This public feature service is maintained for the Nashua Regional Planning Commission's (NRPC) member municipalities, their stakeholders, and the wider GIS community. The service contains the most frequently-requested, general-purpose GIS basemap datasets that are originated and maintained by NRPC. The service can be used by any software that can ingest an ESRI rest endpoint, including ArcGIS Desktop, ArcGIS Pro, and ArcGIS Online.Edits to these datasets are made in NRPC's on-premise GIS database on an ongoing basis; online published data are refreshed weekly through an automatic script.This hosted feature view containing data specific to Merrimack, NH is a derivative of NRPC Open Data - All Communities feature service which is regional in nature; i.e., the geographic coverage includes the entire NRPC region. For convenience, NRPC has published community-specific hosted feature views for each of its 13-member communities. Non-GIS users are invited to browse the data in MapGeo, NRPC's interactive parcel viewer. Please contact Sara Siskavich, NRPC GIS Manager, with any questions.Data DownloadsUse the following links to download the data from this service in a variety of ESRI and open formats.Merrimack Town BoundaryMerrimack ParcelsMerrimack Trail Parking AreasMerrimack Public TrailsMerrimack Conserved LandMerrimack ZoningMerrimack CAMA (assessing data)

This public feature service is maintained for the Nashua Regional Planning Commission's (NRPC) member municipalities, their stakeholders, and the wider GIS community. The service contains the most frequently-requested, general-purpose GIS basemap datasets that are originated and maintained by NRPC. The service can be used by any software that can ingest an ESRI rest endpoint, including ArcGIS Desktop, ArcGIS Pro, and ArcGIS Online.Edits to these datasets are made in NRPC's on-premise GIS database on an ongoing basis; online published data are refreshed weekly through an automatic script.This hosted feature view containing data specific to Merrimack, NH is a derivative of NRPC Open Data - All Communities feature service which is regional in nature; i.e., the geographic coverage includes the entire NRPC region. For convenience, NRPC has published community-specific hosted feature views for each of its 13-member communities. Non-GIS users are invited to browse the data in MapGeo, NRPC's interactive parcel viewer. Please contact Sara Siskavich, NRPC GIS Manager, with any questions.Data DownloadsUse the following links to download the data from this service in a variety of ESRI and open formats.Merrimack Town BoundaryMerrimack ParcelsMerrimack Trail Parking AreasMerrimack Public TrailsMerrimack Conserved LandMerrimack ZoningMerrimack CAMA (assessing data)

This data set represents smoothed, 2-foot bare earth contours (isolines) for the Tannery Brook-Merrimack River (0107000601) HUC 10 unit. It was derived from a data set which was compiled from LIDAR collections in NH available as of spring, 2019. The raster was filtered using the ArcGIS FOCAL STATISTICS tool with a 3x3 circular neighborhood. The contours were generated using the ArcGIS CONTOUR tool while applying a Z factor of 3.2808 to convert the elevation values from meters to feet. The filtered contours were then smoothed using the ArcGIS SMOOTH LINE tool. The data include an INDEX field with values of 10 and 100 to flag 10 and 100-foot contours. Note on HUC 01060000310: Due to limitations in the source LIDAR data, some anomalies exist in the generated contours in coastal areas of the state. These were left in the data so that users can determine what further processing best meets their application needs.

The Merrimack Valley Data Portal from Merrimack Valley Planning Commission (MVPC) provides robust demographic and economic data for our municipalities, businesses, non-profits, and the public at-large. This information shapes how we direct public resources and how businesses make decisions.

These data provide an accurate high-resolution shoreline compiled from imagery of MERRIMACK RIVER AND PLUM ISLAND SOUND, 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 Cartographic Object Attribute Source Table (C-COAST)' was developed to conform the attribution of various sources of shoreline data into one attribution catalog. C-COAST is not a recognized standard, but was influenced by the International Hydrographic Organization's S-57 Object-Attribute standard so the data would be more accurately translated into S-57. This resource is a member of https://www.fisheries.noaa.gov/inport/item/39808

This data set represents smoothed, 2-foot bare earth contours (isolines) for the Nesenkeag Brook-Merrimack River (0107000610) HUC 10 unit. It was derived from a data set which was compiled from LIDAR collections in NH available as of spring, 2019. The raster was filtered using the ArcGIS FOCAL STATISTICS tool with a 3x3 circular neighborhood. The contours were generated using the ArcGIS CONTOUR tool while applying a Z factor of 3.2808 to convert the elevation values from meters to feet. The filtered contours were then smoothed using the ArcGIS SMOOTH LINE tool. The data include an INDEX field with values of 10 and 100 to flag 10 and 100-foot contours. Note on HUC 01060000310: Due to limitations in the source LIDAR data, some anomalies exist in the generated contours in coastal areas of the state. These were left in the data so that users can determine what further processing best meets their application needs.

