mf6ivar.md

MODFLOW 6 INPUT VARIABLES

component	package	block	variable name	type	description
SIM	NAM	OPTIONS	CONTINUE	KEYWORD	keyword flag to indicate that the simulation should continue even if one or more solutions do not converge.
SIM	NAM	OPTIONS	NOCHECK	KEYWORD	keyword flag to indicate that the model input check routines should not be called prior to each time step. Checks are performed by default.
SIM	NAM	OPTIONS	MEMORY_PRINT_OPTION	STRING	is a flag that controls printing of detailed memory manager usage to the end of the simulation list file. NONE means do not print detailed information. SUMMARY means print only the total memory for each simulation component. ALL means print information for each variable stored in the memory manager. NONE is default if MEMORY_PRINT_OPTION is not specified.
SIM	NAM	TIMING	TDIS6	STRING	is the name of the Temporal Discretization (TDIS) Input File.
SIM	NAM	MODELS	MTYPE	STRING	is the type of model to add to simulation.
SIM	NAM	MODELS	MFNAME	STRING	is the file name of the model name file.
SIM	NAM	MODELS	MNAME	STRING	is the user-assigned name of the model. The model name cannot exceed 16 characters and must not have blanks within the name. The model name is case insensitive; any lowercase letters are converted and stored as upper case letters.
SIM	NAM	EXCHANGES	EXGTYPE	STRING	is the exchange type.
SIM	NAM	EXCHANGES	EXGFILE	STRING	is the input file for the exchange.
SIM	NAM	EXCHANGES	EXGMNAMEA	STRING	is the name of the first model that is part of this exchange.
SIM	NAM	EXCHANGES	EXGMNAMEB	STRING	is the name of the second model that is part of this exchange.
SIM	NAM	SOLUTIONGROUP	GROUP_NUM	INTEGER	is the group number of the solution group. Solution groups must be numbered sequentially, starting with group number one.
SIM	NAM	SOLUTIONGROUP	MXITER	INTEGER	is the maximum number of outer iterations for this solution group. The default value is 1. If there is only one solution in the solution group, then MXITER must be 1.
SIM	NAM	SOLUTIONGROUP	SLNTYPE	STRING	is the type of solution. The Integrated Model Solution (IMS6) is the only supported option in this version.
SIM	NAM	SOLUTIONGROUP	SLNFNAME	STRING	name of file containing solution input.
SIM	NAM	SOLUTIONGROUP	SLNMNAMES	STRING (:)	is the array of model names to add to this solution. The number of model names is determined by the number of model names the user provides on this line.
SIM	TDIS	OPTIONS	TIME_UNITS	STRING	is the time units of the simulation. This is a text string that is used as a label within model output files. Values for time_units may be unknown'', seconds'', minutes'', hours'', days'', or years''. The default time unit is ``unknown''.
SIM	TDIS	OPTIONS	START_DATE_TIME	STRING	is the starting date and time of the simulation. This is a text string that is used as a label within the simulation list file. The value has no affect on the simulation. The recommended format for the starting date and time is described at https://www.w3.org/TR/NOTE-datetime.
SIM	TDIS	DIMENSIONS	NPER	INTEGER	is the number of stress periods for the simulation.
SIM	TDIS	PERIODDATA	PERLEN	DOUBLE PRECISION	is the length of a stress period.
SIM	TDIS	PERIODDATA	NSTP	INTEGER	is the number of time steps in a stress period.
SIM	TDIS	PERIODDATA	TSMULT	DOUBLE PRECISION	is the multiplier for the length of successive time steps. The length of a time step is calculated by multiplying the length of the previous time step by TSMULT. The length of the first time step, $\Delta t_1$, is related to PERLEN, NSTP, and TSMULT by the relation $\Delta t_1= perlen \frac{tsmult - 1}{tsmult^{nstp}-1}$.
EXG	GWFGWF	OPTIONS	AUXILIARY	STRING (NAUX)	an array of auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided. Most auxiliary variables will not be used by the GWF-GWF Exchange, but they will be available for use by other parts of the program. If an auxiliary variable with the name ANGLDEGX'' is found, then this information will be used as the angle (provided in degrees) between the connection face normal and the x axis, where a value of zero indicates that a normal vector points directly along the positive x axis. The connection face normal is a normal vector on the cell face shared between the cell in model 1 and the cell in model 2 pointing away from the model 1 cell. Additional information on ANGLDEGX'' is provided in the description of the DISU Package. If an auxiliary variable with the name ``CDIST'' is found, then this information will be used as the straight-line connection distance, including the vertical component, between the two cell centers. Both ANGLDEGX and CDIST are required if specific discharge is calculated for either of the groundwater models.
EXG	GWFGWF	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of exchange entries will be echoed to the listing file immediately after it is read.
EXG	GWFGWF	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of exchange flow rates will be printed to the listing file for every stress period in which ``SAVE BUDGET'' is specified in Output Control.
EXG	GWFGWF	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that cell-by-cell flow terms will be written to the budget file for each model provided that the Output Control for the models are set up with the ``BUDGET SAVE FILE'' option.
EXG	GWFGWF	OPTIONS	CELL_AVERAGING	STRING	is a keyword and text keyword to indicate the method that will be used for calculating the conductance for horizontal cell connections. The text value for CELL_AVERAGING can be HARMONIC'', LOGARITHMIC'', or AMT-LMK'', which means arithmetic-mean thickness and logarithmic-mean hydraulic conductivity''. If the user does not specify a value for CELL_AVERAGING, then the harmonic-mean method will be used.
EXG	GWFGWF	OPTIONS	VARIABLECV	KEYWORD	keyword to indicate that the vertical conductance will be calculated using the saturated thickness and properties of the overlying cell and the thickness and properties of the underlying cell. If the DEWATERED keyword is also specified, then the vertical conductance is calculated using only the saturated thickness and properties of the overlying cell if the head in the underlying cell is below its top. If these keywords are not specified, then the default condition is to calculate the vertical conductance at the start of the simulation using the initial head and the cell properties. The vertical conductance remains constant for the entire simulation.
EXG	GWFGWF	OPTIONS	DEWATERED	KEYWORD	If the DEWATERED keyword is specified, then the vertical conductance is calculated using only the saturated thickness and properties of the overlying cell if the head in the underlying cell is below its top.
EXG	GWFGWF	OPTIONS	NEWTON	KEYWORD	keyword that activates the Newton-Raphson formulation for groundwater flow between connected, convertible groundwater cells. Cells will not dry when this option is used.
EXG	GWFGWF	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
EXG	GWFGWF	OPTIONS	GNC6	KEYWORD	keyword to specify that record corresponds to a ghost-node correction file.
EXG	GWFGWF	OPTIONS	GNC6_FILENAME	STRING	is the file name for ghost node correction input file. Information for the ghost nodes are provided in the file provided with these keywords. The format for specifying the ghost nodes is the same as described for the GNC Package of the GWF Model. This includes specifying OPTIONS, DIMENSIONS, and GNCDATA blocks. The order of the ghost nodes must follow the same order as the order of the cells in the EXCHANGEDATA block. For the GNCDATA, noden and all of the nodej values are assumed to be located in model 1, and nodem is assumed to be in model 2.
EXG	GWFGWF	OPTIONS	MVR6	KEYWORD	keyword to specify that record corresponds to a mover file.
EXG	GWFGWF	OPTIONS	MVR6_FILENAME	STRING	is the file name of the water mover input file to apply to this exchange. Information for the water mover are provided in the file provided with these keywords. The format for specifying the water mover information is the same as described for the Water Mover (MVR) Package of the GWF Model, with two exceptions. First, in the PACKAGES block, the model name must be included as a separate string before each package. Second, the appropriate model name must be included before package name 1 and package name 2 in the BEGIN PERIOD block. This allows providers and receivers to be located in both models listed as part of this exchange.
EXG	GWFGWF	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
EXG	GWFGWF	OPTIONS	OBS6_FILENAME	STRING	is the file name of the observations input file for this exchange. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the GWF-GWF package.
EXG	GWFGWF	DIMENSIONS	NEXG	INTEGER	keyword and integer value specifying the number of GWF-GWF exchanges.
EXG	GWFGWF	EXCHANGEDATA	CELLIDM1	INTEGER	is the cellid of the cell in model 1 as specified in the simulation name file. For a structured grid that uses the DIS input file, CELLIDM1 is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLIDM1 is the layer number and CELL2D number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLIDM1 is the node number for the cell.
EXG	GWFGWF	EXCHANGEDATA	CELLIDM2	INTEGER	is the cellid of the cell in model 2 as specified in the simulation name file. For a structured grid that uses the DIS input file, CELLIDM2 is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLIDM2 is the layer number and CELL2D number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLIDM2 is the node number for the cell.
EXG	GWFGWF	EXCHANGEDATA	IHC	INTEGER	is an integer flag indicating the direction between node n and all of its m connections. If IHC = 0 then the connection is vertical. If IHC = 1 then the connection is horizontal. If IHC = 2 then the connection is horizontal for a vertically staggered grid.
EXG	GWFGWF	EXCHANGEDATA	CL1	DOUBLE PRECISION	is the distance between the center of cell 1 and the its shared face with cell 2.
EXG	GWFGWF	EXCHANGEDATA	CL2	DOUBLE PRECISION	is the distance between the center of cell 2 and the its shared face with cell 1.
EXG	GWFGWF	EXCHANGEDATA	HWVA	DOUBLE PRECISION	is the horizontal width of the flow connection between cell 1 and cell 2 if IHC $>$ 0, or it is the area perpendicular to flow of the vertical connection between cell 1 and cell 2 if IHC = 0.
EXG	GWFGWF	EXCHANGEDATA	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each GWFGWF Exchange. The values of auxiliary variables must be present for each exchange. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block.
SLN	IMS	OPTIONS	PRINT_OPTION	STRING	is a flag that controls printing of convergence information from the solver. NONE means print nothing. SUMMARY means print only the total number of iterations and nonlinear residual reduction summaries. ALL means print linear matrix solver convergence information to the solution listing file and model specific linear matrix solver convergence information to each model listing file in addition to SUMMARY information. NONE is default if PRINT_OPTION is not specified.
SLN	IMS	OPTIONS	COMPLEXITY	STRING	is an optional keyword that defines default non-linear and linear solver parameters. SIMPLE - indicates that default solver input values will be defined that work well for nearly linear models. This would be used for models that do not include nonlinear stress packages and models that are either confined or consist of a single unconfined layer that is thick enough to contain the water table within a single layer. MODERATE - indicates that default solver input values will be defined that work well for moderately nonlinear models. This would be used for models that include nonlinear stress packages and models that consist of one or more unconfined layers. The MODERATE option should be used when the SIMPLE option does not result in successful convergence. COMPLEX - indicates that default solver input values will be defined that work well for highly nonlinear models. This would be used for models that include nonlinear stress packages and models that consist of one or more unconfined layers representing complex geology and surface-water/groundwater interaction. The COMPLEX option should be used when the MODERATE option does not result in successful convergence. Non-linear and linear solver parameters assigned using a specified complexity can be modified in the NONLINEAR and LINEAR blocks. If the COMPLEXITY option is not specified, NONLINEAR and LINEAR variables will be assigned the simple complexity values.
SLN	IMS	OPTIONS	CSV_OUTPUT	KEYWORD	keyword to specify that the record corresponds to the comma separated values solver convergence output.
SLN	IMS	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
SLN	IMS	OPTIONS	CSVFILE	STRING	name of the ascii comma separated values output file to write solver convergence information. If PRINT_OPTION is NONE or SUMMARY, comma separated values output includes maximum head change convergence information at the end of each outer iteration for each time step. If PRINT_OPTION is ALL, comma separated values output includes maximum head change and maximum residual convergence information for the solution and each model (if the solution includes more than one model) and linear acceleration information for each inner iteration.
SLN	IMS	OPTIONS	NO_PTC	KEYWORD	is a flag that is used to disable pseudo-transient continuation (PTC). Option only applies to steady-state stress periods for models using the Newton-Raphson formulation. For many problems, PTC can significantly improve convergence behavior for steady-state simulations, and for this reason it is active by default. In some cases, however, PTC can worsen the convergence behavior, especially when the initial conditions are similar to the solution. When the initial conditions are similar to, or exactly the same as, the solution and convergence is slow, then the NO_PTC FIRST option should be used to deactivate PTC for the first stress period. The NO_PTC ALL option should also be used in order to compare convergence behavior with other MODFLOW versions, as PTC is only available in MODFLOW 6.
SLN	IMS	OPTIONS	NO_PTC_OPTION	STRING	is an optional keyword that is used to define options for disabling pseudo-transient continuation (PTC). FIRST is an optional keyword to disable PTC for the first stress period, if steady-state and one or more model is using the Newton-Raphson formulation. ALL is an optional keyword to disable PTC for all steady-state stress periods for models using the Newton-Raphson formulation. If NO_PTC_OPTION is not specified, the NO_PTC ALL option is used.
SLN	IMS	NONLINEAR	OUTER_HCLOSE	DOUBLE PRECISION	real value defining the head change criterion for convergence of the outer (nonlinear) iterations, in units of length. When the maximum absolute value of the head change at all nodes during an iteration is less than or equal to OUTER_HCLOSE, iteration stops. Commonly, OUTER_HCLOSE equals 0.01.
SLN	IMS	NONLINEAR	OUTER_RCLOSEBND	DOUBLE PRECISION	real value defining the residual tolerance for convergence of model packages that solve a separate equation not solved by the IMS linear solver. This value represents the maximum allowable residual between successive outer iterations at any single model package element. An example of a model package that would use OUTER_RCLOSEBND to evaluate convergence is the SFR package which solves a continuity equation for each reach.
SLN	IMS	NONLINEAR	OUTER_MAXIMUM	INTEGER	integer value defining the maximum number of outer (nonlinear) iterations -- that is, calls to the solution routine. For a linear problem OUTER_MAXIMUM should be 1.
SLN	IMS	NONLINEAR	UNDER_RELAXATION	STRING	is an optional keyword that defines the nonlinear under-relaxation schemes used. By default under-relaxation is not used. NONE - under-relaxation is not used. SIMPLE - Simple under-relaxation scheme with a fixed relaxation factor is used. COOLEY - Cooley under-relaxation scheme is used. DBD - delta-bar-delta under-relaxation is used. Note that the under-relaxation schemes are used in conjunction with problems that use the Newton-Raphson formulation, however, experience has indicated that the Cooley under-relaxation and damping work well also for the Picard scheme with the wet/dry options of MODFLOW 6.
SLN	IMS	NONLINEAR	UNDER_RELAXATION_THETA	DOUBLE PRECISION	real value defining the reduction factor for the learning rate (under-relaxation term) of the delta-bar-delta algorithm. The value of UNDER_RELAXATION_THETA is between zero and one. If the change in the variable (head) is of opposite sign to that of the previous iteration, the under-relaxation term is reduced by a factor of UNDER_RELAXATION_THETA. The value usually ranges from 0.3 to 0.9; a value of 0.7 works well for most problems. UNDER_RELAXATION_THETA only needs to be specified if UNDER_RELAXATION is DBD.
SLN	IMS	NONLINEAR	UNDER_RELAXATION_KAPPA	DOUBLE PRECISION	real value defining the increment for the learning rate (under-relaxation term) of the delta-bar-delta algorithm. The value of UNDER_RELAXATION_kappa is between zero and one. If the change in the variable (head) is of the same sign to that of the previous iteration, the under-relaxation term is increased by an increment of UNDER_RELAXATION_KAPPA. The value usually ranges from 0.03 to 0.3; a value of 0.1 works well for most problems. UNDER_RELAXATION_KAPPA only needs to be specified if UNDER_RELAXATION is DBD.
SLN	IMS	NONLINEAR	UNDER_RELAXATION_GAMMA	DOUBLE PRECISION	real value defining the history or memory term factor of the delta-bar-delta algorithm. UNDER_RELAXATION_GAMMA is between zero and 1 but cannot be equal to one. When UNDER_RELAXATION_GAMMA is zero, only the most recent history (previous iteration value) is maintained. As UNDER_RELAXATION_GAMMA is increased, past history of iteration changes has greater influence on the memory term. The memory term is maintained as an exponential average of past changes. Retaining some past history can overcome granular behavior in the calculated function surface and therefore helps to overcome cyclic patterns of non-convergence. The value usually ranges from 0.1 to 0.3; a value of 0.2 works well for most problems. UNDER_RELAXATION_GAMMA only needs to be specified if UNDER_RELAXATION is not NONE.
SLN	IMS	NONLINEAR	UNDER_RELAXATION_MOMENTUM	DOUBLE PRECISION	real value defining the fraction of past history changes that is added as a momentum term to the step change for a nonlinear iteration. The value of UNDER_RELAXATION_MOMENTUM is between zero and one. A large momentum term should only be used when small learning rates are expected. Small amounts of the momentum term help convergence. The value usually ranges from 0.0001 to 0.1; a value of 0.001 works well for most problems. UNDER_RELAXATION_MOMENTUM only needs to be specified if UNDER_RELAXATION is DBD.
SLN	IMS	NONLINEAR	BACKTRACKING_NUMBER	INTEGER	integer value defining the maximum number of backtracking iterations allowed for residual reduction computations. If BACKTRACKING_NUMBER = 0 then the backtracking iterations are omitted. The value usually ranges from 2 to 20; a value of 10 works well for most problems.
SLN	IMS	NONLINEAR	BACKTRACKING_TOLERANCE	DOUBLE PRECISION	real value defining the tolerance for residual change that is allowed for residual reduction computations. BACKTRACKING_TOLERANCE should not be less than one to avoid getting stuck in local minima. A large value serves to check for extreme residual increases, while a low value serves to control step size more severely. The value usually ranges from 1.0 to 10$^6$; a value of 10$^4$ works well for most problems but lower values like 1.1 may be required for harder problems. BACKTRACKING_TOLERANCE only needs to be specified if BACKTRACKING_NUMBER is greater than zero.
SLN	IMS	NONLINEAR	BACKTRACKING_REDUCTION_FACTOR	DOUBLE PRECISION	real value defining the reduction in step size used for residual reduction computations. The value of BACKTRACKING_REDUCTION_FACTOR is between zero and one. The value usually ranges from 0.1 to 0.3; a value of 0.2 works well for most problems. BACKTRACKING_REDUCTION_FACTOR only needs to be specified if BACKTRACKING_NUMBER is greater than zero.
SLN	IMS	NONLINEAR	BACKTRACKING_RESIDUAL_LIMIT	DOUBLE PRECISION	real value defining the limit to which the residual is reduced with backtracking. If the residual is smaller than BACKTRACKING_RESIDUAL_LIMIT, then further backtracking is not performed. A value of 100 is suitable for large problems and residual reduction to smaller values may only slow down computations. BACKTRACKING_RESIDUAL_LIMIT only needs to be specified if BACKTRACKING_NUMBER is greater than zero.
SLN	IMS	LINEAR	INNER_MAXIMUM	INTEGER	integer value defining the maximum number of inner (linear) iterations. The number typically depends on the characteristics of the matrix solution scheme being used. For nonlinear problems, INNER_MAXIMUM usually ranges from 60 to 600; a value of 100 will be sufficient for most linear problems.
SLN	IMS	LINEAR	INNER_HCLOSE	DOUBLE PRECISION	real value defining the head change criterion for convergence of the inner (linear) iterations, in units of length. When the maximum absolute value of the head change at all nodes during an iteration is less than or equal to INNER_HCLOSE, the matrix solver assumes convergence. Commonly, INNER_HCLOSE is set an order of magnitude less than the OUTER_HCLOSE value specified for the NONLINEAR block.
SLN	IMS	LINEAR	INNER_RCLOSE	DOUBLE PRECISION	real value that defines the flow residual tolerance for convergence of the IMS linear solver and specific flow residual criteria used. This value represents the maximum allowable residual at any single node. Value is in units of length cubed per time, and must be consistent with \mf length and time units. Usually a value of $1.0 \times 10^{-1}$ is sufficient for the flow-residual criteria when meters and seconds are the defined \mf length and time.
SLN	IMS	LINEAR	RCLOSE_OPTION	STRING	an optional keyword that defines the specific flow residual criterion used. STRICT--an optional keyword that is used to specify that INNER_RCLOSE represents a infinity-Norm (absolute convergence criteria) and that the head and flow convergence criteria must be met on the first inner iteration (this criteria is equivalent to the criteria used by the MODFLOW-2005 PCG package~\citep{hill1990preconditioned}). L2NORM_RCLOSE--an optional keyword that is used to specify that INNER_RCLOSE represents a L-2 Norm closure criteria instead of a infinity-Norm (absolute convergence criteria). When L2NORM_RCLOSE is specified, a reasonable initial INNER_RCLOSE value is 0.1 times the number of active cells when meters and seconds are the defined \mf length and time. RELATIVE_RCLOSE--an optional keyword that is used to specify that INNER_RCLOSE represents a relative L-2 Norm reduction closure criteria instead of a infinity-Norm (absolute convergence criteria). When RELATIVE_RCLOSE is specified, a reasonable initial INNER_RCLOSE value is $1.0 \times 10^{-4}$ and convergence is achieved for a given inner (linear) iteration when $\Delta h \le$ INNER_HCLOSE and the current L-2 Norm is $\le$ the product of the RELATIVE_RCLOSE and the initial L-2 Norm for the current inner (linear) iteration. If RCLOSE_OPTION is not specified, an absolute residual (infinity-norm) criterion is used.
SLN	IMS	LINEAR	LINEAR_ACCELERATION	STRING	a keyword that defines the linear acceleration method used by the default IMS linear solvers. CG - preconditioned conjugate gradient method. BICGSTAB - preconditioned bi-conjugate gradient stabilized method.
SLN	IMS	LINEAR	RELAXATION_FACTOR	DOUBLE PRECISION	optional real value that defines the relaxation factor used by the incomplete LU factorization preconditioners (MILU(0) and MILUT). RELAXATION_FACTOR is unitless and should be greater than or equal to 0.0 and less than or equal to 1.0. RELAXATION_FACTOR values of about 1.0 are commonly used, and experience suggests that convergence can be optimized in some cases with relax values of 0.97. A RELAXATION_FACTOR value of 0.0 will result in either ILU(0) or ILUT preconditioning (depending on the value specified for PRECONDITIONER_LEVELS and/or PRECONDITIONER_DROP_TOLERANCE). By default, RELAXATION_FACTOR is zero.
SLN	IMS	LINEAR	PRECONDITIONER_LEVELS	INTEGER	optional integer value defining the level of fill for ILU decomposition used in the ILUT and MILUT preconditioners. Higher levels of fill provide more robustness but also require more memory. For optimal performance, it is suggested that a large level of fill be applied (7 or 8) with use of a drop tolerance. Specification of a PRECONDITIONER_LEVELS value greater than zero results in use of the ILUT preconditioner. By default, PRECONDITIONER_LEVELS is zero and the zero-fill incomplete LU factorization preconditioners (ILU(0) and MILU(0)) are used.
SLN	IMS	LINEAR	PRECONDITIONER_DROP_TOLERANCE	DOUBLE PRECISION	optional real value that defines the drop tolerance used to drop preconditioner terms based on the magnitude of matrix entries in the ILUT and MILUT preconditioners. A value of $10^{-4}$ works well for most problems. By default, PRECONDITIONER_DROP_TOLERANCE is zero and the zero-fill incomplete LU factorization preconditioners (ILU(0) and MILU(0)) are used.
SLN	IMS	LINEAR	NUMBER_ORTHOGONALIZATIONS	INTEGER	optional integer value defining the interval used to explicitly recalculate the residual of the flow equation using the solver coefficient matrix, the latest head estimates, and the right hand side. For problems that benefit from explicit recalculation of the residual, a number between 4 and 10 is appropriate. By default, NUMBER_ORTHOGONALIZATIONS is zero.
SLN	IMS	LINEAR	SCALING_METHOD	STRING	an optional keyword that defines the matrix scaling approach used. By default, matrix scaling is not applied. NONE - no matrix scaling applied. DIAGONAL - symmetric matrix scaling using the POLCG preconditioner scaling method in Hill (1992). L2NORM - symmetric matrix scaling using the L2 norm.
SLN	IMS	LINEAR	REORDERING_METHOD	STRING	an optional keyword that defines the matrix reordering approach used. By default, matrix reordering is not applied. NONE - original ordering. RCM - reverse Cuthill McKee ordering. MD - minimum degree ordering.
GWF	NAM	OPTIONS	LIST	STRING	is name of the listing file to create for this GWF model. If not specified, then the name of the list file will be the basename of the GWF model name file and the '.lst' extension. For example, if the GWF name file is called my.model.nam'' then the list file will be called my.model.lst''.
GWF	NAM	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of all model stress package information will be written to the listing file immediately after it is read.
GWF	NAM	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of all model package flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	NAM	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that all model package flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	NAM	OPTIONS	NEWTON	KEYWORD	keyword that activates the Newton-Raphson formulation for groundwater flow between connected, convertible groundwater cells and stress packages that support calculation of Newton-Raphson terms for groundwater exchanges. Cells will not dry when this option is used. By default, the Newton-Raphson formulation is not applied.
GWF	NAM	OPTIONS	UNDER_RELAXATION	KEYWORD	keyword that indicates whether the groundwater head in a cell will be under-relaxed when water levels fall below the bottom of the model below any given cell. By default, Newton-Raphson UNDER_RELAXATION is not applied.
GWF	NAM	PACKAGES	FTYPE	STRING	is the file type, which must be one of the following character values shown in table~\ref{table:ftype}. Ftype may be entered in any combination of uppercase and lowercase.
GWF	NAM	PACKAGES	FNAME	STRING	is the name of the file containing the package input. The path to the file should be included if the file is not located in the folder where the program was run.
