Erosion & Sea-Level Rise
5. How will erosion and sea-level rise impact the property and surrounding area?
EROSION is the process by which wave action, wind, and storm surges remove sediment from beaches, dunes, bluffs, and headlands. Once removed from the shore, the sediment can be carried away into the coastal lagoons, deposited on the back of coastal barriers, or swept offshore; often, the sediment won’t return to the shoreline.
Extensive erosion in Matunuck, R.I. Tropical Storm Sandy caused severe erosion along the southern Rhode Island coast in 2012.
Although shorelines go through natural periods of change, there has been a net loss of sediment over the past few decades in Rhode Island and many municipalities have faced, or are currently facing erosion issues on both public and private beaches. Notably, the most eroded portions of state’s coastline have lost over 250 feet of beach in just 50 years.
SEA-LEVEL RISE: Since 1930, sea-level rise in Rhode Island has increased an average of 1 inch per decade. However, the rate of sea-level rise has quickened and sea level along Rhode Island’s coast has risen 6 inches over the last 40 years. Accelerated sea-level rise is projected to continue into the next century.
Why it matters: Shoreline change not only impacts beaches and nearby structures, but also affects vital coastal infrastructure, like the roads leading to shoreline properties. For shorefront real estate, it is important to consider how erosion and sea-level rise currently influence the shoreline, and how long-term changes may affect the specific property in the future, and over the course of the design-life of a coastal structure. When assessing the impacts of erosion and sea-level rise on a property, be sure to look at how sewer lines, water lines, and access to a property may be compromised over the long-term.
Find out more: The CRMC has created a series of shoreline change maps that depict past coastal erosion. These maps can help you gauge how much erosion a property may experience in the future. To get an idea of how sea-level rise will impact the state, your community, and your property, use the Rhode Island STORMTOOLS interactive map.
6. Can I install structures along the shore to protect the property and buildings from erosion or flooding?
Types of shoreline protection structures.
Source: http://dcm2.enr.state.nc.us/estuarineshoreline/options.html
Shoreline protection structures are manmade formations like revetments or seawalls designed to protect landforms or structures along the coast. Often, these structures are installed with the intention of preventing shoreline erosion, but shoreline protection structures frequently contribute to increased erosion farther down the coast.
In Rhode Island, the CRMC regulates the installation and maintenance of shoreline protection structures, and differentiates between existing structures and new structures, as well as hardened or natural structures.
Seawalls, groins, jetties, breakwaters, bulkheads, and revetments are examples of hardened shoreline protection structures, meaning they do not utilize natural or “green” infrastructure to protect the shorefront from erosion. Instead, these structures are composed of concrete, quarry stone, wood, or even the remnants of buildings destroyed by extreme coastal weather.
Shoreline protection structures in Rhode Island: a seawall, a riprap revetment, and a bulkhead.
Why it matters: Frequently, hardened structures cause increased erosion in areas farther down the coast by retaining erodible sediment behind the structure and sometimes interrupting alongshore transport of sediment to those properties. This means that if an adjacent property owner has a seawall or revetment, the neighboring property’s beachfront may be impacted in the future.
If there is an existing shoreline protection structure on the property, be advised that many existing older walls and revetments were not designed to withstand the wave forces and storm surges that are produced by storm events. Many of the revetments on properties in Rhode Island were installed prior to state regulations pertaining to shoreline structures and were built haphazardly or too close to the structures they are intended to protect, which can exacerbate damage to homes during storms. Even a properly designed shoreline protection structure may not protect the property under all circumstances.
Find out more: For more information about shoreline protection structures, their installation, and maintenance, refer to Section 300.7 of the CRMC regulations.
NEXT: Coastal Storm Impacts & Rebuilding After a Storm >>
This website has been prepared by the University of Rhode Island’s Coastal Resources Center and Rhode Island Sea Grant for the R.I. Coastal Resources Management Council as a guidance resource. It is not intended nor should be used to give any legal advice nor to supersede any state or federal statutory or regulatory language or interpretation of such language. This website refers the reader to various regulations and policies adopted by federal and state regulatory agencies; the reader is encouraged to review the specific regulation and policy.
Rhode Island Coastal Property Guide Credits & Acknowledgements
