Coastal Hazards Overview

Shorelines are dynamic places. Weather systems generate wind, waves, rain, and other forces that affect shorelines. Accompanying these weather systems are environmental effects including storm surge, overwash, flooding and erosion, creating a complex array of coastal hazards wherever development occurs near the shore. Where they do not create risks to life and property, these hazards are normal and naturally occuring events. In some instances, these events can provide positive benefits to the coastal environment such as depositing sediment to build wetlands and dunes. Climate change is another hazard that commun ities must begin to address, especially those adjacent to the coast where sea level rise and changes in Great Lakes water levels threaten increased flooding and erosion.

New York State communities are likely to experience significant impacts to infrastructure, public health and safety, and natural resources due to climate change. The severity of these impacts and the associated costs to communities can be reduced through planning and adaptation. It is important to initiate actions early, and in coordination with current land use and capital development programs, in order to reduce the scale of the impacts from extreme events and to distribute adaptation costs over time. Understanding hazards and assessing, managing and reducing coastal risks and climate change impacts are essential elements in building community resilience.

The Department of State provides both technical assistance and grant funding to NYS communities for climate change adaptation. Funding is available for planning and implementation projects through the competitive Local Waterfront Revitalization Program’s Environmental Protection Fund grant program.

Coastal hazards are created when development (or an asset) is exposed to risk of loss or damage by natural events like storm surge, overwash, flooding and erosion. Risk will vary with topography, weather, exposure, geology, previous shore protection efforts and local conditions. In assessing waterfront flooding and erosion hazards, examine the following:

• The extent of any federally designated Flood Hazard Areas, floodways, coastal high hazard areas and Coastal Barrier Resources System units
• The extent and nature of any State designated Coastal Erosion Hazard Areas
• The extent of other flooding and erosion risk areas
• The coastal processes at work on your shoreline
• The location of natural protective features such as wetlands, dunes and bluff
• Upland topography
• Inland and shoreline development patterns
• Land ownership details
• Regional weather conditions, historic weather patterns, and predicted future weather conditions
• Information presented in published scientific reports for your shoreline or region
• Navigation charts and bathymetric information
• Data on historic shoreline change and any ongoing shoreline monitoring initiatives
• Location, extent and condition of shore protection structures
• Records, photos and anecdotal information on past shoreline conditions and storm events
• Available maps and information predicting the future risk due to climate change

Knowing the risks associated with flooding and erosion is a critical concern if you live, work, or depend on New York's coasts and waterways. Risk assessment is a method that can help identify relative levels of risk and may include factors such as the magnitude and probability of future hazardous events, exposure and vulnerability to hazards.¹ These hazards extend across wide geographic areas and impact assets in varied ways, which is why assessing risk is an important step in identification and prioritization of risk reduction measures. Since the level of development and type of hazard exposure vary by locality, and the primary land use planning tools - planning, zoning, and infrastructure investment - to manage hazards risks are locally administered, local government is often the primary forum for addressing waterfront hazards and risks.

A local government should develop a plan to address potential hazards, such as a local hazard mitigation plan and integrate hazard management into existing community plans and programs such as Local Waterfront Revitalization Programs. Work with federal and State programs that provide technical assistance to manage flooding and erosion hazards relevant to your local risk factors.

The primary questions to ask when developing plans to address shoreline hazards are:

• What are the types, frequency and scale of the hazards?
• How will the hazards change over the course of time?
• Which areas, buildings, public facilities, institutions and vulnerable populations (e.g., elderly, disabled, low income) are at risk?
• What are the risks to water-dependent uses?
• What are the risks to the transportation network?
• What is the history of past hazard impacts on identified assets?
• What is the structural condition of at-risk assets?
• What other areas are available where development might be directed as the community changes over the course of time, and may such areas become hazardous areas as the climate changes?
• What natural resources are at risk? Do they have room to move in response to climate change?
• What mitigation measures are available to reduce future hazard risk?

( ¹ Exposure relates to local landscape characteristics that tend to either increase or decrease hazard effects. Vulnerability is the capacity of an asset or system to return to service after an event such as a coastal storm.)

Different approaches to reduing risks from coastal hazards may be appropriate according to the nature of the risk and the adjacent use. New York State law (Article 42 of the Executive Law and Article 34 of the Environmental Conservation Law) gives priority to nonstructural measures, including the management of development to avoid hazard areas. Nonstructural approaches maximize protection afforded by natural processes and features. These approaches offer the best opportunity for dependable long term risk reduction, require the least long term maintenance, and have the least detrimental effects on other coastal and waterfront resources and uses.

Structural measures may be the only viable option for highly developed urban areas and water-dependent uses. However, they require repeated maintenance and additional management measures, leave developed areas exposed if conditions occur that exceed structure capacity, and may have negative impacts on other resources as well as adjacent locations.

The following are examples of approaches that can be considered to reduce risk to your waterfront community from flooding and erosion and minimize the threat from coastal hazards:

• Avoid inappropriate siting of structures in hazard areas.
• Protect the natural dynamics of changing shorelines and maintain, improve, and make room for natural features and resources that protect against flooding and erosion.
• Use nonstructural measures to minimize damage to natural resources and property from flooding and erosion, including review of setbacks to ensure new buildings and accessory structures are sited outside of Flood Hazard Zones and Coastal Erosion Hazard Areas.
• Relocate existing buildings and accessory structures out of Flood Zones and Coastal Erosion Hazard Areas.
• Elevate or flood proof existing buildings and accessory structures.
• Stabilize bluff, dune, backshore and beach formations with appropriate plantings of native vegetation.
• Install conveyance structures to direct runoff away from assets (e.g., to help control water flowing over bluffs and bluff faces) and direct water to flood storage or discharge areas.
• After storm events, replace lost sediment to bluffs, dunes, backshores and beaches.
• Limit the use of hard structural erosion protection measures to protecting water dependent uses, where nonstructural approaches to reducing erosion are not effective or where enhancement of natural protective features would not provide erosion protection.
• Where hard structural measures are necessary, design in such a way to reduce impacts to coastal process and habitats (e.g., design the minimal size required to provide risk reduction benefits; include ecological enhancement of hard structures).
• Prepare and plan for post-storm response and recovery.
• Redevelop in a manner that increases community and coastal resilience.
• Develop measures to reduce damages from future storms and climate change impacts.

New York State Department of State
Office of Planning, Development and Community Infrastructure
99 Washington Avenue, Suite 1010, Albany, NY 12231

Office: (518) 474-6000

dos.ny.gov