Home Page

Sea Level Rise Scenario

This floodplain mapper shows the estimated boundary of future coastal floodplains for different sea level rise scenarios. Customize a scenario by choosing the amount of sea level rise in inches and a coastal flood recurrence interval.
1. Sea Level Rise (in)

Select the amount of sea level rise in inches. Options are 12", 18", 24", 36", 48", 60", and 72".
2. Recurrence Interval (yr)

Select the coastal flood recurrence interval (i.e., the likelihood of the flood event) to display. Options are: the 10-year, 50-year, 100-year, or 500-yr flood.
The calculated recurrence interval of a flood event is based on statistical analysis of historical storm event frequency and intensity.
As an example, the 100-year recurrence interval has a 1% chance (1 in 100) of happening in any given year. The term can be misleading: a “100-year flood” is not a flood that happens only once every 100 years. Such an event can happen multiple times in a century. In the context of flood risk, a home in the 100-year floodplain has a 26% chance of flooding over the life of a 30 year mortgage.
3. Community

Type in a county, city, town, or village name to zoom to that location. Use the dropdown menu provided to refine your search. For example, you can select “Project Counties” or “Project Communities” to search for only counties or communities within the project area, or select “Places” to search for distinct locations on the map (e.g., Smith Point Beach).
Statistics Summary

Click on a community or county boundary on the map to see a summary of statistics for that area based on the selected scenario. These statistics include the estimated increase in the extent of coastal flooding and the number of buildings affected by the flooding.
Map Layers

Check or uncheck the box next to each of the map layers listed to add or remove it from the map.
Political Boundaries

This layer shows the boundaries between counties, cities, towns, and villages.

Project areas and counties
Cities, towns, and villages
Floodplains

Depicts the extent of the coastal floodplain for the selected recurrence interval and sea level rise scenario (light blue), compared to today’s (0 inches of sea level rise) floodplain (dark blue).

Today's floodplain
Selected scenario
Wave Action

Depicts the extent of the potential for breaking wave heights over 1.5 ft, for the 100-year recurrence interval and the selected sea level rise scenario. Structures within this area are likely to be subject to structural damage in the case of a 100-yr recurrence interval event. Yellow-shaded areas show how this structural-hazard area grows over today’s condition, shaded as green.
Areas within this shaded zone correspond to the Area of Moderate Wave Action, or the Coastal High Hazard Zone (VE) as defined by FEMA. The American Society of Civil Engineers and FEMA’s Coastal Construction Manual provide improved building construction guidance for homes within this area to improve flood resilience.

Today's wave action
Selected scenario

Units:

Select the unit of measurement for areas as square miles or square feet. Note: 1 mile = 5,280 feet and 1 square mile = 27,878,400 square feet.

sq mi sq ft

View summary data by searching for a county, city, town, or village or by clicking a community on the map.

Increase in Coastal Floodplain: This is the total additional area that will be affected by coastal flooding (in the chosen county/community) under the selected recurrence interval and sea level rise scenario, as compared to the current coastal floodplain.	Select location
Buildings Affected, total: The number of buildings vulnerable to coastal flooding and wave action (in the chosen county/community) for the selected sea level rise scenario and recurrence interval. This information is only provided for areas where building footprint data were available.	Flooding:	Wave Action:
Buildings Affected, change: The change in the number of buildings vulnerable to coastal flooding and wave action for the selected sea level rise scenario and recurrence interval, as compared to the number of buildings affected under current (2012-2014) floodplain conditions. This information is only provided for areas where building footprint data were available.	Flooding:	Wave Action:
Chance of flooding: Represents the percent chance of flooding over a 30-year timeframe for the selected scenario. Provided values are averages for the chosen community/county. The presented value reflects change in flood probability based solely on the increase of flood depth due to each sea level rise scenario.	30-year Chance:

This graph shows how the area flooded by each coastal storm surge recurrence interval changes for the SLR scenarios analyzed by this project. Typically, the higher frequency floodplains (10-yr and 50-yr recurrence intervals) are observed to grow at a faster rate than the lower frequency floodplains (100-yr and 500-yr floodplains). This is due to the fact that the greater flood elevations of the 100-yr and 500-yr floods tend to sit near or at steeper areas of the land topography, which constrains their growth. In contrast, the lower elevation floods tend to have much more room to grow. In fact, this study found that the 10-yr floodplain is expected to increase on average 1.5 times more than the regulatory floodplain (100-yr floodplain).

Coastal New York Future Floodplain Mapper

Disclaimer: