U.S. Geological Survey (USGS) 20150801 vector digital data Reston, Virginia U.S. Geological Survey (USGS) http://wimcloud.usgs.gov/apps/FIM/FloodInundationMapper.html U.S. Geological Survey (USGS) 20150801 document USGS Scientific Investigations Report 2015-5104 Reston, Virginia U.S. Geological Survey (USGS) http://dx.doi.org/10.3133/sir20155104 A series of 17 digital flood-inundation maps were developed for an 8.9-mile reach of the Deerfield River in Franklin County, Massachusetts, by the U.S. Geological Survey (USGS) in cooperation with the Federal Emergency Management Agency (FEMA). The coverage of the maps extends from the confluence with the South River to the confluence with the Green River. Peak flows with 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs) were computed for the reach from updated flood-frequency analyses. These peak flows were routed through a one-dimensional step-backwater hydraulic model to obtain the corresponding peak-water-surface elevations, and to place the flood of tropical storm Irene (August 28, 2011) into historical context. The hydraulic model was used to compute water-surface profiles for flood stages referenced to the streamgage and ranging from 8.5 ft [165.24 ft North American Vertical Datum of 1988 (NAVD88)] to 29.0 ft (185.74 ft NAVD88). The mapped stages, 8.5 to 29.0 ft, were selected to match the stages of flows with AEPs between 20 and 0.2 percent, and thus do not fall at exactly 1-ft increments. The simulated water-surface profiles were combined with a geographic information system (GIS) digital elevation model (DEM) derived from 0.5-foot vertical accuracy light detection and ranging (lidar) data to create a set of flood-inundation maps. These maps delineate the areal extent and depth of flooding corresponding to the selected water levels. This dataset contains the results of the development of a hydraulic model for an 8.9-mile reach of the Deerfield River in Franklin County, Mass., from the confluence with the South River to the confluence with the Green River. 20150801 publication date Complete None planned -72.68 -72.58 42.58 42.51 ISO 19115 Topic Category environment inlandWaters None STATE MA STATE Massachusetts COUNTY Franklin County RIVER Deerfield River COMMUNITY Buckland COMMUNITY Conway COMMUNITY Deerfield COMMUNITY Greenfield COMMUNITY Shelburne None Users must assume responsibility to determine the appropriate use of this data. Users should be aware of the limitations of this dataset if using for critical application. Acknowledgement of the U.S. Geological Survey and the Federal Emergency Management Agency would be appreciated in products derived from these data. ArcGIS 10.1 The hydraulic model was used to compute water-surface profiles for flood stages referenced to the streamgage and ranging from 8.5 ft [165.24 ft above North American Vertical Datum of 1988 (NAVD 88)] to 29.0 ft (185.74 ft above NAVD 88). The mapped stages, 8.5 to 29.0 ft, were selected to match the stages of flows with AEPs between 20 and 0.2 percent, and thus do not fall at exactly 1-ft increments. Although the flood-inundation maps represent the boundaries of inundated areas with a distinct line, some uncertainty is associated with these maps. The flood boundaries shown were estimated on the basis of water stages and streamflows at the USGS streamgage at Deerfield River near West Deerfield, Mass. Water-surface elevations along the stream reaches were estimated by steady-state hydraulic modeling, assuming unobstructed flow, and using streamflows and hydrologic conditions anticipated at the streamgage. The hydraulic model reflects the land-cover characteristics and any bridge, dam, levee, or other hydraulic structures existing as of 2012. Unique meteorological factors (timing and distribution of precipitation) may cause actual streamflows along the modeled reach to vary from those assumed during a flood, which may lead to deviations in the water-surface elevations and inundation boundaries shown. Additional areas may be flooded due to unanticipated conditions such as changes in the streambed elevation or roughness, backwater into major tributaries along a main stem river, or backwater from localized debris or ice jams. The accuracy of the floodwater extent portrayed on these maps will vary with the accuracy of the digital elevation model used to simulate the land surface. U.S. Geological Survey 20130930 http://waterdata.usgs.gov/nwis/uv/?site_no=01170000 online 19411001 20130930 publication date FLOW-GAGE1 Historical flow data for the Deerfield River near West Deerfield, Mass., for use in flood-frequency analysis Process steps include selection of methods and models, preparation of input data, computing and modeling, and mapping output data as floodplains. Preparation of input data involves compilation of rain and flow gage data; delineation of sub-basins; and processing of topographic data. Mapping of output data involves superposition of the modeled water surface over the modeled ground surface to determine areas of flooding; removal of areas that are not clearly hydraulically connected; and clipping out the footprint of superstructures above the floodplain, such as bridges that are not overtopped. 20150501 State Plane Coordinate System 1983 2001 41.71666667 42.68333333 -71.5 41.0 656166.66666667 2460625.0 coordinate pair 0.000172 0.000172 survey feet North American Datum of 1983 Geodetic Reference System 80 6378137 298.257222101 North American Vertical Datum of 1988 0.000172 feet Attribute values This dataset contains the limit lines used to analyze the hydraulics of the Deerfield River, as well as the inundation floodplains and depth grids for selected water-surface elevations resulting from this analysis. Descriptions for the entities and attributes in this dataset can be found in the accompanying scientific investigations report. Gardner Bent U.S. Geological Survey (USGS) mailing

10 Bearfoot Road

Northborough MA 01532 USA 508-490-5041 gbent@usgs.gov This dataset, identified as Flood-Inundation Floodplain Polygons and Depth Grids for the Deerfield River, has been approved for release and publication by the director of the USGS. Although this dataset has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the U.S. Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it may also contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. This coverage may be redistributed if it is not edited and is properly referenced. Inundated areas shown should not be used for navigation, regulatory, permitting, or other legal purposes. The U.S. Geological Survey provides these maps "as-is" for a quick reference, emergency planning tool but assumes no legal liability or responsibility resulting from the use of this information. map none 20150610 Luther Schalk U.S. Geological Survey mailing

196 Whitten Road

Augusta ME 04330 USA 207-622-8201x103 lschalk@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998