
The resulting swells rarely exceed 6 feet, but a strong Chubasco in August/September of
1939 passed directly over the Southern California coast and caused the highest waves on
record at 26.9 feet. Newport is directly exposed to this source and is significantly
affected by the occurrence of these waves.
3. Southern hemisphere swell is generated by winds associated with storms of the austral
winter in the South Pacific. Typical southern hemisphere swells rarely exceed 4 feet in
height in deep water, but with periods ranging up to 18 to 21 seconds, they can break at
over twice the height at the shore. Newport Beach is also directly exposed to these waves
and is significantly affected by their occurrence. Some sheltering from San Clemente
Island does occur.
4. Sea is the term applied to steep, short-period waves which are generated from either
storms that have invaded the Southern California area, strong pressure gradients over the
area of the Eastern Pacific Ocean (Pacific High), or from the diurnal sea breezes. Wave
heights are usually between 2 to 5 feet with an average period of 7 to 9 seconds. The
southeasternmost reach of West Newport Beach near the Pier is directly exposed to these
type of waves and is significantly affected by their occurrence.
A wave exposure diagram is shown in Figure 22,, .. Ne',VJ)_9rt __ _-~~a_c4 J~ .. d.i_!e_ctl_y __ e_:xp2s_e_~ ... t() .9ce_~n
swell entering from two main windows. Winter storm swells enter from between azimuths 285
and 265 degrees relative to true north (0 degrees). The Channel Islands and Santa Catalina
Mufji:ill & Nichol 43 July 2006
, -[ Deleted: 4
Island provide sheltering from these larger waves depending on the approach direction. The
other major exposure window opens to the south between 210 and 155 degrees, allowing swell
from southern hemisphere storms and tropical storms (Chubascos) to enter. No local island
sheltering occurs to these swells.
Swells from the south are more commonly the cause of high surf at Newport Beach and resulting
coastal erosion. Data reviewed for this report indicate every significant erosion event coincided
with high waves incident from the southern direction. Summer southern swell waves exhibit
longer periods than those in the winter because they are generated by storms that are farther from
California and travel farther to reach this shore. At most lOcations, summer southern swell
exemplify milder conditions than winter storm waves, and results in beach-building rather than
erosion, and wider beaches rather than narrower beaches. Newport Beach is an exception to this
general trend. Depending on the direction of the approaching swells, Newport Beach is more
sheltered from winter storm waves than nearby Huntington Beach. Therefore, Newport Beach
experiences less of a typical pattern of high winter waves and corresponding beach narrowing.
• In fact, evidence shows that Newport Beach actually shows a reverse pattern of beach narrowing
as it becomes narrower in summer (USACE, 2002). It should be noted that the beach narrowing
due to southern hemisphere swell is a result of alongshore sediment transport to the northwest,
rather than more typical winter storm wave erosion which results primarily from sand transport
offshore, or cross-shore transport. More information about waves is found at
http://cdip.ucsd.edu.
Nearshore Wave Climate
As waves propagate from deep water, they are affected by the nearshore bathymetry. Variable
bathymetry causes waves to bend or refract over features such as Newport Canyon as they
approach shore. The effects of coastal exposure, island sheltering, and nearshore bathymetry are
evident in Figure 2~_ap.~ _F'.jgt!r~ ~Z,_f~n_:_ ".Yf!Y~S _ a_pp~q_a.9b~ngJ!:o_n_? !4.e_ ~9.~!'l '-1:f!_d_ ".Y~S_t,_ r_e§p_~~!iy~ly '._ __ :: -: -{ Deleted: s
Figure 2~_rn1:1:s_tr_a!e_s _lqc_a_l _~re_~~ gf ~.~y~ fqc:y~iIJg _µ~~r .. ~~~pqf1 ~-e~e:h. 4U.!~ng __ a_ ~o_ut4.~!Q. -~~-~IJ ... . • -Deleted: 6 ,-:..:==-------/ event. The west swell event shown in Figure 2l~e111.~µ_s!_r~t.es _t~_e_m~j_o~ ~ay~ -~~8:~0_v\f_ing ~(f~c.t... .. • ·! tl1:ileted: 5 of offshore islands for the Newport Beach shoreline. -----/ Deleted, 6
In the nearshore zone, wave refraction affects breakers approaching shore. The extent of wave
refraction is affected by the deep water wave approach direction and wave period. Figure 2~ ____ ~ .. -·("D"e"le::•=ed::'_c' _______ _,
shows an example of wave refraction caused by the canyon and the resulting wave approach
direction toward shore. Generally, waves exhibiting longer periods will be refracted more
extensively than shorter period waves. For Newport Beach, the net effect is waves from the
south typically experience greater refraction than those from the west since waves from the south
are higher, and of longer periods than waves from the west. Western waves at Newport Beach
are lower and of shorter periods than those from the south.
Mojfilll & Nichol 44 July 2oor;
Figure 2;l-,: \Vave_ Expos_ure _ofN:e_lV])ort _Beac _______ _ l Deleted: 4
Moffatt & Nichol 45 July2006
_,. -1 Deleted: 5
Figure 2§._-Nearshore Wave Transformation for Southern Swell ___________ ,,,
Mojfi.111 & Nichol 46 July 2006
_. ~ -[ Deleted: 6
Moffatt & Nichol 47 J11ly200fi
Figure 2l!,:: \Vave Refraction During Southern SweH ..
, ,[ Deleted: 7
Mojfalf & Nichol 48 July 2006
Wave refraction can result in wave focusing at certain locations along the shore. Within the
curved embayment of West Newport Beach, wave amplification increases toward the northwest
with distance from the canyon for swells approaching from the south. As southern swell refracts
more than west swell at this location, they will possess greater wave energy and increased
potential to transport sand as one moves from Newport Pier toward the Santa Ana River mouth.
The canyon also causes wave energy to diminish in the vicinity of the canyon head thus leading
to sedimentation near Newport Pier and formation ofa sand protrusion known as Newport Point.
Newport Point acts as an anchor to the shore at that location and creates the benefit of stabilizing
the western portion of the shore along Balboa Peninsula. Newport Point also serves to fix the
position of the beach at the downcoast end of West Newport.
4.3 Wind
Winds are present along the Southern California coastline and have the potential to transport
significant amounts of sand. Newport Beach experiences winds that are predominantly onshore
from the west during the day and offshore from the east at night or early morning. The daily
"seabreeze" is fairly gentle at 5 to 15 miles per hour and generate typically low waves and very
short periods that reach the beach. Land breezes occur during the night and early morning
driving the wind westward toward the shore resulting in offshore winds. Extreme offshore land
breezes occur during "Santa Ana" wind conditions typically occur in fall and winter. Santa Ana
winds are warm and dry and can exceed 50 miles per hour.
High-velocity west winds above 20 miles per hour can occur during passage of a weather front
and can lead to measurable sand transport on the beach. Sand is blown from the beach toward
the homes and street ends and becomes a maintenance requirement to remove.
4.4 Littoral Processes
Currents generated by breaking waves move sand. Wave-induced currents run both in the
longshore (shore-parallel) direction and cross-shore (shore-perpendicular) direction. Both have
the potential to transport significant quantities of sand.
4.4.1 Longshore Transport
Swift longshore currents result in the potential to move large quantities of sand along the coast.
The concept oflongshore sand transport is illustrated in Figure 22, Newport B.eachisasand-rich
environment, so sand transport rates are can be high. Owing to the shore orientation and effects
of the canyon, sand transport in West Newport is highly variable, with periods when it is
predominantly from the southeast to northwest direction, and other periods when it reverses to
the southeast (USACE, 1940, and 1972; Moffatt & Nichol, 1993; Everts, 1996). Studies show
that sand moves in both directions along the Newport coast (USACE, 2002), but overall the sand
moves in a "down coast" or southeasterly direction with periods of strong reversal (USACE,
1.996; Everts, 1996). These transport reversals have historically posed significant erosion on
occasion in this area
M()ffall & Nichol 49 July 2006
·! Deleted: 8
Figure 2&-:: .C:.on_c~pt_ «:t( !-«?1:lg~l!o_r~ _S_e!f!~-~U..f. I.!"~J!~O_r,!. { Deleted: 8
Mojfau & Nichol 50 July2006
Coastlines in north Orange County are exposed to higher winter waves from the west than
Newport Beach. The higher winter waves drive longshore currents and transport sand at a
greater rate than occurs in summer, and thus lead to winter erosion. Newport Beach, on the other
hand is partially sheltered from western swell and therefore behaves opposite from some
Califonia beaches and experiences erosional events in summer, with minor accretion in winter
(USACE, 1972; USACE, 2002).
West Newport Beach apparently experiences a low level of net sand transport to the southeast
out of the groin field under most conditions. Sand can then reverse field and move to the
northwest toward the Santa Ana River under certain southern swell conditions. Sand moves to
the southeast through the groin field and toward Newport Point at a low rate over long periods of
time. Reversals in direction result in sand being lost toward the northwest at a high rate over
short periods of time. Therefore, in a gross sense sand moves in both directions within the groin
field, but the movement to the southeast is slightly greater than that to the northwest over time.
Evidence suggests that the rate of net sand transport to the southeast is less than 26,000 cubic
yards per year (USACE, 2002). Net transport to the northeast during reversals is estimated to be
less than 100,000 cubic yards per year from a study over the period of January 1992 to April
1993 (M&N, 1993).
4.4.2 Cross-Shore Transport
Sand transport also occurs in an onshore-offshore direction seasonally. Summer southern swell
is exemplified by a mild profile due to their long wave length and low to moderate height. This
mild wave profile tends to move sand from nearshore bars up onto the beach face resulting in
widening of the beach, or beach building. Winter western swell is steeper due to greater height
and shorter wave length, and tends to move sand off of the beach face and deposit it in bars in
the nearshore zone as beach retreat. The extent of these processes and their influence on the
beach depends on the exposure of the site to swell conditions. Both processes occur at Newport
Beach, but winter beach retreat is less pronounced due to island sheltering than at other locations
that are more exposed to western swell.
4.5 Dynamic Behavior of the Newport Beach Shoreline
Newport Beach is very dynamic as a result of complicated interactions of the processes described
in the preceding sections. This section presents details of shoreline positions, orientation, and
elevation as measured and observed over time.
4.5.1 Historic Shoreline Positions
Sand is generally lost from West Newport Beach over time from within the narrow shoreline
reach within the groin field between 30th Street and near 46"' Street, and is generally gained at
the Santa Ana River mouth. Newport Point appears to be losing sand from width measurements,
but does not appear to be retreating based on aerial photographs, so that location may be
relatively stable but not accreting. The Point appears to shift in position from west to east based
on swell direction and season, and this may confound estimates of shoreline position changes
MojJGII & Nichol 51 July 2006
and result in apparent retreat during surveys. Balboa Peninsula appears to be stable to slightly
retreating.
The shoreline at the Santa Ana River and Newport Point appears to be stable, while between the
River and Newport Point it forms an embayment that varies in its position. At certain times it
lies farther landward during southern swell erosion events, and shifts seaward during accretional
western swell periods. The amplitude of the curvature of the shoreline planform (viewed from
above) is greatest during periods of erosion, Shorelines were located most landward prior to
installation of the groin field and beach nourishment from 1%8 through 1973 as shown in Figure
JQ.,. __ T'h_~ .~1lqr_eU11e, ~~ya_n_r;~_q s_e_aw_a_rd_ s_i1_1~e, t_h_~ _C()p~t~U:.c_!i_on __ a_f th_e __ g_ro~n_s _and -~91:rr_i~_h_~e,_n_t
projects as shown in Figure 31,
The location of the shoreline along the City's beach has been recorded by both the USACE and
the City in the form of beach profiles and shoreline position measurements. When averaged, the
data show that West Newport Beach has generally advanced from Prospect Street to the Santa
Ana River since installation of the groins and beach nourishment, with stability or slight retreat
in the vicinity of between 30th and 46th Streets.
