CC SR 20241119 01 -Landslide Emergency Extension Nov 19 2024
CITY COUNCIL MEETING DATE: 11/19/2024
AGENDA REPORT AGENDA HEADING: Regular Business
AGENDA TITLE:
Consideration and possible action on the Greater Portuguese Bend-Ancient Altamira
Landslide Complex.
RECOMMENDED COUNCIL ACTION:
(1) Receive and file an update on current activities and conditions in the Greater
Portuguese Bend-Ancient Altamira Landslide Complex;
(2) Receive and file an update on FEMA’s Voluntary Property Acquisition Buyout
Program;
(3) Receive and file an update on City expenditures for emergency protective and
stabilization measures in response to the acceleration of the Greater Portuguese
Bend-Ancient Altamira Landslide Complex;
(4) Adopt Resolution No. 2024-__, A RESOLUTION OF THE CITY COUNCIL OF THE
CITY OF RANCHO PALOS VERDES, CALIFORNIA, CONTINUING THE LOCAL
EMERGENCY DECLARATION AS ESTABLISHED BY RESOLUTION NO. 2023 -
47 ADOPTED ON OCTOBER 3, 2023 FOR AN ADDITIONAL 60 DAY PERIOD;
and
(5) Adopt Resolution No. 2024-__, A RESOLUTION OF THE CITY COUNCIL OF THE
CITY OF RANCHO PALOS VERDES, CALIFORNIA, EXTENDING THE STATE
OF LOCAL EMERGENCY WITHIN THE GEOGRAPHIC BOUNDARIES OF THE
PORTUGUESE BEND COMMUNITY ASSOCIATION, PORTUGUESE BEND
BEACH CLUB, AND SEAVIEW NEIGHBORHOODS BASED ON SUDDEN
ENERGY SHORTAGES, PLANNED DEENERGIZING EVENTS, AND INTERNET
SERVICE SHUT OFFS AS ESTABLISHED BY RESOLUTION NOS. 2024-52 AND
2024-57 FOR AN ADDITIONAL 60 DAYS.
FISCAL IMPACT: The Portuguese Bend landslide emergency response is projected to
reach approximately $43.6 million beginning in October 2022 through the fiscal year
ending June 30, 2025. The $43.6 million is funded through various sources, including the
General Fund, CIP Fund, ARPA, Supervisory Hahn’s Social Program Grant, and Metro
Funds. Of the $43.6 million, approximately $31.9 million is funded in FY 2024-25, of which
$11.4 million, or 36%, comes from the CIP Fund and General Fund reserves (see table
on following page). VR
Amount Budgeted: $31,900,000
Additional Appropriation: None
Account Number(s): $31,900,000 (see table on following page) VR
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CITYOF RANCHO PALOS VERDES
ORIGINATED BY: Ramzi Awwad, Director of Public Works
Vina Ramos, Director of Finance VR
Brandy Forbes, Director of Community Development
Katie Lozano, Open Space Manager
REVIEWED BY: Catherine Jun, Deputy City Manager
APPROVED BY: Ara Mihranian, AICP, City Manager
ATTACHED SUPPORTING DOCUMENTS:
A. Resolution No. 2024-___ Continuing Local Emergency (Page A-1)
B. Resolution No. 2024-___ Continuing Local De-energization Emergency
(Page B-1)
C. Updated Landslide Map (Page C-1)
D. Landslide Monitoring Survey Report through October 29, 2024 (Page D-1)
BACKGROUND:
On October 3, 2023, the City Council conducted a discussion regarding the conditions of
the Greater Portuguese Bend Landslide Complex, sometimes called the Ancient Altamira
Landslide Complex (Landslide Complex). After considering information presented that
evening, including public testimony, the City Council unanimously adopted Resolution No.
2023-47 declaring the existence of a local emergency within the geographic boundaries
of the Landslide Complex and adopted Urgency Ordinance No. 674U to establish a 45-
day moratorium on the acceptance or processing of applications, issuance of permits,
and construction of all structures within the Landslide Complex (Moratorium).
The City Council also requested Staff return in a few weeks with an update on immediate
measures being taken to address the accelerated land movement. At subsequent
meetings, the City Council received updates on conditions in the Landslide Complex as
well as measures underway by various entities to reduce landslide movement . In
response, the City Council extended the local emergency on multiple occasions.
On March 19, 2024, the City Council approved moving forward with emergency work in
the Portuguese Bend Landslide (PBL) consisting of installing two emergency hydrauger
Funding Sources FY 2024-25 TOTAL
In Millions
CIP Fund 10.1
CIP Fund (Reserves)5.0
General Fund 3.4
General Fund (Reserves) 6.4
ARPA Fund 3.4
Metro Funds 1.4
Sup. Hahn's Social Program Grant 2.2
TOTAL $31.9
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systems with five drain arrays each and associated work. On May 7, 2024, the City
Council awarded contracts for construction of the emergency hydraugers and associated
professional services such as engineering and construction management.
The emergency hydraugers were preceded by vertical test boreholes to obtain current
underground condition data and confirm models developed from historical studies. This
was done to avoid expending significant funds on hydraugers only for them to prove
ineffective because they do not target the correct depth or do not extract water due to
particular soil conditions.
The test boreholes revealed that the deeper slip surface (Altamira slip surface) was
activated and found it to be moving at a much faster rate than the shallow PBL slip
surface. Based on those results, it was also likely that the Klondike Canyon Landslide
(KCL) and Abalone Cove Landslide (ACL) were being affected by the deep slip surface.
Additionally, the test boreholes confirmed that artesian water pressure is present in the
lower reaches of the PBL, and confined water is present within the PBL slide surface and
also within and below the Altamira slide surface and the PBL slide surface . This creates
artesian pressure on the PBL and Altamira slide surface.
The confirmed activation of the deeper slip surface where the greatest movement is
occurring represented a significant change in conditions and required changing the
emergency stabilization strategy in response to the new information. Accordingly, on
August 20, 2024, the City Council authorized alternative solutions including deep
dewatering wells (DDWs). Although hydraugers may be part of the long-term strategy;
they will be secondary to the immediate stabilization and protection measures.
On October 1, 2024, the City Council authorized an expansion of the DDW program to
the Abalone Cove area, with associated test boreholes and monitoring wells, and
appropriated $4 million for this work. Additionally, the City Council authorized a
winterization program on City-owned property in the Landslide Complex without waiving
the Abalone Cove Landslide Hazard Abatement District’s (ACLAD) and Klondike Canyon
Landslide Hazard Abatement District’s (KCLAD) responsibilities as identified in their plans
of control; and appropriated $4 million for this work.
Tonight, the City Council is being asked to receive and file an update on activities and
conditions in the Landslide Complex including the latest on the DDWs, as well as consider
adopting two resolutions to extend the state of local emergency within the Landslide
Complex based on those conditions.
DISCUSSION:
1. Current Activities and Conditions
Deep Dewatering Wells
The City installed six DDWs (DDWs 1-6) at the toe of the landslide near the Portuguese
Bend Beach Club and began extracting water from those DDWs sequentially beginning
on September 13. Table 1 shows the dates of installation and water extraction rates for
DDWs 1-6.
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Table 1: DDWs 1-6 Installation Dates and Initial Water Extraction Rates
DDW No. Date Operational Initial Approximate Water Extraction
Rate (Gallons Per Minute)
1 09/13/24 (Partial)
09/19/24 Fully
90
115
2 09/17/24 (Partial)
09/23/24 Fully
100
115
3 09/21/24 120
4 09/21/24 75
5 09/25/24 120
6 09/28/24 (Partial)
10/02/24
45
80
Total 625
DDW1 through DDW6 are currently extracting water at a combined rate of approximately
575 gallons per minute, a slight decrease from the initial rates that is not unexpected
considering the amount of water extraction since the wells began operating.
GPS surveying of land movement showed that land movement in the vicinity of the DDWs
had slowed at a much higher rate than land movement in other areas of the Landslide
Complex due to several months of dry weather and dewatering efforts by KCLAD. Data
from underground monitoring instruments showed a reduction in water pressure,
correlating the reduction in land movement to the reduction in water pressure.
Additionally, the project team expected the six DDWs to each shear within one week of
installation due to the rate of movement of the deep slide; however, after over a month
since installation, only DDW1 is showing signs of pinching, although it is still extracting
water at close to the same rate as when it was originally installed.
Based on the effectiveness of the first six DDWs, an additional two DDWs (DDWs 7&8)
were installed. These were installed near Palos Verdes Drive South (PVDS); one a few
hundred feet east of Peppertree Drive and one at the Archery Range Road. Table 2 shows
the dates of installation and water extraction rates for DDWs 7&8.
Table 2: DDWs 7&8 Installation Dates and Initial Water Extraction Rates
DDW No. Date Operational Initial Approximate Water Extraction
Rate (Gallons Per Minute)
7 10/15/24 20
8 10/17/24 90
Total 110
DDWs 7 & 8 are currently extracting water at a combined rate of approximately 110
gallons per minute.
On October 1, 2024, the City Council also authorized expanding the DDW program to the
Abalone Cove area including funding sufficient for three additional DDWs along with test
boreholes and monitoring wells as needed. As of the date of publication of this staff report,
two of those additional DDWs (DDWs 9&10) have been installed. Table 3 on the following
page shows the dates of installation and initial water extraction rates for DDWs 9&10.
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Table 3: DDWs 9&10 Installation Dates and Initial Water Extraction Rates
DDW No. Date Operational Initial Approximate Water Extraction
Rate (Gallons Per Minute)
9 10/25/24 40
10 10/24/24 115
Total 155
DDW9 sheared on November 7, 2024 and is no longer extracting water. The Project
Geologists, Geo-Logic Associates, Inc. (Geo-Logic), proposed a new site for DDW9,
named DDW9A, where it is more likely to extract a larger amount of water and therefore
survive for a longer duration. DDW10 is continuing to extract water at a rate of
approximately 115 gallons per minute.
Work is nearly complete for the items funded by the City Council on October 1, 2024. The
remaining work is one additional test borehole, installation of DDW11, and the re-
installation of DDW9 as DDW9A. The installation of DDW11 has taken longer than
anticipated because the originally envisioned access, through Olmsted Trail, has proven
more challenging than expected due to land movement. Access improvements are in
progress and alternate routes are being investigated as a backup. Staff expects the
installation of DDW9A to be complete by November 18, 2024, and the remaining test
borehole to be complete by the end of November 2024. The installation of DDW11 is
expected to be completed by early December 2024, depending on access.
Figure 1 on the following page shows the location of the DDWs, test boreholes, and
monitoring wells. Table 4 on the following page shows the current water extraction rates
of each DDW.
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Figure 1: Deep Dewatering Wells
Table 4: DDW Current Water Extraction Rates
DDW No. Current Approximate Water Extraction
Rate (Gallons Per Minute)
1 90
2 110
3 90
4 80
5 110
6 90
7 20
8 90
9 0
10 115
Total 795
As of the date of publication of this staff report, the total combined water extraction rate
of DDWs 1 through 10 is currently approximately 795 gallons per minute or approximately
1.15 million gallons per day. Since the start of the DDW program, approximately 40 million
gallons, or approximately 125 acre-feet, of water have been extracted from certain
locations of the toe of Landslide Complex.
To assess the effectiveness of the DDW program, a survey of a select sample of surface
monitoring points at the toe of the landslide is being conducted on an approximately
weekly basis using Global Positioning System (GPS) surveying. Figure 2 on the following
page presents the results of the weekly GPS surveying as of November 5, 2024.
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N
·4·
s
0 500 1,000 2,000
t--+---1---1---1---+---t Feet
-Layer Oedls: Los Angeles County Public Woru, City of Rancho Palos Verdes Public -c.ltrons.-
,.a
E-1-JC ,,.
E-1-3B
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Dewate ring & Bore hole Programs -All Lo cations
Dewatering Wells Boreholes
• Decommissioned ■ completed
• Completed ■ Proposed
6 In Progress
• Proposed
Figure 2: GPS Survey Movement Rates of Sample Points: Sept 4, 2024 to Nov 5, 2024 (in. / week)
To establish a baseline rate of movement, a survey of the select sample of surface
monitoring points was conducted on September 4, 2024. This survey showed that the
rate of movement at the toe of the Landslide Complex decreased over the summer
months compared to the spring months. Between September 4, 2024 and November 5,
2024, the rate of movement in the vicinity of DDWs 1-8 decreased by over 30% more
than the rate of movement away from the DDWs.
The four sample points in the Seaview and Portuguese Bend Beach Club (PBBC)
neighborhoods have shown no movement for four consecutive surveys (October 13,
October 20, October 29, and Nov 5, 2024). Cessation of movement within the KCL is a
direct response to the DDW program, in conjunction with the KCLAD dewatering wells,
which have been extracting water longer than the DDWs.
Extraction of water from DDWs 9&10 does appear to correlate with some possible
reduction in ground movement of nearby surface survey monuments within the toe region
of the ACL; which are moving at a slower rate than monuments further up in the middle
and upper portions of the ACL. However, the effectiveness of the additional DDWs
authorized by the City Council on October 1, 2024 can be better evaluated after DDW9A
and DDW11 are installed and monitored for at least a few weeks.
In addition to the select sample of GPS survey monitoring points show ing a very strong
correlation between water extraction and a decrease in the rate of surface movement, the
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Survey Points w i t hin
dose proximit y of
Dewatering Wells
groundwater monitoring wells within the DDW areas have shown a significant decrease
in water pressure (the main driving force of landslide movement). The GPS survey data
for the select sample of points will continue to be collected on an approximately weekly
basis to continue to monitor this trend.
The project team expected each DDW to shear within one week due to the rate of
movement of the deep slide. However, at the time of publication of this staff report, only
DDW9 has sheared. DDW1 has shown signs of pinching, although it continues to extract
water at a comparable rate to the other DDWs in its vicinity (DDW 1 was installed on
September 13, 2024). This further confirms the apparent effectiveness of the DDW
program. Each DDW is still expected to shear at some point, and will need to be redrilled
to continue to extract water at an estimated cost of approximately $125,000 per DDW.
The DDWs are being monitored and plans are in place to re-drill them as they shear,
using funding already appropriated by the City Council through at least December 31,
2024.
Staff recommends continuing to implement the DDW program in a staged approach and
based on available resources. Should DDW 9-11 show effective results, Geo-Logic will
likely recommend, at a later time, approximately five more DDWs in the Sacred Cove area
applying a similar concept as that used in the PBBC area.
Depending on current outcomes, a full de-watering build-out is currently being explored
by Geo-Logic which may consist of two additional phases beyond the proposed band of
DDWs at the toe of the landslide. The second phase may include a band of approximately
15 DDWs landward of PVDS. The second band of DDWs is likely to be primarily ACLAD
dewatering wells, with some possible City DDWs depending on proposed locations and
targets of the DDWs. A second phase is being explored because the DDWs at the toe of
the slide are too far to quickly and significantly reduce water pressure and movement at
higher elevations within the Landslide Complex. A third and final phase of de-watering is
also being explored consisting of the installation of hydraugers along with long-term
drainage improvements as originally envisioned in the Portuguese Bend Landslide
Remediation Project. This third phase is envisioned to be part of the re-scoped project
funded by the Federal Emergency Management Agency’s (FEMA) Building Resilient
Infrastructure and Communities (BRIC) grant.
Emergency Stabilization Measures – Winterization
On October 1, 2024, the City Council authorized the winterization of the Landslide
Complex on City property which included funding for filling and lining of fissures in six
canyons as well as the Seaview neighborhood, among other work. Figure 2 on the
following page shows the primary locations of winterization work.
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Figure 2: Winterization Program
Re-grading and shaping of Altamira Canyon is complete. The installation of a pond liner
has started and is expected to be complete by the end of the week of November 18, 2024.
Winterization of Kelvin Canyon is scheduled to start within two weeks and be completed
by the end of December 2024.
Crews are scheduled to mobilize for winterization work on Portuguese, Ishibashi, and
Paintbrush Canyons within two weeks. The work is expected to be completed by the end
of December 2024.
Winterization work on Klondike Canyon has started and is expected to be completed by
the end of November 2024. Crews will fill fissures and install a pond liner in Klondike
Canyon from the City border with Rolling Hills to Palos Verdes Drive South (PVDS). A
temporary pipe will be installed connecting to the existing pipe at the gabion wall in
Klondike Canyon that connects to the overflow inlet at the bottom of the canyon, which
will convey water under PVDS. KCLAD will repair and/or install any additional needed
drainage features to further convey water to the ocean.
Work on the graben at the intersection of Dauntless Drive and Exultant Drive has started
and is expected to be complete by the end of November 2024. The work consists of
shaping surface water runoff into the graben and installing a cap of approximately 6 to 12
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1 • Altam ira Canyon 3 • Klondike Canyon
-Canyon grading & liner at base
-Fill ing fissures and grabens in nearby areas 4 • Seaview Community
-Street re -grading & re-surfac ing : Exultant & Admirable Drive
2 • Portuguese, lshibashl, Paintbrush Canyons -Exultant & Dauntless protect ive measures
inches of an impermeable slurry material, with pumps at the low points to convey the
water further down Dauntless Drive away from graben s and fissures towards the natural
course of street drainage (the street will be inspected for cracks to ensure water runoff
does not percolate into the ground).
Re-grading and filling of the fissure on Exultant Drive has started and work is expected to
be completed by the end of November 2024. The roadway elevation will be raised at the
graben so that there is a downward slope through the area where surface runoff can drain
down Exultant Drive to Schooner Drive. Filling of the smaller fissures on Admirable Drive
and on PVDS will follow.
Drainage pipes in the Seaview neighborhood and along PVDS are being assessed. Some
pipes along PVDS are known to be damaged and plans to convey water are being
developed.
The cost of the work will not exceed the City Council authorization of $4 million; however,
the cost of winterizing some canyons may be more than originally estimated whereas
others may be less than originally anticipated.
Geologic Conditions
The Landslide Complex encompasses four historically active landslide areas in the City:
the PBL, the ACL, the KCL, and the Beach Club Landslide (BCL). However, it also
includes areas outside of the City’s historical boundaries of those known landslides,
predominantly uphill from the PBL and ACL, within the Landslide Complex as mapped by
various agencies (i.e., U.S. Geological Survey and California Geological Survey) and
other researchers.
Since the October 1, 2024 update to the City Council, the City Geologist, Mike Phipps of
CSA conducted additional field mapping throughout the Landslide Complex; observed
conditions at various site-specific locations impacting residential neighborhoods, public
infrastructure, and where trails have been impacted; reviewed additional survey data;
participated in the weekly Portuguese Bend Landslide Complex Working Group,
Community Stakeholders, and Q&A meetings; and conducted site-visits and data review
for the boreholes being installed in advance of the emergency stabilization measures.
The City Geologist is reporting that rainfall and the resulting runoff and infiltration into the
Landslide Complex continues to adversely affect the landslide area, following a
significantly wetter than average rainy season in 2022-23 and 2023-24; which were
approximately 193% and 170% of the season average over the past 67 years of the
Rolling Hills Fire Station rain gauge, respectively. Only 0.07 inches of rain has fallen over
the past 6 months; therefore, the adverse effects of the season’s rainfall are now
manifested as increased groundwater pressures within and beneath the landslide.
Recent GPS survey data published by McGee Surveying Consulting for the approximately
“monthly” monitoring periods of September 4 through October 8 and October 8 through
October 29, 2024 were reviewed and analyzed (Attachment D). For all points monitored
across the entire Landslide Complex, following are the key conclusions over the past
approximately 8 weeks (55 days):
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• Overall average movement velocity decelerated 76%, with a range of 44% to
100% deceleration. Average movement velocity across the entire Landslide
Complex was 3.3 inches per week, as of October 29, 2024. These numbers are
largely influenced by cessation of movement of the Klondike Canyon Landslide by
mid October.
• The ACL (within historical boundaries) decelerated 46% and had actual land
movement of between 2.9 and 4.6 feet over the 55 days
• The greater ACL (within the Altamira Landslide Complex boundaries) decelerated
approximately 29% and had actual land movement of between 2.1 to 4.5 feet over
the 55 days.
• The PBL decelerated approximately 75.3% and had actual land movement of
between approximately 1.5 to 3.95 feet over the past 55 days. The deceleration is
greatest in the lower portion of the landslide where significant dewatering is
occurring through deep pumping wells.
