David Revell, PhD And others. CSBPA Coastal Conditions 2018 Bodega Bay, CA

Transcription

1 David Revell, PhD And others CSBPA Coastal Conditions 2018 Bodega Bay, CA

2 What if? How much does it cost? Beach front homeowners ask what will my house be worth in 30 years? Beach communities ask what will my beach look like in 30 years? Politicians ask how can I make everyone happy?

3 Do Nothing Accommodate Hybrid Protect Inland Relocation

4 Public vs Private perspectives Typically sector focus Green versus gray Modeling of human management decisions Often lack of economics to inform long term decisions Needs evaluation of Maladaptation

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6 Construction Costs Escalating Maintenance Costs Ecology Recreation Views Aesthetics Seawalls destroy beaches and views

7 Developed/ Yard Private structure / land value Beach Public - towel space, sand castles, tourists, locals Intertidal Public surf fishing, beach walking Subtidal Public - Surfing, diving, kiteboarding, $ - willingness to pay, businesses, taxes, avoided costs Natural defenses/ ecology birds, marine mammals, water filtration, erosion protection, aesthetics, human health

8 House = $3 million, armoring is $500K Beach recreation= $? Ecology= $? Human Heath= $? $ = too hard, don t know = $0 So existing coastal management results $3million> $500,000 + $0+ $0 +$0 = save the house CCC Staff - Identify shortcomings, Recommend conditions, CCC approves

9 For each Adaptation Strategy: Armor Relocate Groins Nourishment Dune / Cobble Restoration Beach Width vs Upland Physical modeling (assumes erosion caused by accelerated erosion rates, not direct storm impacts) Physical and Economics over multiple horizons Recreation yes but not habitat valuation Narrow versus wide beach

10 Upland protected Dry sand beaches disappear Only damp sand beaches by Upland 2-3 houses gone Beaches remain Revell Coastal et al 2016

11 Evaluated Armoring, Dune Restoration, Accommodation and Managed Retreat Beach Width vs Upland Physical modeling (assumes erosion caused by accelerated erosion rates, and annualized 100 year storm impacts) Recreation but not habitat valuation Rincon, Phil King, Everest, and Revell Coastal et al 2017

12 Site Yearly Attendance Source % surfers Value of Surfing Total Recreational Value Rincon La Conchita Mussel Shoals Hobson Rincon Parkway North Faria County Rincon Parkway South Mandos Emma Wood C Street San Buenaventura Oxnard Shores Silver Strand Port Hueneme Point Mugu Total 350, BEACON 75% 40, BEACON 25% 10, BEACON 90% 90, Interviews 76% 100, BEACON 30% 100, Interviews 46% 30, BEACON 55% 210, BEACON 80% 240, CA State Parks 43% 400, BEACON 97% 500, CA State Parks 4% 50, BEACON 15% 410, BEACON 33% 50, BEACON 25% 470, CA State Parks 20% 3,050, $ 17,062,500 $ 20,562,500 $ 650,000 $ 1,850,000 $ 585,000 $ 625,000 $ 4,446,000 $ 5,310,000 $ 1,937,000 $ 4,745,000 $ 3,003,000 $ 5,155,000 $ 1,072,500 $ 1,612,500 $ 10,920,000 $ 12,600,000 $ 6,676,800 $ 12,168,000 $ 25,116,000 $ 25,660,000 $ 1,300,000 $ 20,500,000 $ 487,500 $ 2,187,500 $ 8,794,500 $ 19,782,500 $ 812,500 $ 2,312,500 $ 6,110,000 $ 21,150,000 88,973, ,220, Revell Coastal in review

13 Most cases, managed retreat wins typically between the mid to late century (+ 50 years) in the long term Narrower beaches or higher erosion faster Exception was Oxnard Shores (highest urban density) Habitat valuation still difficult CCC input would help Various implementation mechanisms need evaluation Beneficial in community adaptation discussions

14 Think about a more holistic evaluation of our coastal resources and community identity Need data Citizen scientists, graduate students How many people, when, what are they doing? How much do they spend? Changes to the coastal system over time

15 All Adaptation is local, but solutions need regional and technical perspectives Coordination Lack of authority Language and Communication issues Managed retreat Hybrid structural solutions How to monetize non market benefits? Funding resources Limited dollars for adaptation planning