Several data sets are available to review from the USACE that consist of beach profiles
intermittently from 1963 through 2002, beach width measurements at each groin from 1977
through 1992, and beach width measurements between the groins from 1989 through 1998. One
City-generated data set of beach surveys is available for the period from 1976 through 1995, with
more recent surveys done in 2004 and 2005. The data are reasonably comparable although
variations exist for particular measurement locations and thus they are discussed separately, and
then discussed relative to one another,
4.5.2 Historic Beach Widths and Elevations
West Newport
USACE Shoreline Positions From 1963 Through 1997
The USACE performed topographic and bathymetric surveys at West Newport Beach from 1963
through 1997 to show the location of the seabed, shoreline, aud beach. Figure 2.1,.(presented
previously in this report) shows the shoreline positions as mapped during this period. The
shoreline has advanced throughout most of West Newport, particularly near the River. Table 7
shows the average annual change to be nearly +4.8 feet per year at 62"' Street and -0.3 feet per
year at 30th Street. The average of the numbers is a beach width increase over the reach of2 feet
per year. These data demonstrate the trend of a narrow beach in lower West Newport and a
progressively wider beach in upper West Newport and toward the Santa Ana River. All other
data analyzed in this report and presented subsequently indicate the same general trend.
Moffatt & Nichol 52 July 2006
•• St-"'-•-=" -· " Deleted: o
--{ Deleted: 0
' Figure ,ill_-, Narrow _Be_ach _a_t _West_ Newport_ Prior to lJSACE_ Projects,_ Sep_tem_b_er _1968 __________ . _____ . 1 Deleted: 29
Moffatt & Nichol 53 July 2006
Figure 31,,:-Wide Beach at West Newport After USACE Proiect, November 1974 ___ _ , 1_ Deleted: o
Moffatt & Nichol 54 July 2006
USACE Beach Widths at Each Groin From 1977 Through 1992
The USACE recorded beach width data throughout the region by measuring the width of the
beach berm referred to as Clancy beach widths (performed by an agency staff person named
Clancy described in USACE, 2002). These data were recorded at the location at each groin.
Clancy data from 1977 through 1992 for West Newport show that beach lost sand and the beach
retreated. The shoreline position at West Newport retreated during that period at an average rate
of-3.5 feet per year (M&N, 1993) as shown in Table 8. The retreat rate ranged from +3.2 feet
per year at 62"' Street, -0.2 feet per year at 56th Street, and-7.3 feet per year 19th Street. The
retreat progressively increased toward the southeast away from the west end of the groin field
and toward the Point.
Table 7 -West Newport Beach Widths From USACE Surveys 1963 Through 1997
Year 30th St. 38th St 46th St 54th St 62nd St
1963 260,5 149.5 174.1 178.4 202.5
1966 203.9 33.7 93.4 162.9 -212.9
1969 172.1 128.4 166.6 141.9 114.0
1973 186.8 194.2 189.1 321.8 275.3
1991 255.9 212.4 237.2 317.2 324.3
1992 250.9 223.4 255,0 321.5 392.2
1993 232.7 191.4 226.9 281.7 339.1
1994 254.7 203.2 471.6 280.1 409.7
1995 239.3 189.0 203.6 298.2 375.0
1997 249.8 202.5 218.0 274.2 363.8
Shoreline Change
1963-1997 -10.8 53,0 43.9 95,8 161.4
Average Annual
Chan e -0.32 1.56 1.29 2.82 4.75
Note: All distances measured in feet.
An order-of-magnitude volume of annual sand loss at West Newport during this period was
estimated by calculating the area of annual beach lost and converting the area to a volume. The
area ofannual beach lost (in square yards) was calculated by multiplying the retreat rate at each
groin by the length of beach over one-half the distance between the groins. The square footage
of beach lost was then multiplied by a factor of 1.5 to convert it to a volume (in cubic yards),
assuming I square foot of beach lost equates to 1.5 cubic yards of sand lost throughout the beach
profile (USACE, 1984). Based on this method the volume of sand lost from 1977 through 1992
is estimated to be 70,000 cubic yards per year over this period from these data.
Mqf/illl & Nichol 55 July 2006
Table 8-Rate of Beach Width Change at West Newport From 1977 Through 1992
Based on Clancy Data (Source USACE Archives, Jane Grandon)
Location Rate of Beach Width Change (Feet Per
Year)
62"d Street +3.2
56th Street -2.0
52"' Street -3.6
48th Street -2.8
44th Street -3.5
40th Street -4.4
36th Street -4.4
32"d Street -4.7
28th Street -5.1
19th Street -7.3
Average -3.5
The data suggest that the shoreline was retreating into 1993 after the large fills in the late 1960's
and early 1970's (and after the large river delta deposited by the Santa Ana River in 1969
estimated to consist of nearly 3 million cubic yards of sand per the USA CE, 2002). The data
may also be biased by effects of the groins as this data set differs from the subsequent set
described below in that measurements were taken at the location of each groin, while the later set
of Clancy data were taken at beach locations between the groins. Thus the measurements are not
directly comparable, but trends in the shoreline should still be apparent when evaluating the data.
USACE Beach Widths From 1989 Through 1998
The USACE continued to record Clancy data, but the locations of the measurements were moved
in 1989 from the groins to the reaches of beach between the groins. The USACE beach width
data from 1989 through 1998 at West Newport Beach presented in Table 9 show a mix of
accretion and sand lost. The shoreline at West Newport appears to have retreated during that
period at an average rate of -6.3 feet per year. However, the data are biased by readings taken at
the groins for only one year (1993) during that period that show extremely high rates of retreat,
and therefore may skew the results. The retreat rate ranges from a minimum of -4.3 feet per year
Moffa/I & Nichol 56 July 2006
near Sib Street to a maximum of between -19.7 feet per year at 36th Street. The retreat
progressively increases away from the west end of the groin field and toward 36th Street. Care
should be taken when using the beach width data at the groins.
An order-of-magnitude volume of sand loss at West Newport during this period was estimated
using the method described in the previous section of this report (assuming the retreat rate at
each beach applies to the reach of beach between the groins, and assuming 1 square foot of beach
loss equates to 1.5 cubic yards of sand volume lost throughout the beach profile per the USA CE,
1984). Based on this method the volume of sand lost from 1989 through 1998 is estimated to be
126,000 cubic yards per year.
This data set may be slightly biased by readings of substantial shoreline retreat taken at the
locations of the groins in 1993. Although the retreat condition could have existed, these readings
may represent an aberration.
USACE Beach Widths From 1993 Through 1998 (Post-Nourishment Period)
A major nearshore beach nourishment project occurred in mid-1992 at the Santa Ana River
affecting the shoreline. Therefore, the time period of 1993 through 1998, excluding the
potentially aberrant set of 1993 (at the groins) was examined to assess the beach position during
the most recent nourished period. USACE beach width data from 1993 through 1998, minus the
1993-only data set at the groins, is shown in Table 10. The data indicate that the beach at West
Newport remained mostly stable with moderate accretion from 62nd to 34th Street, and retreat
from 32"' through 19th Street. The average rate of change in beach width was + 1.4 feet per year
over the entire measurement reach. The advance rate is high at 62nd Street ( +6.1 feet per year),
relatively low at 46th Street ~+0.4 feet per year), and highest at 38th Street (+8.8 feet per year).
The advance rate ends at 341 Street. Shoreline retreat occurs at 32nd Street and continues to the
southeast through the Point reaching a maximum of -11.8 feet at 19th Street.
An order-of-magnitude volume of sand increase at West Newport during this period was
estimated using the method described in previous sections of this report (by assuming the rate of
beach advance at each measurement point applies to the reach of beach to one-half the distance
between the points, and assuming 1 square foot of beach advance equates to a volume increase of
1.5 cubic yards of sand throughout the beach profile per the USA CE, 1984). Based on this
method the volume of sand gained at West Newport from 1993 through 1998 is estimated to be
28,000 cubic yards per year. This value is relatively close to the value identified in the USACE
sediment budget for West Newport presented in a subsequent section in this report. These values
of shoreline change are also closer in magnitude and trend to those estimated from USACE
shoreline topographic/bathymetric maps from 1963 to 1997 discussed in a subsequent section of
this report.
Mojfalf & Nichol 57 July 2006
Table 9 -Rate of Beach Width Change at West Newport From 1989 Through 1998
Based on Modified Clancy Data
Location Rate of Beach Width Change (Feet Per
Vea,·)
62"' Street 6.1
56th Street -6,5
54th Street 0.2
52"' Street -4.3
50th Street 1.2
48th Street -5.8
46th Street 0.5
• 44th Street -9,1
42"' Street 2,2
40th Street -16.3
38th Street 8.8
36th Street -19.7
34th Street 8.6
32"' Street -16.3
30th Street -2,9
28th Street • -9.6
19th Street 0.1
Average -6.3
Source: USACE CCSTWS 2002, and Unpublished Data Provided by Chuck Mesa of the USACE
Moffa/I & Nichol 58 .July 2006
The Santa Ana River nourishment project is documented to have added sand volume to the
shoreline, resulting in beach widening in upper West Newport (Everts, 1996). This project may
have caused sufficient widening to yield positive changes in the width of the beach throughout
that reach. However, although this sand quantity widened a portion of the shore, locations from
32"d Street through 19th Street were still documented as being erosional. This information
suggests that shoreline retreat may continue at lower West Newport even after nourishment, but
that this shoreline also benefits from nourishment at a "feeder" location such as offshore of the
Santa Ana River. These events can prove useful in considering potential management actions
described later in this report. The rate of average beach change as determined for all of the beach
width measurements presented in this section is -1.6 feet per year, when averaging all of the rates
listed above (average of +2.0, -3.5, -6.3, and +1.4).
Table 10 -Rate of Beach Width Change at West Newport From 1993 Through 1998
Based on Modified Clancy Data (Post-Nourishment Period)
Location Rate of Beach Width Change (Feet Per
Year)
62"d Street 6.1
54th Street 0.2
50"d Street 1.2
46" Street 0.5
42nd Street 2.2
38 th Street 8.8
34th Street 8.6
30th Street -2.9
19th Street -] 1.8
Average 1.4
Mojfalf & Nichol 59 July 2006
Balboa Peninsula
City Beach Dry-Beach Profile Surveys From April 1976 to October 1995
The City of Newport Beach has performed surveys of the dry beach along Balboa Peninsula and
at the east end of the groin field since 1976. Beach surveys were done at Island Street, 10th
Street, 15th Street, and 13th Street (and at 24th Street at West Newport). The data were analyzed
for shoreline position trends at the Peninsula by identifying the break in slope between the berm
and the beach face slope. Movement of the berm indicates a trend of the shoreline either
advancing seaward or retreating landward. As shown in Table 11, surveys indicate that the
beach berm retreated at all sites over the survey period. The rates of retreat were -3 feet per year
at Island Street, •3.3 feet per year at 10th Street, -5.2 feet per year at 15th Street, and-9.2 feet per
year at I 3th Street, for an average retreat rate of •5.2 feet per year. An order-of-magnitude
estimate of the volume of sand loss from this retreat rate is 94,000 cubic yards per year from
1976 through 1995, based on the method described in previous sections ofthis report.
Table 11 • Rate of Beach Width Change at Balboa Peninsula From 1976 Through 1995
Based on City Beach Width Data (Source: City of Newport Beach)
Location Rate of Beach Width Change (Feet Per
Vear)
Island Street •3,0
10th Street .3.3
15th Street -5.2
I 3th Street ·9.2
24th Street (West Newport) -6.2
Average -5.2
Source: City Beach Profile Surveys From April 1976 to May 2000 at Balboa Peninsula
The City also performed surveys of the beach elevation along Balboa Peninsula and into the east
end of the groin field since 1976 (Dunnigan, 2000). Surveys at the Peninsula were done at Island
Street, l 0th Street, 15th Street, and 18th Street. Surveys at West Newport occurred at 24th Street,
30th Street, 38th, and 46th Streets. The data for the Peninsula were analyzed again for shoreline
position trends by measuring the width of the beach berm. Surveys indicate that the beach berm
retreated at all sites over the survey period as shown in Table 12. The rates of retreat were -3.6
feet per year at Island Street, -4.6 feet per year at I 0th Street, .5.4 feet per year at 15th Street, and
-3 .8 feet per year at 18th Street, for an average retreat rate of -4.3 feet per year. The order-of-
Moffa/I & Nichol 60 July 2006
magnitude volume loss at the Peninsula based on these data was 77,400 cubic yards per year
from 1976 through mid-2000 using the method described earlier.
Table 12 -Rate of Beach Width Change at Balboa Peninsula From 1976 Through 2000
Based on City Topographic Survey Data
Location Rate of Beach Width Change (Feet Per
Year)
Island Street -3.6
10th Street -4.6
15th Street -5.4
18th Street -3.8
Average -4.3
Source: City of Newport Beach, Department of Public Works, G.P. Dunigan, Jr., 2000.