GWF	NAM	PACKAGES	PNAME	STRING	is the user-defined name for the package. PNAME is restricted to 16 characters. No spaces are allowed in PNAME. PNAME character values are read and stored by the program for stress packages only. These names may be useful for labeling purposes when multiple stress packages of the same type are located within a single GWF Model. If PNAME is specified for a stress package, then PNAME will be used in the flow budget table in the listing file; it will also be used for the text entry in the cell-by-cell budget file. PNAME is case insensitive and is stored in all upper case letters.
GWF	DIS	OPTIONS	LENGTH_UNITS	STRING	is the length units used for this model. Values can be FEET'', METERS'', or CENTIMETERS''. If not specified, the default is UNKNOWN''.
GWF	DIS	OPTIONS	NOGRB	KEYWORD	keyword to deactivate writing of the binary grid file.
GWF	DIS	OPTIONS	XORIGIN	DOUBLE PRECISION	x-position of the lower-left corner of the model grid. A default value of zero is assigned if not specified. The value for XORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DIS	OPTIONS	YORIGIN	DOUBLE PRECISION	y-position of the lower-left corner of the model grid. If not specified, then a default value equal to zero is used. The value for YORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DIS	OPTIONS	ANGROT	DOUBLE PRECISION	counter-clockwise rotation angle (in degrees) of the lower-left corner of the model grid. If not specified, then a default value of 0.0 is assigned. The value for ANGROT does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DIS	DIMENSIONS	NLAY	INTEGER	is the number of layers in the model grid.
GWF	DIS	DIMENSIONS	NROW	INTEGER	is the number of rows in the model grid.
GWF	DIS	DIMENSIONS	NCOL	INTEGER	is the number of columns in the model grid.
GWF	DIS	GRIDDATA	DELR	DOUBLE PRECISION (NCOL)	is the column spacing in the row direction.
GWF	DIS	GRIDDATA	DELC	DOUBLE PRECISION (NROW)	is the row spacing in the column direction.
GWF	DIS	GRIDDATA	TOP	DOUBLE PRECISION (NCOL, NROW)	is the top elevation for each cell in the top model layer.
GWF	DIS	GRIDDATA	BOTM	DOUBLE PRECISION (NCOL, NROW, NLAY)	is the bottom elevation for each cell.
GWF	DIS	GRIDDATA	IDOMAIN	INTEGER (NCOL, NROW, NLAY)	is an optional array that characterizes the existence status of a cell. If the IDOMAIN array is not specified, then all model cells exist within the solution. If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation. Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution. If the IDOMAIN value for a cell is 1, the cell exists in the simulation. If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation. Furthermore, the first existing cell above will be connected to the first existing cell below. This type of cell is referred to as a ``vertical pass through'' cell.
GWF	DISV	OPTIONS	LENGTH_UNITS	STRING	is the length units used for this model. Values can be FEET'', METERS'', or CENTIMETERS''. If not specified, the default is UNKNOWN''.
GWF	DISV	OPTIONS	NOGRB	KEYWORD	keyword to deactivate writing of the binary grid file.
GWF	DISV	OPTIONS	XORIGIN	DOUBLE PRECISION	x-position of the origin used for model grid vertices. This value should be provided in a real-world coordinate system. A default value of zero is assigned if not specified. The value for XORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISV	OPTIONS	YORIGIN	DOUBLE PRECISION	y-position of the origin used for model grid vertices. This value should be provided in a real-world coordinate system. If not specified, then a default value equal to zero is used. The value for YORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISV	OPTIONS	ANGROT	DOUBLE PRECISION	counter-clockwise rotation angle (in degrees) of the model grid coordinate system relative to a real-world coordinate system. If not specified, then a default value of 0.0 is assigned. The value for ANGROT does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISV	DIMENSIONS	NLAY	INTEGER	is the number of layers in the model grid.
GWF	DISV	DIMENSIONS	NCPL	INTEGER	is the number of cells per layer. This is a constant value for the grid and it applies to all layers.
GWF	DISV	DIMENSIONS	NVERT	INTEGER	is the total number of (x, y) vertex pairs used to characterize the horizontal configuration of the model grid.
GWF	DISV	GRIDDATA	TOP	DOUBLE PRECISION (NCPL)	is the top elevation for each cell in the top model layer.
GWF	DISV	GRIDDATA	BOTM	DOUBLE PRECISION (NLAY, NCPL)	is the bottom elevation for each cell.
GWF	DISV	GRIDDATA	IDOMAIN	INTEGER (NLAY, NCPL)	is an optional array that characterizes the existence status of a cell. If the IDOMAIN array is not specified, then all model cells exist within the solution. If the IDOMAIN value for a cell is 0, the cell does not exist in the simulation. Input and output values will be read and written for the cell, but internal to the program, the cell is excluded from the solution. If the IDOMAIN value for a cell is 1, the cell exists in the simulation. If the IDOMAIN value for a cell is -1, the cell does not exist in the simulation. Furthermore, the first existing cell above will be connected to the first existing cell below. This type of cell is referred to as a ``vertical pass through'' cell.
GWF	DISV	VERTICES	IV	INTEGER	is the vertex number. Records in the VERTICES block must be listed in consecutive order from 1 to NVERT.
GWF	DISV	VERTICES	XV	DOUBLE PRECISION	is the x-coordinate for the vertex.
GWF	DISV	VERTICES	YV	DOUBLE PRECISION	is the y-coordinate for the vertex.
GWF	DISV	CELL2D	ICELL2D	INTEGER	is the CELL2D number. Records in the CELL2D block must be listed in consecutive order from the first to the last.
GWF	DISV	CELL2D	XC	DOUBLE PRECISION	is the x-coordinate for the cell center.
GWF	DISV	CELL2D	YC	DOUBLE PRECISION	is the y-coordinate for the cell center.
GWF	DISV	CELL2D	NCVERT	INTEGER	is the number of vertices required to define the cell. There may be a different number of vertices for each cell.
GWF	DISV	CELL2D	ICVERT	INTEGER (NCVERT)	is an array of integer values containing vertex numbers (in the VERTICES block) used to define the cell. Vertices must be listed in clockwise order. Cells that are connected must share vertices.
GWF	DISU	OPTIONS	LENGTH_UNITS	STRING	is the length units used for this model. Values can be FEET'', METERS'', or CENTIMETERS''. If not specified, the default is UNKNOWN''.
GWF	DISU	OPTIONS	NOGRB	KEYWORD	keyword to deactivate writing of the binary grid file.
GWF	DISU	OPTIONS	XORIGIN	DOUBLE PRECISION	x-position of the origin used for model grid vertices. This value should be provided in a real-world coordinate system. A default value of zero is assigned if not specified. The value for XORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISU	OPTIONS	YORIGIN	DOUBLE PRECISION	y-position of the origin used for model grid vertices. This value should be provided in a real-world coordinate system. If not specified, then a default value equal to zero is used. The value for YORIGIN does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISU	OPTIONS	ANGROT	DOUBLE PRECISION	counter-clockwise rotation angle (in degrees) of the model grid coordinate system relative to a real-world coordinate system. If not specified, then a default value of 0.0 is assigned. The value for ANGROT does not affect the model simulation, but it is written to the binary grid file so that postprocessors can locate the grid in space.
GWF	DISU	DIMENSIONS	NODES	INTEGER	is the number of cells in the model grid.
GWF	DISU	DIMENSIONS	NJA	INTEGER	is the sum of the number of connections and NODES. When calculating the total number of connections, the connection between cell n and cell m is considered to be different from the connection between cell m and cell n. Thus, NJA is equal to the total number of connections, including n to m and m to n, and the total number of cells.
GWF	DISU	DIMENSIONS	NVERT	INTEGER	is the total number of (x, y) vertex pairs used to define the plan-view shape of each cell in the model grid. If NVERT is not specified or is specified as zero, then the VERTICES and CELL2D blocks below are not read. NVERT and the accompanying VERTICES and CELL2D blocks should be specified for most simulations. If the XT3D or SAVE_SPECIFIC_DISCHARGE options are specified in the NPF Package, these this information is required.
GWF	DISU	GRIDDATA	TOP	DOUBLE PRECISION (NODES)	is the top elevation for each cell in the model grid.
GWF	DISU	GRIDDATA	BOT	DOUBLE PRECISION (NODES)	is the bottom elevation for each cell.
GWF	DISU	GRIDDATA	AREA	DOUBLE PRECISION (NODES)	is the cell surface area (in plan view).
GWF	DISU	CONNECTIONDATA	IAC	INTEGER (NODES)	is the number of connections (plus 1) for each cell. The sum of all the entries in IAC must be equal to NJA.
