At their August 2, 2022 meeting, the City Council adopted the City of Carmel-by-the-Sea's Climate Adaptation Plan and Climate Action Plan under Resolution 2022-064. Council commented that implementation of these Plans is imperative and requested the Climate Committee to continue to oversee the implementation of certain projects, including the Coastal Engineering Study.
At the November 2022 meeting, the City Council adopted Resolution 2022-094 awarding a Professional Services Agreement with EMC Planning Group, for a not-to-exceed fee of $175,000, to conduct the Coastal Engineering Study and Adaptation Planning Project. Key subconsultants for this study are Integral Corporation and Haro Kasunich & Associates.
To develop the project’s scope of work, the Consultant team reviewed the 2001 Coastal Development Permit for Scenic Road Armoring Repairs, 2003 Shoreline Management Plan (Shonman and D’Ambrosio), 2016 Carmel Shoreline Assessment Update, 2016 Assessments of Shoreline Improvements at Carmel Beach (Easton Geology), and the City’s 2022 Climate Adaptation and Climate Action Plans.
The Study will be completed in two phases, Phase 1 is funded in the current Capital Improvement Plan (CIP), while Phase 2 has recently been approved for funding by a non-competitive California Coastal Commission grant of $500,000. Phase 2 will include Hazard Policy review and revisions, public outreach, and adaptation pathway development. The results of Phase 2 will be brought back to the Climate Committee in the future.
At today’s Climate Committee meeting, Matt Jamieson, Project Scientist, from Integral Corp will present their key findings of Phase 1, Task 1, Coastal Engineering Condition Evaluation (Attachment #1) and the Phase I Task 2, Carmel Climate Change Vulnerability Assessment and the Shoreline and Beach Change Analysis: Seasonal and Long Term (Attachment #2) to the Committee and the public. Previously, the consultant team presented their findings to the Forest and Beach Commission at the March 2023 and the August 2023 meetings. Below is a brief summary of the key tasks and associated deliverables for Phase 1:
Phase 1 – Coastal Engineering and Hazard Assessment
Task 1 – Coastal Engineering Condition Evaluation
The following table summarizes the key issues of the Condition Assessment.
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Coastal Infrastructure
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Total Number
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In Need of Repair
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High Priority Repairs
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Seawalls
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11
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2-4
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1
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Beach Access Stairs
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11
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9
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3
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Revetments
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6
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4
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3
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Task 2 - Shoreline and Beach Change Analysis – Long Term and Seasonal
This study determined the seasonal and historical trends of shoreline position and beach sand widths using historic reports and imagery data dating back to the 1940s.
Long Term
- The sand affecting Carmel Beach extends beyond the City limits north to include Pebble Beach along the 10th golf course hole.
- Overall, the long-term shoreline position and beach widths have been relatively stable. This indicates a relatively stable amount of sand in the sandy beach compartment.
- On average, the beach widths were narrower south of Eighth Avenue, wider at Pebble Beach, and the widest in the dune-backed areas near the Del Mar parking lot.
Seasonal
- The beach widths change seasonally, where the narrowest beach widths occur in the spring (after winter storm waves), and the widest beach widths occur in the fall (after small summer waves).
- The highest range in beach widths occurs south of Eighth Avenue and near Pescadero Creek (around the offshore rock).
- The beach width was most stable in the dune-backed areas near the Del Mar parking lot.
Storm Impacts and Recovery
- During strong west swells (often in El Niño years), when beach erosion is highest, most of the sand is moved offshore, exposing bedrock under the sand in some areas.
- The highest observed cliff erosion was between 20-40 feet and was observed following the 1982-1983 El Niño.
- Recovery after large storm events occur can take a few years, and the area south of 8th Avenue usually takes the longest.
The additional Phase 1 tasks include:
Task 3 – Shoreline and Beach Erosion Exposure Modeling
Deliverables: Technical memo of methods and maps showing results of the projected existing and future coastal hazard extents, and one public presentation.
Task 4 – Coastal Hazard and Sea Level Rise Vulnerability Assessment
Deliverables: Executive summary of results, up to five sector profile summaries (land use, transportation, utilities, etc.), and one public presentation.
Task 5 – Policy Review
Deliverables: Consultants prepared a memo summarizing the City’s existing coastal hazard policies that will lead into an Action Plan for Revised Hazards Policies to be prepared in Phase 2.
The results of Task 2 will lead into Task 3, Shoreline and Beach Erosion Modeling where Integral will conduct Coastal Hazard Exposure modeling. In Winter of 2023/2024, the consultants will also provide input on the effect of erosion by existing armoring (revetments, seawalls) and what happens when the structures fail or are removed.
In Task 4, the consultants will conduct a vulnerability assessment and summarize the results by hazard type, sea level rise, coastal bluff and roadway impacts. The report will state whether an impact is anticipated in the near-term or long term.
The results of Tasks 3, 4, and 5 will be brought back to the Climate Committee for discussion in the near future.