This cached tiled map service, hosted at MassGIS' ArcGIS Online site, represents FEMA National Flood Hazard Layer (NFHL) data currently available for Massachusetts. At scales 1:80,000 and closer, flood zone abbreviation labels appear (from the FLD_ZONE field). The National Flood Hazard Layer (NFHL) dataset represents the current effective flood risk data for those parts of the country where maps have been modernized by the Federal Emergency Management Agency (FEMA). It is a compilation of effective Flood Insurance Rate Map (FIRM) databases and any Letters of Map Revision (LOMR) that have been issued against those databases since their publication date. The NFHL is updated as new data reaches its designated effective date and becomes valid for regulatory use under the National Flood Insurance Program (NFIP). See full metadata from MassGIS.

All data included in this layer are considered "final" by FEMA. Any preliminary data that appear on maps displayed at community meetings, etc., are not included here.

This map service includes data published by FEMA as of July 2, 2023.

To display a legend for this layer, add https://massgis.maps.arcgis.com/home/item.html?id=8455678914e64b03b565b97d07577279 to your map along with this service

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 Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). Spatial data is georeferenced to the earth surface using the Transverse Mercator projected coordinate system and the North American Datum of 1983. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:6000.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). Spatial data is georeferenced to the earth surface using the Wisconsin Transverse Mercator projected coordinate system and the North American Datum of 1983. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:6000.

Authority: Executive Order No. 149: FEMA and Flood Plain Use. Jurisdiction: Floodplains in the Commonwealth of Massachusetts. Applicability: Construction by state agencies must avoid floodplains. State-administered grant and loan programs must avoid supporting construction in flood plains, to the extent possible. Regulatory Designates the Massachusetts Department of Conservation and Recreation (DCR, formerly the Department of Environmental Management) as the state coordinating agency to implement the National Flood Insurance Program. Requires all state agencies, to the extent possible, to avoid construction, provision of loans or grants, conveying, or permitting projects in floodplains. Provides for Massachusetts participation in the National Flood Insurance Program. Review Process: Contact the Federal Emergency Management Agency (FEMA) to determine if a proposed project is in a floodplain. Projects proposed in floodplains are reviewed in conjunction with Massachusetts Environmental Policy Act (15), Massachusetts Wetlands Protection Act (17), and Massachusetts Office of Coastal Zone Management (22) reviews. Technical assistance is also available from the DCR Flood Hazard Management Program. Forms: No additional forms for floodplain review. Fees No additional fees for floodplain review. Website: FEMA at http://store.msc.fema.gov/webapp/wcs/stores/servlet/FemaWelcomeView?storeId=10001&catalogId=10001&langId=-1 DCR Flood Hazard Management Program at http://www.mass.gov/dcr/stewardship/mitigate/.

The National Flood Hazard Layer (NFHL) dataset represents the current effective flood risk data for those parts of the country where maps have been modernized by the Federal Emergency Management Agency (FEMA).Also see the Map Service and Tile service.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA).

Effective (2017) and Preliminary (2023) FEMA Flood Zones for Arlington, MA and the changes between the data

The FIRM Database is the digital, geospatial version of the flood hazard information (location and attributes for boundaries of flood insurance risk zones) shown on the published paper Flood Insurance Rate Maps (FIRMs). The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA.The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The FIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The FIRM Database serves to archive the information collected during the Flood Risk Project.Informing Worcester is the City of Worcester's open data portal where interested parties can obtain public information at no cost.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA). In addition to the preceding, required text, the Abstract should also describe the projection and coordinate system as well as a general statement about horizontal accuracy.

Overlay zoning districts are in addition to standard town zoning. The districts' boundaries and use limitations &/or development constraints are described in the town's zoning bylaw. The MVC generated these digital spatial boundaries based on the best GIS data available at the time of processing.

Some overlay zoning districts are also Districts of Critical Planning Concern. These are zoning districts established by the Martha's Vineyard Commission and adopted by the town at town meeting.

The boundaries are not survey-grade and are intended for planning purposes only.

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual- chance flood event, and areas of minimal flood risk. The DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by the Federal Emergency Management Agency (FEMA).

Data layers in this child item include high-water mark and storm-sensor data collected by the U.S. Geological Survey (USGS) New England Water Science Center following the January 4, 2018, and March 2-4, 2018, winter-storm events in New England. High-water marks and continuous water-level sensor data range from Portland, Maine, to Provincetown, Massachusetts, and reference the North American Vertical Datum of 1988 (NAVD88). For more information about these storm events and the data collection, please see Bent, G.C., and Taylor, N.J., 2020, Total water level data from the January and March 2018 nor’easters for coastal areas of New England: U.S. Geological Survey Scientific Investigations Report 2020–5048, 47 p., accessed June 3, 2021, at https://doi.org/10.3133/sir20205048 Flood-inundation map layers and interim products used to create them also are included in this child item. The USGS polygon of the stillwater-inundation map reflects a statistical storm with a 1-percent annual exceedance probability from Portland, Maine, to Provincetown, Massachusetts, based on coastal tide-gage data. The January and March 2018 inundation maps are polygon shapefiles of estimated flood extent derived from the high-water mark and storm-sensor data following the storm events. The flood extents and water-surface elevations were derived from simplified estimations of high-water mark and storm-sensor data and delineated using 2-meter-resolution lidar digital-elevation models. Interim data layers that were used to create the flood-inundation polygons include a coastal flood-profile line and coastal watershed boundaries. The compressed zip files contain ESRI shapefiles that include xml metadata files. Detailed processing steps are documented in the metadata for each layer. See the Scientific Investigation Report associated with this data release for more information.