• The KCL decelerated 100% and horizontal land movement has ceased over the
past 55 days. Interim monitoring performed for the dewatering program suggests
the horizontal movement ceased as of October 13, 2024; however, minor vertical
movements (typically less than 0.10 feet) were observed through October 29,
2024.
• The Burma Road switchback points which were previously creeping southwesterly
approximately 0.5 inches/week through September 4, 2024 have ceased moving
as of October 29, 2024.
• Perimeter points that have been historically stable are not moving, indicating that
the areas outside the mapped landslide boundaries are currently unchanged.
• New points that were established on Schooner Drive in the Seaview neighborhood
in August to assess and affirm the limits of the Landslide Complex continue to be
stable.
Over the past approximately 8 weeks, land movement rates (velocities) in the Landslide
Complex have decelerated to a rate of about 3.5 to 5.5 inches per week in the ACL, and
about 0.5 to 3.5 inches per week in the PBL. The KCL has stopped moving. Attachment
C presents the GPS monitoring data graphically. Figures 3-6 of Attachment C present
scaled displacement rates (i.e., movement velocities) and vectors, and contour maps (aka
“heat maps”) of displacement rates for the August 1, September 4, October 8 and October
29 full monitoring periods. These plots dramatically illustrate the decline in movement
rate, particularly in areas where deep dewatering wells have been installed. The largest
decelerations are noted to be in the lower and eastern portion of the PBL and the entire
KCL, the latter of which has stopped moving. The fastest moving areas are now the upper
portion of the ACL (historical boundary) and in the ancient “Altamira” complex behind the
ACL, at >5 inches per week.
The past year has been marked by a significant and unprecedented change in movement
behavior from historical movements of the PBL, ACL and KCL. The entire active
Landslide Complex (area of major land movement now evident at the ground surface)
continues to represent an expansion of the combined historical boundaries of the
ACL/PBL/KCL of about 380 acres to an estimated 700 acres in size within the Altamira
Landslide Complex.
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Creep movement that was occurring on the Burma Road switchbacks between Kelvin
Canyon and Portuguese Canyon has ceased or is below instrument precision; however,
the past movement of this area since early summer likely contributed to a recent water
line break near the upper Burma Road water tank at the beginning of this month.
No additional GPS data for previously reported land movement in Rolling Hills have been
received. However, new GPS points added to RPV’s network north of Burma Road
between Portuguese Canyon and Paintbrush Canyon (CR58 and CR59) are not moving
or are below instrument precision. This, coupled with a lack of movement of GPS points
CW06 and FT10 along Burma Road suggests that the previously reported Rolling Hills
land movement may be isolated and may not be directly connected to the Altamira
Landslide Complex movement. Further evaluation is needed in this area in order to draw
firm conclusions.
Landslide movement within the Landslide Complex continues to manifest at the ground
surface in the form of scarps, fissures, grabens/sinkholes, tensional cracking, shear
zones and thrust features. Deceleration of the Landslide Complex has generally reduced
the rate of expansion or growth of these features and efforts are now being made to
winterize many of these features across the landslide area prior to the rainy season.
Movement along the westerly boundary of the active Landslide Complex in the ACL area
through the Wayfarer’s Chapel property appears to be daylighting through the slope
between Wayfarer’s Chapel and the westbound lanes of PVDS. Solutions to protect
roadway from sloughing landslide debris are continuing to be evaluated by the Wayfarer’s
Chapel board, City Geologist, and Public Works Department.
Road conditions on PVDS across the lower landslide complex continue to be adversely
impacted due to differential rates of land movement currently ranging from about 0 to 5.5
inches per week across the breadth of the Landslide Complex .
In summary, the average movement velocity for the Altamira Landslide Complex has now
decelerated an additional 76% since September 4, 2024. Factoring out the KCL which
has stopped moving, the remaining active landslide area has decelerated an additional
63% since September 4, 2024. The landslide complex as a whole is still moving
approximately 25 times faster than in October 2022. The land movement continues to
significantly impact trails and open space areas, public and private roads, and private
property including 18 red-tagged residential structures and 38 yellow-tagged residential
structures, as well as utility infrastructure.
The City Geologist will be attending the November 19 meeting to provide the City Council
and public with an updated report since the October 1 meeting.
Open Space, Palos Verdes Nature Preserve, Trails, and Beach Conditions
Much of the Portuguese Bend, Filiorum, Abalone Cove, and Forrestal Reserves
(subareas of the Palos Verdes Nature Preserve), the open space area commonly referred
to as the Archery Range (east of Portuguese Point), and Abalone Cove Beach, Sacred
Cove Beach, and the beach below the archery range are located within the Landslide
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Complex and are sustaining substantial landslide-related damage including fissures,
rockslides, sink holes, unstable trails, and large-scale erosion.
On November 2, 2024, a CalWater break caused severe damage to upper Burma Road
Trail and surrounding areas, necessitating the closures of upper Portuguese Bend and
Filiorum Reserves. With this new additional damage, all of the Portuguese Bend Reserve
and upper Filiorum are now temporarily closed until repairs can be made. Additionally,
land movement had previously obliterated most of Burma Road Trail, which is no longer
accessible by vehicle or safely passable by the public. Numerous other damaged trails
within Portuguese Bend, Filiorum, Abalone Cove, and Forrestal Reserves continue to
experience increased damage and elevation changes and further widening of fissures.
In July, the City temporarily closed the Abalone Cove and Sacred Cove Beach access
trails and the beaches themselves due to land movement -related conditions. On
September 27, the City additionally temporarily closed the open space area commonly
referred to as the “Archery Range” and the beach below the Archery Range due to land
movement-related conditions. In October, the City temporarily closed Eucalyptus, Kelvin
Canyon, part of Zote’s Cutacross, and Rattlesnake Trails, because these trails are in
close proximity to the winterization project in Filiorum Reserve and will not be safe to
access during the project’s duration.
In summary, out of concern for public safety and in consultation with the City Geologist,
the City Manager has temporarily closed large areas of the Preserve and open space
areas consisting of approximately 16 miles of passive recreation trails. The City Manager
has also closed Abalone Cove Beach, Sacred Cove Beach, and the beach below the
Archery Range in close coordination with the City Geologist, Los Angeles County
Lifeguards, and the California Coastal Commission. Staff continue to monitor these and
other areas, and extensive repairs will likely be needed before these trails can be
reopened for public use after the area has been stabilized.
Natural Gas
On July 29, 2024, Southern California Gas Company (SoCalGas) shut off natural gas to
the PBCA; stating that engineers determined the system could no longer be safely
operated due to a confluence of issues such as excessive breaks, lines suspended in the
air, and swing joints in tension.
On August 30 and September 6, 2024, SoCalGas shut off natural gas to the part of the
Seaview neighborhood affected by land movement for the same reasons noted above.
On August 2, 2024, SoCalGas began installing isolation valves to create multiple shut-off
points, so that if service needs to be shut off for a short-term repair or for long-term
reasons, the number of homes impacted would be significantly reduced. The installation
was completed, separating homes west of Schooner Drive from those east of Schooner
Drive, and separating the gas lines west of Schooner on a street-by-street basis.
On September 6, 2024, SoCalGas shut off natural gas to the PBBC community for the
same reasons noted above. SoCalGas has stated that re-routing gas lines supplying the
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neighborhoods experiencing shutoffs would not resolve the problems with the system
within the neighborhood.
On October 21, 2024, the City Manager and Public Works Director met with Transtech
Engineers, Cotton Shires & Associates, and SoCalGas to enhance coordination efforts
for service restoration in response to recent movement data trends. The meeting s
focused on updates regarding progress, service restoration efforts, and strategies for both
short- and long-term risk management with an emphasis on restoring gas to the Seaview
and PBBC neighborhoods due to recent GPS data previously discussed in this report .
Discussions emphasized monitoring, safety protocols, and the development of long-term
strategies for stabilization. SoCal Gas emphasized the priority of safety in determining
when gas service could be restored, with a focus on monitoring pipeline strain limits.
The team explored scenarios for safely restoring service to neighborhoods while
maintaining the ability to shut off gas services if land movement resumes. One challenge
identified by SoCalGas was assessing the integrity of underground pipelines, which have
accumulated strain over time, and considering temporary above -ground piping solutions
as needed.
Data sharing and monitoring plans were discussed to ensure alignment between the City
and SoCalGas. Both parties agreed to collaborate on refining monitoring protocols.
Regular data sharing will help establish thresholds for safely restoring utilities. Spe cific
monitoring points were also discussed to generate actionable data for future decision -
making.
The potential impact of heavy rainfall on land movement was a concern raised during the
meeting. SoCalGas stressed the importance of monitoring stability through the rainy
season before fully restoring service. In response, the City is developing a plan to collect
data during the rainy season for use in assessing future risk.
As part of the next steps, the teams agreed to review additional data over the coming
weeks and reconvene in November to assess progress and plan the path forward. A
single point of contact will be designated to streamline data sharing between the City and
SoCalGas.
The meeting concluded with both the City and SoCalGas recognizing the importance of
continued monitoring and analysis. The focus remains on balancing safety with the goal
of restoring utilities, with conditions to be reassessed following the winter season.
On November 11, 2024, the City Manager and Public Works Director reconvened with
representatives from Transtech Engineers, Cotton Shires & Associates, and SoCalGas
to discuss ongoing efforts and progress for reinstating gas service to the affected
communities, particularly the PBBC and Seaview communities, where there has been no
recorded land movement for four consecutive GPS surveys.
SoCalGas reported that while significant efforts have been made, they are not yet in a
position to restore service due to safety concerns that involve potential pipeline strain,
leaks, or damage that could lead to fires or other hazardous incidents. While some areas
have shown reduced or no land movement, SoCalGas continues to conduct detailed
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system integrity assessments to determine the feasibility of safe restoration outlining that
existing infrastructure strain and potential residual stress on pipelines pose additional
risks, requiring detailed assessments and mitigation strategies.
SoCalGas highlighted the complexity of the restoration process, which involves multiple
steps such as performing system integrity tests and ensuring safe re -pressurization and
re-connection of the pipeline system. Despite the challenges, SoCalGas is exploring a
phased approach, potentially restoring service incrementally. Proposed solutions include
the use of advanced safety measures, such as valves and swing joints, to mitigate
potential hazards.
The City emphasized its commitment to supporting the process by expediting permits and
offering resources as needed. To assist with prioritization, the City will share updated data
on affected properties, including red- and yellow-tagged homes. This collaboration aims
to identify opportunities for safe and efficient phased restoration.
SoCalGas will continue testing and developing solutions while maintaining open
communication with the City. A follow-up meeting is scheduled for two weeks, although
SoCalGas agreed to reconvene sooner if partial restoration becomes feasible prior to the
next scheduled meeting. Both the City and SoCalGas expressed a shared urgency to
address community concerns and expedite the process while ensuring the safety and
reliability of the infrastructure for all affected residents.
Electricity
On August 31, 2024, Southern California Edison (SCE) notified 193 metered accounts
(which equates to approximately 140 households and 53 business or city accounts) in the
PBCA that power will be turned off to their property on September 1, 2024 for an indefinite
period of time. SCE stated that the accounts will not be reenergized until land movement
is controlled to a level acceptable to SCE, without specifying the threshold of land
movement. The power shut off not only affects residents in the PBCA, but also the ability
to power the City’s sewer system in the area and the ACLAD’s dewatering wells.
SCE issued a further notice that on September 2, 2024, homes in the Seaview
neighborhood would be subject to the following service shut -offs: 75 properties will be
deenergized for varying hours ranging from 24 hours to 1-3 weeks while a box loop is
constructed and 30 properties will be deenergized indefinitely. This was done to prevent
the risk of wildfires from equipment damaged by the land movement.
On September 6, 2024, SCE notified customers that power would be shut off in the PBBC
neighborhood. SCE followed through, de-energizing the area on September 9th.
Also, on September 9, 2024, SCE restored power to the 38 properties that had been
planned to be without electricity for 1-3 weeks. At this time, 30 properties remain without
electricity in Seaview.
On October 21, 2024, the City Manager and Public Works Director met with
representatives from Transtech Engineers, Cotton Shires & Associates, and SCE to
address power disruptions, infrastructure challenges, and explore potential solutions to
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support re-energization efforts in response to recent land movement data trends. Like the
meeting with SoCalGas, the focus was on updates regarding progress, re-energization
efforts, and strategies for managing both short- and long-term risks.
SCE presented its re-energization plan, prioritizing areas where land movement has
decreased. The initial phase involved restoring power to 16 customers located primarily
on Fruit Tree Road, Plumtree Road, and Narcissa Drive in the western portion of the
Landslide Complex.
A key topic of discussion was the importance of aligning land survey data with
infrastructure assessments to ensure re-energization efforts are conducted safely and
effectively. SCE emphasized that its ability to design a system to restore power to
impacted customers depends on the collection of data that consistently demonstrates
land stability over time. The City offered to prioritize ongoing monitoring in areas that will
further support re-energization and service restoration efforts.
SCE will continue to evaluate conditions and explore alternative methods to enable safe
power restoration. As part of this effort, the City will collaborate with SCE to share land
movement trends, noting that some areas have consistently returned to pre-2023 levels.
To support long-term solutions, SCE announced the establishment of a Project
Management Office (PMO) structure to provide sustained oversight and coordination.
This structure will focus on developing engineering strategies such as tension relief
systems and exploring the potential use of microgrid applications. Both short - and long-
term strategies are being developed to address risks, particularly with the approaching
winter rains, which could introduce additional challenges.
Future meetings were scheduled to maintain progress, including technical discussions
with geologists to refine mitigation strategies. The meeting concluded with participants
reaffirming their commitment to collaboration and ongoing efforts to restore power safely
while ensuring the long-term stability of the area’s infrastructure.
Sanitary Sewer
The sanitary sewer system in the PBCA is known as the Abalone Cove Sanitary Sewer
System and is owned, maintained, and operated by the City. The system includes grinder
pumps that pump wastewater from individual buildings to the main sewer lines at
approximately 40 locations where buildings are at a lower grade than the main sewer
lines, requiring pumping to overcome the grade . The system also includes four pump
stations that receive wastewater from low-lying areas and pump it up to higher elevations
where it can continue to flow via gravity. The grinder pumps and pump stations require
power to operate.
Crews continue to regularly inspect the sewer lines and make repairs as breaks are
identified through inspections or resident notification. Parts of the system have been
brought above ground and have had flexible components installed. Engineers continue
to evaluate the system to determine where additional sections need to be brought above
ground or otherwise modified.
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The sanitary sewer system in the Seaview neighborhood is maintained and operated by
the Los Angeles County Public Works (LACPW), which has been inspecting the sewer
system in areas affected by the landslide and performing repairs when needed. No recent
damage has been observed to the sanitary sewer mains in the Seaview neighborhood
and accordingly no repairs have recently been made. LACPW continues to conduct
regular inspections.
The sanitary sewer system in the PBBC is privately owned, operated, and maintained
and discharges into the Los Angeles County Sanitation Districts (LA CSD) sewer trunk
line on PVDS. LACSD have been coordinating with the PBBC, so that the sewer line
integrity is maintained. It should be noted that this sanitary sewer system is also powered
by SCE.
The sanitary sewer trunk lines adjacent to PVDS are owned, maintained, and operated
by the Los Angeles County Sanitation Districts (San Districts). Work to bring underground
sections of the sewer trunk above ground is now complete. Additional improvements to
increase resiliency of the sewer trunk lines are being considered by San Districts.
Water
On November 2, 2024, a CalWater break was reported by area residents. CalWater
responded to the break and made repairs. Staff have requested a written report from
CalWater detailing the event including, at a minimum, the time that the break was known
to have occurred, the time water discharge stopped, and the amount of water that was
discharged.
The City Geologist opined that this water main break may have been caused by the
accumulation of slow movement in this area over a number of months. The July 1, 2024
GPS survey data showed movement at a rate of approximately 0.14 to 0.19 feet per
month in that area. The cumulative movement of approximately six inches may have
contributed to the water main break. Staff are scheduling a meeting with CalWater to
better assess the conditions surrounding this incident. Additionally, Staff will seek to
understand the water distribution system vulnerabilities in this area and discuss actions
that may mitigate those vulnerabilities.
In other areas, Cal Water continues to install above ground water lines to minimize the
risk of breaks associated with land movement.
Cal Water is preforming water quality testing at the above ground line at the five-point
intersection of Narcissa Drive, Cinnamon Lane, Ginger Root Lane. The water line is
expected to be in service once water quality testing has been completed. Exhibit 1 on the
following page shows the water quality testing.
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Exhibit 1: Water Quality Testing Location at Five-Point Intersection
Cal Water continues to work on bringing additional water lines above ground throughout
the PBCA. They have recently completed the tie-in of the above ground water line along
Narcissa Drive to the water line on Palos Verdes Drive South.
Communications
There are two providers of communications infrastructure in the Landslide Complex area,
Cox Communications and Frontier Communications (Frontier). On September 9, 2024,
Cox Communications disconnected 146 customers in the PBCA. Frontier has indicated
to the City that they will keep their facilities operational so long as they have power supply.
Public Works Staff have been reaching out directly to wireless carries and installers to
increase the number of small wireless facilities (SWFs) and improve cellular service.
Carriers and installers are currently determining feasible locations to install SWFs, but
have indicated that the use of Communications on Wheels (mobile facilities) are not
feasible for economic reasons. Once applications for new facilities are received, Public
Works Staff will work to expedite those applications.
Public Works Staff have engaged in conversations with Frontier about installing fiber optic
communications lines in the PBCA. Frontier is investigating the feasibility and will provide
the City with additional information in the coming weeks.
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Building Division Programs and Permitting
Urgency Ordinance for Temporary Repairs and Housing on Private Property :
Pursuant to City Council direction on July 2, 2024, in response to public concerns
regarding the land movement’s impacts on residences, City Staff explored options for
interim housing solutions within the Landslide Complex.
Examples of hardening and stabilizing solutions to preserve existing structures include,
but are not limited to, placing homes on cargo structures and other leveling systems such
as I-beams and installing alternative foundation systems to help maintain the integrity of
the structure as the land shifts. These measures would be temporary, require a permit to
be issued by the Building and Safety Division, and need the owner to hold the City
harmless. The structure could be occupied if it has adequate ingress/e gress, utility
connections and service, and fire department access.
For temporary housing, this may include temporary structures such as mobile homes that
would not require a foundation. The temporary housing would be on the same site as the
current residence. These structures would be temporary and require a permit issued by
Building and Safety Division and need the owner to hold the City harmless. The temporary
housing would require a stable location (City Geologist’s review), adequate
ingress/egress, above ground utility connections and service, fire department access, and
no major filling.
All temporary housing and storage, as well as stabilizing solutions to shore up existing
structures, may be utilized within the Landslide Complex until December 31, 2026, unless
extended by the City Council. All temporary measures must be approved by the City’s
Building Official to ensure safety.
On September 3, 2024, City Council adopted an Urgency Ordinance establishing
regulations and procedures to install temporary measures to preserve existing structures
and to authorize temporary housing on the same site as an existing residence within the
Landslide Complex. Staff is working collaboratively with the community to preserve
existing structures within the Landslide Complex and consider potential options for
temporary housing. All permit fees are being waived.
Utility Conversion Education and Permitting:
Due to the recent de-energization to many homes in the Landslide Complex by the utility
companies, the City’s Community Development Department prepared informational
handouts related to energy conversion.
• The Alternatives for Natural Gas Service handout outlines alternatives for natural
gas service to continue serving key home appliances and equipment including, but
not limited to, stoves, furnaces and water heaters. The handout also provides
requirements for permit issuance and inspections.
• The Solar Energy Systems handout highlights the City’s solar energy submittal and
permit requirements, which include online permitting and expedited plan review.
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The handouts have been made available to area residents, posted on the City’s
website and placed at the Building & Safety Division public counter.
• The Community Development Department also prepared an information handout
related to the safe installation of generators.
Waiver of Permit and Application Fees:
The City is waiving all permit fees and is waiving the planning process for the above
energy conversions with the understanding that the permits are being issued during the
duration of the City’s declared local state of emergency.