This resource is 3 GIS layers in a web service related to the geology of Merrimack Basin, New Hampshire. It consists of GIS geostatistical Interpolation of a surface that models the depth to bedrock. It is derived from known georeferenced locations where depths to bedrock have been observed. These primarily include bedrock outcrops and well or boring locations. Interpolation method was ordinary kriging, using a lag size of 347 ft, 18 lags, a nugget of 42.24, partial sill of 647.508, and a 4633 ft range. A maximum of 20 neighbors and a minimum of 8 neighbors in a single circular sector were used in interpolation. The data are provided in the following formats: a web map service, a web feature service, and an ERSI Service Endpoint. It was compiled by the New Hampshire Geological Survey and made available for distribution through the National Geothermal Data System.

1) Merrimack Basin Bedrock Depth: This layer displays a GIS geostistical Interpolation of a surface that models the depth to bedrock. It was derived from known georeferenced locations where depths to bedrock have been observed. These primarily include bedrock outcrops and well or boring locations. Interpolation method was ordinary kriging, using a lag size of 448.6 ft. A maximum of 20 neighbors and a minimum of 8 neighbors were used in interpolation. Layer in the web service is "merri_bdkd".

2) Merrimack Basin Bedrock Depth Standard Error: This layer displays the Predicted Standard Error of GIS geostatistical interpolation of a surface that models the depth to bedrock. The predicted standard error is the standard deviation of the predicted surface, and is a function of distance from the nearest data point. Layer in web service is "merri_error".

3) Merrimack Basin Bedrock Depth Contours: This layer displays10 foot contours of a GIS geostatistical interpolation of a surface that models the depth to bedrock. Derived from known georeferenced locations where depths to bedrock have been observed. Contours were smoothed and topology was enforced to ensure that contours did not cross. Features with length less than 100 ft were removed. Layer in web service is "merri_bdkd_contour".

This data set represents smoothed, 2-foot bare earth contours (isolines) for the Little Cohas Brook-Merrimack River (0107000608) HUC 10 unit. It was derived from a data set which was compiled from LIDAR collections in NH available as of spring, 2019. The raster was filtered using the ArcGIS FOCAL STATISTICS tool with a 3x3 circular neighborhood. The contours were generated using the ArcGIS CONTOUR tool while applying a Z factor of 3.2808 to convert the elevation values from meters to feet. The filtered contours were then smoothed using the ArcGIS SMOOTH LINE tool. The data include an INDEX field with values of 10 and 100 to flag 10 and 100-foot contours. Note on HUC 01060000310: Due to limitations in the source LIDAR data, some anomalies exist in the generated contours in coastal areas of the state. These were left in the data so that users can determine what further processing best meets their application needs.

This data set represents smoothed, 2-foot bare earth contours (isolines) for the Powwow River-Merrimack River (0107000614) HUC 10 unit. It was derived from a data set which was compiled from LIDAR collections in NH available as of spring, 2019. The raster was filtered using the ArcGIS FOCAL STATISTICS tool with a 3x3 circular neighborhood. The contours were generated using the ArcGIS CONTOUR tool while applying a Z factor of 3.2808 to convert the elevation values from meters to feet. The filtered contours were then smoothed using the ArcGIS SMOOTH LINE tool. The data include an INDEX field with values of 10 and 100 to flag 10 and 100-foot contours. Note on HUC 01060000310: Due to limitations in the source LIDAR data, some anomalies exist in the generated contours in coastal areas of the state. These were left in the data so that users can determine what further processing best meets their application needs.

The coastal dunes, beaches, and inner neritic zone of the Merrimack Embayment constitute a petrologic province. In addition to heavy mineral analyses, grain size statistics were generated on most of the samples. Neritic and beach sediments can be differentiated using scatter plots of statistics, but statistical parameters are ineffective in differentiating between river and neritic sediments.

