This map includes shoreline change data for the state of Massachusetts hosted by the Massachusetts Office of Coastal Zone Management.The active data layer in this map is Massachusetts Shoreline Change Transect (1970-2014) with short-term shoreline change rates. To view long-term rates, open map in Map Viewer to turn on layer.The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. The shoreline position and change rate are used to inform management decisions regarding the erosion of coastal resources. In 2001, a shoreline from 1994 was added to calculate both long- and short-term shoreline change rates along ocean-facing sections of the Massachusetts coast. In 2013, two oceanfront shorelines for Massachusetts were added using 2008-9 color aerial orthoimagery and 2007 topographic lidar datasets obtained from the National Oceanic and Atmospheric Administration's Ocean Service, Coastal Services Center. In 2018 two new mean high water (MHW) shorelines for Massachusetts were extracted from lidar collected between 2010 and 2014 (described below). 2018 addition shoreline 1The North Shore and South Coast uses 2010 lidar data collected by the U.S. Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of Expertise. The South Shore and Outer Cape uses 2011 lidar data collected by the U.S. Geological Survey's (USGS) National Geospatial Program Office. Nantucket and Martha’s Vineyard uses 2012 lidar data collected by the USACE (post Sandy)from a 2012 USACE Post Sandy Topographic lidar survey. 2018 addition shoreline 2The North Shore, Boston, South Shore, Cape Cod Bay, Outer Cape, South Cape, Nantucket, Martha’s Vineyard, and the South Coast (around Buzzards Bay to the Rhode Island Border) is from 2013-14 lidar data collected by the (USGS) Coastal and Marine Geology Program. This 2018 update of the rate of shoreline change in Massachusetts includes two types of rates. Some of the rates include a proxy-datum bias correction, this is indicated in the filename with “PDB”. The rates that do not account for this correction have “NB” in their file names. The proxy-datum bias is applied because in some areas a proxy shoreline (like a High Water Line shoreline) has a bias when compared to a datum shoreline (like a Mean High Water shoreline). In areas where it exists, this bias should be accounted for when calculating rates using a mix of proxy and datum shorelines. This issue is explained further in Ruggiero and List (2009) and in the process steps of the metadata associated with the rates. This release includes both long-term (~150 years) and short term (~30 years) rates. Files associated with the long-term rates have “LT” in their names, files associated with short-term rates have “ST” in their names.

These data provide an accurate high-resolution shoreline compiled from imagery of Cape Cod, North Eastham to Race Point, MA . This vector shoreline data is based on an office interpretation of imagery that may be suitable as a geographic information system (GIS) data layer. This metadata describes information for both the line and point shapefiles. The NGS attribution scheme 'Coastal Cartogra...

The Massachusetts Office of Coastal Zone Management (MA CZM) launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast by compiling a database of historical (1800's-1989) shoreline positions and shoreline change maps. Trends of shoreline position over long and short-term timescales provide information to landowners, managers, and potential buyers about possible future impacts to coastal resources and infrastructure. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. In 2013 two oceanfront shorelines for Massachusetts were added using 2008-2009 color aerial orthoimagery and 2007 topographic lidar datasets obtained from NOAA's Ocean Service, Coastal Services Center. The 2013 update also included a 2000 lidar shoreline covering most of the open-ocean coast, as well as a 2001 shoreline for the South Shore coastal region. In 2018, two new mean high water (MHW) shorelines for the Massachusetts coast extracted from lidar data collected between 2010-2014 were added to the dataset. This 2021 data release contains a compilation of previously published historical shoreline positions spanning 170 years (1844 to 2014), intended to be used as an authoritative shoreline database for the state. This dataset is an update to the Massachusetts Office of Coastal Zone Management Shoreline Change Project.

The Massachusetts Coast Guide Online maps over 1,900 publicly accessible coastal sites; from parks and beaches, to harbor walks and rights-of-way. The guide also currently includes three additional maps that provide more information on public beaches, boat ramps, and trails. The Office of Coastal Zone Management's Massachusetts Coast Guide Online is a one stop site for sharing locations of public coastal space here in the Commonwealth. Please visit the Massachusetts Office of Coastal Zone Management's website for more information about this product, as well as information regarding other coastal programs.The sites in Coast Guide Online were mapped using the Massachusetts Office of Geographic Information (MassGIS) Level 3 Assessors' Parcel Mapping data layer, which contains property boundaries from each community's assessor. Published documents and websites from government and nonprofit sources were used to confirm and update the information.Despite extensive quality control efforts, neither on-the-ground property boundaries nor individual ownership of all parcels has been independently verified. CZM makes no representations or warranties with respect to the definitiveness of the private or public ownership data presented in Coast Guide Online. All issues related to questions of ownership of coastal property should be investigated at the local Registry of Deeds.