The City has the ability waive any permit or application fees associated with the proposed
reconstruction of a building or other structure that has been damaged or destroyed by a
landslide (see Rancho Palos Verdes Municipal Code ((RPVMC)) below). The applicant
does need to demonstrate that these fees are not covered by the applicant’s
homeowners’ insurance policy. At this time, they would still have to pay the City’s
consultant review fees (geologist, plan check), but City Staff are waiving permit and
application fees as applicable, based on the following:
RPVMC 17.78.010
F. Any permit or application fees (excluding city consultant review fees) associated
with the proposed reconstruction of a building or other structure (or portion thereof)
that has been damaged or destroyed by fire, earthquake, landslide or an
involuntary act of the property owner shall be waived, provided that the rebuilt
building or structure is no more than 250 square feet larger than it was prior to the
damage or destruction, and provided that the applicant can demonstrate that said
fees are not covered by the applicant's homeowners' insurance policy. In the event
that three or more properties are affected by any single incident, the city council
may, in its discretion:
1. Grant a fee waiver without making the findings specified in subsection
(B) of this section; or
2. Deny the waiver in its entirety or grant only a partial waiver, based upon
a finding of adverse fiscal impact to the city.
These are applications/permits that would fall under Exceptions A or C of the moratorium
in Urgency Ordinance 686U (moratorium described below). The City is documenting
these exceptions in the permit tracking software and referencing this section of code when
waiving the permit/application fees.
In addition to waiving fees where applicable, Staff are expediting application and permit
processing for these temporary measures.
Moratorium Exception and Waiver of Statement from Geotechnical Consultant:
On October 3, 2023, the City Council, pursuant to the RPVMC Chapter 2.24 and
Government Code § 8630 and § 8680.9, proclaimed a state of local emergency within the
Landslide Complex. In the event of a proclamation of local emergency, the City Manager,
as Director of Emergency Services, is empowered to make and issue rules and
regulations on matters reasonably related to the protection of life and property as affected
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by such emergency, provided such rules and regulations must be confirmed at the earliest
practicable time by the City Council.
On October 3, 2023, the City Council further adopted Interim Urgency Ordinance No.
674U, approving a moratorium on all construction in the Landslide Complex, renewed the
moratorium by adopting Interim Urgency Ordinance 675U on November 14, 2023 , and
further renewed the moratorium by adopting Urgency Ordinance 686U on September 3,
2024 (the “Moratorium”). The Moratorium will expire on October 2, 2025. Subject to
certain exceptions, “during the effective period of [the moratorium], no application for
permit will be accepted, no consideration of any application for any permit will be made,
and no permit will be issued by the City for any construction on any property within the
Landslide Complex until this Ordinance has expired or has been repealed according to
applicable law.”
Emergency structural and foundation repairs to a home impacted by the significant land
movement qualify under the Exception A category set forth in Section 2 of the Moratorium
(“Exception A”). This Exception is for “[c]onstruction necessary for repair or maintenance
of existing structures, roadways, and any infrastructure such as water lines, sewer lines,
electrical or traffic installations, etc.”
Chapter 15.20 of the RPVMC provides that certain building permits require the applicant
to obtain a geologist report. Based on the speed of land movement, however, no such
geologist report can be obtained. Thus, in order to move forward with temporary repa irs,
a waiver of this requirement is necessary.
The City Manager, through his authority under RPVMC 2.24.060 and Resolution No.
2023-47, as renewed, has authorized waivers for the required geologist reports for these
emergency repairs qualifying under Exception A of the Moratorium, due to the significant
land movement and that these repairs are for temporary emergency repairs. Staff are
requiring that the applicant acknowledges that these repairs are for temporary repairs
during the significant land movement and are being approved under emergency
conditions. The property owner must agree to hold the City harmless, and recognize that
once the emergency is lifted, the temporary foundation or structural repairs may need to
be replaced with permanent repairs and a statement from the geotechnical consultant.
The applicant is also required to sign a waiver acknowledgement form.
On July 2, 2024, the City Council confirmed the City Manager’s action as Director of
Emergency Services to waive the requirement of applicants of permits for emergency
repairs to obtain a statement from the geotechnical consultants.
Staff recommends receiving and filing this update on current conditions in the Greater
Portuguese Bend-Ancient Altamira Landslide Complex
2. FEMA Voluntary Property Acquisition Buyout Program
On October 28, 2024, the City, the Federal Emergency Management Agency (FEMA),
and the California Governor’s Office of Emergency Services (Cal OES) announced a $42
million Voluntary Property Acquisition Buyout Program (Buyout Program) for property
owners in the Landslide Complex whose homes have been damaged or threatened by
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land movement. Established with funding from FEMA’s Hazard Mitigation Grant Program
(HMGP), the Buyout Program is intended to help eligible homeowners relocate to safer
areas by offering a fair market value for their properties based on pre-disaster appraisals.
Properties acquired by the City through this Buyout Program will be permanently
converted to open space and deed-restricted, protecting the community from future
redevelopment risks in these vulnerable areas.
Generally speaking, FEMA’s HMGP is funded whenever a federal disaster is declared by
the President. Funding that becomes available through the HMGP can be applied to any
city in a state for which a federal disaster is declared and is not limited to the aff ected
City. FEMA is funding this Buyout Program in the amount of $42 million to the City based
on the Federally declared California disaster for the winter storms that occurred between
January 31 and February 9, 2024. Additional future Buyout Program cycles may become
available to affected residents depending on whether a federal declared disaster occurs
in California.
The application deadline for property owners of interest with structures that are destroyed,
damaged, or imminently at-risk to be considered eligible within this first round of the
Program offering was November 8, 2024. The City received 85 applications.
The City and Cal OES will review all property applications to ensure that each property
meets FEMA’s eligibility requirements and will pass cost -effectiveness (Benefit Cost
Analysis ((BCA)), environmental and historic preservation (EHP) reviews. The City along
with Cal OES and FEMA must ensure that each application follows program
rules/regulations and comply with BCA and EHP laws and guidance. Properties deemed
eligible by FEMA for the Program will then proceed to the selection process.
Minimum eligibility includes:
• The property is not bank owned (mortgages do not constitute bank ownership for
purposes of this Program). This Program does not apply to properties currently
owned in title by a bank or other institutional financial institution through a
foreclosure or other similar means;
• The property has not sold since December 1, 2022 (based upon Los Angeles
County Tax and/or parcel records;
• The property must be improved with a legally permitted structure(s) based on
records on file with the City’s Building and Safety Division; and,
• Applicants must be the legal owners of the improved structures according to the
Assessor’s records and building permit records on file at the City’s Building and
Safety Division.
A property will be selected by the City to proceed with escrow based on the following
prioritization order:
• Properties with a structure that has been red-tagged by the City’s Building Official;
• Properties with a structure that has been yellow-tagged by the City’s Building
Official;
• Properties with structures that are in imminent jeopardy of becoming red - or yellow-
tagged due to their close proximity to land movement elements (i.e. fissures,
grabens, sinkholes, etc.);
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• Properties that have been de-energized indefinitely;
• Properties that may benefit the City’s Landslide stabilization and winterization
efforts as determined by the City’s Public Works Director; and,
• Properties that contribute to the overall value of the adjacent Palos Verdes Nature
Preserve as determined by the City’s Recreation and Parks Director.
Property owners interested in the provisions of this Buyout Program were encouraged to
request a voluntary inspection by the City’s Building Official. By the application deadline,
78 inspections were conducted. Of those, 18 homes were red-tagged and 38 were yellow-
tagged. Prior to the October 28, 2024 announcement of the program, only 2 homes had
been red-tagged and 4 homes had been yellow-tagged, due to the voluntary nature of
property inspections.
If a property owner voluntary chooses to participate in this Buyout Program, FEMA’s grant
funding will pay 75% of the total fair market value as established on December 1, 2022 .
The total fair market value will include the following:
a. Property value as established by licensed real-estate appraiser
b. Appraisals costs
c. Title search costs
d. Lot survey costs, if necessary
e. Real estate transaction fees
f. Closing costs
g. Demolition costs
h. Environmental/hazardous waste remediation (lead-based paint, asbestos, etc.)
costs
i. Site restoration (grading, seeding) costs
The remaining cost share of 25% for these costs will be borne by the seller (property
owner) except for certain in-kind costs borne by the City estimated at approximately
$330,000 or less than 1% of the total grant program . The contribution of these costs will
be done as a reduction in the final payment at closing to the property owner.
Questions have been raised regarding how the cost share will be addressed. Below is the
City’s general explanation of the buyout monetary explanation relating to the 75% / 25%
cost share formula:
The demolition costs would generally come from the 25% that is withheld. For a
hypothetical case for demonstrative purposes, assume the value of the property with the
improvements is appraised at $3.5 million and that the remaining b. through i. of "Eligi ble
Costs" are approximately $180,000. Of those remaining “Eligible Costs”, the property
owner’s share would be $45,000 (25%). The total costs of items a. through i. would be
$3,680,000. In this scenario, the property owner would cover 25% of that ($920,000)
through the reduced payout from FEMA ($3,500,000-$920,000 = $2,580,000). Another
way to calculate is subtracting the $45,000 from the reduced purchase price (($3,500,000
* .75) - $45,000 = $2,580,000). The property owner would not be required to front the
costs for b. through i., rather they would contribute their 25% through t he reduced payout.
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This Program is strictly voluntary. Homeowners are not being forced to relinquish their
property and the City will not use eminent domain to acquire a property. Property owners
who have been selected to proceed with the purchase of their property may with drawal
at any time prior to closing. Once closing occurs, the real estate transaction is complete
and final.
More information on this program and application materials can be found at the City’s
website at www.rpvca.gov/DocumentCenter/View/22752/Voluntary-Property-Buyout---
Guidelines-and-Application.
3. Financial Report
Expenditures to Date and FY 2024-25 Year-End Estimates
Overall, the City’s estimated expenditures for the Portuguese Bend Landslide from
October 2022 through June 2025 are approximately $43.6 million. Of the $43.6 million,
as presented and approved by the City Council on October 1, 2024, the total budget in
FY 2024-25 is approximately $31.9 million as follows:
• $23.9 million for emergency response, boreholes and deep dewatering wells.
This amount also includes the $9.6 million approved on May 7, 2024 and $6.1
million on October 1, 2024.
• $4 million for emergency stabilization measures for additional deep dewatering
wells approved on October 1, 2024.
• $4 million for winterization approved on October 1, 2024.
As shown in Table 5, total expenditures for FY 2022-23 are $1.9 million, followed by an
increase of 416% to $9.8 million in FY 2023-24. In the current fiscal year, $16.5 million
has been incurred and encumbered, with an additional $15.4 million projected by June
30, 2025 for a total of $31.9 million, reflecting a 226% increase from the prior year. These
costs include emergency response efforts such as test boreholes, deep dewatering wells,
winterization, fissure filling, road repairs, sewer repairs, estimated time and costs for
personnel dedicated to the project, legal services, loans to districts, and increased tax
assessments.
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Table 5 – PB Landslide Costs – Emergency Response/Other – October 2022 - June 2025
ACLAD/KCLAD Loans Update
On August 20, 2024, the City received the signed loan agreements from ACLAD and
KCLAD. Since the City Council’s loan approval in July 2024, the Public Works team has
been working with the two Geologic Hazard Abatement Districts (GHADs) on their
projects as outlined in the agreements. The agreements have not been finalized for City
signatures because certain provisions must be met before issuing the funds to the
GHADs. Thus, as of November 1, 2024, the loans of $1.6 million to ACLAD and $1.9
million to KCLAD have not been disbursed. This amount is included as projected expense
in FY 2024-25 as shown in Table 5 above. In addition, Staff met with KCLAD
representatives, and they are in the process of preparing the necessary documentation
for an approximately $800,000 drawdown, expected in the coming weeks. Staff will
continue to provide updates in future financial reports.
Funding Sources
The $43.6 million is funded through various sources, including the General Fund, CIP
Fund, ARPA, Supervisory Hahn’s Social Program Grant, and Metro Funds (Table 6). Of
the $43.6 million, approximately $32 million is funded in FY 2024-25, of which $11.4
million, or 36%, comes from the CIP Fund and General Fund reserves.
Table 6 – PB Landslide Funding Sources – Emergency Response/Other for Oct 2022 - Jun 2025
DESCRIPTION
FY 22-23
ACTUAL
FY 23-24
ACTUAL
FY 24-25
YTD + PO'S
As of 11/1/24
FY 24-25
BALANCE TOTAL
Stabilization Measures in millions
DDW (approved Oct. 1) 1.5 2.5 4.0
Winterization (approved Oct. 1) 1.2 2.8 4.0
Boreholes/DDW 1.9 9.4 0.0 11.3
Emergency Response
Other (Prof/Tech, Sheriff, Misc) 1.2 1.0 0.3 2.5
Fissure Filling 0.6 0.01 1.2 1.8
Road Repairs 1.0 2.8 0.9 2.6 7.3
Ab Cove Sewer Repairs 0.04 0.8 0.7 0.6 2.1
Personnel Costs 0.1 1.2 0.8 1.8 3.9
Legal Services 0.02 0.1 0.2 0.1 0.4
PBL Remediation 0.5 1.1 0.1 0.0 1.6
ACLAD/KCLAD Loans 3.5 3.5
Tax Assessments 0.2 0.2 0.7 0.0 1.1
TOTAL: October 2022 - June 2025 1.9 9.8 16.5 15.4 43.6
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Staff anticipates a cost recovery of approximately $1.5 million in a form of public
assistance through the disaster recovery program from FEMA and CalOES from the
Winter Storm and Energy Shutoff state of emergency and federal disaster declarations.
These recovery funds are still in the application stage and are not guaranteed. If deemed
eligible, the reimbursement process could take anywhere from one to three years before
the City receives the funds. Due to the uncertainty of the funds and when they will be
received, this source is not included in Table 6.
Staff seeks City Council approval to receive a financial report on City expenditures and
projected year-end for emergency protective and stabilization measures in response to
the acceleration of the Landslide Complex since October 2022 .
4. Extension of the Local Emergency Declaration
On October 3, 2023, the City Council adopted Resolution No. 2023-47 declaring a local
emergency. The emergency declaration is deemed to continue to exist until its termination
is proclaimed by the City Council in accordance with law. Government Code § 8630
requires the City Council to review of the need for continuing the local emergency at least
once every 60 days until the City Council determines the local emergency within the
geographic boundaries of the Landslide Complex has been abated or mitigated to
insignificance. The state of emergency was continued by the City Council on November
14, 2023, pursuant to Resolution No. 2023-56, again on December 19, 2023, pursuant to
Resolution No. 2023-61, again on February 6, 2024, pursuant to Resolution No. 2024 -05,
again on March 19, 2024, pursuant to Resolution No. 2024 -13, again on May 7, 2024
pursuant to Resolution No. 2024-20, again on July 2, 2024 pursuant to Resolution No.
2024-44, again on August 6, 2024 pursuant to Resolution No. 2024-51, and again on
October 1, 2024 pursuant to Resolution No. 2024-50. At this time, the City Council is
being asked to extend the local emergency declaration an additional 60 days through
January 18, 2025, which does not require a public hearing. If extended this evening, the
Council would consider renewing the local emergency declaration again during the next
landslide update on December 17, 2024.
The City Council is being asked to adopt Resolution No. 2024 -__ thereby extending the
Declaration of Local Emergency by 60 days (Attachment A).
Funding Sources TOTAL
In Millions
CIP Fund 18.1
CIP Fund (Reserves)5.0
General Fund (Reserves) 6.4
General Fund 5.2
ARPA Fund 3.4
Metro Funds 3.3
Sup. Hahn's Social Program Grant 2.2
TOTAL $43.6
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5. Extension of the Local Emergency Declaration for Utility Shutoffs
On August 6, 2024, the City Council adopted Resolution No. 2024 -52 declaring a local
state of emergency because of a sudden and severe energy shortage caused by shutting
off of natural gas service to approximately 135 homes in the Portuguese Bend Community
Association due to safety concerns. On September 3, 2024, the City Council adopted
Resolution No. 2024-57, declaring a local state of emergency because of a sudden and
severe energy shortage caused by shutting off of natural gas service, planned
deenergization events, and internet shut-offs in the PBCA, Seaview, and PBBC. The
emergency declaration is deemed to continue to exist until its termination is proclaimed
by the City Council in accordance with law. Government Code § 8630 requires the City
Council to review of the need for continuing the local emergency at least once every 60
days until the City Council determines the local emergency because of a severe energy
shortage has been abated or mitigated to insignificance. The state of emergency was
continued by the City Council on October 1, 2024, pursuant to Resolution No. 2024-61,
At this time, the City Council is being asked to extend the local emergency declaration an
additional 60 days through January 18, 2025, which does not require a public hearing. If
extended this evening, the Council would consider renewing the local emergency
declaration again during the next landslide update on December 17, 2024.
The City Council is being asked to adopt Resolution No. 2024 -__ thereby extending the
Declaration of Local Emergency by 60 days (Attachment B).
ADDITIONAL INFORMATION:
Continuing the Emergency Work and Emergency Contract
As a separate item on tonight’s agenda, the City Council is being provided with an update
on the Portuguese Bend Landslide Emergency construction contracting and being asked
to reconfirm the need to continue the emergency work.
Water Source Study
The City Council previously requested a study into the source of water contributing to land
movement, including water originating outside City limits and from upper watersheds.
Staff prepared a scope of work for an engineering firm to perform such a study, including
proposed solutions to re-direct water away from the landslide. Staff issued a request for
proposals (via the PlanetBids online platform) for qualified engineering firms to perform
this study. Upon completion of the selection process, Staff will bring an agreement for the
City Councils consideration, which is expected to occur in January or February 2025,
depending on industry response levels to the request for proposals.
Rainfall Resistance Quantification
During the October 1, 2024 City Council meeting, Mayor Pro Tem Alegria requested that
Staff calculate the amount of rainfall that can be absorbed into the Landslide Complex
without additional movement under the current and proposed DDW configuration. The
27
project team attempted to perform that calculation , however, there is insufficient data to
produce a reliable result. To create a reliable model of land movement in relation to
rainfall, many more instrumented test boreholes would need to be in place during rainfall
events to collect data that could be used to calibrate the variables of a model: primarily
how much rainfall infiltrates into the ground and how much artesian pressure that rainfall
creates. Over the next rainy season, rainfall infiltration and resultant artesian pressure
data may be collected in existing instrumented monitoring wells, provided they do not
shear before sufficient data is collected. This data could be used as the beginning building
blocks of a rainfall-land movement (hydrologic) model; and provide guidance on additional
data necessary to complete a reliable model.
CalOES and FEMA Meetings
On September 12, 2024, the City Manager and Public Works Director met with Nancy
Ward, Director of CalOES; Robert Fenton, FEMA District 9 Administrator; and Kevin
McGowan, Director of Los Angeles County Office of Emergency Management and their
respective staff. The meeting was in response to the City’s repeated requests for state
and federal assistance with the Landslide Complex; including individual assistance (IA),
public assistance (PA), and technical assistance (TA). The City was informed that IA and
PA would not be deployed for the reasons detailed in the October 1, 2024 staff report.
CalOES and FEMA informed the City that TA would be provided to the City and that
various agencies such as the U.S. Army Corps of Engineers (USACE), the Federal
Highway Administration (FHWA), USGS, and CGS would be deployed. On September
26, 2024, the City Manager, Public Works Director, ACLAD, and K CLAD met with
geologists from USACE, FEMA, CalOES, and CGS. The purpose of the meeting was to
scope the specific TA that would be provided. Representatives of the agencies clearly
stated that they would not provide engineering, project management, or construction
assistance. The City and Districts requested TA in the form of sharing new ideas for
landslide mitigation, peer reviewing planned actions, and providing surveying and/or other
measurements of the landslide. The agencies stated that they would provide peer review
services and consider any other assistance that may be available after consulting with
their leadership.
On November 7, 2024, the City Manager and Public Works Director met with
representatives of FEMA and CalOES for an update on the TA efforts. At that meeting,
the City was informed that the USACE had declined to provide TA. Staff are working to
schedule a meeting with USACE to better understand why USACE was not participating.
FEMA and CalOES also stated that the State Geologist’s Office is reviewing information
the City provided for TA and for the City to expect initial feedback by the end of the month.
BRIC Grant Update
In January 2023, the City applied for a Federal Emergency Management Agency (FEMA)
Building Resilient Infrastructure and Communities (BRIC) FY22 cycle grant for the
Portuguese Bend Landslide Remediation Project (PBL Remediation Project). The grant
application was for the entire project including five hydrauger arrays with five drains each,
surface drainage swales with a flow reduction area, and fissure infilling. The total cost of
construction as well as associated professional services was estimated in Nov ember
28
2022 to be approximately $33.3 million. The City applied for funding for 70%, or $23
million, of the cost of the project. The BRIC program requires the $10 million balance of
the project cost to be funded through non-federal sources.