Big Corona Beach
No historic measurements of Big Corona Beach were identified from either the USACE or the
City. More recent beach profiles were taken at Big Corona by the City in 2004 and 2005. Aerial
photographs and the recent profiles were examined to determine the condition of Big Corona,
along with data from the USACE sediment budget. Big Corona is approximately 300 feet wide
on average, and varies depending on season and year. Beach retreat does not appear to be
occurring at the west portion of this site, but the east end of the beach is retreating as observed by
City staff and local residents and presently encroaches on the main pedestrian coastal accessway
at Inspiration Point.
Elevations of the Beach Over Time
The elevation of the Newport Beach berm has changed over time from natural processes, and
from artificial nourishment and management by man. Beach front residents have recently
expressed concerns about the elevation of the berm. Most issues stem from the fact that the
beach along certain reaches of Newport Beach seems higher than would naturally occur.
Concerns mainly include the scarp that forms along the foreshore under certain conditions that
presents a safety hazard to walkers and small children, and sand gradually burying the rear
portion ofbeachfront lots/yards, and being blown onto street ends. The scarp is felt by some
residents to be high enough to be a safety hazard to small children and people walking on the
beach. It occurs during both summer and winter seasons and forms during higher tidal elevations
as waves reach higher onto the beach and rework the elevated berm. Sand continually blows
Moffa// & Nichol 61 July 2006
landward under daily seabreezes and during storm events and buries yards, patios, and collects at
street ends. Sand deposits constitute a maintenance requirement for the City,
Surveys of historic and recent elevations of the beach berm were made to identify trends.
Surveys were made by the USACE from 1963 through 2002, and by the City in 2004. Table 13
shows berm elevations in 1963 ranged from a minimum of+ 12.5 feet above MLL W at 54'h
Street to a maximum of+ 16.5 feet at Cedar Street. Elevations were lowest in the groin field and
highest toward the Santa Ana River, suggesting formation of dunes along the rear of the beach
near the River where the beach was sufficientlr wide to enable that process to occur. Elevations
in 2002 range from a minimum of+ 11.5 at 26' Street to a maximum of+ 16.5 at Fern Street.
Higher berm elevations occurred within the western portion of the groin field in 2002 with
elevations reaching+ 16 feet MLLW at 54'h Street, compared to an elevation of+ 12.5 feet
MLLW in 1963. Elevations in 2004 showed the highest berm elevation to be at 54"' Street at
+ 15.9 feet MLL W, with lower elevations dropping to both the east and west reaching+ 11.2 at
26'h Street and+ 13.5 at Orange Street.
Comparison of the berm elevations in West Newport was made with other typical coastal
locations to identify any anomalies from natural conditions or within the region. Data from 2004
show berm elevations to be higher at Adams Street and M Street on Balboa Peninsula reaching
up to+ 16 feet MLL Wand+ 18.6 feet MLLW, respectively. The Peninsula received very large
volumes of fill from Harbor construction in the 1930's that has remained on the beach, with the
exception of sand mining between Island Street and 12'h Street in the mid-1960's to nourish West
Newport. The berm may be elevated from that nourishment activity and from City beach
maintenance, Berm elevations at other coastal locations including Huntington Beach were
between+ 15 feet MLL Wand+ 15.8 feet MLL W, and at Big Corona Beach it is +10.6 feet
MLLW. All of these locations experience manipulation by humans in the form of beach
grooming, grading, and reworking for management so they may not truly represent "natural"
conditions.
Natural conditions are for the berm crest to form at the maximum elevation of wave run-up on
the beach to dissipate wave energy, and they to gradually slope slightly downward toward the
hmdward portion of the beach. Wave run-up estimates for Orange County (and specifically at
two locations at Newport Beach) were performed by the USACE in the 2002 study. They
indicate that along Newport Beach wave run-up from breaking waves nearshore during an
extreme storm wave event is between+ 14.5 feet MLLW at West Newport and +16.3 feet at
Balboa Peninsula. Natural berm crest elevations were not likely much higher than these
elevations except where dunes may have formed. If the elevation of the berm is high enough to
cause problems with sand management, then ltc_an ___ be __ ll)ajµt_ai~_e_~_.a_t _a_sui_tab_l(? -~Ieyat_iq_n_to_
reduce most nuisance sand problems.
4.5.3 Historic Aerial Photographs
Aerial photographs from the 1960's, 1970's, 1980's, 1990's, and 2000's were obtained from the
USACE and others and analyzed for visible shoreline changes to check conclusions drawn from
the beach width data. Aerial photographs are presented in Appendix B. The aerial photographic
record clearly shows the trend of Newport Beach to be consistent over time, with widest reach of
the beach farthest west near the SAR, becoming narrow along the groin field with the narrowest
Moffa/I & Nichol 62 .f11fy 2006
-{ Deleted: they
reach between 46th Street and the Pier, and widening again eastward along the Peninsula. The
beach at Big Corona appears stable in position with few changes over time. The only discernible
trend is that the beach at the far West end of Newport appears to be gradually widening, while
other beach widths remain relatively constant.
Beach Berm Elevations in Feet (MLLW)
Location 1963 1978 2002 1994 2004
Big Corona 10.6
M St 18.6
ADAMS 16
18TH 12.8 11.8
26TH ST 13.0 11.5 11.2
38TH ST 14.0 13,5 13.1
46th St 15.0
54TH ST 12.5 16.0 15.9
60th 14.7
CEDAR ST 16.5 16,0 14,5
FERN ST 14.3 16.5 13.2
SONORA ST 15.0 15.0 13.9
BROOKHURST 12.5 15.8
MAGNOLIA ST 13.0 14.5
JACK'S 12.0 15.8
6TH ST No Data 15.0
AVERAGE 13.6 15.0 14.6
Table 13 -Beach Berm Elevations 1963 to 2004 (USACE, 2002)
Evidence of net sand transport to the southeast with periods of reversal exists in aerial
photographs of West Newport Beach. Every aerial photograph reviewed for this project shows
the embayment at West Newport between the Santa Ana River mouth and Newport Point, and
protrusions at the rivermouth and Newport Point. The embayment is indicative of sand being
lost from that reach of beach, while the protrusions are locations where sand is either gained or
remains in balance, without being lost. "
Also, the aerial photographic archive suggests low net rates of sand transport in either the
upcoast or downcoast direction. The direction of net sand transport can be inferred from sand
Deleted: Historic and recent aerial
photographs are included in Appendix B
deposits against the groins. Figure 36r_sJI9F_? _a_ c_0!1'-?~_tt1<!_l _s~i:_i~s __ 1!(g_r9~1_? _a!_lq !l!e_ga_!t_e~f!_ Q~ s_a!}g _. ,, --iLD_e_1e_t_ec1_,_1 _______ __)
Moffatt & Nichol 63 July 2006
deposits, or "fillets," that form by sand moving in predominantly one direction along the shore.
Figure 3].is a concept that showsrelatively sm.allsand deposits along the_ groinssuch as is the
case at West Newport. This condition is indicative of sand moving in both directions along the
coast almost equally, leading to a relatively low differential.
Photographs of Newport show that fillets are visible along the northwest sides of the groins
during most periods, and particularly during winter and spring months reflecting net sand
transport to the southeast. They shift position to the southeast sides of certain groins during
summer and fall months indicating sand transport to the northwest. The overall pattern of fillet
formation is along the upcoast side of the groins indicating net transport to the southeast.
Patterns of fillets at West Newport vary slightly according to season, but rarely do they evolve
into a typical fillet development like shorelines with a high rate of net longshore transport in one
direction as shown in Figure 32, Fifteen setsofaerialphotographs were .eva.luated from 1974 to
2005. They showed fillets along the northwest sides of the groins (indicating net southeast
transport) in 63.3 percent of the photographs, fillets to the southeast (indicating northwest net
transport) in 3.3 percent of the photographs, and no fillets visible in 33.3 percent of the
photographs.
In addition to observations of beach widths, conditions pertaining to the function of the groins as
visible in the photographs that include:
The groins at West Newport generally appear to hold only nomimally more sand within
the groin field than prior to installation of the groins (based on two pre-groin aerials in
1954 and 1966 and all post-groin photographs), leading to an only slightly wider beach
than historically existed. However, the extreme fluctuations in the shoreline position
under severe southern swell wave events may be somewhat retarded by the groins thus
preventing catastrophic beach retreat as occurred in 1934, 1939 and 1968.
The groins do not appear to cause formation of classic fillet deposits, except periodically
at 56" Street (seasonally) and at 28" Street (perpetually) because these are the longest
groins and they are located at the respective upcoast and downcoast ends of the field,
thus beneficially functioning to reduce the range of position shifts of the shoreline
throughout the groin field.
Sand may shift within the groin field seasonally over time and be "trapped" between
28th and 56th Streets, essentially being recycled between these two groins from season
to season.
Summer conditions result in sand held in a fillet southeast of 56th Street extending
southeastward toward the center of the groin field thus widening the narrow reach of the
beach. This may serve the critical purpose of holding the shoreline position of West
Newport farther seaward under periods of southern swell activity than would have
historically occurred, thus reducing the vulnerability of this reach of beach to damage
under severe storm wave conditions in summer/fall seasons.
64 July 2006
• --[ Deleted: 2
-.-[ Deleted: 1
Figure 3J. -Fillet Formation For High Net Sediment Transport Rates ,( Deleted: t
'
In Two Different Directions
Moffa/I & Nichol 65 July 2006
re 3l.-Fillet Formation For Low Net Sediment Transport Rates In Both Directions , { Deleted: 2
Moffatt & Nichol 66 July 2006
Winter conditions result in sand accumulating along the northwest side of the 56th Street
groin causing narrowing of the beach to the southeast that is tempered by the effects of
downcoast groins.
A fillet constantly exists northwest of 28th Street under all seasons, anchoring the
position of the beach at this location and thus benefiting the reach to the northwest.
This fillet changes in size, but is present in all photographs indicating that net sediment
transport is southeast at this location.
4.6 The Newport Beach Sediment Budget
Beach conditions can be described in terms of a sediment, or sand, budget that exists at a beach
over time.
4.6.1 Sediment Budget Concept
The volume of sand at a particular beach changes over time depending on conditions. Larger
sand volumes at a beach result in a wider beach, while smaller sand volumes existing at the same
beach result in a narrower beach. The sediment budget is an attempt to quantify the volume of
sand stored at a beach over time as a result of inputs of sand to the beach versus outputs. Figure
3:1,shows a _concept of a sediment budget..
The sediment budget at Newport Beach is not entirely clear, and thus the conditions of the beach
and causes of those conditions are still not completely understood. Yet several previous studies
have been done to attempt to better understand the budget and existing conditions. Sediment
budgets can be either positive (with a widening beach), negative (with a narrowing beach), or in
equilibrium (with a stable or relatively unchanging beach). Positive budgets occur whi.:n inputs
of sand to a beach are greater than outputs. Negative budgets occur with inputs of sand to a
beach are less than the outputs. Equilibrium conditions exist when inputs of sand to a beach
equal the outputs .. Inputs of sand include that from the adjacent coastal beach, such as
Huntington State Beach and the Santa Ana Rivermouth in this case, and rivers such as the Santa
Ana River and San Diego Creek. Outputs include areas where sand is permanently lost from a
beach such as to the Newport Submarine Canyon, the area of the deeper offshore ocean, and
along the west jetty to the Harbor entrance channel. They can also include sand blown by the
wind onto the land, but this condition is a relatively small component of the budget at Newport.
Two sediment budgets are presented below that differ in their approach and their results.
One budget is by Everts (1996) and is based on detailed wave and current data collected at
Newport Beach over 14 months from 1992 through 1993, is consistent with earlier viewpoints of
local experts (Beach Erosion Control Board, 1938, and 1940; USA CE, 1962, and 1972), and
seems to explain the indented shoreline planform trend apparent in aerial photographs as a
product of wave refraction at canyon. It calls for a low rate of net sediment transport to the
Mojfa/1 & Nichol 67 July 2006
~ , -[ Deleted: 3
Figure 3:! -Concept of a Sediment Budget , , 1 Deleted: 3
'
Moj}UII & Nichol 68 July 2006
northwest. However this budget is based on less available data than subsequent estimates, and is
incomplete and in need of significant supplementation to sufficiently quantify sand movement
and storage throughout the City.
The other budget is by the U.S. Army Corps of Engineers (2002). It calls for a low rate of net
sediment transport to the southeast. This estimate is very complete, contains a certain degree of
uncertainty due to computer extrapolation of areas between measured data, agrees with some
previous reporters but not others, and seems counter-intuitive in light of:
Conditions present during historic erosion events;
Existing nearshore current data; and
The effects of wave refraction at the canyon causing the indented shoreline planform
visible in aerial photographs.
