This application is designed for use on desktop computers and tablets in landscape mode.

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Sea Level Rise Viewer

High Tide Flooding

View areas susceptible to high tide flooding, or "nuisance flooding," and the number of historical flood events that have occurred.

Sea Level Rise

View sea level rise and potential coastal flooding impact areas and relative depth.

Local Scenarios

Compare inundation levels to local relative sea level rise scenarios.

Mapping Confidence

View the level of confidence in the base data used for mapping inundation levels.

Marsh Migration

View potential changes in marsh and other land cover types based on inundation levels.

High Tide Flooding

View areas susceptible to high tide flooding, or "nuisance flooding," and the number of historical flood events that have occurred.

Sea Level Rise

View sea level rise and potential coastal flooding impact areas and relative depth.

Disclaimer

The data and maps in this tool illustrate the scale of potential flooding, not the exact location, and do not account for erosion, subsidence, or future construction. Water levels are shown as they would appear during the highest high tides (excludes wind-driven tides). As with all remotely sensed data, all features should be verified with a site visit. The data and maps in this tool are provided “as is” without warranty to their performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of these data is assumed by the user. This tool should be used strictly as a planning reference tool and should not be used for navigation, permitting, or other legal purposes.

Disclaimer

The data and maps in this tool illustrate the scale of potential flooding, not the exact location, and do not account for erosion, subsidence, or future construction. Water levels are shown as they would appear during the highest high tides (excludes wind-driven tides). As with all remotely sensed data, all features should be verified with a site visit. The data and maps in this tool are provided “as is” without warranty to their performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of these data is assumed by the user. This tool should be used strictly as a planning reference tool and should not be used for navigation, permitting, or other legal purposes.

January 2025

Washington – Remapped with new elevation data and VDatum tidal surfaces. New DEMs available.

California – Santa Cruz County south to San Diego County remapped with new elevation data and VDatum tidal surfaces. New DEMs available.

American Samoa – Tutuila, Tau, Ofu, and Olosega remapped with new elevation data. Rose Atoll mapped for the first time in the Viewer. New DEMs available.

Maine – Remapped with new elevation data. New DEMs available.

New Hampshire – Remapped with new elevation data. New DEM available.

Massachusetts – Remapped with new elevation data. New DEM available.

Rhode Island – Remapped with new elevation data. New DEM available.

Alaska – Regions or communities mapped for the first time in the Viewer:

June 2023

Florida – Peninsula remapped with new elevation data. New DEMs available.

Georgia – Remapped with new elevation data. New DEMs available.

Catalina Island, California – Previously unmapped. New DEM available.

Guam – Remapped with new elevation data. New DEM available.

Northern Mariana Islands – Saipan remapped and new data for Rota, Aguijan, and Tinian. New DEM available.

Local Scenarios and Marsh Tutorials updated to include the 2022 Interagency Sea Level Rise Technical Report scenarios.

March 2022

New sea level rise scenarios from the 2022 Sea Level Rise Technical Report are available under the Local Scenarios tab.

Alabama – Remapped with new elevation data. New DEM available.

Florida – Panhandle remapped with new elevation data. New DEMs available.

Puerto Rico – Remapped with new elevation data. New DEM available.

U.S. Virgin Islands – Remapped with new elevation data. New DEM available.

New Jersey – Central and southern New Jersey remapped with new elevation data. New DEMs available.

July 2020

Users can now zoom in one more level under Sea Level Rise, Scenarios and High Tide Flooding.

All locations – Photo simulations now have images for 7-10ft.

High Tide Flooding Historical Yearly Inundation Events charts now updating dynamically and showing data through 2019.

Washington – Eastern Puget Sound updated with new elevation data for Padilla Bay NERR and Skagit River Delta.

Florida – Remapped with updated VDatum tidal surface.

South Carolina – Remapped with new elevation data. New DEM available.

Louisiana – Remapped with new elevation data. New DEM available.

Texas – Remapped with new elevation data. New DEM available.

July 2019

Puerto Rico – Remapped with new elevation data. New DEM available.

Rhode Island – Remapped with new elevation data. New DEM available.

Massachusetts – Remapped with new elevation data. New DEM available.

New Hampshire – Remapped with new elevation data. New DEM available.

Maine – Remapped with new elevation data. New DEM available.

March 2019

Connecticut – Remapped with new elevation data. New DEM available.

Pennsylvania – Remapped with new elevation data. New DEM available.

Maryland – Northern and western Chesapeake Bay counties remapped with new elevation data. New DEMs available.

Washington – Eastern and southern Puget Sound counties remapped with new elevation data. New DEMs available.

September 2018

All locations - Source land cover data updated from 2006 to 2010.