On August 28, 2023, FEMA announced the PBL Remediation Project was selected, with
$23.3 million being allocated, not obligated, for the City’s project. This means that the
project met the basic eligibility requirements and enters the next phase of the awar ds
review process.
The emergency protective and stabilization measures are separate scope from the PBL
Remediation Project, therefore, the BRIC grant funds cannot be used for the emergency
protective and stabilization measures. Because some of the emergency protective and
stabilization measures overlap with portions of the PBL Remediation Project footprint; the
City was required to submit a revised BRIC grant to exclude any overlap between the
emergency protective and stabilization measures footprint and PBL Remediation Proje ct
footprint. The revised PBL Remediation Project BRIC grant amount is now approximately
$16.4 million, with a required non-federal match of approximately $7 million.
On July 31, 2024, CalOES received notification that FEMA approved Phase 1 of the City’s
application which includes project management, final engineering, environmental
deliverables, construction documents, project agreements, and permits. The total
obligation amount (corrected from what was reported at the July 31 Neighborhood Q&A
and the August 6 Council meeting) is $2,295,091, up to actual approved costs, and a non -
federal share of 30% up to $718,138. A funding decision for Phase 2, or the construction
and related activities phase, will be made upon completion of Phase 1.
KCLAD Activities
• Current Production: two wells are producing a combined 350 gallons per minute,
with a water depth of about 86 feet. The flow was reduced to protect pumps located
at 105 feet.
• Well Inventory: KCLAD has five wells, with two active ones developed in 2024, and
older wells from 1987 and 2023 (#3 and #4 respectively). A shallow pump (Well
#4A will be retired.
• Future Development: Plans include putting Wells #3 and #4 back into production,
adding ultrasonic meters, and investing in a sonic water level to monitor subsurface
water.
• Additional Data: Weekly readings are uploaded to the KCLAD website.
KCLAD and Staff continue to discuss preparations for implementation of KCLAD’s 5 -Step
Plan and coordinate areas of overlap that includes filling fissures and installing drainage
solutions.
ACLAD Activities
ACLAD continues to repair wells and drainage lines as jams and breaks occur. ACLAD
continues to jointly work with the City on winterization of Kelvin Canyon so that surface
water does not infiltrate into the ground and contribute to land movement by recharging
29
the water table. ACLAD is also working on plans to install additional dewatering wells,
with specific locations to be defined and reviewed by the City Geologist.
CONCLUSION:
A GPS survey of sample points at the toe of the landslide continues to show a greater
rate of landslide deceleration in the areas of concentrated DDWs, especially for the KCL,
where landslide movement has ceased. In addition to the select sample of GPS survey
monitoring points showing a very strong correlation between water extraction and a
decrease in the rate of surface movement, the groundwater monitoring wells in DDW
areas have shown a significant decrease in water pressure (the main driving force of
landslide movement).
Extraction of water from DDWs 9&10 does appear to correlate with some possible
reduction in ground movement of nearby surface survey monuments within the toe region
of the ACL; which are moving at a slower rate than monuments further up in the middle
and upper portions of the ACL. However, the effectiveness of the additional DDWs
authorized by the City Council on October 1, 2024 can be better evaluated after DDW9A
and DDW11 are installed and monitored for at least a few weeks.
Staff recommends continuing to implement the DDW program in a staged approach and
based on available resources. Should DDW 9-11 show effective results, future
recommendations for additional DDWs may be forthcoming.
Winterization of Altamira Canyon is well underway and is expected to be complete by the
end of the week of November 18, 2024. Winterization work on Klondike Canyon has
started and is expected to be complete by the end of November 2024.
Crews are scheduled to mobilize for winterization work on Kelvin, Portuguese, Ishibashi,
and Paintbrush Canyons within two weeks. The work is expected to be complete by the
end of December 2024.
Work on the graben at the intersection of Dauntless Drive and Exultant Drive as well as
fissure filling on Exultant Drive has started and is expected to be complete by the end of
November 2024.
Staff recommends that the City Council extend the local emergency declarations for an
additional 60 days.
ALTERNATIVES:
In addition to Staff recommendation, the following alternative actions are available for
the City Council’s consideration:
1. Take no action and simply receive and file this report.
2. Do not adopt one, or both, of the resolutions continuing the local emergency
declarations.
30
01203.0023/1027433.1
RESOLUTION NO. 2024-__
A RESOLUTION OF THE CITY COUNCIL OF THE
CITY OF RANCHO PALOS VERDES, CALIFORNIA,
CONTINUING THE LOCAL EMERGENCY
DECLARATION AS ESTABLISHED BY
RESOLUTION NO. 2023-47 ADOPTED ON
OCTOBER 3, 2023 FOR AN ADDITIONAL 60 DAY
PERIOD
WHEREAS, on October 3, 2023, the City Council of the City of Rancho Palos
Verdes adopted Resolution No. 2023 -47, declaring a local state of emergency because
of the alarming increase of land movement in the Greater Portuguese Bend Landslide
Complex, as depicted in Resolution No. 2023-47 Exhibits “A” and “B”. Resolution No.
2023-47, and the exhibits thereto, is incorporated by reference;
WHEREAS, on October 3, 2023, the City Council by a 4/5 vote also adopted
Interim Urgency Ordinance No. 674U, establishing a moratorium on all construction in the
Landslide Complex;
WHEREAS, on November 14, 2023, the City Council by a 4/5 vote adopted
Resolution No. 2023-56, extending the state of emergency for an additional 60 days;
WHEREAS, on December 19, 2023, the City Council by a 4/5 vote adopted
Resolution No. 2023-61, extending the state of emergency for an additional 60 days;
WHEREAS, on February 6, 2024, the City Council by a 4/5 vote adopted
Resolution No. 2024-05, extending the state of emergency for an additional 60 days;
WHEREAS, on March 19, 2024, the City Council by a 5-0 vote adopted Resolution
No. 2024-13, extending the state of emergency for an additional 60 days;
WHEREAS, on May 7, 2024, the City Council by a 5-0 vote adopted Resolution
No. 2024-20, extending the state of emergency for an additional 60 days;
WHEREAS, on July 2, 2024, the City Council by a 5-0 vote adopted Resolution
No. 2024-44, extending the state of emergency for an additional 60 days;
WHEREAS, on August 6, 2024, the City Council by a 5-0 vote adopted Resolution
No. 2024-51, extending the state of emergency by an additional 60 days ;
WHEREAS, on October 1, 2024, the City Council by a 5-0 vote adopted Resolution
No. 2024-50, extending the state of emergency by an additional 60 days ;
WHEREAS, the state of emergency is deemed to continue to exist until its
termination is proclaimed by the City Council in accordance with law. Government Code
§ 8630 requires the City Council to review of the need for continuing the local emergency
at least once every 60 days until the City Council determines the local emergency within
the geographic boundaries of the Landslide Complex has been abated or mitigated to
insignificance; and,
A-1
Resolution No. 2024-__
Page 2 of 3
WHEREAS, after consideration of all facts reasonably available the City Council
now desires to extend the declaration of a state of local emergency within the Landslide
Complex.
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF RANCHO PALOS
VERDES, CALIFORNIA, HEREBY FINDS, DETERMINES, AND RESOLVES AS
FOLLOWS:
Section 1. Recitals. The City Council hereby determines that the above recitals
are true and correct and incorporates the same as the findings of the City Council.
Section 2. Proclamation of Emergency. The City Council finds, pursuant to
RPVMC Chapter 2.24 and Government Code §§ 8630 and 8680.9, there exists an actual
condition of peril to the safety of persons and property exiting within the Greater
Portuguese Bend Landslide, comprised of the Portuguese Bend Landslide, the Abalone
Cove Landslide, and the Klondike Canyon Landslide), as depicted in Exhibits “A” and “B”
of Resolution No. 2023-47, and based on the staff report and recommendations and
public testimony, and hereby proclaims that a state of local emergency continues to exist
throughout the same.
Section 3. Authority Granted. It is further proclaimed and ordered that during
the existence of said local emergency, the powers, authority, functions and duties of the
Disaster Council, Director, and the City’s emergency services organizations shall be
those prescribed by State Law, City ordinances, Resolution No. 2023-47 and any other
applicable resolutions, and approved plans of the City in order to mitigate the effects of
the local emergency.
Section 4. Immunity Invoked. To the maximum extent permitted by law, and
pursuant to Government Code § 866, the City Council hereby invokes the immunity
afforded to the City of Rancho Palos Verds in adopting and implementing the declaration
of local emergency within the Landslide Complex
Section 5. Duration. The local emergency shall be deemed to continue to exist
until its termination is proclaimed by the City Council in accordance with law.
Section 6. Continuing Declaration. Government Code § 8630 requires the
City Council to review of the need for continuing the local emergency at least once every
60 days until the City Council determines the local emergency within Landslide Complex
has been abated or mitigated to insignificance.
Section 7. Severability. If any subsection, sentence, clause, phrase, or word of
this Resolution or any application of it to any person, structure, gathering, or circumstance
is held to be invalid or unconstitutional by a decision of a court of competent jurisdiction,
then such decision will not affect the validity of the remaining portions or applications of
this Resolution.
Section 8. Effectiveness. This Resolution shall take effect immediately. A copy
of the Proclamation and this Resolution shall be forwarded to the California Emergency
A-2
Resolution No. 2024-__
Page 3 of 3
Management Agency. The City Clerk shall certify to the passage and adoption of this
resolution..
PASSED, APPROVED AND ADOPTED on this 19th day of November, 2024.
________________________________
Mayor
ATTEST:
________________________________
City Clerk
STATE OF CALIFORNIA )
COUNTY OF LOS ANGELES ) ss
CITY OF RANCHO PALOS VERDES )
I, Teresa Takaoka, City Clerk of the City of Rancho Palos Verdes, hereby certify that
the above Resolution No. 2024-__ was duly and regularly passed and adopted by the
said City Council at a regular meeting thereof held on November 19, 2024.
___________________________
City Clerk
A-3
01203.0023/1027441.1
RESOLUTION NO. 2024-__
A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF
RANCHO PALOS VERDES, CALIFORNIA, EXTENDING
THE STATE OF LOCAL EMERGENCY WITHIN THE
GEOGRAPHIC BOUNDARIES OF THE PORTUGUESE
BEND COMMUNITY ASSOCIATION, PORTUGUESE BEND
BEACH CLUB, AND SEAVIEW NEIGHBORHOODS,
BASED ON SUDDEN ENERGY SHORTAGES, PLANNED
DEENERGIZING EVENTS, AND INTERNET SERVICE
SHUT OFFS AS ESTABLISHED BY RESOLUTION NOS.
2024-52 AND 2024-57 FOR AN ADDITIONAL 60 DAYS
WHEREAS, the City of Rancho Palos Verdes is home to four out of five sub -slides
that comprise the Greater Portuguese Landslide Complex (Landslide Complex): the
Portuguese Bend Landslide, Abalone Cove Landslide, Klondike Canyon Landslide, and
Beach Club Landslide. The Portuguese Bend Landslide encompasses the Portuguese
Bend Community Association (PBCA), the Seaview Neighborhood (Seaview), and the
Portuguese Bend Beach Club (PBBC). The Landslide Complex has been active since the
1950s;
WHEREAS, the 2022-2023 rainy season brought exceptional amounts of rain to
the region, dumping 20.9” of rain or 190% of the average annual rainfall in the region ;
WHEREAS, by April 26, 2024, total rainfall for the 2023-24 season (beginning Oct
1, 2023) was 23.01" or 169% of the historical 67-year average of 13.63" for this rain
gauge. (All data based on LACDPW Rainfall Gauge No. 1011B at Rolling Hills FS.);
WHEREAS, beginning in 2018, but particularly since May 2023, the land
movement in the Landslide Complex has increased significantly due to increased rainfall
in the last two rainy seasons, which caused the water table to rise dramatically and
destabilize the landslides. The City has established, via repeated geologic studies, that a
significant factor in the speed of land movement in the Landslide Complex is the amount
of water in the soil;
WHEREAS, on October 3, 2023, the City Council of the City of Rancho Palos
Verdes adopted Resolution No. 2023-47, declaring a local state of emergency due to the
alarming increase of land movement in the Landslide Complex. The state of emergency
based on the land movement has been extended as required by law and is still active;
WHEREAS, on August 6, 2024, the City Council by unanimous vote adopted
Resolution No. 2024-52, declaring a local state of emergency because of a sudden and
severe energy shortage caused by shutting off of natural gas service to approximately
135 homes in the PBCA due to safety concerns;
WHEREAS, on September 3, 2024, the City Council by unanimous vote adopted
Resolution No. 2024-57, declaring a local state of emergency because of a sudden and
severe energy shortage caused by shutting off of natural gas service, planned de-
energization events, and internet shut-offs in the PBCA, Seaview, and PBBC;
B-1
Resolution No. 2024-__
Page 2 of 3
WHEREAS, on October 1, 2024, the City Council by unanimous vote adopted
Resolution No. 2024-61, declaring a local state of emergency because of a sudden and
severe energy shortage caused by shutting off of natural gas service, planned
deenergization events, and internet shut-offs in the PBCA, Seaview, and PBBC; and,
WHEREAS, after consideration of all facts reasonably available the City Council
now desires to extend the declaration of a state of local emergency within the Landslide
Complex.
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF RANCHO PALOS
VERDES, CALIFORNIA, HEREBY FINDS, DETERMINES, AND RESOLVES AS
FOLLOWS:
Section 1. Recitals. The City Council hereby determines that the above recitals
are true and correct and incorporates the same as the findings of the City Council.
Section 2. Extension of Local State of Emergency. The City Council finds,
pursuant to RPVMC Chapter 2.24 and Government Code §§ 8630, 8680.9, and 8558
there exists an actual condition of peril to the safety of persons and property existing
within the PBCA, Seaview, and PBBC, as established by Resolutions No. 2024-52 and
2024-57, and based on the staff report and recommendations and public testimony, and
hereby proclaims that a state of local emergency continues to exist throughout the same.
Section 3. Authority Granted. It is further proclaimed and ordered that during
the existence of said local emergency, the powers, authority, functions and duties of the
Disaster Council, Director, and the City’s emergency services organizations shall be
those prescribed by State Law, City ordinances, Resolution Nos. 2023-52 and 2024-57,
and any other applicable resolutions, and approved plans of the City in order to mitigate
the effects of the local emergency.
Section 4. Immunity Invoked. To the maximum extent permitted by law, and
pursuant to Government Code § 866, the City Council hereby invokes the immunity
afforded to the City of Rancho Palos Verds in adopting and implementing the declaration
of local emergency within the Landslide Complex.
Section 5. Duration. The local emergency shall be deemed to continue to exist
until its termination is proclaimed by the City Council in accordance with law. Government
Code § 8630 requires the City Council to review of the need for continuing the local
emergency at least once every 60 days until the City Council determines the local
emergency within the geographic boundaries of the Landslide Complex has been a bated
or mitigated to insignificance.
Section 6. Continuing Declaration. Government Code § 8630 requires the
City Council to review of the need for continuing the local emergency at least once every
60 days until the City Council determines the local emergency within the PBCA has been
abated or mitigated to insignificance.
B-2
Resolution No. 2024-__
Page 3 of 3
Section 7. Severability. If any subsection, sentence, clause, phrase, or word of
this Resolution or any application of it to any person, structure, gathering, or circumstance
is held to be invalid or unconstitutional by a decision of a court of competent jurisdiction,
then such decision will not affect the va lidity of the remaining portions or applications of
this Resolution.
Section 8. CEQA. The City Council finds that this Resolution is proposed to allow
the City to continue to address and mitigate an imminent threat to public health and safety
and therefore is exempt from CEQA pursuant to Public Resources Code, Section
21080(b)(4) and CEQA Guidelines, Section 15269.
Section 9. Effectiveness. This Resolution shall take effect immediately. A copy
of the Proclamation and this Resolution shall be forwarded to the California Office of
Emergency Management. The City Clerk shall certify to the passage and adoption of this
resolution.
PASSED, APPROVED AND ADOPTED on this 19th day of November, 2024.
________________________________
Mayor
ATTEST:
________________________________
City Clerk
STATE OF CALIFORNIA )
COUNTY OF LOS ANGELES ) ss
CITY OF RANCHO PALOS VERDES )
I, Teresa Takaoka, City Clerk of the City of Rancho Palos Verdes, hereby certify that
the above Resolution No. 2024-__ was duly and regularly passed and adopted by the
said City Council at a regular meeting thereof held on November 19, 2024.
___________________________
City Clerk
B-3
0 250 500 1000
(feet)
PONY TRAIL
PORTUGUESE
BEND
LANDSLIDE
FLYING
TRIANGLE
LANDSLIDE
KLONDIKE
CANYON
LANDSLIDE
ABALONE
COVE
LANDSLIDE
ABALONE
COVE
PORTUGUESE
POINT
INSPIRATION
POINT
SACRED
COVE
APPROXIMATE BOUNDARY OF
ANCIENT PORTUGUESE BEND
LANDSLIDE COMPLEX
BURMA ROAD
PALOS VERDES DRIVE SOUTH
EXPLANATION
Limits of the Ancient Portuguese Bend Landslide Complex
Limits of Historically Mapped Landslides
SEAVIEW TRACT
2023/2024 Landslide Mapping
Current Limits of Major
Landslide Movement
(August 2024)
CURRENT LIMITS OF MAJOR
LANDSLIDE MOVEMENT
(AUGUST 2024)
GPS Monument
Displacement!Rate
(July 1, 2024 to
August 1, 2024)
Displacement Vector!
Scale 1"= 8"/week
Displacement Rate Table
Minimum Rate
(inch/week)
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
Maximum Rate
(inch/week)
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Color
10.00 11.00
11.00 12.00
1.00 2.00
AB04
9.20
AB13
10.64
AB16
7.49
AB17
0.01
AB24
11.23
AB51
8.95
AB53
11.29
AB58
11.00
AB59
12.65
AB60
10.19
AB62
7.08
AB63
9.11
AB65
8.88
AB66
10.10
AB68
9.79
AB70
11.69
AB71 no data
0.00
AB73
10.75
AB74
5.16
AB75
11.99
AB76
0.24
CR07 no data
0.00
CR50
0.33
CW08
0.05
FT06
9.37
KC05
2.41
KC07
0.03
KC13
1.46
KC15
3.91
KC17
3.53
KC18
7.84
KC19
3.40
KC20
3.45
KC23
2.72
KC26
4.09
KC27
3.88
KC30
9.21
PB06
10.07
PB08
10.84
PB12
11.45
PB13
8.82
PB18
11.89
PB20
10.83
PB21
10.41
PB27
10.91
PB55
11.13
PB59
11.36
PB67
12.29PB68
11.15
PB69
11.13PB70
11.58
PB71
12.96
PB72
11.81
PB73
9.39
PB74
11.39
PB75
11.54
RP01
0.02
RP02
0.03
UB02
9.98
AB01
0.06
AB02
0.06
AB05
8.55
AB21
12.43
AB50
6.86
AB57
9.39
AB64
0.48
AB67
7.48
AB77
0.08
CR51
0.47
CR53
0.49
CR54
11.80
CR56
0.07
CW01
0.06
CW05
0.52
CW06
0.05
CW07
0.04
FT08
0.02
FT09
0.01
KC06
3.89
KC14
0.08
KC16
0.03
KC21
0.04KC22
4.09
KC24
5.16
KC25
0.23
KC28
5.60
KC29
6.48
KC31
8.23
KC33
3.84
PB04
11.34
PB07
11.68 PB09
9.92
PB26
9.87
PB29
9.36
PB54
11.89
"Creeping Area"
Approximately 0.5 inch/week
?
?
?
?
?
?
?
?
?
?
12.00 13.00
0.00 1.00
COTTON,S HIRES AND ASSOCIATES, INC.
CONSULTING ENGINEERS AND GEOLOGISTS
RANCHO PALOS VERDES, CALIFORNIA
SC6163
POS
MP 1"=500'
PROJECT NO.
DATENovember 8, 2024
SCALE
APPROVED BY
GEO/ENG BY
GPS MONITORING DISPLACEMENT RATE
CONTOUR MAP (8/1/24 DATA)
FIGURE NO.3
Abalone Cove, Portuguese Bend, Klondike Canyon
Hillshade basemap produced from publicly available LiDAR:
"2015 - 2016 LARIAC Lidar DEM: Los Angeles Region, CA"
C-1
y
----J ♦ ~ _.,,,,_
.,,
__,,.
•
I
I _,,
I
I
\
■
■
■
■
■
■
■
■
■
■
■
■
I
i
l
r ....
r?."" ---
I
I
I
I I
♦ ~
---♦
•• -r -
'1 .0
---••!fr.