GWF	DISU	CONNECTIONDATA	JA	INTEGER (NJA)	is a list of cell number (n) followed by its connecting cell numbers (m) for each of the m cells connected to cell n. The number of values to provide for cell n is IAC(n). This list is sequentially provided for the first to the last cell. The first value in the list must be cell n itself, and the remaining cells must be listed in an increasing order (sorted from lowest number to highest). Note that the cell and its connections are only supplied for the GWF cells and their connections to the other GWF cells. Also note that the JA list input may be divided such that every node and its connectivity list can be on a separate line for ease in readability of the file. To further ease readability of the file, the node number of the cell whose connectivity is subsequently listed, may be expressed as a negative number, the sign of which is subsequently converted to positive by the code.
GWF	DISU	CONNECTIONDATA	IHC	INTEGER (NJA)	is an index array indicating the direction between node n and all of its m connections. If IHC = 0 then cell n and cell m are connected in the vertical direction. Cell n overlies cell m if the cell number for n is less than m; cell m overlies cell n if the cell number for m is less than n. If IHC = 1 then cell n and cell m are connected in the horizontal direction. If IHC = 2 then cell n and cell m are connected in the horizontal direction, and the connection is vertically staggered. A vertically staggered connection is one in which a cell is horizontally connected to more than one cell in a horizontal connection.
GWF	DISU	CONNECTIONDATA	CL12	DOUBLE PRECISION (NJA)	is the array containing connection lengths between the center of cell n and the shared face with each adjacent m cell.
GWF	DISU	CONNECTIONDATA	HWVA	DOUBLE PRECISION (NJA)	is a symmetric array of size NJA. For horizontal connections, entries in HWVA are the horizontal width perpendicular to flow. For vertical connections, entries in HWVA are the vertical area for flow. Thus, values in the HWVA array contain dimensions of both length and area. Entries in the HWVA array have a one-to-one correspondence with the connections specified in the JA array. Likewise, there is a one-to-one correspondence between entries in the HWVA array and entries in the IHC array, which specifies the connection type (horizontal or vertical). Entries in the HWVA array must be symmetric; the program will terminate with an error if the value for HWVA for an n to m connection does not equal the value for HWVA for the corresponding n to m connection.
GWF	DISU	CONNECTIONDATA	ANGLDEGX	DOUBLE PRECISION (NJA)	is the angle (in degrees) between the horizontal x-axis and the outward normal to the face between a cell and its connecting cells. The angle varies between zero and 360.0 degrees, where zero degrees points in the positive x-axis direction, and 90 degrees points in the positive y-axis direction. ANGLDEGX is only needed if horizontal anisotropy is specified in the NPF Package, if the XT3D option is used in the NPF Package, or if the SAVE_SPECIFIC_DISCHARGE option is specifed in the NPF Package. ANGLDEGX does not need to be specified if these conditions are not met. ANGLDEGX is of size NJA; values specified for vertical connections and for the diagonal position are not used. Note that ANGLDEGX is read in degrees, which is different from MODFLOW-USG, which reads a similar variable (ANGLEX) in radians.
GWF	DISU	VERTICES	IV	INTEGER	is the vertex number. Records in the VERTICES block must be listed in consecutive order from 1 to NVERT.
GWF	DISU	VERTICES	XV	DOUBLE PRECISION	is the x-coordinate for the vertex.
GWF	DISU	VERTICES	YV	DOUBLE PRECISION	is the y-coordinate for the vertex.
GWF	DISU	CELL2D	ICELL2D	INTEGER	is the cell2d number. Records in the CELL2D block must be listed in consecutive order from 1 to NODES.
GWF	DISU	CELL2D	XC	DOUBLE PRECISION	is the x-coordinate for the cell center.
GWF	DISU	CELL2D	YC	DOUBLE PRECISION	is the y-coordinate for the cell center.
GWF	DISU	CELL2D	NCVERT	INTEGER	is the number of vertices required to define the cell. There may be a different number of vertices for each cell.
GWF	DISU	CELL2D	ICVERT	INTEGER (NCVERT)	is an array of integer values containing vertex numbers (in the VERTICES block) used to define the cell. Vertices must be listed in clockwise order.
GWF	IC	GRIDDATA	STRT	DOUBLE PRECISION (NODES)	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.
GWF	NPF	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that cell-by-cell flow terms will be written to the file specified with ``BUDGET SAVE FILE'' in Output Control.
GWF	NPF	OPTIONS	ALTERNATIVE_CELL_AVERAGING	STRING	is a text keyword to indicate that an alternative method will be used for calculating the conductance for horizontal cell connections. The text value for ALTERNATIVE_CELL_AVERAGING can be LOGARITHMIC'', AMT-LMK'', or AMT-HMK''. AMT-LMK'' signifies that the conductance will be calculated using arithmetic-mean thickness and logarithmic-mean hydraulic conductivity. ``AMT-HMK'' signifies that the conductance will be calculated using arithmetic-mean thickness and harmonic-mean hydraulic conductivity. If the user does not specify a value for ALTERNATIVE_CELL_AVERAGING, then the harmonic-mean method will be used. This option cannot be used if the XT3D option is invoked.
GWF	NPF	OPTIONS	THICKSTRT	KEYWORD	indicates that cells having a negative ICELLTYPE are confined, and their cell thickness for conductance calculations will be computed as STRT-BOT rather than TOP-BOT.
GWF	NPF	OPTIONS	VARIABLECV	KEYWORD	keyword to indicate that the vertical conductance will be calculated using the saturated thickness and properties of the overlying cell and the thickness and properties of the underlying cell. If the DEWATERED keyword is also specified, then the vertical conductance is calculated using only the saturated thickness and properties of the overlying cell if the head in the underlying cell is below its top. If these keywords are not specified, then the default condition is to calculate the vertical conductance at the start of the simulation using the initial head and the cell properties. The vertical conductance remains constant for the entire simulation.
GWF	NPF	OPTIONS	DEWATERED	KEYWORD	If the DEWATERED keyword is specified, then the vertical conductance is calculated using only the saturated thickness and properties of the overlying cell if the head in the underlying cell is below its top.
GWF	NPF	OPTIONS	PERCHED	KEYWORD	keyword to indicate that when a cell is overlying a dewatered convertible cell, the head difference used in Darcy's Law is equal to the head in the overlying cell minus the bottom elevation of the overlying cell. If not specified, then the default is to use the head difference between the two cells.
GWF	NPF	OPTIONS	REWET	KEYWORD	activates model rewetting. Rewetting is off by default.
GWF	NPF	OPTIONS	WETFCT	DOUBLE PRECISION	is a keyword and factor that is included in the calculation of the head that is initially established at a cell when that cell is converted from dry to wet.
GWF	NPF	OPTIONS	IWETIT	INTEGER	is a keyword and iteration interval for attempting to wet cells. Wetting is attempted every IWETIT iteration. This applies to outer iterations and not inner iterations. If IWETIT is specified as zero or less, then the value is changed to 1.
GWF	NPF	OPTIONS	IHDWET	INTEGER	is a keyword and integer flag that determines which equation is used to define the initial head at cells that become wet. If IHDWET is 0, h = BOT + WETFCT (hm - BOT). If IHDWET is not 0, h = BOT + WETFCT (THRESH).
GWF	NPF	OPTIONS	XT3D	KEYWORD	keyword indicating that the XT3D formulation will be used. If the RHS keyword is also included, then the XT3D additional terms will be added to the right-hand side. If the RHS keyword is excluded, then the XT3D terms will be put into the coefficient matrix. Use of XT3D will substantially increase the computational effort, but will result in improved accuracy for anisotropic conductivity fields and for unstructured grids in which the CVFD requirement is violated. XT3D requires additional information about the shapes of grid cells. If XT3D is active and the DISU Package is used, then the user will need to provide in the DISU Package the angldegx array in the CONNECTIONDATA block and the VERTICES and CELL2D blocks.
GWF	NPF	OPTIONS	RHS	KEYWORD	If the RHS keyword is also included, then the XT3D additional terms will be added to the right-hand side. If the RHS keyword is excluded, then the XT3D terms will be put into the coefficient matrix.
GWF	NPF	OPTIONS	SAVE_SPECIFIC_DISCHARGE	KEYWORD	keyword to indicate that x, y, and z components of specific discharge will be calculated at cell centers and written to the cell-by-cell flow file, which is specified with ``BUDGET SAVE FILE'' in Output Control. If this option is activated, then additional information may be required in the discretization packages and the GWF Exchange package (if GWF models are coupled). Specifically, ANGLDEGX must be specified in the CONNECTIONDATA block of the DISU Package; ANGLDEGX must also be specified for the GWF Exchange as an auxiliary variable.
GWF	NPF	GRIDDATA	ICELLTYPE	INTEGER (NODES)	flag for each cell that specifies how saturated thickness is treated. 0 means saturated thickness is held constant; $>$0 means saturated thickness varies with computed head when head is below the cell top; $<$0 means saturated thickness varies with computed head unless the THICKSTRT option is in effect. When THICKSTRT is in effect, a negative value of icelltype indicates that saturated thickness will be computed as STRT-BOT and held constant.