Effective (2017) and Preliminary (2023) FEMA Flood Zones for Arlington, MA and the changes between the data

This EnviroAtlas dataset describes the total counts and percentage of population, land area, and impervious surface in the 1% Annual Chance Flood Hazard area or 0.2% Annual Chance Flood Hazard area of each block group. The flood hazard area is defined by the National Flood Hazard Layer (NFHL) produced by the Federal Emergency Management Agency (FEMA, www.fema.gov). This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Floodplains in Newton, Massachusetts. The floodplains support Newton's Floodplain Ordinance of 2010. The ordinance defines floodways as the 100 year floodplain as defined in FEMA's Flood Insurance Rate (FIRM) Maps. These correspond to Zone AE on those maps. In addition, the oridinance lists most streams, not studied on the FIRM's by name and established as 30 foot corridor or buffer around each one.

Geospatial data about Worcester FEMA Flood Zones 2011. Export to CAD, GIS, PDF, CSV and access via API.

The purpose of the Flood Plain Overlay District (FPOD) is to preserve and protect streams, brooks, ponds, lakes, and other water courses and their adjoining lands within the Town; to protect the health and safety of persons and property against the hazards of flooding; to preserve the natural flood control characteristics, and the flood storage capacity of the flood plain, and to preserve and maintain the ground water table and water recharge areas within the flood plain; to protect the community against the detrimental use and the development of lands adjoining such water courses and to conserve the watershed areas of the Town for the health, safety, and welfare of the public.

The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin: - GeoHMS (Geospatial Hydrologic Modeling Extension) - ResSIM (Reservoir System Simulation) - RAS (River Analysis System) - FIA (Flood Impact Analysis)

The Connecticut River basin is the largest watershed in New England, extending from the northernmost part of New Hampshire to Long Island Sound. The watershed, which drains in a southerly direction, includes a small area of the Province of Quebec, and parts of New Hampshire, Vermont, Massachusetts, and Connecticut. Long and narrow in shape, it has a maximum length of about 280 miles and a maximum width of approximately 60 miles. The basin is bounded principally by the Androscoggin, Merrimack, and Thames River basins on the east and by the St. Lawrence, Hudson, and Housatonic River basins on the west. Elevations range from sea level to over 5000 ft in the northern headwaters. Areas of well developed flood plains occur from Indian Stream in Pittsburgh, NH to Long Island Sound, the most extensive being in Massachusetts and Connecticut. The basin has a total drainage area of 11,250 square miles of which 114 mi2 are in Quebec, 3046 mi2 in New Hampshire, 3928 mi2 in Vermont, 2726 mi2 in Massachusetts, and 1436 mi2 in Connecticut. The Connecticut River follows a general southerly course along the approximate centerline of its watershed for about 404 miles to its mouth on Long Island Sound at Saybrook, Connecticut. In the first 29 miles below its source, the river flows entirely within the State of New Hampshire, then for a distance of about 238 miles, between New Hampshire and Vermont, the western edge of the river forming the boundary; and finally across Massachusetts for 67 miles and Connecticut for 70 miles. The lower 60-mile reach of the river is tidal, with a mean tidal range during low river stages of 3.4 feet at the mouth, and about 1.2 feet at Hartford, 52 miles above the mouth. The fall in the river is about 2200 feet with the steepest portion averaging 30 feet per mile, occurring in the first 30 miles below the outlet of Third Connecticut Lake. From Wilder Dam, VT to the head of tidewater, 8 miles above Hartford, CT, the fall average about 2 ft per mile. Wide and extensive flood plains are located at various reaches along the main stem. During major floods, these meadowlands become inundated to depths of 10 to 20 feet and act as large detention reservoirs which significantly reduce peak discharge at downstream locations. The most noteworthy are located in the following areas: the reach between West Stewartstown and Lancaster, NH; the 15-mile stretch between Woodsville, NH and Bradford, VT; in central Massachusetts between Montague City and Holyoke; and the extensive flood plains of Connecticut between Windsor Locks and Middletown. There are important hydropower dams on the Connecticut River throughout its length. In the northern areas upstream of White River Junction are the Moore, Comerford, and Wilder projects; the Bellows Falls, Vernon, and Tuners Falls dams are located along the central reaches; and the Holyoke dam is in the southern portion of the basin. The Connecticut River, in its southerly course to the ocean, is fed by numerous rivers and streams entering from the east and west. Rivers and streams on the western side of the basin are generally steeper and because the watersheds are steeper, flood runoff occurs more rapidly and peak contributions to Connecticut River flood flows have higher cfs/mi2 values than the eastern tributaries. The 15 largest tributaries, with watersheds larger than 200 mi2 and an aggregate area equal to 6517 mi2, or about 58 percent of the total basin area, include the Upper Amoonosuc River, Passumpsic River, Amoonosuc River, White River, Mascoma River, Ottauquechee River, Sugar River, Black River, West River, Ashuelot River, Millers River, Deerfield River, Chicopee River, Westfield River, and Farmington River.