4.6.2 Sediment Budget Prepared by Everts (1996)
Everts (1996) states that for this century West Newport Beach is in a negative sediment budget,
with losses exceeding gains by approximately 40,000 cubic yards of sand each year on average.
He also states that the sediment budget for Balboa Peninsula is in a deficit of :20,000 cubic yards
of sand each year on average (Ibid, 1996). Relatively small proportions of these budgets are
attributed to sea level rise, but this is an important component because it is probably the most
clearly understood and can be anticipated. Sea level rise causes the shoreline to more landward,
thus leaving a certain amount of sand in water too deep offshore to return during calm beach-
building periods. Sea level rise accounts for 15% of the losses at West Newport (6,000 cubic
yards per year), and 20% of the losses at Balboa Peninsula (4,000 cubic yards per year). Sand
lost to Newport Submarine Canyon is 1,000 cubic yards per year (2.5% oflosses), and sand lost
to the deeper ocean along the west jetty to the Harbor entrance channel is 400 cubic yards per
year (2% of losses) (Everts, 1996).
Everts indicates that sand transport at West Newport is quite variable, with some researchers
concluding the net movement is to the southeast over time (Hales 1980; Gravens, 1990), while
others indicate it is to the northwest (USACE, 1940; M&N, 1993; Clancey et al, 1983), and still
others indicate it can be in converging directions within the reach (Spencer, 1985; Interstate
Electronics Corporation, 1966). Historic formation of the spit at West Newport and the
Peninsula is direct evidence of transport to the southeast.
Sediment trallsport at Balboa Peninsula is less variable with the net transport very low (near
zero) to the southeast (Everts Coastal, 1995). The rate of sediment transport between West
Newport and Balboa Peninsula is near zero (Everts, 1993), with a slight net movement to the
east.
The other components of the sediment budgets for these beaches that were not well understood at
the time of Everts study included:
1. Sand contributed from the Santa Ana River to West Newport;
M()ffall & Nichol 69 July 2006
2. Sand from Huntington State Beach to West Newport and vice-versa;
3. Sand from West Newport to Balboa Peninsula and vice-versa; and
4, Sand lost from the littoral zone to deeper ocean waters offshore,
Everts (1996) indicates that full accounting of the sand in the sediment budgets cannot be
performed until these components are understood so they are suggested as items offurther study
to more definitively understand the coastal system and future trends. The subsequent study by
the USACE described below addresses these items and other information needs.
4.6.3 Sediment Budget Prepared by the USACE (2002)
West Newport Beach and Balboa Peninsula
The USACE CCSTWS (2002) provides a sediment budget for the period of 1963 to 1995 that
indicates net accretion in West Newport of 80,000 cubic yards of sand each year, and a loss
along Balboa Peninsula of -35,000 cubic yards of sand each year. The portion of the budget
pertaining to West Newport stands in contrast to the Everts' budget and raises the issue of
whether West Newport is accreting or eroding. It also indicates that net sediment transport
through West Newport is to the southeast at a very low rate, which is consistent with many
previous researchers and contrary to some others. The USACE sediment budget is based on
balancing sand volumes measured in the littoral system from Surfside to Newport Harbor
entrance and is very thorough. The USACE sediment budget for Newport Beach is shown in
Figure 3j,
At West Newport, contributions include 26,000 cubic yards of sand per year delivered from
Huntington Beach along the shore and 95,000 cubic yards per year from artificial nourishment
, --( Deleted: 4
activities from the SAR Natural c.gntributions from the SAR are included in the sand delivered ...... ·[ Deleted: c
from Huntington Beach. Losses incfud~ 23~o-o0-c~bfc-Ya~ds-Pef yeru--pa-s;ing ~;ound-thC cruiy~~ -----------~
at Newport Pier to Balboa Peninsula, 10,000 cubic yards per year to the offshore, 1,000 cubic
yards per year to the canyon, and 7,000 cubic yards per year from subsidence of the land from oil
historic extraction activity. The loss rate to the southeast nearly equals the intake from the
northwest at West Newport, indicating that this reach of beach may serve as a "pass through" of
sand from up-to downcoast areas with little storage at this site. Without direct nourishment at
this beach, it would potentially be perpetually narrow as shown in historic maps.
Noteworthy from this estimate is that the beach at West Newport exists mainly due to artificial
beach nourishment. Eliminating artificial nourishment would result in a net loss of sediment
from West Newport of 15,000 cubic yards per year, considering the historic nourishment rate
being 95,000 cubic yards per year and the net accretion at the site being 80,000 cubic yards per
year according to the budget. This suggests the importance of nourishment in maintaining a
beach at West Newport into perpetuity. Also, this budget should be updated to reflect more
recent conditions. Approximately 90,000 cubic yards of nourishment occurred in 2005, If the
budget were updated to extend from May of 1963 to May of 2006, the rate of beach nourishment
would decrease to 73,000 cubic yards per year and the sand volume change at the beach would
decrease to ~OOOcubicyardsperyear,
Moffatt & Nichol 70 July 2006
, -I Deleted: 63
Figure 3~:,-.The. USACES_ediment Budget fo_r_Newport_Beac_h
, 'l Deleted: 4
Moffa/I & Nichol 71 July 2006
At Balboa Peninsula, the only contribution consists of23,000 cubic yards of sand per year
delivered from West Newport Beach along the shore and around the canyon head. Losses
include 3,000 cubic yards per year passing through the west jetty at the entrance to the Harbor,
13,000 cubic yards per year to the offshore, 16,000 cubic yards per year from subsidence of the
land from oil historic extraction activity, and 26,000 cubic yards per year from mining for
nourishment at West Newport. The trend of -35,000 cubic yards net loss of sand from Balboa
Peninsula is consistent with the estimate by Everts (1996).
Noteworthy from this budget estimate is that the only source of sand to Balboa Peninsula is what
is carried around the point from West Newport. If the quantity of sand available at West
Newport were to decline, then the rate of erosion at the Peninsula would increase. Also, a sand
deposit forms along the landward rim of Newport Canyon over time that acts as a surface for the
movement of sand from West Newport to Balboa Peninsula (Everts, 1996). The sand deposit
along the canyon rim episodically collapses into the canyon under certain conditions or when the
deposit grows to a certain size. After the sand deposit collapses, the surface for sediment
transport would be narrower and more sand would fall into the canyon resulting in less sand
moving to Balboa Peninsula. Thus the Peninsula is vulnerable to a reduced sediment supply and
greater erosion under some future conditions.
Big Corona Beach
A sediment budget was prepared for Big Corona Beach for the period of 1927 through 1984 as
part of an effort to quantify sand movement through small cells from Big Corona south to Dana
Point. It was prepared for the USACE regional study (2002) by Everts Coastal (1997). At Big
Corona Beach, a net gain of sediment by 3,100 cy/yr occurs for mild shoreline advance.
Contributions include 2,890 cubic yards of sand per year delivered from offshore, and I ,000
cubic yards per year from artificial nourishment activities. Losses include 790 cubic yards per
year passing around Inspiration Point to Little Corona Beach. No losses occurred to the offshore
or from subsidence of the land from oil historic extraction activity.
The sediment budget for Big Corona indicates stability at a pocket beach. The beach is protected
by the East Jetty to Newport Harbor and Inspiration Point from significant longshore currents,
and is sheltered to a narrow window of wave energy from the south by its orientation.
4.6.4 Conclusions Regarding the Newport Beach Sediment Budget
The actual reality of sediment inputs, storage, and outputs at Newport Beach may be somewhat
intermediate between the two scenarios presented above. The one clear fact evident from these
budgets is the uncertain status of both West Newport Beach and Balboa Peninsula in terms of
sand storage. Both estimates concur that Balboa Peninsula is losing sand, and that is also
confirmed by beach width measurements by the City discussed above. The budgets for West
Newport reflect the complexity of existing processes and conditions. Despite the differing trends
for West Newport in each estimate, the one clear conclusion is that the shoreline is vulnerable to
retreat without the addition of sufficient artificial nourishment to offset losses. West Newport
beach may even retreat at some reaches while other areas accrete.
Moffatt & Nichol 72 July 2006
As the USA CE budget (2002) is based on detailed and recent information, it is considered an
appropriate starting point for identifying potential problem areas, future trends, and any possible
management actions. It will be utilized in this study as the basis for suggested future updates and
improvements to the budget that can be made by the City for more accurate assessment of any
management needs.
It may be that no sediment budget sufficiently explains the processes leading to severe erosion
and damage to the backshore areas as has occurred in the past. These processes may include:
Extensive periods of southern swell activity with high waves;
Cluster storm wave events from the south;
Long periods between renourishment episodes;
Episodic events of coastal flooding and storm damage during southern storm waves
occurring with high tides; and
The velocities of longshore currents to the northwest during southern swells are higher
than those to the southeast during western swells, and have the potential to move more
sand over a shorter period of time.
Moffatt & Nichol 73 July 2006
5.0 State of the Newport Beach Coast -Present Problems
and Needs
Through detailed consideration of the historic behavior of the Newport Beach shoreline (Section
3) and quantitative evaluation of ongoing coastal processes (Section 4), it is evident that there
exist potential problem areas that may need attention. This section summarizes these present
problems and associated needs for the City's attention.
5.1 Erosion
West Newport Beach experienced chronic erosion in the early 1900's, the 1930's and the 1960's.
The shoreline has been relatively stable from late 1968 to the present (2006), most likely due to
construction of the groin field and subsequent large beach nourishment efforts. The shoreline of
West Newport is now relatively stable, exhibiting a wide west end and a relatively narrow central
and southeast end. Evidence suggests that the west end of the beach is accreting over time, while
the central and southeast ends do not, and may become slightly narrower depending on wave
conditions. The central and southeast areas of the groin field do not appear to be significantly
eroding, but are narrow enough to be vulnerable to damage during severe storm wave events.
The beach may still be susceptible to retreat during successive southern swell events, but has not
experienced such conditions and the consequent extent of erosion that occurred during the last
severe erosion period in summer of 1968.
5.1.1 West Newport Beach
Historic erosion at West Newport Beach appears to be episodic and related to years when
southern swells predominate; these storm wave events typically occur in clusters throughout the
summer and fall seasons. The extent of erosion, and damage to houses that occurred in 1934,
1939, and smnmer of 1968 (prior to initiation of the USACE Stages 2 and 3 projects in late 1968
and 1969, respectively) may have been reduced by sand blocking/retention effects of the groins
and beach widening from nourishment. As long as nourishment continues and the groins remain,
the severe erosion events similar to those of the past may occur less often or not occur to the
previous extent. The narrowest reaches of West Newport (20'h Street to 46'' Street) will likely
remain the most vulnerable to erosion over time.
5.1.2 Balboa Peninsula
Balboa Peninsula is retreating as evidenced by analysis of sediment budgets and data consisting
of beach widths, elevation and profiles. The rate of retreat appears to increase from east to west.
Highest rates are near 18th and 19th Streets at Newport Point, and lowest retreat rates are nearer to
Island Street. No long-term data are available for areas east oflsland Street. Data indicate that
the average retreat rate is approximately 5 feet per year. As Balboa Peninsula may be dependent
on sand from West Newport for a beach, maintaining sufficient surplus sand at West Newport
could serve to offset erosion at Balboa Peninsula. Also, elimination of sand removal from
Balboa Peninsula should be specified as a management action to reduce losses from this reach.
Mu,tfa/1 & Nichol 74 July 2006
5.1.3 Big Corona
Present data suggests Big Corona is gaining sand and becoming wider over time along the west
end. The east end of Big Corona is retreating as evidenced from anecdotal observations of City
staff and residents.
5.2 Coastal Flooding and Storm Damage
5.2.1 West Newport Beach
Coastal flooding still has the high potential to occur within the lower West Newport Beach area
from 20th Street to 46th Street during severe storm wave events. Flooding occurred at 20th Street
and 36th Streets as shown in Figures 2J.__an~ __ 2,3., __ il;S .!~c:e}1!ly _a~ ~he_ ~xtr~111,eJy_ ~ey~~e .. s_tc,r_Il?: \¥.:lY~
event of January 1988. Potential flooding can still occur, and could increase over time if sea
level rises relative to land and if the sand volume within this beach declines over time.