GWF	NPF	GRIDDATA	K	DOUBLE PRECISION (NODES)	is the hydraulic conductivity. For the common case in which the user would like to specify the horizontal hydraulic conductivity and the vertical hydraulic conductivity, then K should be assigned as the horizontal hydraulic conductivity, K33 should be assigned as the vertical hydraulic conductivity, and texttt{K22} and the three rotation angles should not be specified. When more sophisticated anisotropy is required, then K corresponds to the K11 hydraulic conductivity axis. All included cells (IDOMAIN $&gt;$ 0) must have a K value greater than zero.
GWF	NPF	GRIDDATA	K22	DOUBLE PRECISION (NODES)	is the hydraulic conductivity of the second ellipsoid axis; for an unrotated case this is the hydraulic conductivity in the y direction. If K22 is not included in the GRIDDATA block, then K22 is set equal to K. For a regular MODFLOW grid (DIS Package is used) in which no rotation angles are specified, K22 is the hydraulic conductivity along columns in the y direction. For an unstructured DISU grid, the user must assign principal x and y axes and provide the angle for each cell face relative to the assigned x direction. All included cells (IDOMAIN $&gt;$ 0) must have a K22 value greater than zero.
GWF	NPF	GRIDDATA	K33	DOUBLE PRECISION (NODES)	is the hydraulic conductivity of the third ellipsoid axis; for an unrotated case, this is the vertical hydraulic conductivity. When anisotropy is applied, K33 corresponds to the K33 tensor component. All included cells (IDOMAIN $&gt;$ 0) must have a K33 value greater than zero.
GWF	NPF	GRIDDATA	ANGLE1	DOUBLE PRECISION (NODES)	is a rotation angle of the hydraulic conductivity tensor in degrees. The angle represents the first of three sequential rotations of the hydraulic conductivity ellipsoid. With the K11, K22, and K33 axes of the ellipsoid initially aligned with the x, y, and z coordinate axes, respectively, ANGLE1 rotates the ellipsoid about its K33 axis (within the x - y plane). A positive value represents counter-clockwise rotation when viewed from any point on the positive K33 axis, looking toward the center of the ellipsoid. A value of zero indicates that the K11 axis lies within the x - z plane. If ANGLE1 is not specified, default values of zero are assigned to ANGLE1, ANGLE2, and ANGLE3, in which case the K11, K22, and K33 axes are aligned with the x, y, and z axes, respectively.
GWF	NPF	GRIDDATA	ANGLE2	DOUBLE PRECISION (NODES)	is a rotation angle of the hydraulic conductivity tensor in degrees. The angle represents the second of three sequential rotations of the hydraulic conductivity ellipsoid. Following the rotation by ANGLE1 described above, ANGLE2 rotates the ellipsoid about its K22 axis (out of the x - y plane). An array can be specified for ANGLE2 only if ANGLE1 is also specified. A positive value of ANGLE2 represents clockwise rotation when viewed from any point on the positive K22 axis, looking toward the center of the ellipsoid. A value of zero indicates that the K11 axis lies within the x - y plane. If ANGLE2 is not specified, default values of zero are assigned to ANGLE2 and ANGLE3; connections that are not user-designated as vertical are assumed to be strictly horizontal (that is, to have no z component to their orientation); and connection lengths are based on horizontal distances.
GWF	NPF	GRIDDATA	ANGLE3	DOUBLE PRECISION (NODES)	is a rotation angle of the hydraulic conductivity tensor in degrees. The angle represents the third of three sequential rotations of the hydraulic conductivity ellipsoid. Following the rotations by ANGLE1 and ANGLE2 described above, ANGLE3 rotates the ellipsoid about its K11 axis. An array can be specified for ANGLE3 only if ANGLE1 and ANGLE2 are also specified. An array must be specified for ANGLE3 if ANGLE2 is specified. A positive value of ANGLE3 represents clockwise rotation when viewed from any point on the positive K11 axis, looking toward the center of the ellipsoid. A value of zero indicates that the K22 axis lies within the x - y plane.
GWF	NPF	GRIDDATA	WETDRY	DOUBLE PRECISION (NODES)	is a combination of the wetting threshold and a flag to indicate which neighboring cells can cause a cell to become wet. If WETDRY $&lt;$ 0, only a cell below a dry cell can cause the cell to become wet. If WETDRY $&gt;$ 0, the cell below a dry cell and horizontally adjacent cells can cause a cell to become wet. If WETDRY is 0, the cell cannot be wetted. The absolute value of WETDRY is the wetting threshold. When the sum of BOT and the absolute value of WETDRY at a dry cell is equaled or exceeded by the head at an adjacent cell, the cell is wetted. WETDRY must be specified if REWET'' is specified in the OPTIONS block. If REWET'' is not specified in the options block, then WETDRY can be entered, and memory will be allocated for it, even though it is not used.
GWF	STO	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that cell-by-cell flow terms will be written to the file specified with ``BUDGET SAVE FILE'' in Output Control.
GWF	STO	OPTIONS	STORAGECOEFFICIENT	KEYWORD	keyword to indicate that the SS array is read as storage coefficient rather than specific storage.
GWF	STO	GRIDDATA	ICONVERT	INTEGER (NODES)	is a flag for each cell that specifies whether or not a cell is convertible for the storage calculation. 0 indicates confined storage is used. $>$0 indicates confined storage is used when head is above cell top and a mixed formulation of unconfined and confined storage is used when head is below cell top.
GWF	STO	GRIDDATA	SS	DOUBLE PRECISION (NODES)	is specific storage (or the storage coefficient if STORAGECOEFFICIENT is specified as an option). Specific storage values must be greater than or equal to 0.
GWF	STO	GRIDDATA	SY	DOUBLE PRECISION (NODES)	is specific yield. Specific yield values must be greater than or equal to 0. Specific yield does not have to be specified if there are no convertible cells (ICONVERT=0 in every cell).
GWF	STO	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	STO	PERIOD	STEADY-STATE	KEYWORD	keyword to indicate that stress period IPER is steady-state. Steady-state conditions will apply until the TRANSIENT keyword is specified in a subsequent BEGIN PERIOD block.
GWF	STO	PERIOD	TRANSIENT	KEYWORD	keyword to indicate that stress period IPER is transient. Transient conditions will apply until the STEADY-STATE keyword is specified in a subsequent BEGIN PERIOD block.
GWF	HFB	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of horizontal flow barriers will be written to the listing file immediately after it is read.
GWF	HFB	DIMENSIONS	MAXHFB	INTEGER	integer value specifying the maximum number of horizontal flow barriers that will be entered in this input file. The value of MAXHFB is used to allocate memory for the horizontal flow barriers.
GWF	HFB	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	HFB	PERIOD	CELLID1	INTEGER (NCELLDIM)	identifier for the first cell. For a structured grid that uses the DIS input file, CELLID1 is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLID1 is the layer number and CELL2D number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLID1 is the node numbers for the cell. The barrier is located between cells designated as CELLID1 and CELLID2. For models that use the DIS and DISV grid types, the layer number for CELLID1 and CELLID2 must be the same. For all grid types, cells must be horizontally adjacent or the program will terminate with an error.
GWF	HFB	PERIOD	CELLID2	INTEGER (NCELLDIM)	identifier for the second cell. See CELLID1 for description of how to specify.
GWF	HFB	PERIOD	HYDCHR	DOUBLE PRECISION	is the hydraulic characteristic of the horizontal-flow barrier. The hydraulic characteristic is the barrier hydraulic conductivity divided by the width of the horizontal-flow barrier. If the hydraulic characteristic is negative, then the absolute value of HYDCHR acts as a multiplier to the conductance between the two model cells specified as containing the barrier. For example, if the value for HYDCHR was specified as -1.5, the conductance calculated for the two cells would be multiplied by 1.5.
GWF	CHD	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	CHD	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of CHD head value.
GWF	CHD	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of constant-head cells.
GWF	CHD	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of constant-head information will be written to the listing file immediately after it is read.
GWF	CHD	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of constant-head flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	CHD	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that constant-head flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	CHD	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	CHD	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	CHD	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	CHD	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	CHD	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the constant-head package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the constant-head package.
GWF	CHD	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of constant-head cells that will be specified for use during any stress period.
GWF	CHD	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	CHD	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	CHD	PERIOD	HEAD	DOUBLE PRECISION	is the head at the boundary.
GWF	CHD	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each constant head. The values of auxiliary variables must be present for each constant head. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	CHD	PERIOD	BOUNDNAME	STRING	name of the constant head boundary cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	WEL	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	WEL	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of well flow rate.
GWF	WEL	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of well cells.
GWF	WEL	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of well information will be written to the listing file immediately after it is read.