9 ,0
-
~
·/
i
-
J -
I { --I-• I
.,,....,,-r _.,-,-,-.
/ / ,,.,....
\ -
•
~tr
0 250 500 1000
(feet)
PONY TRAIL
PORTUGUESE
BEND
LANDSLIDE
FLYING
TRIANGLE
LANDSLIDE
KLONDIKE
CANYON
LANDSLIDE
ABALONE
COVE
LANDSLIDE
ABALONE
COVE
PORTUGUESE
POINT
INSPIRATION
POINT
SACRED
COVE
BURMA ROAD
PALOS VERDES DRIVE SOUTH
BURMA
ROAD
EXPLANATION
Limits of the Ancient Portuguese Bend Landslide Complex
Limits of Historically Mapped Landslides
SEAVIEW TRACT
2023/2024 Landslide Mapping
Current Limits of Major
Landslide Movement
(September 2024)
CURRENT LIMITS OF MAJOR
LANDSLIDE MOVEMENT
(SEPTEMBER 2024)
GPS Monument
Displacement Rate
(August 1, 2024 to
September 4, 2024)
Displacement Vector
Scale 1"= 8"/week
AB04
8.20
AB16
7.30
AB17
0.00
AB21
10.90
AB50
6.20
AB53
10.70
AB57
9.10
AB59
11.70
AB60
9.70
AB62
6.70
AB63
8.10
AB64
0.30
AB66
9.70
AB67
6.80
AB70
11.00
AB73
9.40
AB74
5.30
AB75
10.60
AB76
0.20
AB77
0.00
CR50
0.50
CR53
0.60
CR54
10.70
KC05
2.00
KC06
3.60
KC14
0.10
KC16
0.00
KC17
2.70
KC19
3.10
KC21
0.10KC22
4.00
KC23
2.40
KC24
4.60
KC28
4.70
KC31
7.50
KC33
3.70
KC36
0.10
PB07
9.60
PB09
7.90
PB13
8.50
PB18
11.00
PB20
10.50
PB21
10.40
PB26
9.20
PB29
8.30
PB59
9.70
AB01
0.10
AB02
0.10
AB13
10.10
AB24
10.80
AB51
8.60
AB58
10.40
AB65
8.40
AB68
9.40
CR51
0.60CR56
0.10
CW01
0.00
CW05
0.60
CW06
0.00
CW07
0.00
CW08
0.10
FT06
8.00
FT08
0.00
FT09
0.10
KC07
0.10
KC13
1.30
KC15
3.40
KC18
6.80
KC20
2.60
KC25
0.20
KC26
3.50
KC29
5.50
KC30
7.70
KC34
0.00
KC35
0.00
KC37
0.10
PB04
9.20 PB06
8.00
PB08
8.70
PB12
10.80
PB27
10.70
PB54
10.90
PB55
10.30
PB67
10.10PB68
9.30
PB69
9.60
PB70
10.00
PB71
11.40
PB72
9.80
PB74
9.70
PB75
10.60
RP01
0.00
RP02
0.00
UB02
8.20
"Creeping Area"
Approximately 0.5 inch/week
Displacement Rate Table
Minimum Rate
(inch/week)
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
Maximum Rate
(inch/week)
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Color
10.00 11.00
11.00 12.00
1.00 2.00
12.00 13.00
0.00 1.00
APPROXIMATE BOUNDARY OF
ANCIENT PORTUGUESE BEND
LANDSLIDE COMPLEX
COTTON,S HIRES AND ASSOCIATES, INC.
CONSULTING ENGINEERS AND GEOLOGISTS
RANCHO PALOS VERDES, CALIFORNIA
SC6163
POS
MP 1"=500'
PROJECT NO.
DATENovember 8, 2024
SCALE
APPROVED BY
GEO/ENG BY
GPS MONITORING DISPLACEMENT RATE
CONTOUR MAP (9/4/24 DATA)
FIGURE NO. 4
Abalone Cove, Portuguese Bend, Klondike Canyon
Hillshade basemap produced from publicly available LiDAR:
"2015 - 2016 LARIAC Lidar DEM: Los Angeles Region, CA"
C-2
I I
I r ....
r
~---_____ ...,, i
---J -♦
.,..,-_.,,,,_
.,,
/
~-
__,,.
■
■
,._ l --...... --l --
.... -----~------------~ ------
/ z
0 ~
::J"
J -
I (_ --
-1
___,.i r ----/ /
,
J
■
_.,.....
■
_.
■ --i
■
■
■
-• ♦
✓
■
■
■
■
0 250 500 1000
(feet)
PONY TRAIL
PORTUGUESE
BEND
LANDSLIDE
FLYING
TRIANGLE
LANDSLIDE
KLONDIKE
CANYON
LANDSLIDE
ABALONE
COVE
LANDSLIDE
ABALONE
COVE
PORTUGUESE
POINT
INSPIRATION
POINT
SACRED
COVE
BURMA ROAD
PALOS VERDES DRIVE SOUTH
BURMA
ROAD
EXPLANATION
Limits of the Ancient Portuguese Bend Landslide Complex
Limits of Historically Mapped Landslides
SEAVIEW TRACT
2023/2024 Landslide Mapping
Current Limits of Major
Landslide Movement
(October 2024)
CURRENT LIMITS OF MAJOR
LANDSLIDE MOVEMENT
(OCTOBER 2024)
GPS Monument
Displacement Rate
(September 4, 2024 to
October 8, 2024)
Displacement Vector
Scale 1"= 8"/week
"Creeping Area"
Approximately 0.5 inch/week
Displacement Rate Table
Minimum Rate
(inch/week)
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
Maximum Rate
(inch/week)
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Color
10.00 11.00
11.00 12.00
1.00 2.00
12.00 13.00
0.00 1.00
AB01
0.05
AB04
6.09
AB13
7.23
AB16
5.42
AB17
0.04
AB21
7.29
AB24
7.88
AB50
3.88
AB51
6.18
AB53
7.37
AB57
6.17
AB58
7.44
AB59
7.90
AB60
6.74
AB62
5.03
AB63
6.23
AB64
0.17
AB65
6.14
AB66
6.91
AB67
5.09
AB68
6.82
AB70
7.85
AB73
6.04
AB74
3.86
AB75
7.18
AB76
0.11
AB77
0.06
AB78
1.78
AB79
0.04
AB80
0.04
CR50
0.35 CR51
0.44
CR53
0.43
CR54
6.85
CR56
0.07
CR57
0.11
CR58
0.36
CR59
0.03
CR60
0.00
CW01
0.03
CW05
0.47
CW06
0.07
CW08
0.02
FT08
0.03
FT09
0.04
FT10
0.03
KC05
1.05
KC06
1.57
KC07
0.04
KC13
0.55
KC14
0.05
KC15
1.53
KC16
0.02
KC17
1.34
KC18
2.49 KC19
1.35
KC20
1.29
KC21
0.04
KC22
1.80
KC23
1.05
KC24
1.75
KC25
0.08
KC26
1.34KC28
1.98
KC29
2.27
KC30
3.33
KC31
3.23
KC33
1.67
KC34
0.05
KC35
0.05
KC36
0.03
KC37
0.04
KC38
2.47
PB04
5.74
PB06
4.58
PB07
5.11 PB08
4.62 PB09
4.08
PB12
4.21
PB13
3.04
PB18
6.95
PB20
4.99
PB21
4.96
PB26
4.01
PB27
5.05
PB29
3.42
PB54
6.99
PB55
5.26
PB59
5.88
PB67
4.63PB68
5.71
PB69
5.64PB70
6.03
PB71
7.08
PB72
5.77
PB74
4.54
PB75
6.28
PB76
3.84
RP01
0.04
RP03
0.00
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
UB02
3.74
APPROXIMATE BOUNDARY OF
ANCIENT PORTUGUESE BEND
LANDSLIDE COMPLEX
COTTON,S HIRES AND ASSOCIATES, INC.
CONSULTING ENGINEERS AND GEOLOGISTS
RANCHO PALOS VERDES, CALIFORNIA
SC6163
POS
MP
November 8, 2024
1"=500'
PROJECT NO.
DATE
SCALE
APPROVED BY
GEO/ENG BY
GPS MONITORING DISPLACEMENT RATE
CONTOUR MAP (10/8/24 DATA)
FIGURE NO. 5
Abalone Cove, Portuguese Bend, Klondike Canyon
Hillshade basemap produced from publicly available LiDAR:
"2015 - 2016 LARIAC Lidar DEM: Los Angeles Region, CA"
C-3
~r--"·--~
__,,... ✓~ -
., ,,,...,,,,.. ✓ .,. ,.,.,.,.
----....J -
__,,.
•
.,,
---J -
-----_.,,,,_
-
♦
I
I
\
'
■
■
■
■
■
■
■
■
■
■
■
■
r
r ....
.....---. ..
6.0 I I
♦
.,,
,,
--:....., ,,,
♦
,_ -1•
---
I I
I
/
/ ~-
/ -z
0
/ ♦'
~
::J" I/
♦
J -
I / (_ --1
___,.i r ----/ /
,
J
♦ _.,,...
..... -i -• ♦ ,
0 250 500 1000
(feet)
PONY TRAIL
PORTUGUESE
BEND
LANDSLIDE
FLYING
TRIANGLE
LANDSLIDE
KLONDIKE
CANYON
LANDSLIDE
ABALONE
COVE
LANDSLIDE
ABALONE
COVE
PORTUGUESE
POINT
INSPIRATION
POINT
SACRED
COVE
BURMA ROAD
PALOS VERDES DRIVE SOUTH
BURMA
ROAD
EXPLANATION
Limits of the Ancient Portuguese Bend Landslide Complex
Limits of Historically Mapped Landslides
SEAVIEW TRACT
2023/2024 Landslide Mapping
Current Limits of Major
Landslide Movement
(November 2024)
CURRENT LIMITS OF MAJOR
LANDSLIDE MOVEMENT
(NOVEMBER 2024)
GPS Monument
Displacement Rate
(October 8, 2024 to
October 29, 2024)
Displacement Vector
Scale 1"= 8"/week
Displacement Rate Table
Minimum Rate
(inch/week)
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
Maximum Rate
(inch/week)
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Color
10.00 11.00
11.00 12.00
1.00 2.00
12.00 13.00
0.00 1.00
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
UB02
0.68
AB01
0.13
AB04
4.32
AB13
5.32
AB16
3.91
AB17
0.09
AB21
4.63
AB24
5.64
AB50
2.07
AB51
4.17
AB53
4.51
AB57
4.83
AB58
5.10
AB59
5.04
AB60
5.29
AB62
3.64
AB63
4.37
AB64
0.62
AB65
4.21
AB66
4.74
AB67
3.61
AB68
4.72
AB70
5.46
AB73
3.53
AB74
3.06
AB75
4.70
AB76
0.11
AB77
0.06
AB78
0.13
AB79
0.12
AB80
0.07
CR50
0.08 CR51
0.10
CR53
0.01
CR54
4.68
CR56
0.04
CR57
0.09
CR58
0.07
CR59
0.08
CR60
0.03
CW01
0.02
CW05
0.08
CW06
0.08
CW08
0.16
FT08
0.04
FT09
0.06
FT10
0.07
KC05
0.19
KC06
0.22
KC07
0.11
KC13
0.12
KC14
0.11
KC15
0.19
KC16
0.13
KC17
0.11
KC18
0.14
KC19
0.28
KC20
0.16
KC21
0.04
KC22
0.19
KC23
0.20
KC24
0.11
KC25
0.09
KC26
0.08KC28
0.17
KC29
0.12
KC30
0.16
KC31
0.22
KC33
0.24
KC34
0.14
KC35
0.12
KC36
0.10
KC37
0.16
KC38
0.22
PB04
3.25
PB06
2.21
PB07
2.46 PB08
1.97
PB09
1.67
PB12
1.28
PB13
0.38
PB18
4.01
PB20
2.03
PB21
2.48
PB26
0.56
PB27
2.08
PB29
0.36
PB54
4.23
PB55
2.88
PB59
3.38
PB67
1.14PB68
3.25
PB69
3.63PB70
3.47
PB71
4.36
PB72
3.22
PB74
0.97
PB75
3.49
PB76
1.55
RP01
0.11
RP03
0.01
UB02
0.68
APPROXIMATE BOUNDARY OF
ANCIENT PORTUGUESE BEND
LANDSLIDE COMPLEX
COTTON,S HIRES AND ASSOCIATES, INC.
CONSULTING ENGINEERS AND GEOLOGISTS
RANCHO PALOS VERDES, CALIFORNIA
SC6163
POS
MP
November 8, 2024
1"=500'
FIGURE NO.
PROJECT NO.
DATE
SCALE
APPROVED BY
GEO/ENG BY
GPS MONITORING DISPLACEMENT RATE
CONTOUR MAP (10/29/24 DATA)
6
Abalone Cove, Portuguese Bend, Klondike Canyon
Hillshade basemap produced from publicly available LiDAR:
"2015 - 2016 LARIAC Lidar DEM: Los Angeles Region, CA"
C-4
♦
' ; J / '
/ I
♦ I
,,
I I •
-~ 1/
♦ -
...
I
·,
• ---♦ r
.... r
i
I .
......-..._. .. I
,, -....) ✓ -
------
__,,.
• ■
■
, J
■
■
■
■
■
■
■
■
■
■
Portuguese Bend Land Movement Monitoring Survey
October 10, 2023 (M38) through October 13, 2024 (M49)
Survey Report
for the
City of Rancho Palos Verdes
prepared by
McGee Surveying Consulting
Dated: October 30, 2023 with subsequent updates through November 8, 2024
Portuguese Bend is typically monitored for land movement on a tri-annual basis with an initial survey of all
current monitoring points at the beginning of the rainy season in the fall of each year followed by two
subsequent partial Winter and partial Spring Monitoring Surveys of 30-40 points. In past years, the survey
report was published following the spring survey; however, since the beginning of 2024 due to the excessive
land movement the surveys have been conducted every six weeks and now every month as listed below. The
October 10, 2023 M38 survey is reported here in detail and subsequent surveys are reported as Addendums
beginning with Addendum No. 1 for M39 on page 7. The movement results are listed in the attached “PB
MOVEMENT DATA POSTING M??…..xlsx”. Movements are reported for the average date of the survey listed
below.
List of Reported Monitoring Surveys
M38 Full Survey - October 10, 2023
M39 Full Survey - January 13, 2024
M40 Partial Survey - March 8, 2024
M41 Partial Survey - April 17, 2024
M42 Full Survey - May 28, 2024
M43 Full Survey - July 1, 2024
M44 Full Survey - August 1, 2024
M45 Full Survey - September 4, 2024
M46 Partial Survey - September 20, 2024
M47 Partial Survey - September 27, 2024
M48 Full Survey - October 8, 2024
M49 Partial Survey - October 13, 2024
M50 Partial Survey - October 20, 2024
M51 Full Survey - October 29, 2024
M52 Partial Survey – November 5, 2024
GNSS MONITORING NETWORK (M38)
OVERVIEW: McGee Surveying
Consulting (MSC) performed the 2023-
2024 land movement monitoring surveys
at Portuguese Bend. The surveys were
planned, coordinated, and executed by
Michael McGee, PLS3945 of MSC who
is responsible for the field surveys,
processing observations, network
adjustments, analysis, and reports. For a
general history, details and procedures
utilized in this survey but not re-stated
here, see the “Portuguese Bend Land
Movement 2020-2021 Monitoring
Survey” report dated October 5, 2021,
revised and published May 11, 2022. See
also prior reports.
D-1
RPV Portuguese Bend : Monitoring Survey
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 2 of 26
This Initial October 10, 2023 Survey determined the precise positions of 79 monitoring and control points.
PVE3 and other CSRC CGPS (CGNSS) stations were used to support and reference the survey network and
verify the recovery of the reference frame. This survey included two new points set in July 2023 for the M37
Survey in Klondike Canyon (Seaview) and ten new points set in September 2023. Additional points have been
set on most subsequent surveys as necessary and noted in the addendums. Point KC02 was replaced by KC24
nearby in the October in anticipation of its future destruction. Point AB21 was recovered from the 2007 survey
and substituted for nearby AB20 (destroyed by others) and will facilitated continuous monitoring at this
location. The movements of new points are included in this Report as an Addendums. All monitoring survey
coordinates and movements to date are listed in the spreadsheet “PB MOVEMENT DATA POSTING M??
2007-[present].xlsx” attached to this Report.
PROJECT DATUMS - REFERENCE FRAME
The horizontal and vertical positions of the monitoring points are based on the North American Datum of 1983
(NAD83) Epoch 2007.00 and the North American Vertical Datum of 1988 (NAVD 88) reference frames.
Although more current epoch adjustments are available e.g. NAD83 (2011) Epoch 2010.00, Epoch 2007.00 is
retained to maintain consistently relative positions over time. Orthometric heights (NAVD88 Elevations) are
based on measured ellipsoid heights combined with the NGS Geoid03 model and referenced to NGS
Benchmarks. Although more current geoid models (e.g. Geoid18), are available, Geoid03 is retained to maintain
consistently relative height movements over time as explained in said May 2022 Report. The latitudes and
longitudes determined by GNSS measurements are converted to grid coordinates by projected onto NAD83
California State Plane Coordinates Zone 5 in US Survey Feet.
A valid recovery of the survey reference frame is essential to accurately measure and assess actual movements
of individual points relative to the greater peninsula. The method for recovering the monitoring survey reference
frame was modified in 2019 to improve the efficiency and simplify the processing and analysis of the
monitoring surveys. Since 2007, Point AB02 (at the south end of Portuguese Point) has proven to be stable
relative to PVE3 which is a California Spatial Reference Center (CSRC) Continuously Operated GPS Station
(CGPS) at City Hall. The present procedure fixes PVE3RP (a PK Nail set on the concrete base of PVE3 as a
reference mark to PVE3) and checking to point AB02. The proven positions relative to PVE3 are listed below.
Pt# Latitude Longitude NAVD88 Ht Source)
AB02 33-44-13.84878 118-22-26.19243 116.47 ft 2007 - October 2018 position
PVE3RP 33-44-35.74239 118-24-15.27451 346.88 ft Average of 5 years referencing to PVE3
Comparing the positions of AB02 on Portuguese Point with PVE3RP at City Hall and other CSRC CGPS
Stations provides a redundant verification that the reference frame is stable and successfully recovered for each
monitoring survey. An additional stable check point “RP01” was established near the entrance to the Trump
Golf Course for verification on future surveys.
The rate of movement (velocities) of the land masses have increased over the past five years compared to the
previous 12-year average. See “Assessment of Movements & Accelerations” addressed on Page 11.
Notwithstanding the 2019 monitoring process noted above, the processing of observations was necessarily
modified for this fall survey because of the higher velocities as follows.
The October 2023 observations were processed as follows. The Base Station at AB73 was occupied over a six-
day period and was found to have moved about 0.016 feet per day similar to other monitoring points in the area.
To determine accurate positions and therefore precision movements it was necessary to determine a daily
position of AB73. This was accomplished by processing the static data collected each day at AB73 with static
data downloaded from the CSRC for CGPS stations PVE3 and PVHS. PVE3 is and has always been the basic
constraint for the monitoring survey’s reference frame. PVHS was used to verify the stability of PVE3.
Subsequently positions of AB73 were computed for each day referenced to PVE3. The identity for processing
the daily observations of AB73 and related RTK measurements was to assign to AB73 the identity of AB731,
AB732, AB733, AB734 & AB735 for days 1 through 5 occurring on October 8, 9, 10, 11 & 13.
D-2
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 3 of 26
BASE STATIONS – POINT NAMES
AB61 and AB20 have previously served as suitable GNSS Base Stations for referencing measured positions of
the monitoring points. AB61 is no longer accessed due to its environmental sensitivity and lack of security.
AB73, located on the US Pony Club property was utilized as the Base Station up to the October 2023 survey.
Access was obtained unilaterally by MSC from the Pony Club manager for exclusive permission to enter the
property confirmed prior to each survey entry with the understanding that 5 mph driving protocols are observed.