The Massachusetts Office of Coastal Zone Management (CZM) Coastal Public Access Sites data comprise a set of public access sites that represent beaches, boat ramps, coves, rocky shorelines, public landings, coastal parks, salt marshes, and other open land that has been classified as open to the public. Not all coastal access sites may be shown in this layer. The layer includes coastal sites owned by the state, cities and towns, federal agencies, and private and non-profit entities. The coastal public access sites are parcel based where available, based on the MassGIS Level 3 Assessor Parcel Data. They are symbolized by ownership of the parcel. There are currently over 1800 coastal public access sites displayed in this data layer. The purpose of this data layer is for use in the Massachusetts Coast Guide Online story map. Please visit the Massachusetts Office of Coastal Zone Management's website for more information about this product, as well as information regarding other coastal programs.The sites in Coast Guide Online were mapped using the Massachusetts Office of Geographic Information (MassGIS) Level 3 Assessors' Parcel Mapping data layer, which contains property boundaries from each community's assessor. Published documents and websites from government and nonprofit sources were used to confirm and update the information.Despite extensive quality control efforts, neither on-the-ground property boundaries nor individual ownership of all parcels has been independently verified. CZM makes no representations or warranties with respect to the definitiveness of the private or public ownership data presented in Coast Guide Online. All issues related to questions of ownership of coastal property should be investigated at the local Registry of Deeds.Please email Samantha Coccia-Schillo with any questions on this layer at Samantha.Coccia-Schillo@mass.gov.

Seagrass beds are critical wetlands components of shallow marine ecosystems along the Massachusetts coastline. Seagrass beds provide food and cover for a great variety of commercially and recreationally important fauna and their prey. The leaf canopy of the seagrass bed calms the water, filters suspended matter and together with extensive roots and rhizomes, stabilizes sediment. Seagrasses are often referred to as "Submerged Aquatic Vegetation" or SAV. This distinguishes them from algae, which are not classified as plants by biologists (rather they are often placed in the kingdom protista), and distinguishes them from the "emergent" saltwater plants found in salt marshes.

In Massachusetts, the dominant SAV is Zostera marina or eelgrass. The other species found in the embayments of the Massachusetts coast is Ruppia maritima, commonly called “widgeon grass,” which is present in areas of less salinity along Cape Cod and Buzzards Bay. Widgeon grass, found in the upper reaches of embayments, has a thread-like morphology that makes it difficult to identify using remotely sensed data. It can only be identified and located by on-site survey.

The Massachusetts Department of Environmental Protection (MassDEP) began a program to map the state's SAV resources in the early 1990s and since 1995 the MassDEP Eelgrass Mapping Project has produced multiple surveys of SAV along the Massachusetts coastline, as listed here:

PhaseProject YearsProject Area11995Entire MA Coast22001Coast-wide MA Coast except Elizabeth Islands (Gosnold) and Mount Hope Bay32006/07Selected embayments, coast-wide including Elizabeth Islands42010-20132010 - South Shore of Cape Cod: Woods Hole to Chatham, selected embayments, Pleasant Bay;2012 - North Shore, Boston Harbor, South Shore to Provincetown;2013 - Buzzards Bay, Elizabeth Islands, Martha's Vineyard and Nantucket52015-20172015 - South Shore of Cape Cod, Pleasant Bay, Nantucket;2016 - North Shore, Boston Harbor, South Shore to Canal;2017 - Buzzards Bay, North Shore of Cape Cod, Elizabeth Islands and Martha's Vineyard62019-20232019 - South Shore of Cape Cod, Pleasant Bay, North Shore of Nantucket2020 - Martha’s Vineyard, Buzzards Bay and Elizabeth Islands 2021 - Cape Cod Bay (Provincetown through Duxbury) 2022 - South Shore, Boston Harbor, North Shore (Marshfield through Rockport)2023 - Cape Ann to the New Hampshire border (Essex through Newburyport)

