### GWF-IC

#### Structure of Blocks

_FOR EACH SIMULATION_

```
    BEGIN OPTIONS
      [EXPORT_ARRAY_ASCII]
      [EXPORT_ARRAY_NETCDF]
    END OPTIONS
```
```
    BEGIN GRIDDATA
      STRT [LAYERED] [NETCDF]
            <strt(nodes)> -- READARRAY
    END GRIDDATA
```

#### Explanation of Variables

##### Block: OPTIONS

  * `EXPORT_ARRAY_ASCII` keyword that specifies input griddata arrays should be written to layered ascii output files.

  * <span style="color:red">`EXPORT_ARRAY_NETCDF` keyword that specifies input gridded arrays should be written to the model output NetCDF file with attributes that support using the generated file as a MODFLOW 6 simulation input.  This option only has an effect when an output model NetCDF file is configured and the simulation is run in VALIDATE mode, otherwise it is ignored.</span>

##### Block: GRIDDATA

  * `strt` is the initial (starting) head---that is, head at the beginning of the GWF Model simulation.  STRT must be specified for all simulations, including steady-state simulations. One value is read for every model cell. For simulations in which the first stress period is steady state, the values used for STRT generally do not affect the simulation (exceptions may occur if cells go dry and (or) rewet). The execution time, however, will be less if STRT includes hydraulic heads that are close to the steady-state solution.  A head value lower than the cell bottom can be provided if a cell should start as dry.

#### Example Input File
```
    #The OPTIONS block is optional
    BEGIN OPTIONS
    END OPTIONS
    
    #The GRIDDATA block is required
    BEGIN GRIDDATA
      STRT LAYERED
        CONSTANT   0.0  Initial Head layer   1
        CONSTANT   0.0  Initial Head layer   2
    END GRIDDATA
```