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Published byMartina Margaret Hawkins Modified over 9 years ago
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Broad Beach Sand & Dune Habitat Restoration Project CCC Hearing October 9, 2015
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Broad Beach Restoration Project Objectives Major nourishments: 300,000 cy sand every 5 years to restore historic wide sandy beach and coastal dune system- should provide at least 5 years longevity Interim nourishments to ensure revetment coverage and dry sand beach- subject to beach conditions & objective triggers Authorization to bury emergency revetment under beach and dune sand Backpassing to extend nourishment life and equalize benefit 20 year authorization, with Executive Director evaluation every 5 years 2
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Beach Restoration: Photo Simulation - West 3
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Compromises with CCC staff CCC staff asked for, and received: 1.Reduced footprint to avoid sensitive habitat at West End 2.Reduced major nourishment volume to 300,000 cy; agreed on sand spec 3.Expanded dune footprint with permanent dune area 4.Revetment - major landward relocation of eastern reach (unresolved) 5.BBGHAD increased commitment for interim nourishments to keep revetment buried 6.Future monitoring coordinated with Science Advisory Panel 7.Plan for eliminating individual septic systems (unresolved) 4
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Primary Remaining Issues With CCC 1.Revetment alignment 2.Scope of public/lateral access 3.Permit term 4.Septic conversion timetable 5
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Project Background 6
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7 Existing Conditions (west from 31064)
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Proposed Broad Beach Restoration Sand loss: between 35,000 and 50,000 cy per year Major Nourishment: 300,000 cy (every 5 yrs), avg. 65’ beach width Interim Nourishments: 75,000 cy (as needed per objective triggers) 8
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Progress Since December 2014 Project Footprint: No nourishment west of 31380 Broad Beach Road Revised Dune Plan: 3:1 ratio of dunes restored to dunes impacted Revetment Alignment: Multiple relocation alternatives proposed Public Access: Nourishment commitment increased and access area expanded Extensive Monitoring Plan & Science Advisory Panel: Members selected; agreement on approach Septic Feasibility Study: Multiple meetings; commitment to complete within 3 yrs of CDP 9
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BBGHAD Reformulation Revised Engineer’s Report: Board adopted July 2015 New Assessment Passed 9/6/15: $595/linear foot; 25% for those west of 31380 −90% favorable vote by property owners New Assessment commits approx $3.1M/yr to Project: fully allocated to Project budget estimates 10
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Discussion of Remaining Issues 1. Revetment Alignment 11
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12 Maximum Pullback (ft) Average Pullback (ft) Typical Pullback West (ft) Typical Pullback East (ft) Total Pullback Length (ft) CCC Staff Report 896273611937 REV. Alt 4C (GHAD Proposed) 805347611601 % Variation (relative to CCC) 10%15%36%0%17% Revetment Pullback Comparison 30760 to 30980 Maximum Typical West Typical East 3103030980 CCC Encroachment onto future leach fields 12
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Revetment Alignment Staff Proposal: No allowance for compliant future leach fields – results in starting pullback too far west (31030) BB Rd. 15’ setback for existing leach fields only BBGHAD Proposal: Follows senior staff’s original proposal Accounts for designated “future” fields as required by LCP Reduces risk of potential future overtopping & preserves integrity of existing backyards 13
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14 15’ SETBACK LEACH FIELD DESIGN SWL (8’ MLLW) PRIMARY RESIDENCE BED ROCK 25’ WAVE UPRUSH ZONE S OWTS H b = 9’ +15’ MLLW STAFF PROPOSAL LEACH FIELD SWL PRIMARY RESIDENCE BED ROCK 25’ WAVE UPRUSH ZONE 15’ MIN SETBACK S OWTS DESIGN SWL (8’ MLLW) H b = 9’ +15’ MLLW BBGHAD PROPOSAL Revetment Alignment - Septic Risk Remedy: Accept BBGHAD-proposed relocation subject to further movement seaward if dictated by septic survey results