Point AB73 was not a planned monitoring point but given the increased rates of movement, it fills in a gap
between AB20 and AB50 and moves consistent with AB20. AB50 and AB73 are on the south and north sides of
PVDS respectively. The separation between AB73 and AB50 is diminishing at the rate of about one foot per
month in April 2024 resulting in a steeper slope on the north side of PVDS which may be de-stabilizing.
Due to the continuously increasing velocities of land movement, the present on-site base stations (AB20 and
AB73) are no longer stable for measuring relative movements. In the January 2024 survey the Smartnet RTN
network utilizing remote base stations connected by the Internet was used to measure positions and vectors
which were re-referenced to PVE3RP and PVE3 in a network least squares adjustment. Surveys subsequent to
the January survey are referenced to a new base station monument “RP02” set about 1400 feet northerly of the
entrance to Abalone Cove Park and ¼ mile westerly of the present active slide boundary. See discussion
hereafter.
October 2023 GNSS Survey Monitoring Points Network
The monitoring points names were established in the early surveys. The points are named for the slide they fall
within and given a number. For example, slides AB, PB, KC, CR and FT. The number is increased as new
points are established to replace abandoned or destroyed points or expand the network. Many of the original
points are lost or no longer monitored. For data management purposes the point names are also prefixed with a
sequential monitoring number to distinguish subsequent surveys. For example, for the occupation of AB02 on
the 16th monitoring survey, AB02 is called M16AB02 where M16 indicates the sequence number since the first
Monitoring Survey “M01” in September 2007. The prefix is stripped in the spreadsheet reports.
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Portuguese Bend: Monitoring Survey
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 4 of 26
GNSS October 2023 M38 Survey Parameters, Metadata & Equipment
Date of Annual Initial Survey: M38 – October 10, 2023 (mean date) between 0800-1700 PDST (+7 hrs for UTC).
Constellations: GPS (31 Satellites), Russian GLONASS (23 Satellites), Galileo (23 Satellites) and Beidue (40 Satellites).
Observables (Carrier Waves): GPS (L1, L2, L5), GLONASS (L1, L2), Beidue (L1, L2); & Galileo (4 Carrier Waves)
Data Epoch Rate - 0.2 seconds (20HZ) at the GS18 Rover; 1 second at the GS18 Base
Satellites: 20-40; GDOP: < 2; Elevation Mask: 0° at the Rover and Base Station
Ephemeris: Broadcast for RTK vectors.
Weather: Mostly calm clear skies, temperature 65-75° F, no significant weather.
Space Weather: Boulder K Index 1-3 averaging 2 (gauges ionospheric activity on a scale of 0-9; less than 6 preferred)
Equipment: GNSS Base Receiver Unit No. M11, Operator: M. McGee, PLS; Occupied Base Station
Receiver Make & Model: Leica GS18 with integrated Antenna; Mount: Tripod & Tribrach
GNSS Rover Receiver Unit No. M10, Operator: M. McGee, PLS
Receiver Make & Model: Leica GS18T with integrated Antenna; Mount: Fixed Height Pole #4
Processing & Adjustments: Leica Infinity v4.0 and "Starnet-PRO” version 11.0.6 Software
Prior to 2019, geodetic grade GNSS receivers collected static satellite signal data for post processing. The
instrumentation was upgraded in 2020 to a Leica GS18 Base with a GS18T RTK Rover operating in real-time
with an FM radio system which utilizes the latest technology to deliver increased productivity and precision of
point positions. The GS18 receiver incorporates an Inertial Measurement Unit and tracks four Global Navigation
Satellite Systems (GNSS): GPS, GLONASS, Galileo and Beidue Satellites. The differences in two measured
vectors are acceptable if they fall within 0.03 feet (1 cm) horizontally; otherwise, additional measurements are
usually obtained with some exceptions. Experience has shown the independent measurements generally agree on
average about 0.02 feet when referenced to a local base receiver.
ADJUSTMENTS & ANALYSIS
Network Adjustment: A minimally constrained adjustment is utilized to develop NAD83 (2007) 2007.00
Epoch Zone 5 State Plane Coordinates and NAVD88 Heights of the monitoring points. The NAVD88
orthometric heights (elevations) are determined by combining the measured ellipsoid heights with the Geoid 03
Model. Previously, Point AB02 was fixed, and the stability verified relative to PVE3RP which is 1.5 to 3 miles
westerly and outside the influence of the land movements. AB02 is expected to be stable and unaffected by the
land movement; however, due to the substantially increased rates of movement resulting in dynamically
differential movements the process was modified as noted above to assure accurate positions. This was
accomplished by computing daily positions on the Base Station AB73 (AB731, AB732, AB733, AB734,
AB735) relative to the reference frame fixed at station PVE3 noted above. Listed here are the differences.
Differences in Feet
ID dN dE dZ_
PVE3 0.000 0.000 Fixed Horizontal, CGPS Station at City Hall
AB02 -0.022 -0.008 0.000 Fixed Elevation & Horizontal Check
PVE3RP -0.010 -0.003 -0.055 Closure Check from PVE3 to AB73 to PVE3RP at City Hall
PVHS -0.035 0.003 Horizontal Check on CGPS Station 2 Miles North of PB
Comments: Fixing the CGPS station PVE3 finds the differences at CGPS Station PVHS, Reference Point
PVE3RP and Monitoring point AB02 are insignificant measurement noise. Given that AB02, PVE3RP, PVE3
and PVHS are in good relative agreement, the survey reference frame is deemed stable and successfully
recovered from which local land movements were determined.
NETWORK ADJUSTMENT & ANALYSIS
Vector Residuals: In this Initial Survey, the two-dimensional vector residuals averaged 0.012 feet and the
absolute value of the vertical residuals averaged 0.02 feet as listed below. The vector residuals are based on a
network adjustment of independent point positions.
Vector Lengths(ft) Two Dimensional Residuals Absolute Vertical Residuals
Vary Average Average Std.Dev. Maximum Average Std.Dev. _ Range
131-16391 3792 0.012 0.006 0.029 0.02 0.02 -0.03 to +0.08
Movement Accuracy: A point is deemed to have moved if, at the 95% level of confidence the horizontal
movement (signal) of a point between two epochs is greater than the 95% Error (noise). Based on multiple
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 5 of 26
independent occupations, the horizontal (2D) movements reported between October 2022 (M34) and October
2023 (M38) statistically attained a relative average accuracy of 0.014 feet at the 95% Level of Confidence with
a Standard Deviation of 0.004 feet and a Range of 0.01 to 0.03 feet. See the attached file “PB MOVEMENT
DATA POSTING …..xlsx” for movements and coordinates.
Table of 2D & Vertical Movements for 12.0 Months October 10, 2022 (M34) & October 10, 2023 (M38)
Listed below are the movement Azimuths (directions clockwise from North) in degrees, the two-dimensional
horizontal movements, and the vertical (elevation) changes during the period in US Survey Feet. See the
attached spreadsheet “PB MOVEMENT DATA POSTING…..xlsx”. Note: The horizontal measured movement
confidence is estimated at +/-0.02’ (1/4”); therefore, movements of less than 0.03’ are statistically indeterminate.
The estimated vertical measured movement confidence is +/-0.05’.
* = Control Point for Recovery of the Reference Frame.
Point
ID
Azimuth° Horizontal
Movement
Vertical
Movement
Point
ID
Azimuth° Horizontal
Movement
Vertical
Movement
AB01 244 0.06 0.0 KC02 196 1.99 0.1
AB02 201 0.02 0.0 KC05 219 0.88 -0.1
AB04 223 4.80 -0.6 KC06 253 1.34 -0.5
AB05 231 3.51 -0.6 KC07 256 0.02 0.0
AB13 198 2.48 -0.6 KC13 193 0.70 0.1
AB16 191 1.20 0.0 KC14 259 0.12 -0.1
AB17 187 0.06 0.0 KC15 233 1.36 -0.4
AB20 199 3.06 -0.1 KC16 251 0.03 0.0
AB24 198 2.68 0.0 KC17 222 1.24 -0.3
AB50 236 1.99 0.2 KC18 202 2.86 -0.3
AB51 202 2.05 -0.2 PB04 203 3.62 -0.3
AB53 192 2.75 -0.4 PB06 200 3.35 -0.3
AB57 169 2.37 -0.7 PB07 201 3.85 -0.1
AB58 183 2.22 -0.4 PB08 201 3.61 0.0
AB59 186 3.17 -0.8 PB09 198 3.49 -0.1
AB60 204 2.69 -0.3 PB12 200 4.67 -0.3
AB62 203 3.73 -0.4 PB13 201 3.83 0.1
AB63 207 3.58 -0.9 PB18 187 3.51 -0.5
AB64 155 0.35 -0.1 PB20 199 4.23 -0.4
AB65 167 1.49 -0.3 PB21 195 3.93 -0.6
AB66 196 2.29 -0.5 PB26 192 3.94 -0.4
AB67 180 1.12 -0.2 PB27 195 4.18 -0.8
AB68 193 2.03 -0.6 PB29 200 4.02 -1.0
AB70 203 2.97 -0.1 PB54 196 3.39 -0.2
AB71 158 1.76 -0.6 PB55 199 3.86 -0.8
AB73 203 3.00 -0.3 PB59 199 4.11 -0.6
CR07 171 1.87 -1.6 PB67 194 5.93 -0.8
CR50 225 0.11 -0.1 PB68 202 3.49 -0.1
CR51 223 0.08 0.0 PB69 202 3.91 -0.3
CR53 231 0.21 0.0 PB70 207 3.58 -0.8
FT06 192 3.66 -1.7 PB71 198 3.65 -0.4
FT08 257 0.06 0.0 UB02 189 4.17 0.3
FT09 271 0.08 -0.1 *PVE3RP 195 0.01 0.0
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 6 of 26
October 10, 2022 to October 10, 2023 Movement Distances (Feet) & Directions as Indicated
Note: Distances are exaggerated x 100 for viewing
Enlargement (PVDS) Enlargement (Seaview)
MONITORING POINT MONUMENT NOTES & STATUS
See the May 2022 Survey Report for prior monument notes.
2023: 16 points added to the monitoring program as listed below. AB20 destroyed after October 2023 Survey and replaced
by AB21. All other Point Descriptions are listed in prior Reports
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
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MONITORING POINT MONUMENT DESCRIPTIONS
California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and NAVD88 Datums are listed in the
attached spreadsheet file “PB MOVEMENT DATA POSTING….”.
Point Description
Points added in July and October 2023
AB21 2" Punched GIP in “Cable Box”, Replaced AB20 after Oct. 2023 survey
PB72 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
PB73 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
PB74 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
PB75 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
CR54 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
CW05 Found ½” x 48” Punched Rebar in Concrete Collar set June 2022 for CalWater
CW06 Found ½” x 48” Punched Rebar in Concrete Collar set June 2022 for CalWater
CW07 Found ½” x 48” Punched Rebar in Concrete Collar set June 2022 for CalWater
CW08 Found 2” Mag nail in Concrete Base of 3’ Bollard set June 2022 for CalWater
KC19 2” Mag Nail Drilled in a Concrete Curb on South side of Dauntless Dr.
KC20 2” Mag Nail Drilled in a Concrete Curb on West side of Excelsior Dr.
KC21 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
KC22 2" mag nail & washer in conc. in 2"x 24" GIP Collared in Concrete
KC23 2” Mag Nail Drilled in a Concrete Curb on South side of Admirable Dr.
KC24 2” Mag Nail Drilled in the Southwest Corner of a Concrete Vault, KC02 planned replacement
RP01 Check Point at Trump Golf Course established in July 2023 for verifying the
recovery of a stabile reference frame. Point is the top open part of the “B”
on the south side of the rim of a manhole on the south side of PVDS at Conqueror Dr.
Addendum No. 1 Report
Portuguese Bend Land Movement Monitoring Survey
Early Winter Full Monitoring Survey No. M39 - January 13, 2024
A special Portuguese Bend Full Monitoring Surveys (M39) was requested by the City in January 2024. The
average date of the survey is January 13, 2024, 3.1 months after the October 10, 2023 Initial Monitoring for
2023-2024 reported above. The M39 survey included 79 monitoring points representing the present full
network. A central base station (usually occupying AB73) was not feasible due to the excessive rate of land
movement and reliance was made on the remote Smartnet RTN Stations which resulted in a lesser accuracy. For
this survey, this was not an issue since the signal (measured movement) was much greater than the noise of the
measurements expected to be less than 0.05’. A typical minimally constrained adjustment, as described above
for M38, was processed for M39 to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates
and NAVD88 Heights.
The horizontal (2D) vector residuals averaged 0.03 feet with a Standard Deviation of 0.02 feet. The absolute
value of the vertical residuals averaged 0.04 feet with a Standard Deviation of 0.04 feet. At the 95% Level of
Confidence, estimated accuracy of the horizontal (2D) movements is 0.05 feet.
NETWORK ADJUSTMENT & ANALYSIS
The network adjustment fixed point PVE3RP (an indirect fix on PVE3) and checked to other points found to be
stable. Differences from the known fixed positions to the measured positions in this survey are listed here with
their north, east and vertical components in feet. The successful recovery of a stable reference frame (coordinate
system) is confirmed.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.00 0.00 0.00 Fixed Reference at City Hall
AB02 0.01 0.01 -0.05 Check Point at Portuguese Point
RP01 -0.01 0.01 0.05 Check Point at Trump Golf Course
Table of 2D & Vertical Movements for 3.1 Months October 10, 2023 (M38) & January 13, 2024 (M39)
Listed below are the movement Azimuths (directions clockwise from North) in degrees, the two-dimensional
horizontal movements, and the vertical (elevation) changes during the period in US Survey Feet. See the
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 8 of 26
attached spreadsheet “PB MOVEMENT DATA POSTING (Revised 012224) 2007-Jan2024.xlsx”. Note: The
horizontal measured movement confidence is estimated at +/-0.04’ (1/2”); therefore, indicated movements of
less than 0.05’ are statistically indeterminate. The estimated vertical measured movement confidence is +/-0.08’.
* = Control Point for Recovery of the Reference Frame.
Point
ID
Azimuth° Horizontal
Movement
Vertical
Movement
Point
ID
Azimuth° Horizontal
Movement
Vertical
Movement
AB01 23 0.01 -0.1 KC13 188 0.44 0.0
AB02 27 0.01 0.0 KC14 262 0.03 0.0
AB04 223 3.52 -0.4 KC15 233 0.91 -0.3
AB05 230 2.76 -0.4 KC16 88 0.02 0.0
AB13 195 2.44 -0.4 KC17 218 0.80 -0.3
AB16 190 1.71 -0.1 KC18 200 2.03 -0.3
AB17 118 0.03 0.0 KC19 269 0.74 -0.2
AB21 197 2.80 0.1 KC20 277 0.67 -0.2
AB24 195 2.71 0.0 KC21 92 0.04 0.0
AB50 234 1.63 0.0 KC22 255 1.07 -0.5
AB51 200 2.08 0.0 KC23 237 0.57 -0.3
AB53 190 2.79 -0.3 KC24 199 1.22 -0.1
AB57 170 1.77 -0.5 PB04 202 2.63 0.0
AB58 179 2.50 -0.4 PB06 200 2.43 -0.2
AB59 185 3.11 -0.8 PB07 201 2.62 0.0
AB60 204 2.54 -0.2 PB08 201 2.60 0.0
AB62 203 2.62 -0.3 PB09 197 2.40 -0.1
AB63 207 2.79 -0.8 PB12 199 3.16 -0.3
AB64 128 0.19 0.0 PB13 199 2.51 0.0
AB65 167 1.98 -0.6 PB18 185 2.94 -0.5
AB66 193 2.41 -0.4 PB20 198 2.82 -0.3
AB67 181 1.56 -0.3 PB21 194 2.66 -0.5
AB68 191 2.28 -0.4 PB26 193 2.65 -0.2
AB70 200 2.85 -0.2 PB27 196 2.75 -0.5
AB71 158 1.35 -0.4 PB29 200 2.60 -0.7
AB73 202 2.52 -0.1 PB54 192 2.90 0.0
CR07 164 1.47 -1.2 PB55 198 2.88 -0.5
CR50 37 0.04 0.0 PB59 200 2.86 -0.3
CR51 107 0.04 0.2 PB67 195 3.32 -0.3
CR53 180 0.02 0.1 PB68 202 2.57 0.0
CR54 185 2.81 -0.9 PB69 201 2.82 -0.1
CW05 185 0.02 0.1 PB70 204 2.72 -0.3
CW06 59 0.05 0.1 PB71 197 2.90 0.0
FT06 191 2.48 -1.1 PB72 206 2.73 0.3
FT09 148 0.02 0.2 PB73 190 2.49 -0.4
KC02 193 1.30 0.0 PB74 193 3.08 -0.4
KC05 215 0.55 0.0 PB75 193 2.89 -0.1
KC06 256 0.94 -0.4 UB02 189 2.74 0.2
KC07 135 0.01 0.0 *PVE3RP 0 0 0.1
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 9 of 26
October 10, 2023 to January 13, 2024 Movement Distances (Feet) & Directions as Indicated
Note: Movement distances exaggerated 100x for viewing
Enlargement (PVDS) Enlargement (Seaview )
D-9
Movements Oct. 10, 2023 to Jan. 13, 2024
Movements Oct. 10, 2023 to Jan .13, 2024
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 10 of 26
ASSESSMENT of MOVEMENT VELOCITIES & ACCELERATIONS 2014 to 2024
Others performed monitoring surveys of the Portuguese Bend land movement between 1994 and 2006. McGee
Surveying Consulting assumed responsibility and defensibility for the Portuguese Bend Monitoring Program in
2007. The annual measured movements between 2007 and 2018 were fairly small and stable as shown below by
the averages and maximums of a sampling of points for the 2014-2018 period. The fall 2019 monitoring survey
found the annual rate of movements (velocities) increased (accelerated) about 4 to 6 times and remained stable
for the next four years through 2022. A “year” here is defined as the 12-month period beginning with the rainy
season on October 1st.
Annual Average Movements in Feet, Maximum Movements & Change in the Average of a Sample of Points
2014-2018(4 Yrs) 2018-2022(4 Yrs) Change in
ID Average Max. Average Max.__ _ Average
AB20 0.09 0.20 0.48 0.54 +5X
AB53 0.07 0.18 0.43 0.49 +6X
AB68 0.05 0.11 0.31 0.32 +6X
CR07 0.06 0.13 0.30 0.32 +5X
KC06 0.04 0.09 0.16 0.22 +4X
PB55 0.89 1.31 0.89 1.23 +1X (No Change)
In the following twelve months between October 2022 and October 2023, the annual rate of movements were
found to have again accelerated. The table below shows a sample of points within Abalone Cove (AB),
Klondike Canyon (KC) and Portuguese Bend (PB). The left half of the table compares the annual movements
and rate of movements per month for the October 2021 to October 2022 with the October 2022 to October 2023
period. The annual rate of movement for the sample averages in each slide increased about 6x for AB, 8x for KC
and 5x for PB.
In the same 12-month period between October 2022 and October 2023, accelerations were noted in the first
seven months over the previous year and again in the last five months over the previous seven months as shown
in the right half of the table below. The average rate of movement in each slide for these samples in the first
seven months October 2022 through April 2023 increased about 3x for AB, 4x for KC and 2x for PB over the
previous 12-month period of October 2021 to October 2022. The average rate of movements in each slide for
the samples in the last five months May 2023 to October 2023 increased 4x for AB, 4x for KC and 3x for PB
over the previous seven months.
October 2021 to October 2023 Movements & Rates per Month (Feet) M32 > M34 (12 Mo.) M34 > M38 (12 Mo.) M34 > M36 (7 Mo.) M36 > M38 (5 Mo.)
