- Author, Margaret Peloso
Adapting to Rising Sea Levels: Legal Challenges and Opportunities
Adapting to Rising Sea Levels discusses the ways in which the structure of the United States’ legal system shapes adaptation. Written to be accessible to a broad audience, the book provides the necessary background on the science of sea level rise and the basic legal principles that animate decision-making in the coastal zone, including the takings doctrine. The book explores the role of federal flood insurance and disaster relief in shaping adaptation decisions, presents case studies from states, and concludes with a high level overview of some of the unique challenges faced by corporations operating in the coastal zone.
Explore the figures shown in the book by chapter below.
What is Relative Sea Level Rise?
Global Distribution of Tide Gauges
Satellite Altimetry Map of Sea Level Rise Differences
Explanation of Atlantic Meridional Overturning Circulation and Sea Surface Height
Thermohaline circulation is the circulation of ocean waters that is driven by differences in temperature and salinity. In the North Atlantic Ocean, the formation of sea ice causes the surrounding water to become colder and saltier, increasing its density. This denser water sinks becoming part of the deep ocean currents that are sometimes referred to as the “ocean conveyor belt.”
Explanation of Impact of North Atlantic Oscillation on Landfalling Hurricanes
The North Atlantic Oscillation (“NAO”) is a large-scale atmospheric circulation feature that is characterized by positive and negative phases based on the location of two pressure centers over the North Atlantic. The NAO, which can vary considerably both seasonally or multi-year time scales impacts storm tracks including those of hurricanes. Positive phases of the NAO will cause hurricanes to track closer to the U.S. East coast, while negative phases will tend to steer hurricanes out to sea.
Map of Projected Sea Level Rise on the Texas Coast
Map of Projected Sea Level Rise on the North Carolina Coast
Map of Projected Sea Level Rise in San Francisco Bay
Ecological Impacts of Seawalls
In the absence of structures that prevent landward movement (e.g., seawalls, coastal
roads), coastal wetlands and other important habitats will move landward in response to
rising sea levels to maintain their position relative to the water. However, when seawalls or
other hardened structures are built to protect coastal property, they prevent this landward
movement and coastal habitats will ultimately be drowned by rising sea levels.
Erosion, Beach Nourishment and Economic Benefits
Coastal setbacks are often measured with respect to either the mean high tide line or the
first line of vegetation, allowing them to be dynamic over time.
Spatial and Temporal Correlation of Flood Risks
In a flood, if one house in the neighborhood floods, all of the others will too. This is different from a fire, where if one house burns down others might not.
What Is the “Built Environment”?
When considering resilience of a coastal community to climate changes, there are two different types of resilience to consider: social and ecological. As explained in Chapter 2, social resilience can be enhanced at the expense of ecological resilience (e.g., by building seawalls) or by using natural systems to protect coastal communities (e.g., through wetland restoration and setbacks). In evaluating adaptation options, it can be helpful to distinguish between the systems we are trying to protect. Therefore the “built environment” is a term that is useful to distinguish human development, including homes, roads, and coastal infrastructure, from coastal ecosystems, such as sandy beaches and wetlands.
This distinction is particularly important when considering insurance as an adaptation strategy. Insurance covers physical structures that are part of the built environment and is a mechanism to allow physical structures to be restored to their pre- storm condition. Because insurance does not cover coastal ecosystems, it can facilitate rebuilding at the expense of these systems that would otherwise provide natural hazard protection in future events.
Flood Hazard Mapping
FEMA Flood Risk maps classify communities into zones based on flood risk. In the coastal zone the primary zones are:
Zone A: The 100- year flood plan (1% annual flood risk)
Zone V: The 100- year flood plan with additional hazards from storm waves
Zone VE: The V zone with additional risk from erosion
Flood Risk Information Resources from FEMA
To help property owners understand the flood risks to which they are exposed, FEMA has created an extensive set of resources at its public outreach website, floodsmart.gov. The website provides information on flood risks, flood safety, and the availability of flood insurance policies under the NFIP.
FEMA also maintains the Map Service Center, an official online public resource for flood mapping. Through the Map Service Center’s online tools, property owners can enter their addresses and explore their flood risk.
Key Coastal Boundary Lines
Accretion and Erosion
Grand Central Station, New York
Explanation of the Lucas Properties
Map Showing the Palazzolo Property
Explanation of the Nollan case
Explanation of the Dolan case
The Erosion Control Line
BCDC Sea Level Rise Map
Bluff Undercutting Erosion
The Pleasure Point Seawall Under Construction in 2009 and in 2014
Capitola Sea Cave
Scope of BCDC Jurisdiction
South Bay Salt Ponds Restoration
The Saltworks Site
The North Carolina Coast
Sandbag Placement Along the North Carolina Coast
The Riggings Complex
Kure Beach Coastline
Living shorelines focus on using natural littoral landscapes as the border between land and sea. In contrast to seawalls (bottom), the living shoreline will migrate landward as sea levels rise.
Example of Living Shoreline and Setback at River Dunes
Map of Eroding Areas on the Texas Coast
The Great Galveston Hurricane of 1900
Rebuilding a Groin in Front of the Galveston Seawall
Galveston Seawall in 2016
Babe’s Beach in front of the Galveston Seawall in 2016 after beach nourishment. The nourishment project established a beach along this stretch of the seawall for the first time in nearly 20 years. Photo Credit: Ellis Pickett
The Severance Properties
Rebuilding under Section 15.13 of the Beach and Dune Rules
Application of the Doctrine of Avulsion after Severance
Role of Base Flood Elevation and Army Corps Jurisdiction in Shaping Development
John Mecom’s Flamingo Isles
Overview of Harborwalk Showing Infeasibility of Living Shorelines Given the Existing Canal and Lot Structure
Bulkheads at Harborwalk
Coastal Development That Is a Danger to Public Health and Safety
CERCLA Remedies That May Be Subject to Five- Year Reviews
Submergence of an Upland Cap Due to Sea Level Rise