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Discussion of Remaining Issues 2. Public Access 15
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PUBLIC/PUBLIC ACCESS 2010 MHTL LIMIT OF VEGETATION PRIVATE PRIVATE/ RESTORED DUNE HABITAT AREA PRIMARY RESIDENCE Public Access – Nourished Beach LEACH FIELD 16
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Public Access Staff proposal: Nourished Beach Public property from 2010 MHTL seaward: AGREED Public access provided seaward of dune vegetation limit and 2010 MHTL up to seaward revetment crest: AGREED Eroding Beach In revetment area when beach erodes, public access available on some public property seaward of 2010 MHTL and landward of dune vegetation limit: AGREED In revetment area, public access and passive recreational use over seaward portion of private property extending 25’ inland from landward extent of “wet sand” until wet sand reaches seaward face of revetment: DISAGREE 17
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PUBLIC ACCESS BBGHAD PROPOSED ACCESS PUBLIC ACCESS STAFF PROPOSED ACCESS 25’ Public Access – Eroding Beach ACCESS MOVES LANDWARD BASED ON “WET SAND” PRIVATE PRIMARY RESIDENCE AREA MOVES LANDWARD BASED ON PASSABILITY 2010 MHTL SEAWARD REVETMENT FACE AMBULATORY AREA TO SEAWARD REVETMENT FACE 25’ 25’ WIDE ON ERODING BEACH UNTIL DUNE TOE AMBULATORY ACCESS TO SEAWARD REVETMENT FACE SEAWARD REVETMENT FACE 10’ 10’ WIDE PASS AND REPASS UNTIL SEAWARD REVETMENT FACE 18
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Public Access - Dunes Eroding Beach BBGHAD cannot accept CCC staff proposal: “Wet sand” too ambiguous and will create conflict; people typically walk on wet sand without problem Proposal of 25’ wide area: too destructive of restored dune area Remedy: –Change “wet sand” to area where beach becomes impassable –Change 25’ to 10’ wide ambulatory access area in dune field 19
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Public Access – Completely Eroded Beach STAFF PROPOSED ACCESS BBGHAD PROPOSED ACCESS PUBLIC ACCESS SIMILAR TO PRE- PROJECT CONDITION UNTIL NEXT NOURISHMENT EVENT (SEPTEMBER) PRIMARY RESIDENCE PRIVATE 2010 MHTL BACKYARD 10’PATH ROCK STAIRS TO PATH PRIMARY RESIDENCE PRIVATE 2010 MHTL BACKYARD 20
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Public Access Staff proposal (cont’d): Eroded Beach If 10’ dry sand beach does not exist along seaward face of revetment, BBGHAD to provide lateral public access via 10' walkway in backyards landward of revetment. DISAGREE BBGHAD to provide stone access stairs extending from seaward toe of revetment to 10’ wide public pedestrian path in backyards. DISAGREE Prior to issuance of CDP, 78 separate license agreements signed by each owner governing public access on private property once nourished, and as beach erodes between nourishments. DISAGREE 21
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Proposed 10’ Path in Backyards 22 Eroded Beach BBGHAD cannot accept staff proposal: Extreme privacy, security, public safety, and liability concerns over prospect of opening private backyards to public when nourished beach completely erodes
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Proposed Public Stairs Eroded Beach BBGHAD cannot accept staff proposal: Stairs through exposed revetment from beach to backyards: extreme safety hazard and liability risk No handrails, not to code 23 Extreme Safety Hazard
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Proposed License Agreements BBGHAD cannot accept CCC staff proposal: Impossible to obtain all 78 signatures and gives each of the 78 owners veto power over the entire Project Remedy: –BBGHAD committed to maintaining sand nourishment –If revetment exposed, nourishment will occur when next construction period opens (September) 24
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Beachfill Longevity Avg. Beach Width based on Initial 300,000 with 75,000 added at Year 2: Time after Initial Fill Average Beach Width Added 0.5 year79 ft 1 year63 ft 2 years44 ft 2.5 years60 ft 3 years50 ft 4 years29 ft Recent sand loss rate up to 50,000 cy per year = 250,000 loss in 5 yrs Fill of 300,000 should last 5 years Sand spec will maximize dry beach longevity Based on comparable SANDAG I and II experience BBGHAD committed to maintain beach and cover revetment 25
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Discussion of Remaining Issues 3. Permit & Revetment Duration 26
