A hydrographic shapefile data set for part of Concord, Massachusetts,
  USA comprising the following files:
 
     concord_hydro_area.dbf
     concord_hydro_area.shp
     concord_hydro_area.shx
     concord_hydro_line.dbf
     concord_hydro_line.shp
     concord_hydro_line.shx
 
  Source
  ------
  Office of Geographic and Environmental Information (MassGIS),
  Commonwealth of Massachusetts  Executive Office of Environmental Affairs
  (http://www.state.ma.us/mgis/)
 
  Coordinate system/projection
  ----------------------------
  All data distributed by MassGIS are registered to the NAD83 datum,
  Massachusetts State Plane Mainland Zone coordinate system. Units are in
  meters.
 
  Data set construction
  ---------------------
  This data set was constructed by concatenating MassGIS hydrographic
  shapefiles for the Maynard and Concord USGS Quadrangles, from compressed
  files hd97.exe and hd104.exe.
 
  Features were selected with bounding boxes intersecting the following
  box:
            [206500 (min easting)  910500 (min northing)
             211500 (max easting)  913500 (max northing)]
 
  The following attributes were retained for area features (derived from
  shapefiles hd97p1 and hd104p1):
 
                        'AREA', 'PERIMETER'
 
  and the 'LENGTH' attribute was retained for linear features (from
  shapefiles  hd97a1 and hd104a1).
 
  Construction date
  -----------------
  November 17, 2003.