All locations - Sea level rise, mapping confidence, and marsh migration mapped to 10 feet.

Hawaii, Guam, Saipan, American Samoa, Puerto Rico, and the U.S. Virgin Islands - High tide flooding mapping added.

Oahu, Hawaii - Remapped with new elevation data. New DEM available.

Guam - Remapped with new elevation data. New DEM available.

April 2017

Mississippi - Remapped with new elevation data. New DEM available.

San Francisco Bay - Remapped with updated VDatum tidal surface.

Important – Transformation uncertainties in the "Louisiana/Mississippi–Eastern Louisiana to Mississippi Sound" regional model have been found to range from 20 to 50 centimeters in particular locations from the Mississippi River Delta north to Lake Pontchartrain. These issues most likely can be attributed to subsidence, newly established datums, and changes to the understanding of NAVD88 based on new versions of the GEOID. The VDatum team is currently looking at resolving these uncertainties.

August 2016

Northern South Carolina, North Carolina, Virginia, Maryland, Delaware, New Jersey, and New York – Remapped with new elevation data based on Post-Sandy lidar from USGS and NOAA National Geodetic Survey. New DEMs available.

2015

San Francisco Bay, CA – Remapped to fix leveed areas. Levees and leveed areas displayed.

Louisiana – Mapped and added to viewer. Levees and leveed areas displayed.

U.S. Virgin Islands – Remapped with new elevation data based on 2013 lidar from NOAA

Port Arthur, TX – Remapped to fix leveed area

Freeport, TX – Remapped to fix leveed area

Texas City, TX – Remapped to fix leveed area

Maryland/Delaware border – Remapped to fix edge matching issue.

North Carolina/South Carolina border – Remapped to fix edge matching issue

Palm City, FL – Fixed elevation model and remapped

Charles and Mystic Rivers near Boston, MA – Fixed elevation model and remapped to fix dam protected area

Tillamook Bay, OR – Added elevation data and remapped to fill data gap

Oregon and Texas – Marsh tab updated with 2010 Coastal Change Analysis Program (C-CAP) land cover data

Water Level
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Current MHHW
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Sea Level Rise

Use the vertical slider to simulate water level rise, the resulting inundation footprint, and relative depth. Click on map icons to view sea level rise simulations at specific locations.

Water levels are relative to the local Mean Higher High Water (MHHW) Datum. Areas that are connected hydrologically to the ocean are shown in shades of blue (darker blue = greater depth).

Low-lying areas, displayed in green, are hydrologically unconnected areas that may also flood. These areas are determined solely by how well the elevation data captures the area’s drainage characteristics. The mapping may not accurately capture detailed hydrologic and hydraulic features such as canals, ditches, and stormwater infrastructure. A more detailed analysis may be required to determine the area’s actual susceptibility to flooding.

There is not 100 percent confidence in the elevation data or mapping process. It is important not to focus on the exact extent of inundation but rather to examine the level of confidence that the extent of inundation is accurate (see Mapping Confidence).

Scenarios

Zoom in on your area of interest, and click on the closest Scenario Location icon or grid cell in the map. The selected station location or grid cell ID will be displayed at the bottom of the slider panel. Station locations will display scenarios associated with long-term NOAA tide gauges. Grid cells will display scenarios for each individual cell based on regional scenarios. Regional observational extrapolation values are displayed under the station location or grid cell ID. These values represent estimates of relative sea level rise projected out to 2050 and are based on tide gauge data from 1970 to 2020.

To create these trajectories, the rate of sea level rise is calculated from regional sets of tide gauge observations and then extrapolated to 2050. These trajectories have been adjusted for large-scale natural cycles such as the El Niño/La Niña Pacific Decadal Oscillation and North Atlantic Oscillation. Regional values may be higher or lower than the local tide gauge projections, because regional curves are based on the median of all stations within the region.

Regional observational extrapolation values are very similar to the model-based projections through 2050, showing evidence for the confidence in the near-term trajectory of sea level rise.

“View by Year” (default): Select a year by sliding the year marker (on the right). The left side will show the amount of relative sea level rise associated with that year for each of the six local sea level rise scenarios—low, intermediate low, intermediate, intermediate high, high, and extreme (only available for 2017 scenarios). Adjust the half-foot-increment map layers control to view the potential inundation impacts for each scenario.

“View by Scenario”: Select a local scenario by sliding the scenario marker (on the right). The left side will show the amount of relative sea level rise associated with that scenario in 20-year increments. Adjust the half-foot- increment map layers control to view the potential inundation impacts for each year increment.

Choose which sea level rise scenarios to view:

  • 2022 - Based on NOAA, 2022
  • 2017 - Based on NOAA, 2017 (Note: A grid is not provided for 2017 scenarios.)