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Permit & Revetment Duration Staff proposal: 10-year permitting with Executive Director review at year 5 Requires perpetual “review” and re-permitting efforts Substantial additional BBGHAD costs BBGHAD Proposal: 20-year CDP & Revetment w/ E.D. review every 5 years 27
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Discussion of Remaining Issues 4. Septic Conversion Timetable 28
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Septic Conversion Staff Proposal: Feasibility Study completed within 2 years of CDP hearing 6 year implementation goal BBGHAD Proposal : Feasibility Study completed within 3 years of CDP issuance Implementation goal - to be determined by results of feasibility study Allows BBGHAD to focus on Project, then handle septics 29
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Discussion of Remaining Issues 5. Other Details 30
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Technical details for resolution with staff: 31 SAP and monitoring (via Final Habitat Monitoring and Mitigation Plan) Dune restoration acreage (via Final Dune Restoration Plan) Trigger language refinements (via Final Adaptive Management Plan)
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Public and Homeowners Deserve a Restored Beach Public beach created at private expense Benefits Zuma Beach and downcoast Commitment to new waste treatment solution Final dune design subject to approved dune restoration plan 32
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END
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West End Nourishment Limitation Ends nourishment at 31380 Broad Beach Rd. Preserves “boulder field” between 31444 and 31380 Limits depth of cover to approximately natural conditions west of 31380 Boulder Field 31380 34
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Summary of West End Analyses GOAL 1: Natural sedimentation levels determined - Spring accumulation varies up to 3 feet - Fall accumulation up to 5 feet GOAL 2: Project-related sand transport & burial determined - 3D mapping used to quantify Project burial exceeding natural levels GOAL 3: Impacts to sensitive resources analyzed - No predicted impact to eelgrass and kelp - Impacts to surfgrass predicted to be less than significant - Impacts to lower intertidal boulder field predicted to be less than significant - As expected, beach nourishment project adds sand to upper intertidal and sandy habitats 35
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Proposed Backpassing & Renourishment Triggers ActivityTriggered when… BackpassingWest end beach less than 75’ for 3 months and sufficient sand at east end to backpass: likely 1-2x per 5 years Interim Nourishment West end beach less than 30’ for 6 months Add up to 75,000 cy: proposed assessment funds no more than 3 per 5 yrs. Avoid summer placement Discretionary Erosion Nourishment Less that 10’ dry beach width fronting revetment Place at least 75,000 cy / avoid summer placement Not discretionary – GHAD commits to keep minimum 10’ beach width fronting revetment instead of providing lateral access easements landward of revetment Maximum 3 erosion nourishments within 10-yr period 36
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BBGHAD’s Proposed Monitoring Resource Monitoring During Construction Adaptive Management and Monitoring Dune Habitat Restoration and Monitoring Plan Long-term Marine Resources Monitoring, Reporting, and Mitigation Plan Public Access Management Program Science Advisory Panel ("SAP“) Cost: Approximately $3M/10 years 37
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Winter 2009-2010 Emergency Conditions Temporary sandbagging attempted as a “soft solution”. Sandbags failed when El Niño storm waves and high tides impacted the shoreline. Result: threatened and damaged residential structures and debris along the beach. 38
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Existing Conditions (east from 31450) March 3, 2014 Tide Approx. Mean Sea Level 39
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Existing Conditions (30712 PCH- East End & No Revetment) February 2, 2014 40
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2010 MHTL PRIMARY RESIDENCE LEACH FIELDS PUBLICPRIVATE 2010 MHTL PRIMARY RESIDENCE LEACH FIELDS RELOCATED REVETMENT DUNES BEACH PRIVATE/PUBLIC ACCESS PRIVATE EXISTING BBGHAD PROPOSED NOURISHED BEACH PUBLIC Public Access – Revetment Pullback
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