CC SR 20230919 02 - PB Landslide Utilities Report
CITY COUNCIL MEETING DATE: 09/19/2023
AGENDA REPORT AGENDA HEADING: Regular Business
AGENDA TITLE:
Consideration and possible action to receive a report from Cal Water and Southern
California Gas Company regarding their response and mitigation efforts to the Portuguese
Bend Landslide.
RECOMMENDED COUNCIL ACTION:
(1) Receive a report from Cal Water regarding their response and mitigation efforts to
the Portuguese Bend Landslide as it relates water pipelines;
(2) Receive a report from Southern California Gas Company regarding their response
and mitigation efforts to the Portuguese Bend Landslide as it relates to the gas
pipelines;
(3) If desired, direct Staff to return at a future City Council meeting to consider an
additional appropriation to fund engineering review, collaboration, and
coordination with utility companies on their plans for response and mitigation
efforts; and,
(4) If warranted, request the utility companies to return on a specific date with updated
information on a short-term and long-term action plan and timeline for addressing
mitigation efforts within the Portuguese Bend Landslide.
FISCAL IMPACT: None
Amount Budgeted: N/A
Additional Appropriation: N/A
Account Number(s): N/A
ORIGINATED BY: Ramzi Awwad, Public Works Director
REVIEWED BY: Same as above
APPROVED BY: Ara Mihranian, AICP, City Manager
ATTACHED SUPPORTING DOCUMENTS:
None
Staff has been advised that Cal Water and Southern California Gas Company will be
submitting, as late correspondence, a formal written response to the Council’s request to
attend tonight’s meeting.
1
BACKGROUND:
Over the past few years, movement in the Portuguese Bend Landslide Complex has
accelerated, impacting roadways, utilities, and structures in the immediate area. Streets
are experiencing significant cracking, horizontal and vertical movement, and occasional
sink holes. Structures in both the Abalone Cove and Klondike Canyon Landslide
Abatement Districts are experiencing movement resulting in cracking, and in the Seaview
neighborhood two homes have been red-tagged by the City. Utility impacts include broken
water and gas distribution pipes, moving sanitary sewer collection pipes, and leaning
utility poles.
At the September 5, 2023 City Council meeting, two property owners from the Seaview
neighborhood within the Klondike Canyon Landslide Abatement District (KCLAD)
expressed concerns with the damage occurring to their properties due to the landslide
and recurring damage to utility infrastructure, particularly water distribution pipes.
Residents expressed grave concern that the recurring water distribution pipe breaks are
resulting in water being discharged into the ground, which will exacerbate land movement.
In response, that evening, the City Council requested that the water distribution utility,
California Water Service (Cal Water) be invited to the next meeting to report on their
response and mitigation efforts.
The following evening, Mayor Pro Tem Cruikshank and Councilmember Bradley, as the
City Council Landslide Subcommittee, joined City Manager Mihranian, Public Works
Director Awwad, and Building Official Rasor at a Seaview Neighborhood Meeting on the
landslide. Approximately 70 people attended in person plus another 70 people
participated online to hear from the City. That evening, residents also expressed a
concern with the recurring broken utility pipes and their alleged impact to the landslide.
For purposes of this report, the Portuguese Bend Landslide Complex is comprised of the
following areas:
2
Tonight, Local Public Affairs Government Relations Managers from Cal Water and
Southern California Gas Company (So Cal Gas) for the Peninsula cities, confirmed their
participation. They will be reporting on their response and mitigation efforts to the
Portuguese Bend Landslide.
DISCUSSION:
Cal Water
Many water pipe leaks have been reported in the landslide area, some of which have
gone undetected for unknown periods of time, and some of which have not been
immediately repaired. Because infiltration of water increases landslide movement, Staff
have demanded that Cal Water take the following actions to respond to the breaks and
mitigate effects on the landslide:
1) Deploy real-time leak detection technology so that any leak will be immediately
detected.
2) Deploy leak isolation and automatic shut-off devices so that a leaking pipe is
immediately isolated and shut-off upon detection.
3) Begin repairs to leaking pipes immediately.
4) Install the most modern innovative materials to increase resiliency of pipes & joints
to landslide movement.
5) Explore long-term solutions such as encasing or re-routing water distribution lines.
In response to Staff demands, Cal Water representatives informed Staff that they are
taking the following immediate steps:
1) Placing leak detection equipment and pressure monitoring devices at strategic
locations within the landslide area.
2) Working with City staff to identify areas within the Preserve for which signs will be
installed with Cal Water’s leak report telephone number.
3) Treating all leaks in the broader landslide area at the highest internal response
level and adding redundancy to internal processing of leak reports to minimize the
potential for human error delaying a leak repair response.
Additionally, Cal Water representatives informed Staff that they are willing to review
options for installing different pipe materials, encasing pipes, or re -routing pipes in
collaboration with the City.
Cal Water is requesting that public report water pipe breaks to their 24/7 customer service
line at 310-257-1400.
Southern California Gas Company
Due to the ongoing gas pipe breaks, particularly within the Portuguese Bend Community
Association, Staff demanded that So Cal Gas take similar actions to those identified for
Cal Water.
In response to Staff demands, So Cal Gas representatives informed Staff of the following:
3
• Leaks in the Portuguese Bend Landslide have historically been caused by
corrosion and tree root damage rather than land movement.
• Leak response is based on location, spread, concentration of gas, and imminence
of hazard to people or property.
• Gas pipes in the Portuguese Bend Landslide are on an annual leak survey.
• An engineering assessment of areas of concern by the community has been
conducted and results are being reviewed to identify future infrastructure changes.
ADDITIONAL INFORMATION:
Sanitary Sewers
In response to the significant movement that occurred in the Seaview neighborhood in
July 2023; Staff coordinated a closed-circuit television (CCTV) inspection with the Los
Angeles County Public Works Department (LACPW), who maintains and operates the
City’s local sanitary sewers pipes (outside of the Abalone Cove Sanitary Sewer System).
Those inspections revealed joint displacements of up to three inches which create a lip
at pipe joints whereby flow cascades over an adjoining pipe rather than flowing through it
smoothly. However, according to LACPW, unlike pressurized water distribution pipes,
sanitary sewer pipes use gravity to flow. This means that velocities are insufficient to
create erosion. Therefore, flow continues through the pipes and only nominal water
infiltration occurs.
Staff are working with LACPW to develop an inspection protocol that will identify future
leaks in a timely manner and create a plan to respond quickly. Additionally, Staff are
exploring the possibility of re-routing sanitary sewer pipes to areas less affected by land
movement.
Community Notification
Tonight’s agenda item will be shared with board members for the Portuguese Bend
Community Association, ACLAD, KCLAD, Seaview, and Portuguese Bend Beach Club
with a request that they notify their members.
ACLAD
On September 15, 2023, ACLAD Board Members and City Manager Mihranian will be
meeting with Supervisor Janice Hahn to discuss the on-going land movement issues the
area is experiencing with the ongoing and accelerated movement of the Portuguese Bend
Landslide.
CONCLUSION:
Staff recommends the City Council receive a report from the various utility companies on
their response and mitigation efforts to the Portuguese Bend Landslide.
4