GWF	WEL	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of well flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	WEL	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that well flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	WEL	OPTIONS	AUTO_FLOW_REDUCE	DOUBLE PRECISION	keyword and real value that defines the fraction of the cell thickness used as an interval for smoothly adjusting negative pumping rates to 0 in cells with head values less than or equal to the bottom of the cell. Negative pumping rates are adjusted to 0 or a smaller negative value when the head in the cell is equal to or less than the calculated interval above the cell bottom. AUTO_FLOW_REDUCE is set to 0.1 if the specified value is less than or equal to zero. By default, negative pumping rates are not reduced during a simulation.
GWF	WEL	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	WEL	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	WEL	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	WEL	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	WEL	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Well package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Well package.
GWF	WEL	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the Well Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	WEL	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of wells cells that will be specified for use during any stress period.
GWF	WEL	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	WEL	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	WEL	PERIOD	Q	DOUBLE PRECISION	is the volumetric well rate. A positive value indicates recharge (injection) and a negative value indicates discharge (extraction). If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	WEL	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each well. The values of auxiliary variables must be present for each well. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	WEL	PERIOD	BOUNDNAME	STRING	name of the well cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	DRN	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	DRN	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of drain conductance.
GWF	DRN	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of drain cells.
GWF	DRN	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of drain information will be written to the listing file immediately after it is read.
GWF	DRN	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of drain flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	DRN	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that drain flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	DRN	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	DRN	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	DRN	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	DRN	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	DRN	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Drain package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Drain package.
GWF	DRN	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the Drain Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	DRN	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of drains cells that will be specified for use during any stress period.
GWF	DRN	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	DRN	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	DRN	PERIOD	ELEV	DOUBLE PRECISION	is the elevation of the drain. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	DRN	PERIOD	COND	DOUBLE PRECISION	is the hydraulic conductance of the interface between the aquifer and the drain. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	DRN	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each drain. The values of auxiliary variables must be present for each drain. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	DRN	PERIOD	BOUNDNAME	STRING	name of the drain cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	RIV	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	RIV	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of riverbed conductance.
GWF	RIV	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of river cells.
GWF	RIV	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of river information will be written to the listing file immediately after it is read.
GWF	RIV	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of river flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	RIV	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that river flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	RIV	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	RIV	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	RIV	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	RIV	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	RIV	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the River package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the River package.
GWF	RIV	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the River Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	RIV	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of rivers cells that will be specified for use during any stress period.
GWF	RIV	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	RIV	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	RIV	PERIOD	STAGE	DOUBLE PRECISION	is the head in the river. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	RIV	PERIOD	COND	DOUBLE PRECISION	is the riverbed hydraulic conductance. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	RIV	PERIOD	RBOT	DOUBLE PRECISION	is the elevation of the bottom of the riverbed. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	RIV	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each river. The values of auxiliary variables must be present for each river. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	RIV	PERIOD	BOUNDNAME	STRING	name of the river cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	GHB	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	GHB	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of general-head boundary conductance.
GWF	GHB	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of general-head boundary cells.
GWF	GHB	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of general-head boundary information will be written to the listing file immediately after it is read.
GWF	GHB	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of general-head boundary flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	GHB	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that general-head boundary flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	GHB	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	GHB	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	GHB	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	GHB	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	GHB	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the General-Head Boundary package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the General-Head Boundary package.
GWF	GHB	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the General-Head Boundary Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	GHB	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of general-head boundary cells that will be specified for use during any stress period.
GWF	GHB	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	GHB	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	GHB	PERIOD	BHEAD	DOUBLE PRECISION	is the boundary head. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	GHB	PERIOD	COND	DOUBLE PRECISION	is the hydraulic conductance of the interface between the aquifer cell and the boundary. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	GHB	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each general-head boundary. The values of auxiliary variables must be present for each general-head boundary. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	GHB	PERIOD	BOUNDNAME	STRING	name of the general-head boundary cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	RCH	OPTIONS	FIXED_CELL	KEYWORD	indicates that recharge will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.
GWF	RCH	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	RCH	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of recharge.
GWF	RCH	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of recharge cells.
GWF	RCH	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of recharge information will be written to the listing file immediately after it is read.
GWF	RCH	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of recharge flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	RCH	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that recharge flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	RCH	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	RCH	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	RCH	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	RCH	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	RCH	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Recharge package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Recharge package.
GWF	RCH	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of recharge cells cells that will be specified for use during any stress period.
GWF	RCH	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	RCH	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	RCH	PERIOD	RECHARGE	DOUBLE PRECISION	is the recharge flux rate ($LT^{-1}$). This rate is multiplied inside the program by the surface area of the cell to calculate the volumetric recharge rate. A time-series name may be specified.
GWF	RCH	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each recharge. The values of auxiliary variables must be present for each recharge. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	RCH	PERIOD	BOUNDNAME	STRING	name of the recharge cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	RCHA	OPTIONS	READASARRAYS	KEYWORD	indicates that array-based input will be used for the Recharge Package. This keyword must be specified to use array-based input.
GWF	RCHA	OPTIONS	FIXED_CELL	KEYWORD	indicates that recharge will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.
GWF	RCHA	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	RCHA	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of recharge.
GWF	RCHA	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of recharge information will be written to the listing file immediately after it is read.
GWF	RCHA	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of recharge flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	RCHA	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that recharge flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	RCHA	OPTIONS	TAS6	KEYWORD	keyword to specify that record corresponds to a time-array-series file.
GWF	RCHA	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	RCHA	OPTIONS	TAS6_FILENAME	STRING	defines a time-array-series file defining a time-array series that can be used to assign time-varying values. See the Time-Variable Input section for instructions on using the time-array series capability.
GWF	RCHA	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	RCHA	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Recharge package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Recharge package.
GWF	RCHA	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	RCHA	PERIOD	IRCH	INTEGER (NCOL*NROW; NCPL)	IRCH is the layer number that defines the layer in each vertical column where recharge is applied. If IRCH is omitted, recharge by default is applied to cells in layer 1. IRCH can only be used if READASARRAYS is specified in the OPTIONS block. If IRCH is specified, it must be specified as the first variable in the PERIOD block or MODFLOW will terminate with an error.
GWF	RCHA	PERIOD	RECHARGE	DOUBLE PRECISION (NCOL*NROW; NCPL)	is the recharge flux rate ($LT^{-1}$). This rate is multiplied inside the program by the surface area of the cell to calculate the volumetric recharge rate. The recharge array may be defined by a time-array series (see the "Using Time-Array Series in a Package" section).
GWF	RCHA	PERIOD	AUX	DOUBLE PRECISION (NCOL*NROW; NCPL)	is an array of values for auxiliary variable aux(iaux), where iaux is a value from 1 to naux, and aux(iaux) must be listed as part of the auxiliary variables. A separate array can be specified for each auxiliary variable. If an array is not specified for an auxiliary variable, then a value of zero is assigned. If the value specified here for the auxiliary variable is the same as auxmultname, then the recharge array will be multiplied by this array.
GWF	EVT	OPTIONS	FIXED_CELL	KEYWORD	indicates that evapotranspiration will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.
GWF	EVT	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	EVT	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of evapotranspiration rate.
GWF	EVT	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of evapotranspiration cells.
GWF	EVT	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of evapotranspiration information will be written to the listing file immediately after it is read.
GWF	EVT	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of evapotranspiration flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	EVT	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that evapotranspiration flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	EVT	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	EVT	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	EVT	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	EVT	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	EVT	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Evapotranspiration package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Evapotranspiration package.
GWF	EVT	OPTIONS	SURF_RATE_SPECIFIED	KEYWORD	indicates that the evapotranspiration rate at the ET surface will be specified as PETM0 in list input.
GWF	EVT	DIMENSIONS	MAXBOUND	INTEGER	integer value specifying the maximum number of evapotranspiration cells cells that will be specified for use during any stress period.
GWF	EVT	DIMENSIONS	NSEG	INTEGER	number of ET segments. Default is one. When NSEG is greater than 1, PXDP and PETM arrays must be specified NSEG - 1 times each, in order from the uppermost segment down. PXDP defines the extinction-depth proportion at the bottom of a segment. PETM defines the proportion of the maximum ET flux rate at the bottom of a segment.
GWF	EVT	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	EVT	PERIOD	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	EVT	PERIOD	SURFACE	DOUBLE PRECISION	is the elevation of the ET surface ($L$). A time-series name may be specified.
GWF	EVT	PERIOD	RATE	DOUBLE PRECISION	is the maximum ET flux rate ($LT^{-1}$). A time-series name may be specified.
GWF	EVT	PERIOD	DEPTH	DOUBLE PRECISION	is the ET extinction depth ($L$). A time-series name may be specified.
GWF	EVT	PERIOD	PXDP	DOUBLE PRECISION (NSEG-1)	is the proportion of the ET extinction depth at the bottom of a segment (dimensionless). A time-series name may be specified.
