Import MODFLOW Packages – Block Centered Package The Import MODFLOW Packages – Block Centered Package command displays the standard Windows Open File dialog box. Only files with a bcf file extension are shown. The file must be in text format and in the standard input format for the MODFLOW block centered flow package. Select a file and click on the Open button. Graphic Groundwater will then import a MODFLOW block centered flow package file which contains information on an existing MODFLOW model. This command must be preceded by the Import MODFLOW Packages – Basic Package. The command is only enabled if you successfully import the basic package. If the block centered flow package is successfully imported, Graphic Groundwater will display the imported grid in Model Mode. Consult Chapter 4 for more information on this command.