Point Oct '21 > Oct '22 Oct '22 > Oct '23 Oct '22 > May '23 May '22 > Oct '23 Movement Rate/Mo Movement Rate/Mo Movement Rate/Mo Movement Rate/Mo
AB20 0.51 0.042 3.06 0.255 0.84 0.119 2.22 0.444
AB53 0.49 0.041 2.75 0.229 0.74 0.105 2.01 0.403
AB58 0.41 0.034 2.22 0.185 0.60 0.085 1.62 0.325
AB60 0.45 0.038 2.69 0.224 0.80 0.114 1.90 0.379
AB67 0.18 0.015 1.12 0.094 0.32 0.046 0.80 0.160
AB68 0.32 0.027 2.03 0.169 0.54 0.077 1.49 0.299
AB70 0.48 0.040 2.97 0.248 0.84 0.120 2.14 0.427
CR07 0.31 0.026 1.87 0.156 0.44 0.062 1.43 0.287
Av Move 0.39 0.033 2.34 0.195 0.64 0.091 1.70 0.340
KC06 0.16 0.014 1.34 0.111 0.33 0.047 1.01 0.202
KC13 0.09 0.007 0.70 0.058 0.19 0.027 0.51 0.102
KC17 0.14 0.012 1.24 0.104 0.31 0.044 0.93 0.187
Av Move 0.13 0.011 1.09 0.091 0.27 0.039 0.82 0.163
PB55 0.80 0.067 3.86 0.321 1.06 0.151 2.80 0.560
PB70 0.72 0.060 3.58 0.299 1.14 0.163 2.44 0.488
Av Move 0.76 0.063 3.72 0.310 1.10 0.157 2.62 0.524
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McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 11 of 26
Movement & Rate of Movement per Month
In the last 3-month period October 10, 2023 to January 13, 2024,
accelerations were noted again relative to the previous 12-months.
The average rate of movements in each slide for the last 3-months
for these samples increased about 4x for AB, 3x for KC and 3x for
PB over the previous 12-month period of October 2022 to October
2023.
RECOMMENDATION
Continuity in the methods, precision and reporting of the monitoring surveys are necessary to evaluating results
relative to and consistent with prior 2007-2024 monitoring survey campaigns. Monitoring survey campaigns
require the services of an independent GNSS/Geodetic expert to evaluate and validate results to assure program
integrity and defensibility.
Maintaining a clearing of foliage in a 10’ radius around monitoring points and trimming nearby trees and brush
above eye height is necessary to assure a clear view of the sky for tracking satellites. Satellites, although unseen,
can appear anywhere in the sky above the horizon and the radio signals passing through foliage degrade the
required survey accuracy and productivity. Points AB04, AB13, AB17, AB24, AB51, AB58, AB66, PB18, PB54,
PB55, CR51 and CR53 have foliage obstructions limiting sky (satellite) visibility and require clearing to facilitate
accurate results of the surveys.
Addendum No. 2 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M40 – March 8, 2024
This is the mid-winter Partial Monitoring Survey No. M40 Report. The average date of the survey is March 8,
2024, 1.8 months after the January 13, 2024 Full Monitoring Survey. The survey included 44 monitoring points
and 3 reference control points. Occupying a central base station (usually AB73) was not feasible due to the
excessive rate of land movement and reliance was made on the remote Smartnet RTN Stations which resulted in
a lesser accuracy. For this survey, this was not an issue since the signal (measured movement) was much greater
than the noise of the measurements expected to be about less than 0.05’.
NETWORK ADJUSTMENT & ANALYSIS
A typical minimally constrained network adjustment, as described above for survey M38, was processed for
M40 to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. The
adjustment fixed point PVE3RP and checked to other points expected to be and found stable. Differences from
Point M38 > M39 (3.1 Mo.) Oct. 10, 2023
to Jan. 13, 2024 Movement Rate/Mo
AB20 2.80 0.90
AB53 2.79 0.90
AB58 2.50 0.81
AB60 2.54 0.82
AB67 1.56 0.50
AB68 2.28 0.73
AB70 2.85 0.92
CR07 1.47 0.47
Average 2.35 0.76
KC06 0.94 0.30
KC13 0.44 0.14
KC17 0.80 0.26
Average 0.73 0.24
PB55 2.88 0.93
PB70 2.72 0.88
Average 2.80 0.90
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the known fixed positions to the measured positions in this survey are listed here with their north, east and
vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.00 0.00 0.00 Fixed Reference at City Hall
AB02 0.02 0.01 -0.09 Check Point on Portuguese Point
RP01 0.00 0.02 -0.10 Check Point at Trump Golf Course
The successful recovery of a stable horizontal reference frame confirmed. The Z height variations are attribted
to the noise in the Smartnet Network solution. RP01 is intended to replace AB02.
2D Horizontal & Vertical Movements for 1.8 Months January 13, 2024 (M39) to March 8, 2024 (M40)
The general rate of land movement increased significantly over the January 13, 2024 survey assessment. See the
attached spreadsheet “PB MOVEMENT DATA POSTING…. .xlsx” for the movement Azimuths (directions
clockwise from North) in degrees, the two-dimensional horizontal movements, and the vertical (elevation)
changes during the period in US Survey Feet. See also the column for the rate of movement for each period
annualized for an average month.
Accuracy Statements
The horizontal (2D) vector residuals averaged 0.04 feet with a Standard Deviation of 0.03 feet. The absolute
value of the vertical residuals averaged 0.04 feet with a Standard Deviation of 0.03 feet.
At the 95% Level of Confidence, the accuracy of the horizontal (2D) movements is estimated to be less than
0.04’. Movements of less than 0.05’ are statistically indeterminate. The estimated vertical measured movement
confidence is 0.06’ to 0.09’.
Addendum No. 3 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M41 – April 17, 2024
This is the Spring Partial Monitoring Survey No. M41 Addendum Report. The field survey took place April 16-
18, 2024, average date of April 17, 2024, 1.35 months after the last March 8, 2024 Monitoring Survey. The
survey included 55 monitoring points and 3 reference control points. Eleven new monitoring points were set and
surveyed. The location of two new points were identified and will be surveyed on the next campaign in late May
after the monuments are set by others. See the points descriptions below.
Occupying previous base stations was not feasible due to the excessive rate of land movement. The Smartnet
RTN Network does not require a base station but results in a somewhat lesser accuracy. Smartnet may be used
in the future; however, it was deemed beneficial to establish a new base station outside the slide complex to
facilitate future surveys. A new base station point “RP02” was set westerly of the slide complex and north of
Abalone Cove Park.
NETWORK ADJUSTMENT & ANALYSIS
A typical minimally constrained adjustment, as described above for the M38 survey, was processed for M41 to
develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least
sqaures network adjustment was fixed at point PVE3RP to establish a position on the base at RP02 and thereby
all other points in the survey. A check to RP01 easterluy outside the slide complex was made as noted below.
This process will be the standard on future surveys. Differences from the known fixed positions to the measured
positions in this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.00 0.00 0.00 Fixed Reference at City Hall
RP01 -0.01 0.00 -0.03 Check Point at Trump Golf Course
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Page 13 of 26
The successful recovery of a stable horizontal reference frame is confirmed. Point AB02 replaced by RP01, was
used in previous surveys to also confirm recovery of the reference frame has limited access do to the slides.
2D Horizontal & Vertical Movements for 1.35 Months March 8, 2024 (M40) to April 17, 2024 (M41)
The general rate of land movement increased significantly over the March survey. On average the velocities
increased 76% with a maximum of 143%. Eight points doubled their velocities in the last six weeks over the
previous eight weeks. In Abalone Cove and Portuguese Bend Slides many points are moving about three feet per
month and in the Seaside Klondike Canyon Slide about ¾ of a foot per month. See the attached spreadsheet “PB
MOVEMENT DATA POSTING…. .xlsx” for the movement Azimuths (directions clockwise from North) in
degrees, the two-dimensional horizontal movements, and the vertical (elevation) changes during the period in
US Survey Feet. See also the column for the rate of movement for each period annualized for an average month.
Accuracy Statements
The horizontal (2D) vector residuals averaged 0.04 feet with a Standard Deviation of 0.03 feet. The absolute
value of the vertical residuals averaged 0.04 feet with a Standard Deviation of 0.03 feet.
The land is moving 0.05’ to 0.10’ daily. Most points are measured a day apart resulting in large residuals but
accurate positions of the mean coordinate. Therefore, it is at estimated the 95% Level of Confidence, the
accuracy of the horizontal (2D) movements is estimated to be less than 0.03’. Movements of less than 0.04’ are
statistically indeterminate. The estimated vertical measured movement confidence is 0.05’ to 0.10’.
Monitoring Point Monument Descriptions
See prior Reports for all other Point Descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING….” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and NAVD88 Datums n
Point Description of Points added in April 2024
AB74 8" Spike set as temporary monument to be replaced with a 2” GIP by others
AB75 8" Spike set as temporary monument to be replaced with a 2” GIP by others
AB76 8" Spike set as temporary monument to be replaced with a 2” GIP by others
AB77 Location identified, 2” GIP to be set by others
CR55 Set Mag Nail drilled in a Concrete walk/valley gutter
CR56 Location identified, 2” GIP to be set by others
KC25 Set Mag Nail drilled in a concrete & rock wall
KC26 Set Mag Nail drilled in a concrete wall
KC27 Set Mag Nail drilled in a concrete 6’ fire pit
KC28 Set Mag Nail drilled in a concrete headwall
KC29 Set Mag Nail drilled in a concrete headwall
KC30 8" Spike set as temporary monument to be replaced with a 2” GIP by others
KC31 8" Spike set as temporary monument to be replaced with a 2” GIP by others
RP02 ½” x 4’ rebar in large sloping meadow with T-bar witness for new base station
Addendum No. 4 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M42 – May 28, 2024
This is Full Monitoring Survey No. 42 Addendum Report. The field survey took place May 27-30, 2024, with an
average date of May 28, 2024, 1.35 months after the last April 17, 2024 Partial Monitoring Survey. The survey
included 93 monitoring points and 3 reference control points. Two new monitoring points (AB77 & CR56) were
set and surveyed. Seven temporary monuments were reset with a permanent monument. Monuments CW01,
CW07 and CW08, set in 2022 for CalWater, were adopted for the purpose of these surveys. See the point
descriptions below.
There are 14 monitoring points in the upper portion of the Reserve which are now difficult and time consuming
to access due to the slides. An assistant provided by sub-contractor Chris Nelson & Associates (CNA) has been
assigned these locations beginning with this May survey. CNA conducted their survey measurements with a
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Trimble R12 referenced to the Smartnet RTN for positioning. These monitoring point observations were
referenced to the RPV Portuguese Bend network by way of connections to RP01, RP02 & PVE3RP. In the late
June survey, CAN will be using Leica instrument similar to those used by McGee Surveying Consulting to
assure the highest precision and increased productivity.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment, as described above for the above M38 Survey Report, was processed for
M42 to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A
least sqaures network adjustment was fixed at point PVE3RP to establish a position on the base at RP02 and
thereby all other points in the survey. A check to RP01 easterly outside the slide complex and other nearly stable
points were made as noted below. Differences from the known fixed positions to the measured positions by this
survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.00 -0.00 -0.00 Fixed Reference at City Hall
RP01 -0.00 0.01 -0.01
RP02 -0.03 0.02 -0.01
AB02 0.00 -0.02 0.09
The successful recovery of a stable reference frame is confirmed. Point RP01 is intended to superseded AB02
used in previous surveys to confirm recovery of the reference frame. AB02 now has limited access do to the
slides. Additionally, California Spatial Reference Center CGPS (Continous Operating GPS Stations) PVE3 and
PVHS are incorporated from time to time to verify the stability of the refence frame.
2D Horizontal & Vertical Movements for 1.35 Months April 17, 2024 (M41) to May 28, 2024 (M42)
The general rate of land movement increased in the last six weeks over the April survey. On average the
velocities increased about 40% which is an increased rate of movement; however, the rate of acceleration is less
than the estimated average of 76% in the previous six weeks. See the attached spreadsheet “PB MOVEMENT
DATA POSTING…. .xlsx” for the movement Azimuths (directions clockwise from North) in degrees, the two-
dimensional horizontal movements, and the vertical (elevation) changes during the period in US Survey Feet.
See also the column for the rate of movement for each period annualized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
The rate of land movement varies and is as much as 0.12’ daily. It is estimated at the 95% Level of Confidence,
the accuracy of the horizontal (2D) movements is estimated to be 0.04-0.06’. Movements less than the
Confidence Interval are statistically indeterminate. The estimated vertical measured movement confidence is
0.05’ to 0.10’.
Monitoring Point Monument Descriptions
See prior Reports for all other Point Descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING….” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and NAVD88 Datums n
Addendum No. 5 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M43 – July 1, 2024
This is Full Monitoring Survey No. 43 Addendum Report. The field survey took place June 30, 2024 to July 3,
2024 with an average date taken as July 1, 2024, 1.12 months after the last May 28 Monitoring Survey. The
survey included 93 monitoring points and 3 reference control points.
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14 monitoring points in the upper portion of the Reserve require about three miles of hiking to access due to the
slides. An assistant provided by sub-contractor Chris Nelson & Associates (CNA) is assigned these locations. A
loaner GS18 Leica instrument same as used by McGee Surveying Consulting (MSC) and connected to MSC’s
RTK base station is utilized to assure the highest precision and increased productivity.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment, as described above for the above M38 Survey Report, was processed for
M43 to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A
least sqaures network adjustment was fixed at point PVE3RP to verify the position on the base at RP02 and
thereby all points in the survey. A check to RP01 easterly outside the slide complex, AB02 and other nearly
stable points were made as noted below. Differences from the known fixed positions to the measured positions
by this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.00 -0.00 -0.00 Fixed Reference at City Hall
RP01 +0.01 -0.01 -0.00
RP02 -0.03 0.02 -0.01
AB02 -0.01 -0.02 +0.03
PVE3 +0.01 +0.00 -0.11 CSRC CGPS Station at City Hall
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Because AB02 has limited access do to the slides, Point RP01 is
intended to suplement AB02 used in previous surveys to confirm recovery of the reference frame. Additionally,
California Spatial Reference Center CGPS (Continous Operating GPS Stations) PVE3 and PVHS are
incorporated to verify the stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for 1.12 Months M42 to M43
The rate of land movement varies and averages about 3 feet per average month with a maximum of 4.88 feet.
The general rate of land movement increased about 25% on average; however, the rate of acceleration is less as
indicated by the estimated average increase of 41% in the rate of land movement in the previous month. See the
attached spreadsheet “PB MOVEMENT DATA POSTING…. .xlsx” for the movement Azimuths (directions
clockwise from North) in degrees, the two-dimensional horizontal movements, and the vertical (elevation)
changes during the period in US Survey Feet. See also the column for the rate of movement for each period
annualized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
It is estimated at the 95% Level of Confidence, the accuracy of the horizontal (2D) movements is estimated to
be 0.04-0.06’. Movements less than the Confidence Interval are statistically indeterminate. The estimated
vertical measured movement confidence is 0.05’ to 0.10’.
Monitoring Point Monument Descriptions
See prior Reports for Point Descriptions. See the attached spreadsheet file “PB MOVEMENT DATA POSTING….” for
California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and elevations in the NAVD88 Datum.
Point Description: Update of Points set in April & May
AB74 1/2” x 4’ rebar encased in concrete witnessed by a steel t-bar post
AB75 1/2” x 4’ rebar encased in concrete witnessed by a steel t-bar post
AB76 1/2” x 4’ rebar encased in concrete witnessed by a steel t-bar post
AB77 1” x 24” GIP with cap “Control Point” encased in concrete witnessed by a steel t-bar post
CR56 1” x 24” GIP with cap “Control Point” encased in concrete witnessed by a steel t-bar post
CW07 ½” x 4’ punched rebar in concrete with T-bar witness post
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CW08 ½” x 4’ punched rebar in concrete with T-bar witness post
KC30 1/2” x 4’ rebar encased in concrete witnessed by a steel t-bar post
KC31 8” spike set between two steel posts in line with a string of boulders
KC32 Temporary reference to KC31, took west side of chain link fence post south of PVDS
KC33 Found 1.5” GIP for Property Corner on top of dyke
RP02 ½” x 4’ punched rebar in concrete in large sloping meadow witnessed by a steel T-bar post
Addendum No. 6 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M44 – August 1, 2024
This is Full Monitoring Survey No. 44 Addendum Report. The field survey took place July 30, 2024 to August
3, 2024 with an average date taken as August 1, 2024, 1.02 months after the last July 1 Monitoring Survey. The
survey included 98 monitoring points and 3 reference control points (RP01, RP02, PVE3RP & AB02).
Many of the monitoring points in the upper portion of the Reserve require substantial hiking for access due to
the slides. An assistant provided by sub-contractor Chris Nelson & Associates (CNA) is assigned these
locations.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment, as described above for the above M38 Survey Report, was processed for
M44 to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A
least sqaures network adjustment was fixed at point PVE3RP to verify the position at the base station point
RP02 and thereby all points in the survey. A check to RP01 easterly outside the slide complex, AB02 and other
nearly stable points were made as noted below. Differences from the known fixed positions to the measured
positions by this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.00 -0.00 -0.00 Fixed Reference at City Hall
RP01 0.03 -0.03 0.01 Check Point
RP02 -0.00 0.01 0.07 Base Station
AB02 -0.01 0.00 0.07 Check Point
AB17 0.00 0.00 0.05 Point Historically Not Moving
CW01 0.01 0.02 0.11 Point Historically Not Moving
KC16 0.00 0.01 0.10 Point Historically Not Moving
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Because AB02 has limited access do to the slides, Point RP01 is
intended to supplement AB02 used in previous surveys to confirm recovery of the reference frame.
Additionally, California Spatial Reference Center CGPS (Continous Operating GPS Stations) PVE3 and PVHS
are incorporated at times for additional verification of the stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for 1.02 Months M43 to M44
The rate of land movement varies and averaged about 2.8 feet per average month in the last period with a
maximum of 4.69 feet per month. The general change in the rate of land movement (velocity) slowed and varied
from about -13% to +13% and averaged nearly zero. See the attached spreadsheet “PB MOVEMENT DATA
POSTING…. .xlsx” for the movement Azimuths (directions clockwise from North) in degrees, the two-
dimensional horizontal movements, vertical (elevation) changes during the period in US Survey Feet. See also
the column for the rate of movement for each period annualized for an average 30.42-day month.
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Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
It is estimated at the 95% Level of Confidence, the accuracy of the horizontal (2D) movements is estimated to
be 0.04’. Movements less than the Confidence Interval are statistically indeterminate. The estimated vertical
measured movement confidence is about 0.05’ to 0.10’.
Monitoring Point Monument Descriptions
See prior Reports for Point Descriptions. See the attached spreadsheet file “PB MOVEMENT DATA POSTING….” for
California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and elevations in the NAVD88 Datum.
Points AB71 and CR07 destroyed since the last monitoring survey by slides and construction.
Point Description: Update of Set Points
AB78 2” Magnetic Nail drilled in a concrete curb on the N. side of Vanderlip Dr., replaced AB71
CR57 ½” x 4’ punched rebar in concrete with T-bar witness post, replaces CR07
KC34 2” Magnetic Nail set in Stalwart Dr. East of Schooner Dr.
KC35 2” Magnetic Nail set in Xn of Schooner & Stalwart Dr.
KC36 2” Magnetic Nail set in Xn of Schooner & Admirable Dr.
KC37 Punch mark on north side Sewer MH in Admirable Dr. East of Schooner Dr.
Addendum No. 7 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M45 – September 4, 2024
This is Full Monitoring Survey No. 45 Addendum Report. The field survey took place September 3, 2024 to
September 6, 2024 with an average date taken as September 4, 2024, 1.12 months after the last Monitoring
Survey. The survey included 102 monitoring points and 3 reference control points (RP01, RP02, PVE3RP &
AB02).
Many of the monitoring points in the upper portion of the Reserve require substantial hiking for access due to
the slides. An assistant provided by sub-contractor Chris Nelson & Associates (CNA) is assigned these
locations.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed for the M45 survey to develop NAD83 (2007) Epoch
2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was
fixed at point PVE3RP to verify the position at the base station point RP02 and thereby all points in the survey.
A check to RP01 easterly outside the slide complex, AB02 and other nearly stable points were made as noted
below. Differences from the known fixed positions to the measured positions by this survey are listed here with
their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
AB02 -0.02 -0.02 0.00 Check Point
PVE3RP -0.00 -0.00 -0.00 Fixed Reference at City Hall
RP01 -0.02 0.01 0.05 Check Point
RP02 0.01 0.00 0.02 Base Station
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Because AB02 has limited access do to the slides, Point RP01 is
intended to supplement AB02 used in previous surveys to confirm recovery of the reference frame.