Essentially, an acute erosion problem has historically occurred during storm wave conditions
from the southern direction, particularly if several occur close in a time sequence, referred to as
"cluster" storm wave events. Southem waves tend to accelerate sediment loss from West
Newport due to wave refraction effects of Newport Canyon. No such erosion events have
occurred since summer of 1968 because no cluster southern storm wave events have occurred
and major shore protection projects were completed.
The beach has widened mainly in far west Newport, northeast of Prospect Street. The beach
between 30th Street and 46th Street has not significantly widened, but has remained stable in
position with slight narrowing at 30th Street. Even with the significant shore protection projects
and lack of southern storm waves, the narrowest reach of West Newport Beach remains narrow
and actually retreats. This indicates that the beach is in a precarious situation and could either
retreat more if no nourishment occurs., or can remain relatively stable if nourishment occurs at
the historic rates or at a rate to offset current losses (15,000 cubic yards per year).
The volume of sand at the beach can therefore be managed by man. However, rising sea levels
relative to land are largely outside of man's influence and may further add to the potential for a
retreating beach at West Newport, Sea level rise will occnr throughout the future and will
correspondingly shift the location of beach landward. The rate of sea level rise is slow, but when
added to a pre-disposition toward erosion along this reach, could cause accelerated problems.
Beach retreat and high water levels may cause flooding of coastal areas and damage to
infrastructure. Flooding occurs in streets and can occur at the first floor of homes. Damage to
infrastructure occurs in the form of broken windows, undermined patio foundations, damaged
landscaping and hardscape, and eventually structural damage to homes.
5.2.2 Balboa Peninsula
Balboa Peninsula floods dnring combined high tides and high waves as described by City staff
on December 8, 2005 (Jim Turner and Eric Bauer, Personal Communication, 2005; Tom
Anderson, Personal Communication, December 14, 2005). "\\rater overtops the beach berm and
Moffatt & Nichol 75 July 2006
: · f ~~leted, I .
-Deleted: 2
then ponds in the "peanut ponds" between Island and 12th Streets. A sand dike is sometimes
erected in this area to protect against overtopping. Waves can also overrun the Peninsula at E
Street under certain conditions of high tides and high southern swell from hurricanes as occurred
in 1939, and at B Street and flood Balboa Boulevard (Tom Anderson, Personal Communication,
2005). City staff indicate that B Street is the lowest point along the Peninsula. This situation
should become worse over time with retreat of the beach and sea level rise.
Balboa Peninsula is in a sediment deficit that causes the volume of sediment to decline at a
steady rate each year. Decreasing sediment at the beach leads to narrowing of the coast and
retreat. The beach has been documented in every data set exan1ined for this study to be
narrowing. The rate of narrowing is greatest near I 8th Street and least at Island Street. With
narrowing of the beach, problems with low areas that are overwashed, and rising sea level,
Balboa Peninsula may experience more acute problems of coastal flooding in the future.
Similar to that described for West Newport Beach, beach retreat and high water levels may cause
flooding of coastal areas and damage to infrastructure, Flooding occurs at the beach, in streets,
parking lots, and can occur at the first floor of homes. Damage to infrastructure occurs in the
form of broken windows, undermined patio foundations, damaged landscaping and hardscape,
and eventually structural damage to homes.
5.2.3 Big Corona
Other areas of the City such as the west end of Big Corona Beach do not appear to have a
flooding problem over time. The west end of the beach at Big Corona is stable and accreting.
However, the east end of Big Corona is retreating and is expected to become narrower over time.
The west end of Big Corona is predicted to remain a wide beach with little vulnerability during
storm wave events while the east end of this beach is expected to retreat. As such, flooding and
damage to the public access ramp at Inspiration Point is anticipated to occur at this beach in the
future.
Moffa/! & Nichol 76 July 2006
6.0 State of the Newport Beach Coast -Predicted Future
Conditions
Predicted future conditions at Newport Beach under the scenarios of maintaining the status quo
of beach nourishment as has historically occurred, and eliminating beach nourishment are
presented to assess future needs.
6.1 Scenario One -Future Conditions With Maintenance of Historic Beach
Nourishment Levels
Beach nourishment has occurred at all of the beaches in Newport over time. Projected future
conditions, assuming this approach continues, are described below.
6.1.1 West Newport
West Newport Beach is essentially dependent on beach nourishment to remain stable and/or
accrete. The USACE sediment budget indicates that West Newport has grown at a rate ofup to
80,000 cubic yards of sand per year from 1963 to 1995 while artificial nourishment rates were
95,000 cubic yards of sand per year. These data suggest that 15,000 cubic yards of nourishment
sand is lost from West Newport Beach. Note that the present growth trend of 80,000 cubic yards
of sand per year may actually be lower as beach nourishment rates have declined since 1992.
This means that, for an average year, if the beach nourishment rate were to drop to 15,000 cubic
yards per year, the beach growth rate would become zero and the beach would remain stable. If
the beach nourishment rate were to exceed 15,000 cubic yards per year, then the beach should
grow by the net increase in the nourishment rate above that amount. If the City determines a
desired growth rate at West Newport, this information can be used as a guideline to determine
the appropriate beach nourishment rate.
The USACE sediment budget suggests a net annual gain in beach sand volume in this area from
1967 through 1995. Without any sediment budget update, the USACE beach accretion rate is
used as the basis of this analysis, although potential loss rates discussed herein should also be
considered in ramifications of future planning, and they should also be the focus of additional
work in the future to identify the rate of sand gain or loss that occurs at West Newport on
average. The USACE numbers are skewed by large gains in the northwest reach (Peter Gadd,
Coastal Frontiers Corporation, Personal Communication, 2006).
Growth at West Newport has most discernibly occurred from Prospect Street toward the Santa
Ana River. The beach from 46th Street to the east has remained relatively narrow. Based on the
USACE sediment budget, any future accretion along West Newport would likely occur at the
west end of the beach and less, if any, would occur in the narrower portion of the groin field.
Based on the aerial photographic record throughout the period from 1963 to the present, the
reach of lower West Newport will remain similar to its present day average width if the recent
historic rates of nourishment continue.
Moffatt & Nichol 77 July 2006
6.1.2 Balboa Peninsula
Balboa Peninsula is retreating based on USACE profiles and observations made by City
lifeguards (Jim Turner and Eric Bauer, Personal Communication, 2005). The USACE sediment
budget indicates that the Peninsula is presently losing sand at a rate of 35,000 cubic yards per
year, chiefly due to sand removal of 26,000 cubic yards per year to nourish West Newport Beach
and a combination of other effects. If historic actions continue, Balboa Peninsula will continue
to retreat. If sand removal were no longer allowed, the beach would still lose sand a rate of
9,000 cubic yards per year which equals the differential between the sand loss rate and past
removal rate (35,000 cubic yards per year minus 26,000 cubic yards per year).
The sand loss rate at Balboa Peninsula based on beach width measurements taken by the City
yields an average rate of retreat of 4.8 feet per year. When applied over the 12,000 foot-long-
reach of the Peninsula and converted to a volume, the net sand loss rate is 85,000 cubic yards per
year. Assuming that 26,000 cubic yards per year is attributed to past sand removal, the net loss
rate would be 59,000 cubic yards per year (85,000 cubic yards per year minus 26,000 cubic yards
per year). The actual loss rate is likely somewhere between the rates estimated by the USACE
and from City surveys, but for purposes of this study the rate estimated by the USACE is used
for future projections.
No beach nourishment material has been placed directly along the Peninsula since 1935.
Without beach nourishment, the beach would continue to retreat at the Peninsula by at least
9,000 cubic yards per year. Applied over the 12,000 foot length of the Peninsula and converted
to a rate of beach lost, this loss rate will result in retreat of the beach of approximately 0.5 feet
per year. This rate appears to be very low compared to actual survey data. Thus, a higher rate of
3 feet per year should be used as obtained by averaging the rates from the measured data
presented in Section 4 of this report with the rate from the USACE sediment bud&<e.t,
Additionally, sea level rise could increase this retreat rate by 0.1 foot per year to 2025, 0.2 feet
per year from 2025 to 2050, and 0.4 feet per year from 2050 to 2100.
6.1.3 Big Corona
Big Corona Beach has remained fairly stable over the years along its west end. It was nourished
in 1981 with a relatively modest volume of 82,000 cubic yards of sand. The US ACE sediment
budget indicates that this beach gains a volume of3,100 cubi, yards of sand per year with a
nourishment rate of 1,000 cubic yards per year. If nourishment were to continue, this net gain in
sediment, averaged over the length of the beach of2,200 feet, would result in gradual widening
of the beach at a rate of 1.5 feet per year mainly along the western end of the beach. The east
end of this beach is expected to retreat.
The rate of widening at the west end could be offset by effects of sea level rise, while retreat at
the east end would be accelerated by sea level rise. Sea level rise could reduce the rate of beach
advance of the west end of the beach by the same factors as at Balboa Peninsula, namely 0.1 foot
per year to 2025, 0.2 feet per year from 2025 to 2050, and 0.4 feet per year from 2050 to 2100.
Beach retreat at the east end of the beach could be increased by the same amounts, respectively.
Moffatt & Nichol 78 July 2006
6.2 Scenario Two -Future Conditions Without Beach Nourishment
Although beach nourishment has occurred at all of the beaches in Newport over time, no
guarantees exist that it will be as readily available in the future. Future conditions, assuming the
possible scenario ofno beach nourishment, are described below.
6.2.1 West Newport
In the absence of beach nourishment at West Newport, the average beach retreat rate can be
estimated based on historic data. The minimum sand loss rate is 15,000 cubic yards per year
according to the sediment budget estimate by the USACE, for an average rate of beach retreat of
-1.1 feet per year. As the rate of beach changes vary throughout the groin field, these rates will
affect the area nearer to the Santa Ana River differently than the narrower portion of the groin
field. Less retreat would be expected nearer to upper West Newport and greater retreat would
occur in lower West Newport below 46th Street. The groins should slow the retreat rate, but it
would lil,ely still occur. Additionally, sea level rise could increase this retreat rate by 0.1 foot
per year to 2025, 0.2 feet per year from 2025 to 2050, and 0.4 feet per year from 2050 to 2100.
6.2.2 Balboa Peninsula
Assuming no additional sand mining or nourishment to take place along the Balboa Peninsula,
the beach will lose sand at a rate of at least 9,000 cubic yards per year and retreat at a minimum
average fate of between 0.5 and 3.0 feet per year. Sea level rise could increase this retreat rate
by 0.1 foot per year to 2025, 0.2 feet per year from 2025 to 2050, and 0.4 feet per year from 2050
to 2100.
6.2.3 Big Corona
Based on historic data, the west end of Big Corona beach will continue to accrete at a rate of
2,100 cubic yards per year in the absence of nourishment according to the sediment budget
prepared by the USACE. At this rate, the western beach will advance by an average rate of 1.0
foot per year. Sea level rise could reduce the rate of west beach advance by the same factors as
at other beaches in Newport, namely 0.1 foot per year to 2025, 0.2 feet per year from 2025 to
2050, and 0.4 feet per year from 2050 to 2100.
The east end of Big Corona Beach is expected to continue to retreat at the present rate or increase
in retreat with no nourishment. The rate of retreat,p.1~y __ a9~_e_ler_at,~_.f~()-~ __ ef:(e()t_s _9.f _~ea_ l~y~l ___ r_is_~.;._
The beach retreat rate may increase by 0.1 foot per year to 2025, 0.2 feet per year from 2025 to
2050, and 0.4 feet per year from 2050 to 2100.
Mojfi:llf & Nichol 79 July 2006
• Deleted: will likely continue to be
similar to the recent rate and
7.0 Recommended Future Actions
The City of Newport Beach has the opportunity to manage a valuable man-influenced resource to
preserve its integrity into the future. Many beaches require some maintenance to~ain sufficient_.-.. -·1c:D:..:•:..:l•=••::d::_: .::m=''::_' _____ _,
beach width for safe public use and storm protection. While significant improvements have been
constructed to reduce erosion problems along the City's coast, regular maintenance should be
considered to protect this investment. This section provides a list of recommended future actions
based on the findings of this report. Actions are categorized into the following areas:
1. Beach monitoring and measurements to improve the understanding of sand transport and
deposition;
2. Beach sand management operations to maintain a more optimal distribution: and
3. Watershed-wide planning strategies to better protect and preserve beach sand resources.
7.1 Beach Monitoring and Measurements
The rate of sand gain and loss along the City's shoreline is a result of a complex interaction of
dynamic physical processes and cannot be clearly defined. Estimates made in previous studies
are highly variable and sometimes conflicting. The most practical methods to improve the ability
to predict conditions of the beach are to systematically measure its dimensions, measure the
longshore currents that transport sand over time, and record conditions using aerial photography.