Understanding the Scenarios

Regional sea level rise scenarios (station locations and grid cells) represent possible future sea level changes. Use these scenarios to ask “what if” questions about the future.

Some regions are experiencing sea level fall relative to the land (e.g., Southeast Alaska) which causes negative projection value. Projections falling below zero will not appear on the slider.

2022 Sea Level Rise Technical Report

The five relative sea level (RSL) rise scenarios shown in this tab are derived from the 2022 Sea Level Rise Technical Report using the same methods as the U.S. Army Corps of Engineers’ Sea Level Analysis Tool and NOAA’s Sea Level Calculator. These new scenarios were developed by the U.S. Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force as input into the the U.S. Global Change Research Program’s Sustained Assessment process and the Fifth National Climate Assessment. These relative sea level rise scenarios provide an update to NOAA’s 2017 scenarios, which were developed as input to the Fourth National Climate Assessment.

While these relative sea level rise scenarios begin in 2005, they have been adjusted to the year 2000 for easier comparison with 2017 scenarios. These scenarios take into account global mean sea level (GMSL) rise, regional changes in ocean circulation, changes in Earth’s gravity field due to ice melt redistribution, and local vertical land motion. By 2050 (relative to sea level in 2000), relative sea level rise projections range from 0.40–0.45 meters along the East Coast, 0.55–0.65 meters along the Gulf Coast, 0.20–0.30 meters along the West Coast, 0.20–0.35 meters along the Caribbean and Hawaiian Islands, 0.30 meters along the northern coast of Alaska, and a relative sea level decrease along the southern coast of Alaska.

The exclusion of the extreme (2.5 meter) scenario is an important change from the 2017 scenarios. Based on the most recent scientific understanding, and as discussed in the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, the uncertain physical processes that could lead to much higher increases in sea level are now viewed as less plausible in the coming decades before potentially becoming a factor toward the end of the twenty-first century. A global mean sea level increase of 2.5 meters is thus viewed as less plausible, and the associated scenario has been removed.

2017 Sea Level Rise Technical Report

The five relative sea level (RSL) rise scenarios shown in this tab are derived from NOAA Technical Report NOS CO-OPS 083: Global and Regional Sea Level Rise Scenarios for the United States. These scenarios were developed by the Sea Level Rise and Coastal Flood Hazard Scenarios and Tools Interagency Task Force, jointly convened by the U.S. Global Change Research Program and the National Ocean Council, as input into the U.S. Global Change Research Program’s Sustained Assessment process and the Fourth National Climate Assessment. These relative sea level rise scenarios provide a revision to the global scenarios that were developed (Parris et. al 2012) as input into the Third National Climate Assessment.

These relative sea level rise scenarios begin in 2000 and take into account global mean sea level rise, regional changes in ocean circulation, changes in Earth’s gravity field due to ice melt redistribution, and local vertical land motion.

For almost all the scenarios, relative sea level rise is likely to be greater than the global average in the U.S. Northeast and the western Gulf of America. In intermediate and low scenarios, relative sea level rise is likely to be less than the global average in much of the Pacific Northwest and Alaska. For high scenarios, relative sea level rise is likely to be higher than the global average along all U.S. coastlines outside Alaska.

Additional Information:

A relative sea level change adjustment to the current National Tidal Datum Epoch (1983–2001) will cause a minimal offset that may be needed for some applications. NOAA’s Sea Level Calculator allows users to change the reference year from 2000 to 1992 and to correct for this offset.

Rounding to the nearest half-foot mapping increment to view potential impacts is appropriate based on the accuracy of the elevation and tidal surface data used as mapping inputs.

Mapping Confidence

The inundation areas depicted in the Sea Level Rise tab are not as precise as they may appear. There are many unknowns when mapping future conditions, including natural evolution of the coastal landforms (e.g., barrier island overwash and migration), as well as the data used to predict the changes. The confidence presented in these maps only represents the known error in the elevation data and tidal corrections.

Blue areas denote a high confidence of inundation, orange areas denote a high degree of uncertainty, and unshaded areas denote a high confidence that these areas will be dry given the chosen water level.

In this application, 80 percent is considered a high degree of confidence such that, for example, the blue areas denote locations that may be correctly mapped as 'inundated' more than 8 out of 10 times. Areas with a high degree of uncertainty represent locations that may be mapped correctly (either as inundated or dry) less than 8 out of 10 times. For a detailed description of the confidence levels and their computation, see the methods document.

Marsh

Zoom in on your area of interest, and click the closest Scenario Location icon or grid cell in the map. The selected station location or grid cell ID will be displayed on the bottom of the slider panel. Station locations will display scenarios associated with long-term NOAA tide gauges. Grid cells will display scenarios for each individual cell based on regional scenarios.