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Additionally, California Spatial Reference Center CGPS (Continous Operating GPS Stations) PVE3 and PVHS
are incorporated periodically for additional verification of the stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for 1.12 Months M44 to M45
The rate of land movement varies and averaged about 2.6 feet per average month in the last period with a
maximum of 4.0 feet per month. The general change in the rate of land movement (velocity) slowed and varied
from about -25% to +1% and averaged -13%. See the attached spreadsheet “PB MOVEMENT DATA
POSTING…M??. .xlsx” for the movement Azimuths (directions clockwise from North) in degrees, the two-
dimensional horizontal movements, vertical (elevation) changes during the period in US Survey Feet. See also
the column for the rate of movement for each period annualized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
It is estimated at the 95% Level of Confidence, the accuracy of the horizontal (2D) movements are estimated at
0.04’. Movements less than the Confidence Interval are statistically indeterminate. The estimated vertical measured
movement confidence is about 0.05’ to 0.10’.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…M??.” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
Points KC27 and PB73 were destroyed since the last monitoring survey by construction. PB73 was reset nearby
as new point PB76. Other new points are reported as follows: AB79, AB80, CR55A (replaces CR55), CR58,
CR59, FT10, & KC38 on the offshore uplift. The uplifted area is generally about 11 feet above mean lower low
water. Points KC34, KC35, KC36 & KC37 were set last month along and easterly of Schooner to assess if
movement was occurring in that area. No movement was detected above the noise level of the measurements.
Point Description: Update of Set Points
AB79 Found L&T on curb of 31&34 San Clemente Dr.
AB80 2” Magnetic Nail drilled into the asphalt road on Santa Catalina Dr.
CR55A Punch in center of square plastic marker in centerline of Valley View Dr.
CR58 Set 5/8”x 4’ rebar/ plastic cap “Control Pt”
CR59 Set 5/8”x 4’ rebar/ plastic cap “Control Pt”
FT10 Set 1”x 18” GIP/ plastic cap “Control Pt”
KC38 8” Spike on small bentonite rise in uplift 300’ south of old shoreline
Addendum No. 8 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M46 – September 20, 2024
This is Partial Monitoring Survey No. 46 Addendum Report. The field survey took place September 20 2024
0.53 months after the last M45 Monitoring Survey. The survey included 19 monitoring points along PVDS and
4 reference control points (RP01, RP02, RP03 & PVE3RP).
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed for the M46 survey to develop NAD83 (2007) Epoch
2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was
fixed at point RP02 and a check was made to PVE3RP and RP01 noted below. Differences from the known
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fixed positions to the measured positions by this survey are listed here with their north, east and vertical
components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.01 0.00 0.02 Reference at City Hall
RP01 -0.03 0.00 0.02 Check Point
RP02 0.00 0.00 0.00 Fixed Base Station
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Additionally, California Spatial Reference Center CGPS (Continous
Operating GPS Stations) PVE3 and PVHS are incorporated periodically for additional verification of the
stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for 0.56 Months M45 to M46
The rate of land movement for this sub-set of 19 points along PVDS varies and averaged about 1.9 feet per
average month in the last period with a maximum of 2.6 feet per month. The general change in the rate of land
movement (velocity) slowed and varied from about -47% to -7% and averaged -27%. See the attached
spreadsheet “PB MOVEMENT DATA POSTING…M??. .xlsx” for the movement Azimuths (directions
clockwise from North) in degrees, the two-dimensional horizontal movements, vertical (elevation) changes
during the period in US Survey Feet. See also the column for the rate of movement for each period annualized
for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
It is estimated at the 95% Level of Confidence, the accuracy of the horizontal (2D) movements are estimated at
0.04’. Movements less than the Confidence Interval are statistically indeterminate. The estimated vertical
measured movement confidence is about 0.05’ to 0.10’.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…M??.” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
Point Description: Update of Set Points
RP03 Set 1/2”x 4’ rebar in open field, bears N69-30E 44.37’ from RP02 Set as a new reference point to
allow for operating a second base station and for a check.
Addendum No. 9 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M47 – September 27, 2024
This is Partial Monitoring Survey No. 47 Addendum Report. The field survey took place September 27, 2024
0.23 months after the last M46 Monitoring Survey. The survey included 19 monitoring points along PVDS and
4 reference control points (RP01, RP02, RP03 & PVE3RP). See the attached spreadsheet “PB MOVEMENT
DATA POSTING... .xlsx” for the movements.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed for the M47 survey to develop NAD83 (2007) Epoch
2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was
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fixed at point RP02 and a check was made to PVE3RP and RP01 noted below. Differences from the known
fixed positions to the measured positions by this survey are listed here with their north, east and vertical
components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.00 -0.01 0.03 Reference at City Hall
RP01 -0.02 0.04 0.00 Check Point
RP02 -0.00 -0.00 -0.00 Check Point
RP03 0.00 0.00 -0.01 Fixed Base Station
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Additionally, California Spatial Reference Center CGPS (Continous
Operating GPS Stations) PVE3 and PVHS are incorporated periodically for additional verification of the
stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for 0.23 Months M46 to M47
In the “PB MOVEMENT DATA POSTING” spreadsheet, the measured land movements are listed for the
period and also for a normalized average month of 30.42 days for comparing the rates of movement for previous
periods. This survey included a sub-set of 19 points along PVDS. The movements vary and average about 1.4
feet with a maximum of 2.2 feet for an average month. The change in the rate of land movement (velocity) over
the previous period slowed and varies from about -55% to -15% averaging about -30%. The attached
spreadsheet “PB MOVEMENT DATA POSTING... .xlsx” lists the movement azimuths (directions clockwise
from north) in degrees, the two-dimensional horizontal movements, and vertical (elevation) changes during the
period in US Survey Feet. See also the column for the rate of movement for each period normalized for an
average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.02 feet with a Standard Deviation of 0.03 feet. The
absolute value of the vertical vector residuals are estimated at 0.03 feet with a Standard Deviation of 0.04 feet.
Between two surveys, the accuracy of the measured horizontal (2D) movements is estimated, at the 95% Level
of Confidence, at 0.04’. Movements less than the Confidence Interval are statistically indeterminate. The
estimated vertical measured movement confidence is about 0.05’ to 0.10’ depending on obstructions to satellite
signals.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING….” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
Addendum No. 10 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M48 – October 8, 2024
This is Full Monitoring Survey No. M48 Addendum Report. The field survey took place October 7-10, 2024,
1.12 months after M45 the last Full Monitoring Survey. The survey included 105 monitoring points and 4
reference control points (RP01, RP02, RP03 & PVE3RP). See the attached spreadsheet “PB MOVEMENT
DATA POSTING... .xlsx” for the movements. Partial surveys of 19 points along PVDS were published as M46
and M47 as listed in the spreadsheet. The report for M45 to M48 is addressed here and in the spreadsheet.
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NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed for the M48 survey to develop NAD83 (2007) Epoch
2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was
fixed at point RP02 and a check was made to PVE3RP, RP01 and RP03 noted below. Differences from the
known fixed positions to the measured positions by this survey are listed here with their north, east and vertical
components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP 0.00 0.00 0.02 Reference at City Hall
RP01 -0.02 0.00 0.05 Check Point
RP02 -0.00 -0.00 -0.00 Fixed Base Station
RP03 0.00 0.00 0.02 Check Point
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Additionally, California Spatial Reference Center CGPS (Continous
Operating GPS Stations) PVE3 and PVHS are incorporated periodically for additional verification of the
stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for M45 to M48
In the attached “PB MOVEMENT DATA POSTING… xlsx” spreadsheet, the measured land movements are
listed for the period and also for a normalized average month of 30.42 days for comparing the rates of
movement for previous periods. This survey included 105 points. For the stated period, the normalized
movements vary and average about 1.5 feet with a maximum of 2.6 feet for an average month. The change in
the rate of land movement (velocity) over the previous period slowed and varies from about -63% to -19%
averaging about -41%. The attached spreadsheet “PB MOVEMENT DATA POSTING... .xlsx” lists the
movement azimuths (directions clockwise from north) in degrees, the two-dimensional horizontal movements,
and vertical (elevation) changes during the period in US Survey Feet. See also the column for the rate of
movement for each period normalized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.01 feet with a Standard Deviation of 0.01 feet and range
0.00 to 0.05’. The absolute value of the vertical vector residuals are estimated at 0.02 feet with a Standard
Deviation of 0.02 feet, and range -0.06 to +0.08’. .
The accuracy or uncertainty of the measured horizontal (2D) movements between two monitoring surveys is
estimated to be 0.04’ at the 95% Level of Confidence. Movements less than the Confidence Interval are
statistically indeterminate. The estimated vertical measured movement confidence is about 0.05’ to 0.10’
depending on obstructions to satellite signals. “Deflection Analysis” or “Trend Analysis” is an alternate method
for assessing uncertainties.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…. .xlsx” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum
Point Description: Update of Set Points
CR60 Set 1/2”x 4’ rebar with plastic cap “Control Point” in open field, northeast of the Ishibashi
Trail
D-21
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 22 of 26
Addendum No. 11 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M49 – October 13, 2024
This is Partial Monitoring Survey No. M49 Addendum Report. The field survey took place October 13, 2024,
6 days or 0.23 months after the last M48 Partial Monitoring Survey dated October 7, 2024. The survey included
19 monitoring points along PVDS and 4 reference control points (RP01, RP02, RP03 & PVE3RP). See the
attached spreadsheet “PB MOVEMENT DATA POSTING... .xlsx” for the movements.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed for the M49 survey to develop NAD83 (2007) Epoch
2007.00 CA Zone 5 State Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was
fixed at point RP02 and a check was made to PVE3RP, RP01 and RP03 noted below. Differences from the
known fixed positions to the measured positions by this survey are listed here with their north, east and vertical
components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.01 -0.01 0.06 Reference at City Hall
RP01 -0.02 0.02 -0.01 Check Point
RP02 -0.00 -0.00 -0.00 Fixed Base Station
RP03 0.00 0.00 0.02 Check Point
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame. Additionally, California Spatial Reference Center CGPS (Continous
Operating GPS Stations) PVE3 and PVHS are incorporated periodically for additional verification of the
stability and recovery of the refence frame.
2D Horizontal & Vertical Movements for M48 to M49
In the attached “PB MOVEMENT DATA POSTING…” spreadsheet, the measured land movements are listed
for the period and also for a normalized average month of 30.42 days for comparing the rates of movement for
previous periods. This survey included 19 points and four reference points. For the stated period, the
normalized movements vary and average about 0.9 feet with a maximum of 1.7 feet for an average month. The
change in the rate of land movement (velocity) over the previous period slowed and varies from about -54% to -
5% averaging about -22%. The attached spreadsheet “PB MOVEMENT DATA POSTING... .xlsx” lists the
movement azimuths (directions clockwise from north) in degrees, the two-dimensional horizontal movements,
and vertical (elevation) changes during the period in US Survey Feet. See also the column for the rate of
movement for each period normalized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.01 feet with a Standard Deviation of 0.01 feet and range
0.00 to 0.05’. The absolute value of the vertical vector residuals are estimated at 0.02 feet with a Standard
Deviation of 0.02 feet, and range -0.06 to +0.08’. .
The accuracy or uncertainty of the measured horizontal (2D) movements between two monitoring surveys is
estimated to be 0.04’ at the 95% Level of Confidence. Movements less than the Confidence Interval are
statistically indeterminate. The estimated vertical measured movement confidence is about 0.05’ to 0.10’
depending on obstructions to satellite signals.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING… xlsx” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
D-22
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 23 of 26
Addendum No. 12 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M50 – October 20, 2024
This is Partial Monitoring Survey No. M50 Addendum Report. The field survey took place October 20, 2024,
7 days or 0.23 months after the last M48 Monitoring Survey dated October 7, 2024. The survey included 19
monitoring points along PVDS and 4 reference control points (RP01, RP02, RP03 & PVE3RP). See the attached
spreadsheet “PB MOVEMENT DATA POSTING… .xlsx” for the movements. This survey utilized the
Smartnet RTN regional stations to measure vectors and determine the positions of monitoring points. This was
to assess the accuracy of the RTN for monitoring in-lieu of the usual local base station. The results indicate a
slightly larger uncertainty in the measurements. Subsequent surveys use the local base at RP02 procedure .
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State
Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was fixed at point RP02 and a
check was made to PVE3RP, RP01, and RP03 noted below. Differences from the known fixed positions to the
measured positions by this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.03 0.05 0.07 Reference at City Hall
RP01 -0.05 0.00 -0.11 Check Point
RP02 -0.00 -0.00 -0.00 Fixed Base Station
RP03 -0.01 0.00 0.00 Check Point
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame.
2D Horizontal & Vertical Movements for M48 to M49
In the attached “PB MOVEMENT DATA POSTING…” spreadsheet, the measured land movements are listed
for the period and also for a normalized average month of 30.42 days for comparing the rates of movement for
previous periods. This survey included 19 points and four reference points. For the stated period, the general
normalized movements vary and average about 0.8 feet with a maximum of 1.6 feet for an average month. The
generalized change in the rate of land movement (velocity) over the previous period slowed and varies from
about -26% to +2% averaging about -11%. The attached spreadsheet “PB MOVEMENT DATA POSTING...
.xlsx” lists the movement azimuths (directions clockwise from north) in degrees, the two-dimensional horizontal
movements, and vertical (elevation) changes during the period in US Survey Feet. See also the column for the
rate of movement for each period normalized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.01 feet with a Standard Deviation of 0.01 feet and range
0.01 to 0.03’. The absolute value of the vertical vector residuals are estimated at 0.03 feet with a Standard
Deviation of 0.01 feet, and range -0.06 to +0.10’. .
The accuracy or uncertainty of the measured horizontal (2D) movements between two monitoring surveys is
estimated to be 0.05’ at the 95% Level of Confidence. Movements less than the Confidence Interval are
statistically indeterminate. The estimated vertical measured movement confidence is about 0.05’ to 0.10’
depending on obstructions to satellite signals. “Deflection Analysis” and “Trend Analysis” are an alternate
method for assessing uncertainties.
D-23
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 24 of 26
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…. .xlsx” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
Addendum No. 13 Report
Portuguese Bend Land Movement Monitoring Survey
Full Monitoring Survey No. M51 – October 29, 2024
This is Full Monitoring Survey No. M51 Addendum Report. The field survey took place October 27-30, 2024,
0.23 months after M50 the last Partial Monitoring Survey and 0.69 months after M48 the last Full Monitoring
Survey. The survey included 105 monitoring points and 4 reference control points (RP01, RP02, RP03 &
PVE3RP). See the attached spreadsheet “PB MOVEMENT DATA POSTING... .xlsx” for the movements. The
report for M48 to M51 is addressed here and in the spreadsheet.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State
Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was fixed at point RP02 and a
check was made to PVE3RP, RP01, and RP03 noted below. Differences from the known fixed positions to the
measured positions by this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.01 -0.01 0.00 Reference at City Hall
RP01 -0.03 0.03 -0.02 Check Point
RP02 -0.00 -0.00 -0.00 Fixed Base Station
RP03 0.00 0.00 0.02 Check Point
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame.
2D Horizontal & Vertical Movements for M48 to M51
In the attached “PB MOVEMENT DATA POSTING…” spreadsheet, the measured land movements are listed
for the period and also for a normalized average month of 30.42 days for comparing the rates of movement for
previous periods. For the stated period, the general normalized movements of the 105 points excepting those
with little or no movement detected vary and average about 0.1 feet with a maximum of 2.0 feet for an average
month. The generalized change in the rate of land movement (velocity) over the previous period slowed and
varies from about -82% to +21% averaging about -43%. The attached spreadsheet “PB MOVEMENT DATA
POSTING... .xlsx” lists the movement azimuths (directions clockwise from north) in degrees, the two-
dimensional horizontal movements, and vertical (elevation) changes during the period in US Survey Feet. See
also the column for the rate of movement for each period normalized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.01 feet with a Standard Deviation of 0.01 feet and range
0.00 to 0.06’. The absolute value of the vertical vector residuals are estimated at 0.02 feet with a Standard
Deviation of 0.02 feet, and range -0.10 to +0.13’.
The accuracy or uncertainty of the measured horizontal (2D) movements between two monitoring surveys is
estimated to be 0.04’ at the 95% Level of Confidence. Movements less than the Confidence Interval are
statistically indeterminate. The estimated vertical measured movement confidence is about 0.05’ to 0.10’
depending on obstructions to satellite signals. “Deflection Analysis” and “Trend Analysis” are an alternate
method for assessing uncertainties.
D-24
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 25 of 26
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…. .xlsx” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
Addendum No. 14 Report
Portuguese Bend Land Movement Monitoring Survey
Partial Monitoring Survey No. M52 – November 5, 2024
This is Partial Monitoring Survey No. M52 Addendum Report. The field survey took place November 5, 2024,
9 days or 0.30 months after the last M51 Monitoring Survey dated October 27, 2024. The survey included 19
monitoring points along PVDS and 4 reference control points (RP01, RP02, RP03 & PVE3RP). See the attached
spreadsheet “PB MOVEMENT DATA POSTING… .xlsx” for the movements. This survey utilized the
Smartnet RTN regional stations to measure vectors and determine the positions of monitoring points. This was
to assess the accuracy of the RTN for monitoring in-lieu of the usual local base station. The results indicate a
slightly larger uncertainty in the measurements. Subsequent surveys use the procedure for a local base station at
RP02.
NETWORK ADJUSTMENT & ANALYSIS
A minimally constrained adjustment was processed to develop NAD83 (2007) Epoch 2007.00 CA Zone 5 State
Plane Coordinates and NAVD88 Heights. A least sqaures network adjustment was fixed at point RP02 and a
check was made to PVE3RP, RP01, and RP03 noted below. Differences from the known fixed positions to the
measured positions by this survey are listed here with their north, east and vertical components in feet.
Differences in Feet
ID dN dE dZ_
PVE3RP -0.03 0.05 0.07 Reference at City Hall
RP01 -0.05 0.00 -0.11 Check Point
RP02 -0.00 -0.00 -0.00 Fixed Base Station
RP03 -0.01 0.00 0.00 Check Point
Recovery and confirmation of a stable reference frame is essential to assess the actual movement of the
monitoruing points. The diffeences listed above are at the noise level of the measurements confirming a
successful recovery of the reference frame.
2D Horizontal & Vertical Movements for M51 to M52
In the attached “PB MOVEMENT DATA POSTING…” spreadsheet, the measured land movements are listed
for the period and also for a normalized average month of 30.42 days for comparing the rates of movement for
previous periods. This survey included 19 points and four reference points. For the stated period, the general
normalized movements vary and average about 0.2 feet with a maximum of 1.6 feet for an average month. The
generalized change in the rate of land movement (velocity) over the previous period slowed and varies from
about -25% to +50 averaging about +13%. The attached spreadsheet “PB MOVEMENT DATA POSTING...
.xlsx” lists the movement azimuths (directions clockwise from north) in degrees, the two-dimensional horizontal
movements, and vertical (elevation) changes during the period in US Survey Feet. See also the column for the
rate of movement for each period normalized for an average 30.42-day month.
Accuracy Statements
The horizontal (2D) vector residuals are estimated at 0.01 feet with a Standard Deviation of 0.02 feet. The
absolute value of the vertical vector residuals are estimated at 0.03 feet with a Standard Deviation of 0.03 feet.
D-25
McGEE SURVEYING CONSULTING
5290 Overpass Road, Ste#107, Santa Barbara, CA 93111
Page 26 of 26
The accuracy or uncertainty of the measured horizontal (2D) movements between two monitoring surveys is
estimated to be 0.04’ at the 95% Level of Confidence. Movements less than the Confidence Interval are
statistically indeterminate. The estimated vertical measured movement confidence is about 0.05’ to 0.10’
depending on obstructions to satellite signals. “Deflection Analysis” and “Trend Analysis” are an alternate
method for assessing uncertainties.
Monitoring Point Monument Notes & Descriptions
See prior Reports for existing point descriptions. See the attached spreadsheet file “PB MOVEMENT DATA
POSTING…. .xlsx” for California State Plane Coordinates Zone 5 in the NAD83 (2007) Epoch 2007.00 and
elevations in the NAVD88 Datum.
SURVEYOR'S STATEMENT
The M38 Fall October 2023 Full Survey and subsequent 2024 Surveys
and Addendum Reports on the procedures, criteria, and results of the
City of Rancho Palos Verdes Portuguese Bend Land Movement
Monitoring Surveys were prepared by me on October 30, 2023 with
updates through November 8, 2024 at the request of Ramzi Awwad,
Director of Public Works for the City of Rancho Palos Verdes.
D-26
,m ~L~
Michael R. McGee, PLS3945