These actions should commence as soon as possible.
7.1.1 Beach and Nearshore Surveys
The City has been measuring the dry beach width and elevation on a quasi-regular basis since the
mid-1970's. The USACE ha.s measured complete beach profiles, from the dry beach out to
depths of 40 feet, along Newport Beach from 1963 through 2002. The efforts have not been
coordinated in the past, but the data are extremely valuable and should continue to be gathered in
modified form.
Complete beach profile surveys and beach width measurements should be performed regularly
and at consistent locations. With completion of their CCSTWS, the USACE may discontinue
their beach profile measurement efforts in this region, thereby requiring the City to bear the
responsibility of continuing the program. The program is invaluable as it is the only accurate
means of calculating the change in sand volume along the City's shoreline,
Beach Profile Survey Program
Beach profiles should be surveyed twice per year, in October and April, to represent fully-
developed seasonal extremes for summer and winter, respectively. Surveys should be
performed at consistent locations over time, based on sites used most recently by the City as part
of the lower Santa Ana River maintenance project. Locations of beach profiles taken in 2004
and 2005 by the City are_shown in the Table 14, with the exception ofll_\g,_Corona Beach,,~S!.h,
Moffa/I & Nichol 80 July 2006
· -I Deleted: Little
east end. These locations also correspond to USACE beach profile locations with five
exceptions that are additional locations used only by the City. Surveys should be conducted by
professional personnel familiar with ocean surveys.
Profiles should be taken at West Newport, Balboa Peninsula, and Big Corona Beach, with one
additional one added at the far east end of Big Corona Beach. Figure 3f,,,~_d_ T~bJe_ 14 identify ___ .... -·['-D_e_le_te_d_, _s ______ _
the locations of recommended beach profiles.
Table 14 -Beach Profile Locations
Profile Number Profile Location (Street lJSACE CCSTWS
And/or Beach) Designation
1 Sonora Street 639+35
2 Orange Street 648+33
3 Cedar Street 657+31
4 60th Street Not Applicable
5 54th Street 678+96
6 46th Street Not Applicable
7 38th Street 713+49
8 26th Street 741+31
9 Adams Street (Peninsula) Not Applicable
10 M Street (Peninsula) Not Applicable
II Big Corona Beach Not Applicable
12 Big Corona Beach -East End Not Applicable
Beach Width Measurements
Beach width measurements should be taken at the same locations used by the City for previous
surveys. The method can be simplified from previous efforts and not require formal topographic
surveys. Beach width measurements can be made with a measuring tape, DGPS, or similar
instrument to record the width of the J,each frm_n_ th_estreetendtoJhe_ water. These w_idth ..
measurements should be made each month to increase the frequency from historic data. Past
surveys made by topographic surveyors have provided detail and accuracy not required for this
simple effort. Greater accuracy will be provided in the semi-annual beach profile surveys.
Figure 3]._~}:lQV(S_ the)()'?_a!i9.1.1~ 9{ rep91p._11?-"e.:11:~~cl P~l:!.c_h_'!'i_~!~_ 1:n.~~s_u_r~n:ie_~t~ ~t. ~_e§t __ N"~vyJ.?qrj: _
Beach, Balboa Peninsula, and at Big Corona Beach.
Mn.flat/ & Nichol 81 July 2006
Deleted: level berm
Deleted: the break in slope toward
--{ Deleted: 6
, { Deleted: s
MDffalt & Mchn/ 82 .!uly2006
Figure 3.1 ~-Rec{)D,11:11.en~_e_d_ ~e~~l_! ~NtA Measur!!ll!en_t_l,1,1~t_i',1)!~
, { Deleted: 6
Moffa/I & Nichol 83 July2006
Beach Berm Elevation Measurements
Some beach berm (horizontal beach surface) elevations along reaches of West Newport Beach
and Balboa Peninsula are relatively high and can nuisance sand to reach street ends and
backyards. The elevation of the berm along the rear portion of the City beach should be
determined from the beach profile surveys done semi-annually to determine if it is higher than
what is needed for protection. A typical beach berm elevation at West Newport should be at
least approximately+ 14.5 feet MLLW and the berm elevation along the Peninsula should be
+ 16.3 feet MLL W to provide protection from wave run-up. Areas that exceed these elevations
could be managed as discussed in a subsequent section ofthis report. City staff indicate this
sand-moving operation occurs presently (Tom Anderson, Personal Communication, 2005). This
practice should continue and be optimized in the future.
7.1.2 Littoral Environmental Observations
Observations of currents that transport sand alongshore have been made previously by the City in
the form ofa Littoral Environmental Observation (LEO) program, and should be re-initiated
possibly in simplified form. A LEO program provides an excellent source of low-cost coastal
data that can be obtained by City staff. A LEO program involves observing waves, tides,
currents, and winds several times daily and recording the data on standardized forms. City
lifeguards performed the work as part of a LEO program for West Newport in all of 1992 and
early-1993 and at Balboa Peninsula in 1994 and a portion of 1995.
Marine Safety Officers (lifeguards) should make daily measurements of current speed and
direction, wave height and approach direction, wave period, and type of breaking wave per
directions in Everts (1996). Observations should occur at a fixed time in the morning, such as 7
AM, at seven stations shown in Figure 3Jl., Staff should note thetime _and day, and ocean
properties such as currents, waves, and other notable conditions. Current speed and direction
should be measured by timing the alongshore movement of the center ofa mass ofa small, non-
toxic dye packet thrown into the surf zone. Alternatively, staff could simply throw floats such as
a group of oranges into the surf zone and track the group'~-t!].~Y~~~l!_t _d_9~11_tb~ !i~!!cP..: _Vf~!'.e ___ _
height and approach direction should be estimated by eye at each station. Wave period should be
measured):,y __ d_o()1_1n1~[1_tj_11_g_ t_h~ _tim_eJ_eq~i_re.4. fo.~ J ~ .. ~ay_e __ c_re_sts __ t_o _ _p_a_~s __ tl: ~~~~., .. t4e..n .. 4iyi_d_i11g ~h_at
value by 10. The type of breaking wave should also be visually determined at each station.
LEO observations should be made primarily at West Newport Beach and Balboa Peninsula as
they are most vulnerable to erosion and existing data of coastal processes are least clear.
Observations could also be made at Big Corona Beach to establish a baseline of data. However,
this reach is not considered as complex a problem (sand shifting in this cell is clearer to
understand) and therefore not included here in order to better focus resources at key problem
areas. Emphasis should be placed on maintaining a regular program with a site at Newport Pier
(at a minimum) to build a better understanding of alongshore currents and sediment transport
between West Newport Beach and Balboa Peninsula.
Mojfulf & Nichol 84 July 2006
·( Deleted: 7
[ Deleted: it
• Deleted: at three equally-spaced
stations
Deleted: measur
, { Deleted: 7
The LEO program measurements should be part ofa long-term monitoring program. However,
for practical and cost considerations the full program can be implemented intermittently, such as
every other year or even every five years as long as it is conducted in a systematic fashion and
repeatable over time. The data should be recorded on a standardized form, and then entered
electronically into a commercial database (e.g., Excel spreadsheet) and filed with the City. Data
files should be regularly analyzed for trends and interpreted for management purposes.
7.1.3 Aerial Photography
Aerial photographs of the shoreline should be taken concurrent with the spring season beach
profile survey either annually or bi-annually (yearly or every other year) to provide a continuous
shoreline map between the surveyed profiles. An aerial photographic record is also useful to
detect important changes that may not be discernable by other measurements, such as effects of
the groins. The scale of the photography should be at I: 12,000 to be consistent with prior aerial
photographic missions completed by the USACE. Digital color images of the coast should be
obtained for processing and analyses. An existing aerial photographic record exists with
approximately twenty sets of images along the coast from 1966 to the present. Continuing this
record into the future would be most beneficial for long-term management of the coast.
7.1.4 Monitor and Maintain the Groins
The groins at Newport appear to be beneficial at retaining sand within the groin field for longer
than would occur in their absence. They should periodically be inspected and monitored to
identify any maintenance actions needed. Inspections can consist of observing and
photographing each groin side at low tide and noting any possible damage caused by storm
waves, and taking survey measurement points on their crests once every five years or so to
identify any settling of the groins or possible damage. A record of these data should be archived
and compared/analyzed over time to identify if any trends of groin deterioration or damage exists
that would require maintenance. Maintenance actions could range from simply replacing lost or
displaced stones, to significant rebuilding after major damage.
7.2 Beach Sand Management
A beach sand management program is critical to effectively preserve and maintain this critical
resource. The range of recommended actions varies along the City's coast, and involves moving
sand from areas where it is over-abundant and placing i!..at areas that are in need. Specific sand
management options are described as follows in order of level of effort, from least to greatest.
The objective is to first manage the existing sand volume on City beaches on an as-needed basis.
The need for additional sand to be imported from outside sourcesllwm also be necessary and_ - - - -.. _, -·-! Deleted: must also be assessed and
should be)mplemented as needed on a less frequent basis. It is noteworthy that adding sand to
the groin field area should reduce the existing hazard posed by the groins to swimmers and
surfers as sand covers more of their surface area.
Moffa/I & Nichol 86 July 2006
7.2.1 Manage the Beach Berm Elevation
The City presently manages the elevation of the beach berm along the back of the beach near
street ends and homes. This existing practice should continue with the objectives of keeping the
beach near the elevation of the street end for access to the beach by public safety and emergency
vehicles, and to minimize nuisance sand on neighboring properties.,_an? .!~_e __ ~.a.1:1? .~9r.i!r~b-~!_i9t1 !Cl
the street. The excess sand generated by this operation should be moved to fill low spots or areas
on the beach berm as presently occurs. Lowering the berm below the street end is undesirable fo~
coastal flood protection and limits the access of City police and other emergency vehicles (Tom
Anderson, Personal Communication, May 2, 2006), _
Lowering the beach berm to below the elevations of the street is not advisable so that protection
to residents is maintained under worst-case conditions. As mentioned previously, studies were
done by the USACE of wave run-up on the beach during stonn events as part of the CCSTWS.
Results show that wave run-up can reach elevations of+ 14.5 feet at West Newport Beach and
+ 16.3 feet at Balboa Peninsula during certain storms as shown in Figures 32,and :1(1,.
respectively. Their conclusions were that coastal flooding may be possible at West Newport if
the protective backshore is severely eroded during a storm event due to its relatively low
elevation, and that flooding of Balboa Peninsula was not expected due to its slightly higher
elevation.
7.2.2 Backpass Sand From Excessively Wide Reaches to Narrow Reaches of West
Newport
The beaches at West Newport west of Prospect Street are perpetually wide and possess excess
sand that could be used to nourish the narrower reaches of Newport. .&.nd backnassingshould
occur i.fthe beach is less than 250 wide between 32nd Street and 52nd Street and wider than 1Q0 -----------··--···-----·---·····-------" feet between Prospect Street and the Santa Ana River. When thi.5..9.9nd:ition exists, ~~d __ from , , "
along the mean high tide line west of Prospect Street should be removed by earthmoving
equipment and delivered to the reach of West Newport between 32nd Street and 44th Street
(assuming it will likely spread in both up-and downcoast directions), _Backxiassi.ng should occur
relatively frequently as a maintenance action such fili.:'!_n_nµ~lb;, 9~ ~t_a_ f!19~e_ a_p_prQP.!~aJ:~ fr~gl_!e_npy _
as determined by the City (e.g., bi-annually). Sand couhi,be placed withiv several groin -
compartments (e,g., two) each year. This operation should only occur during the off-season for
beach use, which in this area is typically between November and April (the winter wet season),
to minimize impacts to users and residents.
The sand should be removed from the widest reach of beach. The initial reach of sand removal
should be nearest the Santa Ana River mouth, and then progress southeast toward Prospect
Street. Sand removal should result in a relatively straight orientation of the coast from Prospect
Street to the west, rather than the existing curve of the shoreline. Sand placed between 32nd
Street and 44th Street should be placed as beach fill on the foreshore slope between the waterline
and the beach berm. It should be spread along a slope at a ratio of approximately 10: 1
(horizontal to vertical units in dimension). The objective is to widen the beach at the placement
location rather than elevating it above the existing grade. This is a sand backpassing operation
that removes the perpetual sand deposit near the Santa Ana River and uses the sand to widen the
beach along its narrowest reach. A conceptual sand bypassing plan is shown in Figure 4].. __
Moffa// & Nichol 87 July 2006
··[ Deleted:,
Deleted: , and for coastal flood
protection
• ·: Deleted: 8
Deleted: 39
Deleted: Semi-annual beach profile
surveys and annual or biannual aerial
photographs can be u~ed to quantify this
condition.
