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Shoreline Change in Urban Massachusetts, Time for Retreat?

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2013 February. Workshop presentation at the American Association for the Advancement of Science (AAAS), Annual Meeting, Boston, MA, of co-authored research, Shoreline Change in Urban Massachusetts, Time for Retreat?

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Shoreline Change in Urban Massachusetts, Time for Retreat?

  1. 1. Guy Billout, “Civil Engineering” Atlantic Monthly (2001) Shoreline Change in Urban Massachusetts: Time for Retreat? Porter Hoagland Marine Policy Center Woods Hole Oceanographic Institution Lisa Granquist Ph.D. Candidate Law & Public Policy Northeastern University AAAS February 2013
  2. 2. “The ocean is huge, powerful, and eternal. Puny man can scarcely expect to win by overwhelming it, and anyone who counters its attack with brute-force solutions is doomed to expensive disappointment.” Willard Bascom Waves and Beaches (1961) http://www.panoramio.com/photo/34182602 Minot Beach Community Scituate, MA 2010
  3. 3. Some Relevant Socio-economic Studies  Sea-level rise (Yohe et al.): Normative  Erosion risk (Kriesel et al.): Positive Also: • Barrier alterations and vulnerability (McNamara, Werner) • Beach nourishment between linked communities (Slott) • Coordinated management of curved beaches (Jin, Ashton) • Beaches and coastal property values (Landry, Pompe, Edwards) • Optimal nourishment of beaches (Smith, Murray, Gopalakrishnan) • Non-market values (Landry, Parsons, Whitehead)
  4. 4. Adaptation in the Face of Sea-Level Rise (Yohe et al.) • Socially optimal timing: • Delay • Protect • Abandon Sea Ranch, CA 2009 Chatham, MA 2009 Springhill Beach Sandwich, MA 2008 Springhill Beach Sandwich, MA 2008 Massachusetts coastal urban areas
  5. 5. Urban Areas • Urban areas comprise urbanized areas (UAs) and urban clusters (UCs) • An “urbanized area” is an urban area of 50,000 or more people • An “urban cluster” is an urban area of between 2,500 to 50,000 people • Dark blue indicates 80-100% of the coastal Massachusetts population resides in urban areas (with the exceptions of Dukes and Nantucket counties) http://www.census.gov/geo/www/maps/2010_census_UA_maps/imgs/UA2010_Urban_Pop_Map.pdf
  6. 6. Massachusetts South Shore • Combination of urbanized areas and urban clusters • Hingham 22,157 • Hull 10,293 • Cohasset 7,542 • Scituate 18,133 • Marshfield 25,132 • Duxbury 15,059 • Kingston 12,629 • Plymouth 56,468 • Bourne 19,754 • Sandwich 20,675 • TOTAL 207,842 people http://www2.census.gov/geo/maps/dc10map/UAUC_RefMap/ua/ua09271_boston_ma--nh--ri/DC10UA09271.pdf
  7. 7. Massachusetts Coastal Structures (n=3,767) • Seawalls • Revetments • Groynes, Jetties • Bulkheads • Gabions • Dune reconstructions • Beach nourishments Source: MCZM
  8. 8. “If the [coastal engineer] builds any new shoreline facilities that stop the flow of sand, there will be trouble both at the place where the sand stops and the place where it would have gone.” Willard Bascom (1961) http://www.marineinsight.com/misc/marine-safety/a-barrier-with-a-difference-sea-walls/ “Sea walls are extremely utilitarian … it becomes important to build such preventive structures in order to lessen the menace of … natural calamities and to assure the people of their safety through a very visible, physically demonstrative and effective barrier.” MarineInsight.com (2010)
  9. 9. Problems with Massachusetts Hard Structures www.bostonglobe.com/metro/2013/02/09/lose-power-storm-expected-continue-into-midday/1I0rzzSPGsdJ58jf0LfFIK/picture.html http://www.boston.com/yourtown/scituate/articles/2011/05/29/scituate_sea_wall_repairs_to_be_done_in_several_cycles/ “Attempting to halt the natural process of erosion with seawalls and other hard structures … simply shifts the problem, subjecting downdrift property owners to similar losses.” “…the undermining of sea walls, some of which are many decades old, can result in significant economic and emotional loss in a system of fixed property lines and ownership. “ Both quotes are from the “Draft Old Colony Hazard Mitigation Plan” (2012) Scituate, MA “Winter Storm Nemo” (February 2013)
