Coastal Property Damage Mitigation Risk Assessment GEOL 4093

Mitigation Engineering –Strengthen or move buildings –Armor the coast Land Use Planning –Limit or reduce development density –Can help implement new techniques such as clustered housing –Easiest with new developments

Responses to an Eroding Shoreline Hard Stabilization –Seawalls, groins, breakwaters, etc. Soft Stabilization –Beach replenishment, dune building Relocation or retreat –Move back from eroding shoreline

Hard Stabilization (Seawalls, etc.) Advantages –Most dependable way to save beachfront property Disadvantages –Degrades the recreational beach –Reduces beach access –Costly –unsightly

New Jerseyization

Modes of Beach Destruction by Seawalls Placement Loss –Seawall is built on the recreational beach Passive Loss –Beach continues to retreat and narrows in front of the seawall Active Loss –Seawall directly causes erosion

Metropolitan San Juan Dry Beach Widths

Soft Stabilization (Beach Nourishment) Advantages –Widens the beach –Protects buildings while beach is in place Disadvantages –Temporary –Costly –Unknown environmental effects

Relocation or Retreat Advantages –Responds to sea-level rise –Preserves the beach –Saves shoreline stabilization costs –Preserves builidings Disadvantages –Politically difficult –Potentially costly –Loss of land

Mitigation Options Hard Stabilization Soft Stabilization Vegetation Development and infrastructure Zoning and land use planning

Our Approach to Mitigation Coastal landform protection, restoration, augmentation Mostly low cost Many things individuals can do Environmentally sensitive Considers geologic/oceanographic processes

PAR For the Shore Preserve, Augment, Restore –Dunes (frontal and interior) –Coastal barriers of all types Mangroves Shoals River mouth bars Maritime forest –Add new sand to island

Pandora’s Island—Mitigation on the Beach

Pandora’s Island—Mitigation back from the beach

Pandora’s Island becomes Fantasy Island