This GIS datalayer is based upon the NH Conserved/Public Lands attribute model published by NH Granit. In 2014 NRPC began with that statewide dataset and refined the geography of those parcels to coincide with the NRPC parcel dataset. From there, NRPC mapped approximately 400 additional conserved land trascts based upon input from the area's conservaton commissions. Using the Hillsborough County Registry of Deeds online databse, the NRPC conducted extensive deed research to determine key attributes such as primary protection mechanism(s), managing agency, etc. NRPC publishes these data on maps and in its flagship online viewer. There is no systematic process for maintenance; rather, corrections and edits are made as they are reported by stakeholders. Disclaimer: This dataset is an NRPC interpretation of original source material and maps. It is appropriate for mapping and planning purposes; it should not be utilized where legal and surveyed boundaries are required. NRPC does not make any warranty, representation, or guarantee as to the content, sequence, accuracy, timeliness, or completeness of this information. The user should not rely on these data without verifying its accuracy independently. NRPC and its member communities, respectively, explicitly, disclaim any representations and warranties including, without limitation, the implied warranties of merchantability and fitness for a particular purpose. NRPC and its member communities shall assume no liability for errors, omissions, inaccuracies in the information provided regardless of how caused and for any decision made or action take or not taken by the user in reliance upon any information or data furnished hereunder.

This sediment database contains location, description, and texture of samples taken by numerous marine sampling programs. Most of the samples are from the Atlantic Continental Margin of the United States, but some are from as diverse locations as Lake Baikal, Russia, the Hawaiian Islands region, Puerto Rico, the Gulf of Mexico, and Lake Michigan. The database presently contains data for over 27,000 samples, which includes texture data for approximately 3800 samples taken or analyzed by the Atlantic Continental Margin Program (ACMP), a joint U.S. Geological Survey/Woods Hole Oceanographic Institution project conducted from 1962 to 1970. As part of the ACMP, some historical data from samples collected between 1955 and 1962 were also incorporated into the dataset.

This data set contains both true color (RGB) and infrared (IR) ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative for the Merrimack River - Plum Island Sound region of Massachusetts. The source imagery was acquired on 20110619. The images were acquired with an Applanix Digital Sensor System (DSS). The original images were acquired at a higher resolution than the final ortho-rectified mosaic. Ortho-rectified mosaic tiles are an ancillary product of NOAA's Coastal Mapping Program (CMP), created through a wider Integrated Ocean and Coastal Mapping initiative to increase support for multiple uses of the data.

Data for this region are in two subdirectories, which hold RGB and IR imagery for both mean high water (MHW) and mean lower low water (MLLW) periods. (MLLW, i.e. the average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, comparison of simultaneous observations with a control tide station is made in order to derive the equivalent datum of the National Tidal Datum Epoch).

Imagery is in .tif format with associated browse graphic (.jpg), .omd, .his, and metadata files in Federal Geographic Data Committee (FGDC) format.

The ground sample distance (GSD) for each pixel is 0.50 m.

This datalayer is an NRPC interpretation of the local ordinance describing zoning district in each of our communities and does not represent official zoning. The town's own official zoning map and current ordinance should be consulted as the authoritative source on permitted uses, zoning boundary questions, or other issues. Overlay districts, which generally add a level of restriction, are not represented in this datalayer. To facilitate regional use of these data and town-by-town comparisons, NRPC created a field called PRIM_USE based on NPRC's interpretations of highest density permitted use, broadly defined, regardless of zoning district nomenclature. When density failed to distinguish between zoning districts in a town, the overall intentions of the zoning district, as stated in the ordinance, were considered. Lot sizes represent the smallest permissible lot.

PFOA was detected in a tap water sample that Saint-Gobain collected inside their facility in 2016. The tap water at Saint-Gobain was from the public water system operated by the Merrimack Village District, which obtains groundwater from a network of water supply wells. This detection of PFOA in the public water system prompted NHDES to immediately initiate an investigation into the source and extent of PFAS contamination. The investigation, conducted by NHDES and Saint-Gobain’s environmental consultants, involved sampling various media, including groundwater, surface water, stormwater, soil and facility emissions. The Saint-Gobain Consent Decree Outer Boundary can be viewed here as a shaded area that encompasses parts of Bedford, Hudson, Litchfield, Londonderry, Manchester and Merrimack. For more information refer to the NHDES Saint-Gobain Performance Plastics site.