CC SR 20241106 K - Landslide Emergency Contract Continuation
CITY COUNCIL MEETING DATE: 11/06/2024
AGENDA REPORT AGENDA HEADING: Consent Calendar
AGENDA TITLE:
Consideration and possible action to reconfirm continuing the emergency justification for
work and emergency contract for the Greater Portuguese Bend-Ancient Altamira
Landslide Emergency Project.
RECOMMENDED COUNCIL ACTION:
1) Reconfirm, by a four-fifths vote, there is a need to continue the work on the Deep
Vertical Dewatering Emergency Project declared by Council-adopted Resolution
No. 2024-20 on May 7, 2024, finding an emergency exists requiring immediate
action in the Greater Portuguese Bend-Ancient Altamira Landslide Complex to
seek to mitigate the movement of the landslide; and
2) Direct the City Clerk to confirm the same in the minutes of this City Council
meeting, via Minute Order, reflecting this action.
FISCAL IMPACT: There is no fiscal impact associated with the recommended Council
action as the City Council appropriated $9,635,000 for emergency work outside the
normal bidding process due to the emergency declaration. Additionally, as presented and
approved on October 1, 2024, the City Council approved additional appropriations
bringing the total to $32 million in FY 2024-25 as follows: VR
• $24 million for emergency response which includes the $9.6 million approved
on May 7, 2024 and $6.1 million on October 1, 2024. The $24 million includes,
but not limited to, sewer repairs, fissure filling, road repairs, legal, equipment,
personnel costs, district loans, and tax assessments.
• $4 million for emergency stabilization measures for deep dewatering wells.
• $4 million for winterization.
FY 2024-25 Funding Sources $17.9M:
• $10.1 million CIP (Fund 330)
• $3.4 million General Fund
(Fund 101)
• $1.4 million Prop C (Fund 215)
• $2.9 million ARPA (Fund 333)
Additional FY 2024-25 Funding Sources $14.1M approved on October 1, 2024:
• $500,000 ARPA (Fund 333)
• $2.2 million Sup. Hahn Grant
(General Fund - Grant 101)
• $5 million CIP Emergency
Reserves (Fund 330)
• $6.4 million General Fund
Excess Reserves (Fund 101)
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Amount Budgeted: See Fiscal Impact
Additional Appropriation: N/A
Account Number(s): Account numbers TBD based on the above
Fiscal Impact VR
ORIGINATED BY: David Copp, Deputy Public Works Director
REVIEWED BY: Ramzi Awwad, Public Works Director
APPROVED BY: Ara Mihranian, AICP, City Manager
ATTACHED SUPPORTING DOCUMENTS:
A. October 15, 2024 staff report – Emergency Hydraugers Contract
Continuation
B. October 1, 2024 staff report – Consideration and Possible Action on the
Greater Portuguese Bend-Ancient Altamira Landslide Complex
C. August 20, 2024 staff report
D. May 7, 2024 staff report
E. Map of Effect of Deep Dewatering on Landslide (page E-1)
F. Map of Borehole and Deep Dewatering Programs (page F-1)
BACKGROUND:
On October 3, 2023, the City Council adopted Resolution No. 2023-47, declaring a state
of local emergency relating to the land movement in the landslide complex. The state of
emergency has been timely renewed and is current.
On May 7, 2024, the City Council extended the Local State of Emergency pursuant to
Resolution No. 2024-20 and approved, among other things, a Public Works Contract with
Malcolm Drilling Inc. (Malcolm) to perform the work of the Portuguese Bend Landslide
Emergency Hydraugers Project (Attachment D).
On August 20, 2024, the City Council approved expanding the scope of the emergency
hydraugers project and considering new alternatives including the installation of deep
vertical dewatering wells (Attachment C). On October 1, 2024, the City Council approved
expanding the scope of work to include winterization work and the installation of additional
vertical deep dewatering wells (Attachment B).
On October 15, 2024, the City Council reconfirmed the need to continue the emergency
stabilization and winterization work at its regularly scheduled meeting (Attachment A).
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DISCUSSION:
Pursuant to Public Contract Code § 22050, the City Manager and Director of Public Works
must report to the City Council at its regular meeting the reasons justifying why the
emergency continues to exist and why action outside of the normal bidding process is
necessary to respond to the emergency. Furthermore, Public Contract Code § 22050
states that the City Council shall, at every regularly scheduled meeting , consider and
reaffirm that there is a need to continue to remediate the emergency until the authorized
emergency repairs have been completed. Accordingly, because the work has not yet
been completed, this item is on tonight’s agenda. This item will be placed on each
subsequent agenda until all aspects of the project are completed.