Deleted: I
Deleted: 2
Deleted:,
-Deleted: on an
Deleted: basis
_ ,[ Deleted: o _J
•
Moffa/I & Nichol
100.Vr _R:etum W•v .. ·.. . . . .. ?
I eaekinore 1
! Ell!Vatlons I , .
-..
•.•
. . -.. . .
> . 1. 1& 18
wave_·period (se<:)
lnthoft B_reakingWavea
wave period (sec)
. .
20
•+1:em,m1Jw
~+2.1m,mllw-
•+2Am;rnl~
.o-'1'2.7rn, mlt.v
*:+1,Sm,mllw •1:2, 1m; _maw ..,.+2A!Tlirnttw·
;,,· +2;.1rn; m11w
(Source: U.S. Army Corps of Engineers, 2002)
88
, , [ Deleted: 8
July 2006
Moffa/I & Nichol
•
,I; ~ er•·• i. w §.
~u I • ,.
101).yl" RetumWaVn
wave period (seo}
11\choni-Breakfns:'Wavaa
6aekshore EleVaUOOs
14 16
wave period (sec)
20
•1-um,m11w
•-+2.1m.mffw •-t2Am.mliw •+2.1m.~
1-1
•+1,ain,mltw ++2._1m,,n))~
• +2Am"m11W • +2.7m, mltw
Figure ::!Jl,_-_ Computed_ \Va_v_e _Run-U_ps_at _Ada_ms_ Street, B_albo_a_B~ach _________ . • •
(Source: U.S. Army Corps of Engineers, 2002)
89 July 2006
, -I Deleted: 39
Sand removal from near the Santa Ana River will provide for increased storage capacity for sand
at this natural staging area for future mining by the City.
7.2.3 Beach Nourishment
As the management actions above are being implemented, the City will be able to discern from
surveys, aerial photographs, and other observations whether they need nourishment from inside
and outside of the City. All evidence reviewed for this study indicates that West Newport Beach
is dependent on nourishment to exist in its present condition (being sufficiently wide to protect
backshore development from a severe storm wave event or cluster storm wave event). Therefore
it is expected that some type of outside nourishment will be required on a regular, but relatively
infrequent basis.
Sand supplies for nourishment can vary, but the most obvious large-scale local sand supply that
is available to the City is from the Santa Ana River. The Santa Ana River is the natural source of
sediment in. the region, so local beaches are compatible with this sand source. Flood control
channel maintenance operations within the Santa Ana River are required of Orange County on a
regular basis, typically every 10 to 15 years, and can provide Newport Beach with sand. Sand
from the River may need to be screened to remove rocks or debris prior to placement on the
beach. Only the highest quality sand from the River should be used, and silts, rocks, debris
should be avoided. Quality control of the high-quality sand being used should be required
through targeting only areas with high proportions of sand (e.g., trimming off top layers of silt
and using only lower layers of pure sand), making regular observations of deliveries, and
performing appropriate sampling and testing during the project. This operation should be a
controlled operation by the City, with the sand remaining along West Newport.
Other sources of sand may become available that the City may discover through notification or
research, such as sand from Talbert Marsh from maintenance clearing and restoration, sand
dredged from Newport Bay·, and sand from upland sources. Reach nourishment operations
should only occur during the off-season for beach use, typically between November and April to
minimize impacts to users and residents. The result should be a project providing maximum
benefit with minimal impact by trucking high-quality sand during the off-season.
City staff have indicated that small-scale sand sources such as from excavation for projects at
individual houses (underground parking garages) periodically become available and are accepted
for placement near the 20th Street location of the Lifeguard Headquarters (Eric Bauer, Personal
Communication, May 2, 2006). That practice should continue assuming the sand is compatible
with characteristic of the receiving beach.
West Newport Beach
The priority location for initial nourishment is between 32nd Street and 44th Street, and if the
quantity of sand to be provided is larger than the capacity of this reach, then the secondary
locations for fill are southeast to Newport Pier and northwest to 52nd Street. Sand sources
comprising relatively small quantities, such as 5,000 cubic yards or less, could be placed in front
of the Marine Safety Headquarters building for direct protection as that beach retreats and
threatens the structure. As with other sand placement scenarios discussed above, the sand should
Moffa!/ & Nichol 90 July 2006
be placed as beach fill on the foreshore slope between the waterline and the beach berm. It
should be spread along a slope at a ratio of approximately I 0: I (horizontal to vertical units in
dimension). A conceptual West Newport beach nourishment plan is shown in Figure 4-¼!J.tJc! ~-__ .-...• t~~~~d:" 1_ .. , __ , ____ ~·-.. ---~,J
typical section is shown in Figure 4.3.,.. foeleted: 2 l
Balboa Peninsula Via West Newport Beach
Sand is difficult to deliver to Balboa Peninsula as trucks have to use City streets. Therefore it is
not advisable to directly nourish the beach berm at this site from a land-based operation. Rather,
it is recommended to nourish the Peninsula with land-based sand by "over-nourishing" West
Newport and placing the sand relatively close to Newport Pier. This "feeder beach" approach
allows Balboa Peninsula to be fed by sand from West Newport, so placing a larger proportion of
sand near the Pier will result in indirect sand nourishment to the Peninsula. Sand should be
placed along the western end of West Newport Beach on the foreshore slope between the
waterline and the beach berm, and spread along a slope similar to that discussed above. Figure
41,.shows. theconcept of indirect land'.basednoudshmenttobenefitBalboa Peninsula in plan .and
profile. One other placement option for the City to consider along the Peninsula is within the
low areas of"PeanutLake" near 15th Street.
Big Corona Beach
Nourishment should occur at the east end of Big Corona Beach to fill a local area of erosion at
the foot of the public access ramp from Inspiration Point. Sand should be placed within the
"bowl" at the toe of the bluff area between the ramp end and the bluff toe on top of existing rip-
rap. Sand could be placed in a beach berm or level layer over the existing beach to partially bury
the lower portion of the ramp and the toe of the bluff. The beach at this site could be raised as
much as 5 to 10 feet. Sand placed at this site would likely move naturally to the west over time
and "feed" the rest of Big Corona Beach for an overall benefit, while providing important short-
term protection for the access ramp. Beach nourishment should be done sensitively at this site to
prevent impacts lo ru,.;ky int~rti<lal habitat to the east toward Little Corona Beach. Sand grain
sizes should be similar to the existing beach with low percentages of silts and clays to prevent
transport of finer-grained materials from the site toward the east to potentially deposit at rocky
intertidal habitat areas.
Equilibrium Beach Profile Formation
Beach nourishment should result in formation of an equilibrium beach profile over time and not
an over-elevated, over-steepened beach as Balboa Peninsula is perceived to be by some users.
The post-construction nourished beach fill profile will be steeper than the pre-construction beach
profile, but will naturally evolve toward an equilibrium average nearshore slope which is a
function of sediment and wave characteristics. The existing profile of the beach at 38th Street in
West Newport Beach between+ 12 and -10 feet MLL Wis approximately 20:1 (H:V). While the
concept design in this report specifies that construction profiles be approximately 10:1, the beach
fill will naturally disperse over a wider portion of the beach and nearshore zone resulting in a
flatter profile that varies toward the offshore area. Flattening of the slope and profile adjustment
causes reduction of the berm width from the post-construction profile. The volume of sand
within the profile may remain relatively constant, however. Natural beach profile adjustment
Moffatt & Nichol 91 July 2006
'----------~
·i Deleted: 3
from post-construction conditions is shown in Figure 4;\,_ The figur_esho\Vs a __ hypothet_ical ___ _
scenario with an existing beach profile, an as-bu'ilt constructed profile, and a subsequent natural
equilibrium profile.
The level of protection afforded by the additional beach area after natural profile adjustment may
remain approximately the same as that provided immediately after beach fill construction. This
occurs because water depths will decrease in the nearshore zone causing waves to break farther
from shore, reducing wave runup elevations at the beach from pre-project conditions.
Periodic re-grading of the post-construction beach fill may be required to minimize scarping.
Bulldozers can be used to reduce a vertical scarp, which may form as waves rework the seaward
edge of the beach fill slope. This operation is discussed in more detail in subsequent sections of
this report.
Nourishment sand will form a beach profile that is in a dynamic equilibrium of ocean forces
acting on the material and the angle of repose (slope) that the material would form if dropped
into a pile. The angle of repose is based on grain size, with relatively steeper slopes being
formed by coarser material, and relatively flatter slopes formed by finer-grained material. Using
sand that possesses grain sizes similar to that at Newport Beach would result in an equilibrium
beach profile that is similar to that at the existing beach.
Finally, placing the nourishment material in the nearshore zone in shallow ocean water off the
beach is another placement option for the City. Nearshore placement may be suitable for sand
under possible conditions of:
Sources come from submerged sites such as Newport Bay;
Sources possess a higher than desirable content of fine-grained materials (silts and
clays) for placement on the dry beach;
The quantity of beach fill material exceeds the receiving capacity of the beach
placement sites and the City wishes to not reject a portion of the opportunity; and
The City anticipates problems from construction-related disturbance ( equipment driving
on the beach) of beach fill operations that extend over time.
Mo,[fi:1// & Nichol 92 Jufy2006
·I Deleted: 4
Figure 41.:-_ S.a_n_d_ Back_p_assingPlan fo,r_ ':"_e~t l'!e,vport _______________ ,,,
, 1 Deleted: o
Moffatt & Nichol 93 July 2006
Figure 41-Concept Nourishmentplan for West Newport ,-, -[ Deleted: 1
94 July 2006
,_,,
~.--...,
::;; -~
1 u::
r:: ..,,.
! m
21) \
Etxis!i.\!l; B~a~(I
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•·-~-~u~•i~-fe~•-••·
Figure 4;J,_-, Typic_al Section of Beach NourishJDentatWest_ Newport Beach _______ _
Moffatt & Nichol 95
000
---( Deleted: 2
July2006
, -( Deleted: 3
Moffatt & Nichol 96 July 2006
Under conditions described by the third and fourth items above, the City may wish to place the
sand as a combination of onshore placement and nearshore placement. Nearshore placement
adds to the cost of placing material that is generated from the Santa Ana River or upland sources,
but it is cost~effective for placement for materials generated from submerged or submarine
sources. A concept for nearshore placement is shown in Figure 4ifQr_ W_e§t_~~~2Qr.! ~1-!4 !3,~l_b.9~ _ .-,, · -[LD-'•cc'•=••=•=• ,.:._ ______ _)
Peninsula.
7.2.4 Reduce the Beach Scarp as a Grooming Operation
Short vertical slopes (scarps) typically form along artificially nourished beaches as the
constructed beach profile readjusts to become a more natural, equilibrium profile as shown in
Figure 4g,,_ They also _f~rin uncier completely naturalc_onditions dming peri~ds of spring tides. __
Scarps formed along the length of Newport Beach should be managed at least in the areas under
the most intensive public use, including West Newport between 28th and 56'" Streets, and along
Balboa Peninsula near Balboa Pier. Earthmoving equipment should be used to flatten out the
scarp after the spring tide period ceases and tidal ranges decrease to less than six feet as
determined from a standard tidal prediction chart. Scarp maintenance may be required twice per
month, and may be most frequent or necessary after sand moving operations. Figure 47. ~_h_o¥;_S_ a
conceptual scarp management scenario.
7.3 Watershed-Wide Planning Strategies
Other actions the City can take to improve and maintain the high quality of their beach are at the
planning level. Planning strategies should be incorporated into the overall management effort to
maximize effects. One such strategy is to eliminate sand removal from Balboa Peninsula for use
elsewhere. Sand removal at the Peninsula occurred in the 1960's for nourishment West
Newport. Newport Beach depends more upon natural and artificial delivery of sand from the
Santa Ana River watershed and from updrift for beach maintenance. Existing sand at Newport
Beach needs to be preserved. Other examples of local and regional strategies are described
below. The City may generate more over time that should be added to this menu.
