City Council Meeting: August 14, 2007

Agenda Item: 1-I  

To:                   Mayor and City Council 

From:              Craig Perkins, Director – Environmental and Public Works Management

Subject:          Adopt a Resolution Approving a Mitigated Negative Declaration/Mitigation Monitoring Reporting Program for the Palisades Bluff Improvement Project and Authorize the City Engineer to Proceed with the Development of Bidding Documents to Implement the Project

 

Recommended Action

Staff recommends that the City Council:

  1. adopt the attached resolution approving the Mitigated Negative Declaration /Mitigation Monitoring Reporting Program prepared for the Palisades Bluff Improvement Project; and,
  2.  authorize the City Engineer to proceed with the development of bidding documents for implementation of the Palisades Bluffs Improvement project as recommended in the Geotechnical Study of the Palisades Bluffs and as described in this report.

 

Executive Summary

The Palisades Bluffs Improvement Project involves the implementation of geotechnical improvements to the Palisades Bluffs from the McClure Tunnel to the Northwest boundary of the City of Santa Monica to reduce the risk of future landslides and bluff erosion.  The proposed improvements include the installation of drainage measures, a limited demonstration of surface treatment measures which consist of applications of chemical grouting to determine the aesthetic impacts prior to broader implementation, planting of native vegetation and other safety measures as recommended in the Geotechnical Study of the Palisades Bluffs (October 2004).  The California Environmental Quality Act guidelines require the City to assess the project’s potential impact on the environment prior to commencement of construction.  The City prepared an Initial Study/Mitigated Negative Declaration that concludes that the proposed project would have no significant impact on the surrounding environment with the incorporation of mitigation measures.  The Mitigation Monitoring Reporting Program is designed to ensure compliance with mitigation measures during project implementation.  This report recommends that City Council adopt the attached resolution approving the Mitigated Negative Declaration/ Mitigation Monitoring Reporting Program and authorize the City Engineer to proceed with the development of bidding documents to implement the improvements to the Palisades Bluffs as described in this report. 

 

Discussion

The geotechnical investigation of the Santa Monica Palisades Bluffs was performed by URS Corporation in 2004 on behalf of the City.  The objective of the investigation was to develop conceptual design recommendations and cost estimates for enhancing stability of the Bluffs adjacent to Pacific Coast Highway (PCH) along the length of Palisades Park (approximately 1.6 miles of the coastal bluffs).  An important aspect of this task was to preserve the Bluffs’ natural appearance.  The scope of work included a comprehensive review of existing data, field conditions and geological mapping, drilling of vertical and horizontal exploratory holes, installation of groundwater observation wells and horizontal drains, laboratory and field testing of soils, assessment of potential slope-failure mechanisms, and the development of improvement alternatives for the Bluffs, without destroying their natural beauty.  At the conclusion of the investigation, a Geotechnical Study (Final Draft Report) was prepared.  The Geotechnical Study recommended a series of non-intrusive improvement elements, which can be applied individually, or in combination, for different areas of the Bluffs, as appropriate.  Consistent with the Geotechnical Study, the following scope of work is recommended for this project:

 

·        Drainage Improvements

Horizontal drains (hydraugers) are proposed to be installed north of the California Incline.  The drains consist of a small diameter perforated pipe drilled into the base of the bluffs adjacent to PCH.  The drains will collect excess ground water and provide a path for water to exit the Bluffs to improve stability.  Similar systems were installed as part of the Santa Monica Palisades Bluffs Slope Repair project following the 1998 landslide and proved to be successful in removing excess water.

·        Surface Treatments

Surface treatment is intended to reduce erosion of exposed surfaces along the Bluffs. Surface treatments will be installed in areas that are not visible from PCH or areas adjacent to PCH.  Surface treatments will initially be installed in a limited area along the Bluffs from the McClure Tunnel to the northern City limit.  The surface treatments consist of measures such as the application of a spray-on chemical grout and a soil/chemical grout mixture.    The surface treatment will be tested in this limited area to ensure that it will not be visible from PCH or the California Incline and will be assessed by a licensed landscape architect.  If the demonstration installations are successful, staff will propose to implement more extensive surface treatments as a second phase.

