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Related pages:   FEMA LIDAR  |   Watershed Boundaries

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Buzzards Bay NEP GIS Data

Note: These data are in ArcViewTM shapefiles, with NAD83 meters coordinates, consistent with MassGIS coverages. The shapefile coverages are all contained in zip files unless otherwise specified. You should right click on the link to save the file to your computer if it is very large, or you can left click to have your browser open the zip file. This is not a complete list of files on our website, and you might wish to use the search button to see if we have a particular coverage.


General Buzzards Bay Data Sets

September 2011 release of Buzzards Bay watershed towns Protected Open Space (

2007 Shellfish Bed classification map, status for 1 July

2003 Buzzards Bay NEP’s Filled Wetlands Atlas Volume I sites

Urbanized Areas

Census 1990 and Census 2000 urbanized areas, and Phase 2 combined areas.

2010 shapefile of urbanized areas of Massachusetts (5 MB zipped)

Google Earth file showing the changes between 2000 and 2010.

Buzzards Bay Salt Marsh Atlas Tidal Restrictions and Phragmites areas
(two coverages included in a 178 kb zip files)

Buzzards Bay Sewered Areas
This is a generalized coverage best for watershed and regional maps. Data coverage for Otis Air Force base is estimated.

Buzzards Bay NEP’s Stormwater Atlas, 2012 update

Zipped GIS file discharges:
Zipped GIS file catchbasins:
Zipped GIS file flows:
Google Earth KMZ files: bbnep_catchbasins_2012.kml
discharges: bbnep_discharges_2012.kml
flows: bbnep_flows_2012.kml

Town Parcel Data Sets

Go to the MassGIS Parcel Level 3 Coverage page to download the latest Level 3 parcel data sets for Buzzards Bay municipalities.

Buzzards Bay watershed and subbasin lines used by the BBNEP

2009 Updates of the Buzzards Bay Study Area

In 2009, as part of the update of the new Buzzards Bay CCMP, the Buzzards Bay NEP adopted a slightly revised “Study Area” definition (jurisdictional interests of the program) shown in the figure below. The southern bay boundary is now consistent with the Massachusetts Ocean Plan area and coincident with the boundary of Massachusetts state waters, and within recently defined state and federal designations for the boundary of Buzzards Bay. The NEP study area totals 684 square miles (=438,142 acres or 1,773 square kilometers). This study area consists of 434 square miles of land (=277,606 acres or 1,123 square kilometers; includes land in both Massachusetts and Rhode Island [6.8 sq miles], freshwater pond area not broken out) and 250 square miles of water in Massachusetts (160,536 acres or 650 sq. kilometers; includes a small portion of areas on nautical charts sometimes labeled Rhode Island Sound in Massachusetts waters). This coverage builds upon earlier coverages. In 2009, two significant updates were made. First the ocean boundary of Buzzards Bay was set to coincide with MCZM’s Massachusetts Ocean Plan Boundary (see Second, USGS better defined the groundwater contribution area in the Plymouth-Carver and Cape Cod aquifers. This GIS coverage, available at: The USGS data set was smoothed to 100 m intervals and was intersected with earlier Buzzards Bay watershed coverages. Other details about the changing watershed definition is available at on our Buzzards Bay Boundary page.

buzzards Bay Study Area
Click to enlarge

In 2014, we refined the northern boundary, and Cape Cod boundary further to reflect new watershed boundaries defined by the Massachusetts Estuaries Project in those areas. Download the zipped shapefile: For comparison, we also provide the Buzzards Bay 2006 watershed major basin boundary. (zipped GIS shape file) we had previously used.

Buzzards Bay Subbasins

This 2017 subbasin coverage is currently being used by the Buzzards Bay NEP: We are also making available this July 2012 coverage. Although the Buzzards Bay subbasins are superseded, the boundaries in this file might have been used in some past studies, and it also contains subbasins for all of Southeastern Massachusetts: . For comparison, here is the 2009 sub-basin boundaries (zipped GIS shape file) we posted previously.

In 2009, the Buzzards Bay NEP updated it subbasin coverage to make it consistent with our major basin boundary and the latest GIS data and subwatershed delineations (including groundwater boundaries) from the MEP, DEP, and USGS. MEP defined boundaries were given precedence where inconsistencies existed between data sets. More information about these coverages can be found on our Nitrogen Management origins page. More information about these coverages can be found on our Nitrogen Management origins page and our Buzzards Bay watershed boundary page.

Specialized Coverages

New Bedford Harbor Bathymetry
New Bedford Harbor Bathymetry
(color coded map, 496 kb JPG)

New Bedford Harbor Bathymetry GIS Shapefiles
This is a 565 kb zip file that opens into the three necessary ArcView files. Depths as NGVD29 feet at MLLW (mean lower low water). This data is shown in the image to the right.

Links to Other Data Download Sites with Buzzards Bay Coverages

Best Site:Massachusetts GIS data center download page
Jump to MassGIS’ download page. Includes most of the data files we use and even some data sets developed or funded by the BBP.

Best BB Town Site:Town of Falmouth interactive GIS page

Massachusetts Bay Information Server
A clearinghouse for data and information sponsored by the MIT Sea Grant College Program and the USGS.

Massachusetts MORIS Shoreline Change Browser
Data from Mass CZM on shoreline change and erosion in Massachusetts.
Additional information about this data set is at: Massachusetts shoreline change project information page.

NOAA Nautical Chart Viewer and downloader including GIS format

Data from Mass CZM on shoreline change and erosion in Massachusetts

Great Aerial Photo and Topo Map Display Sites

Map Server at

Google Maps
Install Google Earth With Google earth, you can select aerials from different dates as the base map.

Converting xy coordinates into a shapefile

Step 1. Create an xy data base file in Excel. The file should look like this:

X Y ID field1 field2
373.2330 603.3111 marker1 catchbasin treated
373.2330 603.3111 marker2 catchbasin untreated

[Note: the IDs can all be zero, or a discreet numeric or string identifier. Your “x value” is longitude or easting. For decimal degrees, don’t forget to add a negative sign for our hemisphere.]

Step 2. Export the file as a Dbase IV file.
[A quirk of Excel is that after you modify the database, you may have to close the database and reopen it before exporting to ensure the dbf file looks like the xls file. It is a good idea to format numeric cells with the preferred number of significant digits and format non-numeric fields as text to avoid other hitches.

Step 3. Open ArcView, click on tables, and ADD Table. Add the table from the directory where you saved it

Step 4: Click on View-Add Event Theme. ArcView may default to the dbf table you just added.

Step 5: use a script or tool like Xtools ® to convert points into a polygon if desired

Step 6: If you entered UTM data from a quad sheet, convert the data to Mass State plane 1983 meters.


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