Timeline

June 2016 – Earthwork/Street improvement project is complete

January 2016 – Additional scope to install a manifold connection and discharge water from the dewatering improvements is added to the earthwork/street improvement project.

May 2015 – Contractor mobilized to complete the earthwork/street improvement project.

October 2014 – Begin design for the earthwork/street improvement project which will install rip rap along the beach along the bluff, demolition of paved areas and perform grade the area to allow for proper stormwater drainage, and will install a turnaround at the intersection of Paseo Del Mar and Weymoth.

February 14, 2014 – All anchors installed and in service

November 12, 2013 - HBI began drilling the first of nine upper row ground anchors using a track mounted air rotary drill rig. Each anchor was drilled to a depth of approximately 165 feet then grouted, proof tested, and stressed. The nine lower row anchors were installed using the same air rotary drill mounted on a custom made drilling platform that was anchored to the bluff using four micropiles. The final lower row anchor was stressed on June 17, 2014.

Each Anchor utilized a 7x7x2-foot concrete bearing pad to distribute the load to the bluff. The upper row anchor bearing pads were constructed of standard concrete and have a smooth finish as these will be covered with earth during the next phase of work. The lower row anchor bearing pads will remain exposed and were constructed using a colored and textured concrete to make them blend in with the bluff. HBI finished installation of the anchors and demobilized on July 21, 2014. Shannon & Wilson completed their construction monitoring of the anchor installation and has produced a draft Geotechnical Construction Observation Report, White Point Landslide – Ground Anchors, dated July 15, 2014.

BOE continues to petition the Regional and State Water Quality Control Board for an exemption from permitting for the disposal of the dewatering drain water to the ocean. In the interim, the drain water continues to be collected and pumped into the local sewer on Paseo Del Mar 3 times per week. The BOE has retained a contractor for this purpose and for general maintenance of the site while plans are finalized for the next phase of work which includes final grading of the anchor construction bench, construction of traffic turnarounds, and reconfigured fencing for pedestrian safety.

May 30, 2014 – Surface improvements complete

October 15, 2013 - Hayward Baker Inc. (HBI) began the slope anchor installation phase of work and began excavating a bench on the edge of the bluff between the landslide scarp and Weymouth Avenue. This bench facilitated the drilling and installation of 18 ground anchors designed to stabilize the bluff. During this excavation a ground crack was exposed on the surface of the newly excavated bench. Shannon & Wilson (S&W) was on-site to measure, analyze, and monitor the ground crack and determined the area was safe to proceed with anchor installation.

May 17, 2013 – Start of procurement and fabrication of slope anchors

February 7, 2013 – May 31st, 2013: Dewatering Improvements

November 2012 – As recommended by Shannon & Wilson, Inc., and authorized by BOE, investigative studies and geotechnical analyses have continued in order to evaluate and design stabilization improvement measures: install a subsurface dewatering system, construct soil anchors on the beach bluff east the landslide, construct traffic control measures, and perform limited grading in the headward area of the landslide. BOE is working to implement these recommendations with an emphasis on tasks that help prepare for this winter season.

An initial shape and trim phase of grading in the landslide area, designed to remove debris, improve safety of the steep slope around the edge of the landslide, and to improve drainage conditions at the head of the landslide, is near completion.

Shannon & Wilson, Inc. continue with the geotechnical investigation of the landslide and have completed drilling and instrumentation in two additional borings on the east side of the landslide.

Stability and hydrogeologic analyses for the de-watering project are completed. Preliminary plans and a draft geotechnical report for the de-watering system are complete and currently under review by the Bureau.

The slope anchor system stabilization improvement measure design is on-going. Interim measures to improve traffic in the area, such as re-striping the street at the corner of Paseo del Mar and Weymouth, are being implemented.

We expect to see periodic detachment of the scarp material throughout the upcoming winter and spring months if the corrective grading is not completed prior to the rainy season. The main landslide mass will likely move ocean-ward during and after periods of heavy precipitation.

February 2012 – The BOE coordinated the opening and observation of the abandoned White Point LA-43 Nike Missile Site subterranean silos located in the White Point Nature Preserve. A team of professionals visited the site, noted site conditions, photographed, and surveyed the silos. The team included City geologists, a City structural engineer, City Surveyors, and a State Registered Engineering Geologist from the private consulting firm Shannon & Wilson, Inc. At BOE direction Shannon & Wilson completed an observation report which provides a description of their findings. Evidence of ponding water within the main areas of the silos was not observed.

The BOE continues survey monitoring of points set on the street, curb and ground around the landslide to check for evidence of ground movement which might indicate landslide movement or enlargement.

January 6, 2012 – The Draft Preliminary Report was submitted to the City on January 6, 2012. The report included a preliminary geologic map, preliminary boring logs, inclinometer baseline readings, and preliminary observations regarding the landslide and immediate areas adjacent to the landslide. The base map includes the Navigate LA 2006 topographic contours.

December 21, 2011 – Completion of the subsurface exploration program

December 13, 2011 – Aerial Survey

Subsurface exploration includes completion of borings B-1 through B-4. Instrumentation will be read on weekly basis for the first month following installation to monitor the landslide area for groundwater elevations and possible subsurface movement.

Waste Handling techniques have consisted of stockpiling the existing soils on-site either next to the existing borings, using it for backfill in the bucket borings, or stockpiling within the Paseo Del Mar R/W. Additional cuttings and waste water from B-1 are stored in barrels on site

Geophysical logging has been completed on B-1, consisting of both optical televiewer and acoustic televiewer logging.

Laboratory testing to date consists of limited environmental sampling of completed surface soil samples from the bucket auger borings.

Construction of geologic cross sections has been started.

Site observations for landslide movement following rainfall on 12/13/11 and 12/15/11. Based on visual observations, no ground fractures have appeared at the fenced perimeter of the landslide area.

December 1, 2011 – Access routes for boring exploration were cleared by a Shannon and Wilson biologist and a representative of Palos Verdes Land Conservancy Preliminary report tasks include the completion of a proposed boring map incorporating the City’s survey data and Navigate LA 2006 topographic contours.

November 29, 2011 – Geologic mapping was completed along the toe of the existing landslide and of exposures in the surf zone by Shannon and Wilson.

November 21, 2011 – The Bureau of Engineering authorized the private geotechnical firm, Shannon and Wilson, Inc. to immediately begin a geotechnical study of the landslide area, and in particular an assessment of the stability of the area around the existing landslide. Study involves several different drilling methods to allow for direct observation of subsurface geological conditions with instruments placed within exploratory borings to measure ground water and movement.

November 20, 2011 – 420 feet of Paseo Del Mar slid southward toward the ocean approximately 53 feet.

November 3, 2011 – Three survey monitoring points near the intersection of Weymouth Avenue and Paseo Del Mar are installed.

October 2011 – Bureau of Engineering personnel continued to investigate the pavement damage on Paseo del Mar. The investigation revealed that the cracks had grown larger in the recent months, and were of the size and type that indicated landslide activity. Street access was closed, utility relocation began, and a perimeter fence was constructed to protect the public.

July 2011 – Bureau of Engineering investigates tension cracks that had formed in Paseo Del Mar