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This U.S. Geological Survey data release contains coastal wetland synthesis products for Massachusetts. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and tidal range are calculated for smaller units delineated from a digital elevation model, providing the spatial variability of physical factors that influence wetland health. The U.S. Geological Survey has been expanding national assessment of coastal change hazards and forecast products to coastal wetlands with the intent of providing federal, state, and local managers with tools to estimate the vulnerability and ecosystem service potential of these wetlands. For this purpose, the response and resilience of coastal wetlands to physical factors need to be assessed in terms of the ensuing change to their vulnerability and ecosystem services.These USGS datasets are mirrored from the published coastal wetlands datasets on USGS ScienceBase. To download data and metadata: Ackerman, K.V., Defne, Z., and Ganju, N.K., 2021, Geospatial characterization of salt marshes for Massachusetts: U.S. Geological Survey data release, https://doi.org/10.5066/P97E086F.

This layer is sourced from maps.coast.noaa.gov.

This map service presents spatial information developed as part of the National Oceanic and Atmospheric Administration (NOAA) Office for Coastal Management’s Coastal Flood Exposure Mapper. The purpose of the online mapping tool is to provide coastal managers, planners, and stakeholders a preliminary look at exposures to coastal flooding hazards. The Mapper is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help communities initiate resilience planning efforts. Currently the extent of the Coastal Flood Exposure Mapper covers U.S. coastal areas along the Gulf of Mexico and Atlantic Ocean. NOAA provides the information “as-is” and shall incur no responsibility or liability as to the completeness or accuracy of this information. NOAA assumes no responsibility arising from the use of this information. For additional information, please contact the NOAA Office for Coastal Management (coastal.info@noaa.gov).

© NOAA Office for Coastal Management

The Massachusetts Coastal Zone data layer was compiled by the Massachusetts Office of Coastal Zone Management (CZM) to represent the Massachusetts coastal zone as defined in the October 2011 Massachusetts Office of Coastal Zone Management Policy Guide ("Policy Guide"). Appendix 2 of the Policy Guide contains the most recent description of the official Massachusetts coastal zone and should be used in connection with the following two sources depicting maps of the boundary: (1) the CZM Coastal Atlas (Volume II of the 1977 Massachusetts Coastal Zone Management Program and Draft Environmental Impact Statement) and (2) this data layer developed by CZM to depict the coastal zone in digital map format. This boundary was created per the Federal Coastal Zone Management Act (CZMA) of 1972 (Public Law 92-583, 16 U.S.C. 1451-1456). The boundary description is the specification of the major roads, rail lines, other visible rights-of-way, or coordinates marking the inland boundary of the coastal zone. The actual boundary is 100 feet inland of the landward side of the described line, with the exception of municipal boundaries, where the municipal boundary is the limit of the boundary description. This dataset represents the actual boundary.Please see https://www.mass.gov/info-details/massachusetts-coastal-zone-boundary for more details.\Map service also available.

Accurate data and maps of sea floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. To address these concerns the U.S. Geological Survey, in cooperation with the Massachusetts Office of Coastal Zone Management (CZM), comprehensively mapped the Cape Cod Bay sea floor to characterize the surface and shallow subsurface geologic framework. Geophysical data collected include swath bathymetry, backscatter, and seismic reflection profile data. Ground-truth data, including sediment samples, underwater video, and bottom photographs were also collected. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State's waters, support research on the Quaternary evolution of coastal Massachusetts, the influence of sea-level change and sediment supply on coastal evolution, and efforts to understand the type, distribution, and quality of subtidal marine habitats. This collaboration produces high-resolution geologic maps and Geographic Information System (GIS) data that serve the needs of research, management and the public. Data collected as part of this mapping cooperative continue to be released in a series of USGS Open-File Reports and Data Releases (https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor). This data release provides the geophysical and geologic sampling data collected in Cape Cod Bay during USGS Field Activities 2019-002-FA and 2019-034-FA in 2019.

