CITY OF PACIFICA
COUNCIL AGENDA SUMMARY REPORT
2/28/2022
1 SUBJECT:
Approval of 400 Esplanade Infrastructure Preservation Feasibility Report RECOMMENDED ACTION:
Approve the 400 Esplanade Infrastructure Preservation Feasibility Report and direct staff to proceed with conceptual design of preferred alternative STAFF CONTACT:
Ryan Marquez, P.E.- Associate Civil Engineer
(650) 738-3769
[email protected]
Sam Bautista, P.E. - Deputy Director of Public Works/City Engineer (650) 738-3767
[email protected]
Lisa Petersen, P.E. - Director of Public Works
(650) 738-3770
[email protected]
BACKGROUND/DISCUSSION:
Over the past several decades, the northern coastline of Pacifica has seen progressive coastal bluff erosion. The combination of poorly cemented bluff sand and high energy waves cause episodic bluff erosion resulting in a loss of land. In early 2017, a large bluff retreat was documented within the City-owned property at the 400 Block of Esplanade, just south of the Manor Drive and Esplanade Avenue intersection. The major bluff retreat occurred and formed a cove between two areas that have rock protection and shortened the distance to the City’s roadway (at its nearest point) to approximately thirty-two feet.
After this severe bluff retreat in February 2017, staff formulated a two-phase plan to protect the road and infrastructure behind the cove. The first phase, which was completed in the summer of 2018, installed an emergency protective measure by constructing a rock revetment to armor the bluff. Meanwhile, the planning and design of a permanent measure (second phase) could be carried out. To help fund this project, staff immediately reached out to State and Federal emergency agencies to seek possible funding sources for both phases of work. Staff successfully submitted the first phase of work (emergency) to FEMA’s Public Assistance Program for funding and then submitted a funding request for the second phase of work (permanent) in October of 2017 to CalOES’s Hazard Mitigation Grant Program (HMGP).
The first phase for the temporary work was completed in the summer of 2018 after receiving emergency permitting from the California Coastal Commission. After the submittal of the City’s CalOES HMGP application for the permanent repair work, the City received an award to begin the preliminary work in July of 2020.
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Since the approval of the consultant agreement with Moffatt & Nichol in November of 2020, project feasibility work on the project progressed. The project team reviewed the physical settings of the site through topographical and bathymetric surveying, assessed a variety of coastal engineering elements including sea-level rise, performed a geotechnical condition assessment through borings and material analysis, and completed biological and cultural resource assessments (See Attachment 1 - Feasibility Report). This extensive emergency repair assessment has allowed staff to progress to a point to recommend for Council’s consideration an alternative to move forward for the final repair of this coastal area.
Moffatt & Nichol used the above information to consider a wide array of alternatives that meet the main project goal of protecting the City’s infrastructure in this area. These alternatives included: removal of rock and utilities in the area, hard armoring, beach nourishment, and beach nourishment with sand retention structures. After the first analysis by Moffat & Nichol, five feasible conceptual level alternatives were brought forth for further analysis. The five alternatives analyzed in depth were:
1. No protection alternative - remove the rock revetment and all directly threatened infrastructure allowing natural bluff erosion.
2. Rock Revetment - rock revetment similar to what is currently in place with minor changes.
3. Low Shotcrete Wall - a combination of buried rock revetment and shotcrete seawall supported by tiebacks to approximately 32 feet in elevation.
4. High Shotcrete Wall - a combination of buried rock revetment and shotcrete seawall supported by tiebacks to approximately 65 feet in elevation.
5. Rock Revetment & Stitch Piles - rock revetment similar to what is currently in place with minor changes and stitched piles installed at the bluff top.
Each alternative has pros & cons which are discussed throughout Attachment 1 - Feasibility Report. Each alternative was ranked by the project team according to an agreed-upon methodology that assessed technical performance, lifecycle costs, and environmental impacts of each alternative. The alternatives and scoring of alternatives were discussed with the California Coastal Commission in late 2021 to update them on the project and to ensure the project’s analysis was going to be sufficient to support their requirements when applying for a Coastal Development Permit.
Ultimately, rock revetment (alternative 2) scored the highest overall in the report’s analysis. This rock revetment alternative was estimated to be the most cost-effective alternative being estimated at almost $1M less than the next alternative, alternative 5. As the recommended alternative will likely include most of the emergency rock revetment placed in 2018, changes to the in-place revetment may be minor. Staff anticipates the final cost will be significantly less than the study’s median estimate of $2.4M, which was estimated as if there was no rock revetment there to allow for a fair comparison with the other alternatives. This alternative is also consistent with both the 1980 LCLUP and the 2020 Draft LCLUP. Furthermore, rock revetment would match what exists to the north and south of the project site, does not adversely affect public access but rather protects the construction access ramp that is used by the public, and allows the upper portion of the bluff to retreat to a stable slope. Additionally, while the rock revetment does take some beach space laterally, the beach space it occupies is located between two existing rock revetments and can only be accessed during low tides and consequently is not often used by the public.
As noted, approval of the staff recommended alternative may lead to a project cost savings when compared with what has been originally estimated for this project. The project estimate was originally from $3-$6 million with the assumption a vertical wall was going to be needed.
Should the project be approved by California Coastal Commission, staff believes there could be Pacifica City Council 3
February 28, 2022
significant savings. It is staff’s intention that improvements to recreational access will help offset any mitigations the Coastal Commission may seek to impose on the project.
Thus, it is the City Manager’s recommendation to approve the attached feasibility report and direct staff to continue with the conceptual design of alternative 2, rock revetment.
ALTERNATIVE ACTION:
1. Reject the project team’s recommendation of the rock revetment in favor of another alternative. This alternative action could have long-term impacts that could include higher project costs, elongated timelines, and cause difficulty in permitting.
2. Direct the project team to further study certain technical aspects where there might not be clarity. This alternative action may require further budget approval by City Council for the project team to undertake additional work as well as delays in the overall project timeline.
These actions are not recommended by the City Manager at this time.
RELATION TO CITY COUNCIL GOALS AND WORK PLAN:
This item is consistent with the following Council-adopted goals and Work Plan initiatives:
• “An Engaged Community” includes taking actions to restore trust in city government, expanding communication, and building community.
• “Stewardship of City Infrastructure” includes repairing/replacing outdated city facilities such as city hall, the libraries, fire stations, etc., improving streets, and responding to impacts of sea level rise.
• “Maintaining a Safe Community” includes supporting our first responders (police, fire, public works), responding to storm emergencies, protecting people, property, businesses, and our infrastructure (streets, sidewalks, storm, seawall, and wastewater), and engaging in emergency preparedness activities.
• City Council Priority Item 5. Continue Esplanade Avenue Bluff Erosion Infrastructure Protection Projects.
FISCAL IMPACT:
Selection of this alternative is anticipated to save costs in both design and construction fees.
ORIGINATED BY:
Engineering
ATTACHMENT LIST:
Attachment 1 - Feasibility Report (PDF)