Since the most recent update to the City Council on October 15, 2024, the need for the
emergency work is ongoing. The status of the project at the time of publication of this staff
report on October 30, 2024 is as follows:
Deep Dewatering Wells
• 16 instrumented vertical test boreholes to characterize subsurface conditions and
support the execution of dewatering operations have been installed.
• Six deep dewatering wells (DDWs 1-6) have been installed west of the
Portuguese Bend Beach Club community (PBBC) and are currently discharging
water at a combined rate of approximately 600 gallons per minute (GPM).
• Two deep dewatering wells (DDWs 7&8) have been installed near Palos Verdes
Drive South- one east of Peppertree Drive and one near the entrance to the South
Bay Archery Range, with a combined discharge rate of approximately 100 GPM.
• Two deep dewatering wells (DDWs 9&10) have been installed along the coast of
Abalone Cove. These DDWs are discharging water at a combined rate of
approximately 160 GPM.
• The total combined water extraction rate of DDWs 1 thr ough 10 is currently over
850 gallons per minute or approximately 1.25 million gallons per day.
• Since the start of the DDW program; approximately 28 million gallons, or
approximately 85 acre-feet, of water have been extracted from certain locations
of the toe of the Landslide Complex.
• Access is being developed for a third deep dewatering wells (DDW 11) in the
Abalone Cove area.
• The Contractor will mobilize a drill rig this week to the Portuguese Bend
Community Neighborhood to conduct additional test boreholes.
• Deceleration of land movement in the areas of the installed DDWs continues to
be observed, based on a sampling of points from GPS monitoring data
(Attachment E).
• Four sample points in the Seaview and PBBC have shown no movement for two
consecutive surveys (October 13, 2024 and October 20, 2024).
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Winterization
• Fissure filling of Altamira Canyon and nearby areas is ongoing and is expected to
be completed by the end of this week. A protective pond liner will be installed at
the base of the canyon starting next week.
• Mobilization for fissure filling and lining of Kelvin, Portuguese, Ishibashi,
Paintbrush, and Klondike canyons is expected to start next week.
• Construction crews have mobilized to the Seaview Neighborhood and have begun
winterization of the Exultant & Dauntless intersection, as well as sections of
Admirable and Exultant Drives. The work is expected to be completed within the
next two to three weeks.
Environmental and cultural monitoring is being conducted in conjunction with the above
construction activities.
In anticipation of potential rain over the weekend of November 2 and 3, staff is working
with residents to provide sandbags and fill fissures in areas of significant concern.
The emergency conditions necessitating the project continue to exist.
CONCLUSION:
The effects of the ongoing land movement continue to be felt in the Greater Portuguese
Bend-Ancient Altamira Landslide Complex. Staff recommends reconfirming that there is
a need to continue to remediate the emergency identified by City Council -adopted
Resolution No. 2024-20 (originally by Resolution No. 2023-47), and reconfirm, by a four-
fifths vote, the need for continuing the work on the Portuguese Bend Landslide
Emergency Project.
ALTERNATIVES:
In addition to Staff recommendation, the following alternative action is available for the
City Council’s consideration:
1. Take other action or provide direction, as deemed appropriate.
4
43%
8.52”,4.83”
46%
7.05”, 3.81”
70%
6.6”, 1.98”
100%
1.34”, 0.0”
100%
2.88”, 0.0”
100%
3.6”, 0.0”
100%
7.95”,0.0”
85%
9.0”, 1.32”
89%
10.29”, 1.14”
88%, 11.46”, 1.38”
90%
10.65”, 1.08”
74%
8.34”, 2.43”
78%
9.24”, 2.01”
78%
8.64”, 1.89”
77%
10.11”, 2.31”71%
8.49”,2.48”
63%
9.75”,3.57”
62%
10.62”, 4.08”
Effect of Deep Dewatering Wells on Land Movement
Between 9/4/24 and 10/20/24
Survey Points within
close proximity of
Dewatering Wells
Deep
Dewatering
Well
Numbers in boxes represent
percent decrease in surface
movement for the stated
time period. Red = rate on
9/4/24 and Black = rate on
10/20/24 in inches per week
E-1
ABALONE COVE
SACRED COVE
F-1