Define the MODFLOW parameters using the well and the pumping rate assigned to the well.
Select MODFLOW | Parameters to open the Parameters dialog.
Click the New button.
Turn on Show all columns checkbox.
Change the Type column to "WELL".
In the Key column, enter actual pumping rate.
Enter inverse of pumping rate value in the Value column.
Enter Min and Max values greater than 0. These and “Value” will be multiplied by the Q factor later which will be negative 1, so positive values here will actually be negative.