This dataset includes shorelines from 161 years ranging from 1848 to 2009 within the Cape Cod Bay coastal region from the Cape Cod Canal in Sandwich to Long Point in Provincetown. Shorelines were compiled from T-sheets and air-photos obtained from the National Oceanic and Atmospheric Administration (NOAA) and the Massachusetts Office of Coastal Zone Management (MA CZM), and lidar obtained from the US Geological Survey (USGS). Historical shoreline positions serve as easily understood features that can be used to describe the movement of beaches through time. These data are used to calculate rates of shoreline change for the MA CZM Shoreline Change Project. Rates of long-term and short-term shoreline change were generated in a GIS using the Digital Shoreline Analysis System (DSAS) version 4.3. DSAS uses a measurement baseline method to calculate rate-of-change statistics. Transects are cast from the reference baseline to intersect each shoreline, establishing measurement points used to calculate shoreline change rates. For publication purposes, the shoreline data for Massachusetts were organized by region in order match the extent of previously published uncertainty files used in shoreline change calculations. Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. The Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management, has compiled reliable historical shoreline data along open-facing sections of the Massachusetts coast under the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update. Two oceanfront shorelines for Massachusetts (approximately 1,800 km) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management (MA CZM) and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS). .

This dataset includes shorelines from 163 years ranging from 1846 to 2009 within the Massachusetts coastal region from Salisbury, to Westport, including Cape Cod, Martha's Vineyard, Nantucket and the Elizabeth Islands. Shorelines were compiled from T-sheets and air-photos obtained from the National Oceanic and Atmospheric Administration (NOAA) and the Massachusetts Office of Coastal Zone Management (MA CZM), and lidar obtained from the US Geological Survey (USGS). Historical shoreline positions serve as easily understood features that can be used to describe the movement of beaches through time. These data are used to calculate rates of shoreline change for the MA CZM Shoreline Change Project. Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. The Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management, has compiled reliable historical shoreline data along open-facing sections of the Massachusetts coast under the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update. Two oceanfront shorelines for Massachusetts (approximately 1,800 km) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management (MA CZM) and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS). .

The U.S. Geological Survey has conducted geologic mapping to characterize the sea floor offshore of Massachusetts. The mapping was carried out using a Simrad Subsea EM 1000 Multibeam Echo Sounder on the Frederick G. Creed on four cruises conducted between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick.

The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) project that presents images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys that will serve the needs of research, management and the public.

Accurate data and maps of sea floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. To address these concerns the U.S. Geological Survey, in cooperation with the Massachusetts Office of Coastal Zone Management (CZM), comprehensively mapped the Cape Cod Bay sea floor to characterize the surface and shallow subsurface geologic framework. Geophysical data collected include swath bathymetry, backscatter, and seismic reflection profile data. Ground-truth data, including sediment samples, underwater video, and bottom photographs were also collected. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State’s waters, support research on the Quaternary evolution of coastal Massachusetts, the influence of sea-level change and sediment supply on coastal evolution, and efforts to understand the type, distribution, and quality of subtidal marine habitats. This collaboration produces high-resolution geologic maps and Geographic Information System (GIS) data that serve the needs of research, management and the public. Data collected as part of this mapping cooperative continue to be released in a series of USGS Open-File Reports and Data Releases (https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor). This data release provides the geophysical and geologic sampling data collected in Cape Cod Bay during USGS Field Activities 2019-002-FA and 2019-034-FA in 2019.

The political boundary datalayer is a polygon representation of town boundaries created from arcs developed from survey coordinates extracted from the 68-volume Harbor and Lands Commission Town Boundary Atlas for the 351 communities (cities and towns) in Massachusetts. The Atlas was published in the early 1900's and is maintained by the Survey Section of Massachusetts Highway Department. For communities with a coastal boundary, MassGIS has collaborated with Massachusetts Water Resources Authority and the Department of Environmental Protection to complete a 1:12000 scale coastline. The boundary for the coastline was defined as being the upland side of tidal flats and rocky inter-tidal zones. Note that the 351 communities are the official municipal names, not including "villages" or other sections of towns.This datalayer was created for the purposes of providing an up-to-date polygon version of the town boundaries for the 351 cities and towns of the Commonwealth of Massachusetts. The legislative intent for some boundaries could not be mapped. Boundaries where that is true are identified in the attribute information. This layer contains multi-part polygons, one for each municipality. The coastline on this layer has been generalized for small-scale cartography and faster display in web map services.See the layer metadata for details.