NOTE: Currently, marsh migration data for Alaska is unavailable due to lack of adequate land cover data.

“View by Year” (default): Select a year by sliding the year marker (on the right). The left side will show the amount of relative net sea level associated with that year for each of the six local sea level rise scenarios (low, intermediate low, intermediate, intermediate high, high, extreme). Adjust the half-foot-increment map layers control to view the potential net sea level changes for each scenario.

“View by Scenario”: Select a local scenario by sliding the scenario marker (on the right). The left side will show the amount of relative net sea level change associated with that scenario in 20-year increments. Adjust the half- foot-increment map layers control to view the potential changes for each year increment.

“Accretion Rate”: Customize the selected accretion rate to reflect sediment accumulation conditions that best reflect your area. These rates are flat values applied across the landscape and can be used to highlight how accretion can offset sea level rise.

Choose which sea level rise scenarios to view:

  • 2022 - Based on NOAA, 2022
  • 2017 - Based on NOAA, 2017

Predictions represent the potential distribution of each wetland type (see legend) based on their elevation and how frequently they may be inundated under each scenario. As sea levels increase, some marshes may migrate into neighboring low-lying areas, while other sections of marsh will change type or be lost to open water.

Understanding the Scenarios

The scenarios are derived from NOAA’s Sea Level Rise Technical Reports and take into account global mean sea level (GMSL) rise, regional changes in ocean circulation, changes in Earth’s gravity field due to ice melt redistribution, and local vertical land motion. You can learn more about them within the Local Scenarios tab of this viewer.

High Tide Flooding

Annual occurrences of tidal flooding have increased 5- to 10-fold since the 1960s in several U.S. coastal cities. The changes in high tide flooding over time are greatest where elevation is lower, local relative sea level rise is higher, or extreme variability is less.

In a sense, today’s flood will become tomorrow’s high tide, as sea level rise will cause flooding to occur more frequently and last for longer durations of time.

Three tidal flooding levels are provided—minor, moderate, and major—each representing a threshold for impacts to coastal communities.

Click a NOAA tide station icon on the map to view historical inundation events in flood days per year for the selected tidal flooding level. The flood thresholds used in these plots are derived national flood thresholds from NOAA Technical Report NOS CO-OPS 086: Patterns and Projections of High Tide Flooding Along the U.S. Coastline Using a Common Impact Threshold. The derived thresholds used provide a national definition of coastal flooding and forecasting impacts for quantifying and communicating risk. These thresholds may deviate from National Weather Service (NWS) impact thresholds that take into account local flood risk and are used to issue NWS coastal flood watches, warnings, and advisories.

  • satellite
  • streets
  • dark
  • NOS Minor Swatch
    NOS Minor
  • NOS Moderate Swatch
    NOS Moderate
  • NOS Major Swatch
    NOS Major

About

The map viewer provides a preliminary look at sea level rise and coastal flooding impacts to coastal resource managers and planners. This screening-level tool uses best-available, nationally consistent datasets and analyses. The data and maps provided can be used at several scales to help estimate impacts and prioritize actions.

The data and maps in this tool illustrate the scale of potential flooding, not the exact location, and do not account for erosion, subsidence, or future construction. Water levels are shown as they would appear during the highest high tides (excludes wind-driven tides). As with all remotely sensed data, all features should be verified with a site visit. The data and maps in this tool are provided “as is” without warranty to their performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of these data is assumed by the user. This tool should be used strictly as a planning reference tool and should not be used for navigation, permitting, or other legal purposes.

Additional Resources

Leveed Areas Disclaimer

Levees are displayed as yellow lines, and enclosed leveed areas are displayed as a white stippled pattern.

Major federal leveed areas were assumed high enough and strong enough to protect against inundation depicted in this viewer, and therefore no inundation was mapped in these regions.

Minor (nonfederal) leveed areas were mapped using the best available elevation data that capture leveed features. In some cases, however, breaks in elevation occur along leveed areas because of flood control features being removed from elevation data, limitations of the horizontal and vertical resolution of the elevation data, the occurrence of levee drainage features, and so forth. Flooding behind levees is only depicted if breaks in elevation data occur or if the levee elevations are overtopped by the water surface. At some flood levels, alternate pathways around—not through—levees, walls, dams, and flood gates may exist that allow water to flow into areas protected at lower levels. In general, imperfect levee and elevation data make assessing protection difficult, and small data errors can have large consequences.

As new elevation data become available, or as stakeholders provide additional levee information, the NOAA Office for Coastal Management will periodically update the inundation and levee data.