EFDC_Explorer allows the option of importing of multiple grids and joining them together within the Grid Generator module.
...
Figure 3 Load the second Subsub-Domain domain grid.
Figure 4 Number of Subsub-Domain grid domain grids loaded.
Figure 5 Sub-Domain grids viewed in EE.
...
Figure 6 Sub-Domain grids in 2D PlanviewViewPlan.
Figure 7 New cell connection options.
For example, select New Single Cell Connection then LMC to select the adjoining cell, and an N-S connector will be made as shown in Figure 8. Two options involve using polylines to define the cells on each grid that are to be connected. The New Group Connection across 2 polyines lets the user draw a polyline (LMC to start, RMC to end) on each grid. When the second polyline is completed EE will prompt the user for setting N-S, E-W or both kinds of connectors to be assigned. The New Group Connection across an existing polyines files allows the user to use predefined polylines which have been saved by the user to be loaded and used to set the connectors.
Figure 8 N-S connector established.
...