These data are qualitatively derived interpretive polygon shapefiles and selected source raster data defining surficial geology, sediment type and distribution, and physiographic zones of the sea floor from Nahant to Northern Cape Cod Bay. Much of the geophysical data used to create the interpretive layers were collected under a cooperative agreement among the Massachusetts Office of Coastal Zone Management (CZM), the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Army Corps of Engineers (USACE). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of seafloor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes because of natural or human effects. The project is focused on the inshore waters of coastal Massachusetts. Data collected during the mapping cooperative involving the USGS have been released in a series of USGS Open-File Reports (http://woodshole.er.usgs.gov/project-pages/coastal_mass/html/current_map.html). The interpretations released in this study are for an area extending from the southern tip of Nahant to Northern Cape Cod Bay, Massachusetts. A combination of geophysical and sample data including high resolution bathymetry and lidar, acoustic-backscatter intensity, seismic-reflection profiles, bottom photographs, and sediment samples are used to create the data interpretations. Most of the nearshore geophysical and sample data (including the bottom photographs) were collected during several cruises between 2000 and 2008. More information about the cruises and the data collected can be found at the Geologic Mapping of the Seafloor Offshore of Massachusetts Web page: http://woodshole.er.usgs.gov/project-pages/coastal_mass/.

This data set contains the 1995-era and 2000-era classifications of US Coast zone 65 and can be used to analyze change. This imagery was collected as part of the Multi-Resolution Land Characteristics program in a multi- agency effort to provide baseline multi-scale environmental characteristics and to monitor environmental change. This data set utilized 41 full or partial Landsat 5 and 7 scenes which were analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine land cover. Note: These data were reprojected from their native projection into North American Datum 1983 (NAD83) / Massachusetts State Plane coordinate system, Mainland Zone (Fipszone 2001) meters by the Massachusetts Office of Coastal Zone Management on Oct. 12, 2006. All data classified as unchanged (e.g. Deciduous Forest 1996 to Deciduous Forest 2001) were grouped and converted to No Data.

Polygonal extents of federal (US Army Corps of Engineers) dredge projects along the Massachusetts marine coastline; historical to 16 December 1998; includes navigational channels, anchorages, harbors, beaches and dikes. Feature attributes include hyperlinks to respective USACE project descriptions, histories, and maps.

This Feature Service published by MassGIS represents Mouth of River (MOR) lines for Massachusetts coastal rivers originally published by the Massachusetts Department of Environmental Protection (MassDEP) on March 1, 2005 as PDF maps. The PDF maps identify the mouth of the river for coastal rivers in order to provide a clear, consistent, and predictable means of locating all river mouths in the Commonwealth. They are the final MOR maps for each community and represent the culmination of a year's effort that included distribution of draft maps for public comment, receipt and review of over 100 written comments, and field surveys for many of the more difficult mouth of river lines. Each Massachusetts coastal community received a set of maps corresponding to the rivers in their community.

The MOR map lines are intended to

identify where a river ends pursuant to 310 CMR 10.58(2)(c). As provided in 310 CMR 10.58(2)(c) "When a river flows into coastal waters or an embayment, the river shall end at the mouth of coastal river line as delineated on the current mouth of coastal river map series maintained by the Department." represent the limit of Riverfront Area jurisdiction under the Wetlands Protection Act. Land upstream of the MOR line includes Riverfront Areas subject to the protections afforded by the Wetlands regulations; any land seaward of the MOR line is not subject to jurisdiction as a Riverfront Area but remains subject to other inland and coastal provisions of the Wetlands Protection Act.By adopting a uniform approach to mapping river mouths, this data should reduce the need for individual MOR delineations and in turn provide a predictable means for project review for landowners, conservation commissions and MassDEP.See full metadataAlso see the Map Service.

These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://coast.noaa.gov/slr. This metadata record describes the Rhode Island digital elevation model (DEM), which is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer described above. This DEM includes the best available lidar known to exist at the time of DEM creation that met project specifications. This DEM includes data for the entire state. The DEM was produced from the following lidar data sets: 1. 2013 - 2014 USGS Hurricane Sandy Supplemental for NE (RI, MA, NH) 2. 2011 USGS ARRA Lidar for the Northeast: Rhode Island 3. 2010 FEMA Narragansett River Lidar The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88, Geoid12B) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 3 meters.