7.3.1 Reduce Mining Upstream in the Santa Ana River
Sand mining occurs in the Santa Ana River upstream of the coast. Contractors to the USACE
and County of Orange remove sandy material from the river bed during maintenance clearing
and haul it inland to be brokered. Sediment within the Santa Ana River channel should be able
Moffatt & Nichol 97 July 2006
·[ Deleted: 5
·I Deleted: 6
Figure 4;i.-Equilibrium Beach Profile Development , -[ Deleted: 4
Moffatt & Nichol 98 July2006
Figure 4§._--,N_earshore NourishmentPI_an_forN:ewport _Beach -{ Deleted: 5
Beach Profile 7 -38th St
20 ,---------------------------------------------------~
10 t----\-------------------------------------------------1
0
~ _, _,
~ • :_ -10
c I Profile 055_1204 .!2 • DecenJber 2004 Profile > • w -20
-301----------=------~::::::::::==-t
-40 ~-------------------------------------------------'
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Range in Feet
Moffatt & Nichol 99 July2006
.2□-r---,---~----,----,----,.~..,..,.77---,-,--,-,-,--~-,.-~.,.,,..,,..__---,~-----,.-~~-
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{ Deleted: 6
Moffatt & Niclwl 100 July2006
to eventually reach the beach, either by natural movement or human intervention. The City
should coordinate with the County and USACE during flood control maintenance operations and
strongly encourage sand retention in the river bed or removal and delivery to the coast, rather
than removal upland. Legislation is appropriate to pursue to preserve sand in the Santa Ana as a
public resource for the benefit of future generations.
7.3.2 Management Actions in the Entire Littoral Cell
Sand management throughout the Huntington Beach Littoral Cell will affect Newport Beach,
located at the downcoast end of the cell. Sand management is presently performed by the
USACE in the form of the Surfside/Sunset Beach Replenishment Project. Sand is typically
dredged offshore and placed at Surfside/Sunset Beach as a feeder for the rest of the littoral cell.
Maintaining that operation is critical for Newport Beach, so the City should be active in
overseeing federal project plans to ensure receipt of sand into perpetuity.
Also, other projects occur within the littoral cell such as restoration and maintenance ofBolsa
Chica wetlands and Huntington Beach wetlands that may affect the sand quantity passing
downcoast to Newport Beach. Both projects include mandatory sand management to prevent
sand trapping within the wetlands and adverse downcoast effects, but the City should monitor
project developments and remain informed of maintenance activities at these sites that may
affect the City's coast.
The City should participate any regional sand management efforts that occur within the local
littoral cell, and be proactive in supporting government programs that will improve sand
management such as the Coastal Sediment Management Plan. This plan is led by the USACE
and co-managed by the state of California. The plan's purpose is to enable government to
proactively manage coastal sediment. The value of the Orange County coast is sufficient to keep
the littoral cell high on the priority list for this effort. See the project website at
www.dhw.ca.gov/csmw/csmw.ht.m for more information.
M()ffall & Nichol JOI July 2006
8.0 Conclusions
The condition of the ocean coastline at Newport Beach can be maintained and further enhanced
with informed decisions and actions. This study was performed to more clearly understand the
condition of the shoreline and provide optimized management tools. Conclusions include:
_!._Erosion has occurred at Balboa Peninsula and to critical levels at West Newport in the
past. The west end of Big Corona Beach has remained stable and advanced over time,
while the east end of this beach has retreated. Significant intervention has occurred to
widen and stabilize both West Newport Beach and Balboa Peninsula. Both are now
much more stable, but are gradually retreating over f!I,rJ.fil!).,'1f_e!_iS_ c1.n_4 __ E:4v,ap.c,ip.g_9y~r .. "
llfu;,r areas.
b_Major studies show conflicting results about the loss or gain of sand at each beach and
indicate the complexity of the City's coastal system. Monitoring should occur to better
understand this coast.
L West Newport Beach retreats at a rate of 15,000 cubic yards of sand per year and requires
nourishment of that amount to remain stable. Sea level rise could cause this loss rate to
increase incrementally over the next 100 years and beyond.
:L_Balboa Peninsula retreats at a rate ofat least 9,000 cubic yards of sand per year and may
actually retreat by a much greater rate closer to between 20,000 and 50,000 cubic yards
per year. Nourishment of between I 0,000 and 50,000 cubic yards of sand per year is
required for it to remain stable. Sea level rise may cause this loss rate to increase
incrementally over time.
i_ The east end of Big Corona Beach has retreated according to observations. Strategic
placement of sand as nourishment at this location at the foot of the public access ramp is
suggested to offset future erosion and to feed the rest of this pocket beach.
£:._Urbanization, flood control, and navigation works in Southern California have interrupted
natural coastal processes and natural sources of beach quality sand have been
significantly reduced over time. This interruption of the natural processes requires coastal
jurisdictions to have to identify new sources of sand to maintain healthy beaches.
L_For management actions, the City should:
fh,_Perform beach profile surveys and beach width measurements at established
stations to document the elevation and width of the beaches over time;
LReinitiate the Littoral Environmental Observations program to quantify the
direction and magnitude of sediment transport;
£:_ Continue to manage beach berm areas and place the sand at low spots;
Q,__Backpass sand from near the Santa Ana River to between 30th and 46th Streets;
Moffa/! & Nichol 102 July 2006
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Moffat/ & Nichol
h_Nourish the beach to offset sediment losses at West Newport and Balboa
Peninsula;
f._Knock-down high beach scarps when they form; and
&_.,Participate in local, regional, state and federal coastal and watershed planning,
specifically the Surfside/Sunset Beach Project, to preserve existing sources of
sand available for the future.
!L_Consider establishing an Opportunistic Beachfill Program to capitalize on surplus
sand opportunities throughout the area as potential beachfill source material.
103 July 2006
9.0 References
Anderson, Tom. Beach Maintenance Supervisor, City of Newport Beach, Personal
Communication on December 14, 2005 and May 2, 2006.
Bauer, Eric. Newport Beach Fire Department, Lifeguard Battalion Chief, Personal
Communication on December 8 and 14, 2005, and May 2, 2006
Beach Erosion Control Board. 1938. Cooperative Beach Erosion Study, Orange County,
California. Enclosures 4 -A Study of Streams & Drainage Areas, 5 - A Study of
Wind & Weather, 7 -History of Beach Changes, 9 -Analyses of Sand Samples, and
JO-Alongshore Drift Observations. Submitted by R.L. Patterson, City of Newport
Beach to the Board of Supervisors, Orange County.
California Coastal Commission. 2001. Overview of Sea Level Rise and Some
Implications for Coastal California. Prepared by the Staff of the California Coastal
Commission. June 1, 2001.
California Data Information Program. 2006. Center for Coastal Studies, Scripps Institute
of Oceanography, URL: <http://cdip.ucsd.edu/>.
California State Department of Boating and Waterways. 2005. Coastal Sediment
Management Workgroup, URL: <www.dbw.ca.gov/csmw/csmw.htrn>.
City of Newport Beach. 2005. Beach Profile Surveys, Unpublished Data, City of
Newport Beach, Public Works Department.
Clancey, R.M., F.E. Camfield, and C. Schneider, 1983. Low-Cost Measurements of
Shoreline Change. U.S. Army Corps of Engineers, Coastal Engineering Research
Center, Vicksburg, MS, Report 83-11, pp 717-726.
Daily Pilot Newspaper. 1968. September 3 Edition.
Dunigan, Pat. 2000. A Report on Newport Peninsula Beach Surveys, 1974-1995. City of
Newport Beach, Data Updated Through May 2000, Unpublished Report.
Everts Coastal. 1995. Wave and Current Data Summary: Balboa Peninsula, Newport
Beach, California, September 1994-0ctober 1995. Unpublished Report Prepared for
the City of Newport Beach.
1996. Coast of Newport Beach: Shoreline Behavior and Coastal Processes.
1997. Sediment Budget Analysis, Dana Point to Newport Bay, California.
Report prepared for the U.S. Army Corps of Engineers, Coast of California Storm and
Tidal Wave Study, 2002.
Mo.[fall & Nichol 104 July 2006
Flick, R.E. 1998. Comparison of California Tides, Storm Surges, and Mean Sea Level
During the California El Nino Winters of 1982-83 a11d 1997-98. Shore a11d Beach,
Volume 66, number 3,
Gadd, Peter. Coastal Frontiers Corporation, Chatsworth, CA, Personal Communication
on February 24, 2006.
Gravens, Mark, 1990, Balsa Bay, California, Proposed Ocean Entrance System Study
Report 2, Comprehensive Shoreline Response Computer Simulation, Balsa Bay, CA.
U.S. Army Corps of Engineers, Coastal Engineering Research Center, Waterways
Experiment Station, Vicksburg, MS, Miscellaneous Paper CERC-89-17, pp 159, plus
appendices.
Hales, L.Z, 1980, Littoral Processes Study, Vicinity of the Santa Ana River Mouth from
Anaheim Bay to Newport Bay, California, U.S. Army Corps of Engineers Waterways
Experiment Station, Hydraulics Laboratory, Vicksburg, MS, Technical Report
HL-80-9, pp 107, plus appendices.
Interstate Electronics Corporation. 1966. Flourescent Sand Tracer Study, Orange
County, California. Unpublished Final Report Prepared for the U.S. Am1y Corps of
Engineers. March 1966.
Moffatt & Nichol Engineers, 1993, Wave and Current Data Summary, West Newport
Beach, 6 Jan 1992-5 Mar 1993, Final Report. Prepared for the City of Newport
Beach, Public Works Department.
National Oceanic and Atmospheric Administration/National Ocean Service. 2006.
Center for Operational and Oceanographic Products, URL: <http://co-
ops.nos.noaa.gov/data~res.html>.
National Research Council. 1995. Beach Nourishment and Protection. National
Academy Press, Washington, D.C.
Orange County Register. 1968. September 16, 1968 Edition,
Patterson, R,L. 1961. Engineering Report on Ordinary High Tide Line Changes Along
the Pacific Ocean Shore Line, Newport Beach, Calif0rnia, to the City Attorney.
Report dated April 19, 1961.
Seymour, Richard. 1989, Wave Observations in the Storm of 17-18 January, 1988,
Shore & Beach, Volume 57, Number 4, pp 10-13, October 1989.
Spencer, D.G. 1985. The Newport Beach Groin Field, Ora11ge County, California, pp
151-202 in California's Battered Coast, Proceedings a/Conference on Coastal
Erosion, California Coastal Commission, San Diego, February 6-8, pp 403.
Moffa/I & Nichol 105 July 2006
Turner, Jim. Lifeguard Battalion Chief, Newport Beach Fire Department, Personal
Communication on December 8 and 14, 2005.
United States Army Corps of Engineers. 1962. Beach Erosion Control Report:
Cooperative Study of the Coast of Southern Califorina, Point Conception to the
Mexican Bounda7,. U.S. Army Engineer District; Los Angeles, Los Angeles, CA,
Appendix VII, 2" Interim Report dated August 24, 1962.
---. 1969. Shore Protection Improvement; Design Memorandum/or Stage 3
Construction, Beach Stabilization with Groins and Beach Fill at Newport Beach,
Orange County, California. U.S. Army Engineer District, Los Angeles, Las Angeles,
CA, January 1969.
---. 1972. Shore Protection Improvement; Design Memorandum/or Stages 4B and
5 Construction, Beach Stabilization with Groins and Beach Fill at Newport Beach,
Orange County, California. U.S. Army Engineer District, Los Angeles, Los Angeles,
CA, March 1972.
---. 1984. Shore Protection Manual. US Anny Corps of Engineers, Waterways
Experiment Station, Vicksburg, MS.
---. 1996. Energy Flux and Longshore Transport, Orange County, Final Report
96-6. Report dated February 1996.
---. 2002, Coast of California Storm and Tidal Wave Study, South Coast Region,
Orange County. U.S. Army Engineer District, Los Angeles, Los Angeles, CA,
December 2002.
U.S. Army Corps of Engineers and California Department of Water Resources. 1966.
Inspection Tour of Shoreline, Santa Barbara to Imperial Beach. June 1966.
United States Beach Erosion Board. 1940. Report on Orange County, California.
Office of the ChiefofEngineers, War Department, January 10, 1040.
Mojfafl & Niclw/ 106 .!11/y 2006
Appendix A -Significant Events for the Coast of
Newport Beach
Moffatt & Nichol 107 July 2006
Appendix B -Aerial Photographs
Mvj}l111 & Nichol 108 July 2006
Appendix C -Newspaper Accounts of the Southern
Swell in August of 1968
Mojji:itt & Nichol 109 July 2006
Moffatt & Nichol July 2006
Moffa// & Nichol Ill July 2006
Mojfaf/ & Nichol 112 July 2006
Moffatt & Nichol 113 J11ly 2006