User can define boundary condition location lines spatially along 2D Flow Areas and storage areas. This is accomplished using the SA/2D Area BC Lines drawing tool on the Geometric Data editor Tools button bar. To use this option, select the SA/2D Area Conn tool button at the top of the geometric data editor, then draw a line along the outer boundary of the 2D flow Area (or storage area) where you want the boundary condition to be located. Once the line is drawn the interface will ask you to enter a unique name for the boundary condition line. After you have drawn all the boundary condition lines you want along 2D flow Areas and Storage areas, save the geometry data. Then you can go into the Unsteady Flow Data editor and define the boundary condition types/data for each of these boundary condition lines.