·        Planting of Native Vegetation

To prevent soil erosion, native southern California coastal bluff scrub habitat plant species would be used for planting and landscaping of the Bluffs at various locations where appropriate.  The use of native plants would require no watering after the initial planting, or once the plants are established.  The plant species chosen would be characteristic of southern California coastal bluffs.

·        Other Safety Measures

Several areas along the Bluff have overhanging soil blocks, old pavement, abandon concrete structures and pipes.  These items are to be removed or stabilized where possible to enhance the safety of traffic and pedestrians along PCH.

 

Environmental Analysis

A draft Initial Study and Mitigated Negative Declaration was prepared pursuant to Sections 15063(c) and 15070(b) (1) of the California Environmental Quality Act Guidelines to addresses the potential environmental effects of the improvement elements recommended in the Geotechnical Study.  The Initial Study/Mitigated Negative Declaration identified environmental impacts that would be potentially affected by the project including aesthetics, biological resources, construction effects, cultural and historic resources, geology/soils, hydrology/water quality, and neighborhood effects.  The Initial Study/Mitigated Negative Declaration was circulated for a 30-day public review period from February 5, 2007 to March 7, 2007.  Three (3) comments were received on the Draft Initial Study/Mitigated Negative Declaration.  The comments and responses to the comments are included in the Final Initial Study/Mitigated Negative Declaration.  The Initial Study/Mitigated Negative Declaration concluded that, with the incorporation of proposed mitigation measures, the proposed project would not result in significant impacts.  The required mitigation measures are detailed in the Mitigation Monitoring and Reporting Program, which is included in the Initial Study/Mitigated Negative Declaration and attached to the proposed Resolution.    

 

Public Outreach

After circulation of the Mitigated Negative Declaration, City staff met separately with the PCH Residents Association, Santa Monica Canyon Civic Association and Palisades Neighborhood Council in June 2007 to provide updated information on the proposed project and environmental approval process.  At these informational meetings, the community voiced three areas of concern: 1) the temporary traffic impacts on PCH associated with the implementation of the Bluffs project; 2) the coordination/cumulative temporary traffic impact of this project with the proposed project to reconstruct the California Incline; and 3) potential aesthetic impacts associated with the proposed improvements.  In response to these concerns, the implementation schedule will be coordinated with other projects including the reconstruction of the California Incline to minimize temporary construction traffic impacts. 

 

The Bluffs Improvement Project will be completed prior to the proposed closure and reconstruction of the California Incline. A detailed Construction Traffic Management Plan will be developed during preparation of the bidding documents in accordance with the mitigation requirements established in the Mitigated Negative Declaration.  The Construction Traffic Management Plan will also be coordinated with Caltrans and the City of Los Angeles.  Additionally, the proposed surface treatment will be performed in a limited area as an initial demonstration project to ensure that a viewer from PCH or the California Incline could not discern the difference between the treated and natural areas before the treatment is applied to a broader area of the Bluffs.

 

 

Previous Council Items

On July 25, 2006, the City Council approved Contract No. 8467 (CCS) with URS Corporation to provide environmental program management services for the Santa Monica Bluffs Improvement Project.  URS Corporation has been contracted to conduct slope erosion inspection and to work with the project’s environmental consultant, Rincon, to complete the environmental review process.  Upon approval of the Mitigated Negative Declaration /Mitigation Monitoring Reporting Program and as authorized by the City Engineer, URS Corporation will proceed with the development of bidding documents for the improvement project as the next phase of their current professional services agreement.  This agreement was authorized by City Council on April 26, 2005.

 

Budget/Financial Impact

The recommendation presented in this report does not have a budget or financial impact. 

 

Prepared by:

Spiros Lazaris, P.E., Civil Engineer

 

 

 

 

Approved:

 

Forwarded to Council:

 

 

 

 

Craig Perkins, Director

Environmental and Public Works Management Department

 

P. Lamont Ewell

City Manager

 

 

Attachments:              Resolution

 

 

Exhibit 2 – Vertical Interceptor Drains (Not Designed)