  10. 10. • MCZM now compiling data on vintages, conditions, repair costs • Many gaps in the data • Ownership (=> responsibility for maintenance) sometimes unclear • Est. ~$700 million to repair
  11. 11. The Gurnet Plymouth, MA
  12. 12. Estimating Erosion Costs (Kriesel et al.) • Data on the geographic position of shorelines over time => shoreline change rates • Measure the distances from coastal properties to the shorelines • Calculate the “time to inundation” for coastal properties • Estimate the costs of erosion risks using hedonic pricing approaches 20% 30% 40% 50% 60% 70% 80% 90% 100% 0102030405060708090100expected years away from the shoreline % of 200 yr value Kriesel Atlantic1978-1994 Linear Model1952-2005 Linear Model
  13. 13. A Negotiated Solution? (Kriesel et al. 2000) • Inland property owners observe significant premiums in home values due to the existence of beaches for recreation in front of proximate waterfront properties • As erosion occurs, waterfront property owners seek to protect their properties with hard structures (seawalls, revetments) • often waterfront property owners have the legal right to do this … • “In theory,” to protect their own home values, inland property owners could pay waterfront property owners to forego hard structural protections or to replenish sand on the beach
  14. 14. A Negotiated Solution in Massachusetts? • But in Massachusetts, private property rights extend to mean low water (i.e., there is only very limited access by inland property owners—fishing and fowling) • Hard structural responses are already widespread • Wetlands Protection Act attempts to control hard structuring (but pre-existing structures, grandfathering, variances, illicit activity) • Nevertheless, there may still be an externality due to the increased risks of erosion to properties adjacent to structures • Consequently, there may be an opportunity for a negotiated solution among waterfront property owners
  15. 15. Harlow’s Landing Plymouth, MA
  16. 16. Harlow’s Landing Plymouth, MA • Structure(s): 172’ Revetment (with some seawall sections), built circa 1959(?); another structure attached and extending to the north • Shorelines: • Before: 1909, 1952 • After: 1978, 1994 • Challenges: • Accuracies of shoreline measurements • Accelerated SLR?
  17. 17. Economic Effects • Can estimate increased costs of risks faced by properties with no structures (both waterfront and inland) near waterfront properties with structures with Kriesel et al. approach (hedonic pricing models) • Challenges: • Data limitations (Shorelines, Structures, Vintages) • Statewide problem? • Public areas (Beaches, Wetlands)
  18. 18. Impacts on Natural Areas?
  19. 19. Potential Policy Solutions • Uncertainty makes negotiated solutions problematic • Retreat from the coast likely now optimal in many places 1. FEMA’s Hazard Mitigation Grant Program • Purchase coastal properties and prohibit development • State/Local Hazard Mitigation Plans • Presidential declared disaster area • Cost of repair > 50% of home value • Must have “willing” sellers • FEMA (75%); State/local (25%) • Open space, recreation, or wetlands management 2. NPS’s “reservations of use and occupancy” Boston Region Metropolitan Planning Orgsanization “All Hazards Planning” http://www.town.scituate.ma.us/flood/Scituate_Hazard_Mitigation_Plan.pdf
  20. 20. Acknowledgements Funding: • NSF/CNH • WHOI Coastal Ocean Institute • WHOI Marine Policy Center • Data and Analysis: • Andy Beet • Jim O’Connell • Rob Thieler • Other colleagues: • Andrew Ashton • Ilya Buynevich • Jeff Donnelly • Steve Eberbach • Rob Evans • Di Jin • Hauke Kite-Powell • Jorge Lorenzo-Trueba

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