Facilitating migration of coastal landforms and habitats by removing shore protection structures: An adaptation strategy for Northeast Region units of the National Park Service
Nordstrom KF and Jackson NL. 2016. Facilitating migration of coastal landforms and habitats by removing shore protection structures: An adaptation strategy for Northeast Region units of the National Park Service. Natural Resource Report. NPS/NER/NRR—2016/1240. National Park Service. Fort Collins, Colorado
Increases in sea level, intensity of storms and coastal erosion are expected in the future in many locations. Removing the barriers that shore protection structures create between coastal and upland habitats would reestablish exchanges of sediment and the ecological functions of the natural ecotone. The potential for removing shore protection structures or allowing them to deteriorate was evaluated in 12 national parks managed by the U.S. National Park Service (NPS). Criteria for potential removal included condition of structures, influence of natural processes following removal, environmental benefits and public safety, access and use. A total of 407 individual structures provide at least some obstruction to natural reworking of coastal formations by waves and currents in 10 of the 12 parks. Reasons for not suggesting removal of structures were many and varied, but they can be synthesized into six general categories, including (1) threat to a bridge or key park resource (cultural, historical or recreational) that is not easily moved (23.3%); (2) threat to a road that is historic or difficult to relocate (15.5%); (3) threat to features outside park jurisdiction (19.4%); (4) limited potential for new habitat to form because of lack of space landward (22.8%); (5) limited effect on landforms that already exist because the structure is raised (e.g. pier) or is a protection structure of similar rock type to formations landward of the protected infrastructure (13.6%); and (6) potential for pollutant release (landfills) or difficulties obtaining a permit for structures in water (5.3%). We suggest that 145 structures could be removed or allowed to deteriorate, although we acknowledge that many of these would be initially controversial. Our suggestions are based on a reconnaissance level investigation of all parks and could be different from local managers, operating under existing guidelines and making use of more detailed local knowledge and evolving plans for management. The structures are in Boston Harbor Islands National Recreation Area, Cape Cod National Seashore, Fire Island National Seashore, Gateway National Recreation Area, Assateague Island National Seashore and Colonial National Historical Park. No structures are suggested for removal in Acadia National Seashore, Salem Maritime National Historic Site, Saugus Iron Works National Historic Site, Sagamore Hill National Historic Site, Fort McHenry National Monument and Historic Shrine and George Washington Birthplace National Monument. Reasons for suggesting removal were varied, but synthesized into four general categories, including (1) protecting removable but functional facilities, including roads (14.2%); (2) protecting buildings and infrastructure no longer in active use (37.5%); (3) fronting land with limited facilities (e.g. trails, campsites) and having space and sediment sources favoring ready development of landforms (21.4%); and (4) in locations where the protection structures have no clear value, e.g. backed by other, more effective, protection structures or having no facilities landward (26.8%). Protection structures are in no better than fair condition or are in poor condition in 77% of the locations where removal was suggested. Adaptation plans can be broadly characterized by three approaches: defend, elevate, or retreat. We highlight three adaptation projects involving retreat that are currently being planned or conducted in coastal parks. These projects show great potential, although they are limited in size. They include (1) moving user facilities farther landward and building them in way that facilitates future relocation; (2) removing bulkheads to allow beaches to become more self-sustaining; and (3) abandoning roads and building new ones farther landward with erodible, temporary surfaces in anticipation of future retreat.
- Type
- Published Report
- Authors
- Nordstrom, Karl; Jackson, Nancy
- Date of Issue
- 2016-06
- Publisher
- National Park Service
- Units
- ACAD , ADAM , AFBG , ALPO , APCO , APLO , APPA , ASIS , BEFR , BLAC , BLRV , BLUE , BOAF , BOHA , BOSO , BOST , BOWA , CACL , CACO , CAME , CBPO , CEBE , COAG , COLO , COLP , COLT , DELA , DELE , DEWA , EDAL , EDIS , EISE , ELIS , ELRO , ERIE , ESSE , FARM , FEHA , FIIS , FLNI , FOMC , FOMR , FONE , FOST , FRED , FRHI , FRLA , FRSP , FRST , GARI , GATE , GEGR , GETC , GETT , GEWA , GLDE , GOIS , GREG , GRSP , HAGR , HAMP , HATU , HOFR , HOFU , INDE , JAME , JOFI , JOFL , LAMP , LOEA , LONG , LOWE , MAAC , MABI , MASI , MAUR , MAVA , MAWA , MIMA , MORR , NEBE , NECRC , NEEN , NEJE , NELO , NER , NERI , NERO , NMSC , NRLO , NRSS , PAGR , PETE , PHSO , PINE , POGR , QUSH , RICH , ROCA , ROVA , ROWI , SACR , SAGA , SAHI , SAIR , SAMA , SAPA , SARA , SHEN , SPAR , STEA , STLI , STSP , SUAS , THCO , THKO , THRB , THRI , TOSY , UPDE , VAFO , VAMA , WARO , WEFA , WIBR , WORI , YONB , YORK , THST
- Keywords
- 2230271, Acadia National Seashore, Assateague Island National Seashore and Colonial National Historical Park, Boston Harbor Islands National Recreation Area, bulkheads, Cape Cod National Seashore, coastal erosion, exchanges of sediment, Fire Island National Seashore, Fort McHenry National Monument and Historic Shrine and George Washington Birthplace National Monument, Gateway National Recreation Area, natural ecotone, NER, Northeast Region, Sagamore Hill National Historic Site, Salem Maritime National Historic Site, Saugus Iron Works National Historic Site, sea level, shore protection structures, storms