GWF	EVT	PERIOD	PETM	DOUBLE PRECISION (NSEG-1)	is the proportion of the maximum ET flux rate at the bottom of a segment (dimensionless). A time-series name may be specified.
GWF	EVT	PERIOD	PETM0	DOUBLE PRECISION	is the proportion of the maximum ET flux rate that will apply when head is at or above the ET surface (dimensionless). PETM0 is read only when the SURF_RATE_SPECIFIED option is used. A time-series name may be specified.
GWF	EVT	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each evapotranspiration. The values of auxiliary variables must be present for each evapotranspiration. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	EVT	PERIOD	BOUNDNAME	STRING	name of the evapotranspiration cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	EVTA	OPTIONS	READASARRAYS	KEYWORD	indicates that array-based input will be used for the Evapotranspiration Package. This keyword must be specified to use array-based input.
GWF	EVTA	OPTIONS	FIXED_CELL	KEYWORD	indicates that evapotranspiration will not be reassigned to a cell underlying the cell specified in the list if the specified cell is inactive.
GWF	EVTA	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	EVTA	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of evapotranspiration rate.
GWF	EVTA	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of evapotranspiration information will be written to the listing file immediately after it is read.
GWF	EVTA	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of evapotranspiration flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	EVTA	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that evapotranspiration flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	EVTA	OPTIONS	TAS6	KEYWORD	keyword to specify that record corresponds to a time-array-series file.
GWF	EVTA	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	EVTA	OPTIONS	TAS6_FILENAME	STRING	defines a time-array-series file defining a time-array series that can be used to assign time-varying values. See the Time-Variable Input section for instructions on using the time-array series capability.
GWF	EVTA	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	EVTA	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the Evapotranspiration package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the Evapotranspiration package.
GWF	EVTA	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	EVTA	PERIOD	IEVT	INTEGER (NCOL*NROW; NCPL)	IEVT is the layer number that defines the layer in each vertical column where evapotranspiration is applied. If IEVT is omitted, evapotranspiration by default is applied to cells in layer 1. If IEVT is specified, it must be specified as the first variable in the PERIOD block or MODFLOW will terminate with an error.
GWF	EVTA	PERIOD	SURFACE	DOUBLE PRECISION (NCOL*NROW; NCPL)	is the elevation of the ET surface ($L$).
GWF	EVTA	PERIOD	RATE	DOUBLE PRECISION (NCOL*NROW; NCPL)	is the maximum ET flux rate ($LT^{-1}$).
GWF	EVTA	PERIOD	DEPTH	DOUBLE PRECISION (NCOL*NROW; NCPL)	is the ET extinction depth ($L$).
GWF	EVTA	PERIOD	AUX(IAUX)	DOUBLE PRECISION (NCOL*NROW; NCPL)	is an array of values for auxiliary variable AUX(IAUX), where iaux is a value from 1 to NAUX, and AUX(IAUX) must be listed as part of the auxiliary variables. A separate array can be specified for each auxiliary variable. If an array is not specified for an auxiliary variable, then a value of zero is assigned. If the value specified here for the auxiliary variable is the same as auxmultname, then the evapotranspiration rate will be multiplied by this array.
GWF	MAW	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	MAW	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of multi-aquifer well cells.
GWF	MAW	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of multi-aquifer well information will be written to the listing file immediately after it is read.
GWF	MAW	OPTIONS	PRINT_HEAD	KEYWORD	keyword to indicate that the list of multi-aquifer well heads will be printed to the listing file for every stress period in which ``HEAD PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_HEAD is specified, then heads are printed for the last time step of each stress period.
GWF	MAW	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of multi-aquifer well flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	MAW	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that multi-aquifer well flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	MAW	OPTIONS	HEAD	KEYWORD	keyword to specify that record corresponds to head.
GWF	MAW	OPTIONS	HEADFILE	STRING	name of the binary output file to write stage information.
GWF	MAW	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	MAW	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	MAW	OPTIONS	BUDGETFILE	STRING	name of the binary output file to write budget information.
GWF	MAW	OPTIONS	NO_WELL_STORAGE	KEYWORD	keyword that deactivates inclusion of well storage contributions to the multi-aquifer well package continuity equation.
GWF	MAW	OPTIONS	FLOWING_WELLS	KEYWORD	keyword that activates the flowing wells option for the multi-aquifer well package.
GWF	MAW	OPTIONS	SHUTDOWN_THETA	DOUBLE PRECISION	value that defines the weight applied to discharge rate for wells that limit the water level in a discharging well (defined using the HEAD_LIMIT keyword in the stress period data). SHUTDOWN_THETA is used to control discharge rate oscillations when the flow rate from the aquifer is less than the specified flow rate from the aquifer to the well. Values range between 0.0 and 1.0, and larger values increase the weight (decrease under-relaxation) applied to the well discharge rate. The HEAD_LIMIT option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the RATE_SCALING option instead of the HEAD_LIMIT option is recommended. By default, SHUTDOWN_THETA is 0.7.
GWF	MAW	OPTIONS	SHUTDOWN_KAPPA	DOUBLE PRECISION	value that defines the weight applied to discharge rate for wells that limit the water level in a discharging well (defined using the HEAD_LIMIT keyword in the stress period data). SHUTDOWN_KAPPA is used to control discharge rate oscillations when the flow rate from the aquifer is less than the specified flow rate from the aquifer to the well. Values range between 0.0 and 1.0, and larger values increase the weight applied to the well discharge rate. The HEAD_LIMIT option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the RATE_SCALING option instead of the HEAD_LIMIT option is recommended. By default, SHUTDOWN_KAPPA is 0.0001.
GWF	MAW	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	MAW	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	MAW	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	MAW	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	MAW	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the MAW package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the MAW package.
GWF	MAW	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the MAW Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	MAW	DIMENSIONS	NMAWWELLS	INTEGER	integer value specifying the number of multi-aquifer wells that will be simulated for all stress periods.
GWF	MAW	PACKAGEDATA	WELLNO	INTEGER	integer value that defines the well number associated with the specified PACKAGEDATA data on the line. WELLNO must be greater than zero and less than or equal to NMAWWELLS. Multi-aquifer well information must be specified for every multi-aquifer well or the program will terminate with an error. The program will also terminate with an error if information for a multi-aquifer well is specified more than once.
GWF	MAW	PACKAGEDATA	RADIUS	DOUBLE PRECISION	radius for the multi-aquifer well.
GWF	MAW	PACKAGEDATA	BOTTOM	DOUBLE PRECISION	bottom elevation of the multi-aquifer well. The well bottom is reset to the cell bottom in the lowermost GWF cell connection in cases where the specified well bottom is above the bottom of this GWF cell.
GWF	MAW	PACKAGEDATA	STRT	DOUBLE PRECISION	starting head for the multi-aquifer well.
GWF	MAW	PACKAGEDATA	CONDEQN	STRING	character string that defines the conductance equation that is used to calculate the saturated conductance for the multi-aquifer well. Possible multi-aquifer well CONDEQN strings include: SPECIFIED--character keyword to indicate the multi-aquifer well saturated conductance will be specified. THIEM--character keyword to indicate the multi-aquifer well saturated conductance will be calculated using the Thiem equation, which considers the cell top and bottom, aquifer hydraulic conductivity, and effective cell and well radius. SKIN--character keyword to indicate that the multi-aquifer well saturated conductance will be calculated using the cell top and bottom, aquifer and screen hydraulic conductivity, and well and skin radius. CUMULATIVE--character keyword to indicate that the multi-aquifer well saturated conductance will be calculated using a combination of the Thiem and SKIN equations. MEAN--character keyword to indicate the multi-aquifer well saturated conductance will be calculated using the aquifer and screen top and bottom, aquifer and screen hydraulic conductivity, and well and skin radius.
GWF	MAW	PACKAGEDATA	NGWFNODES	INTEGER	integer value that defines the number of GWF nodes connected to this (WELLNO) multi-aquifer well. NGWFNODES must be greater than zero.
GWF	MAW	PACKAGEDATA	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each multi-aquifer well. The values of auxiliary variables must be present for each multi-aquifer well. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	MAW	PACKAGEDATA	BOUNDNAME	STRING	name of the multi-aquifer well cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	MAW	CONNECTIONDATA	WELLNO	INTEGER	integer value that defines the well number associated with the specified CONNECTIONDATA data on the line. WELLNO must be greater than zero and less than or equal to NMAWWELLS. Multi-aquifer well connection information must be specified for every multi-aquifer well connection to the GWF model (NGWFNODES) or the program will terminate with an error. The program will also terminate with an error if connection information for a multi-aquifer well connection to the GWF model is specified more than once.
GWF	MAW	CONNECTIONDATA	ICON	INTEGER	integer value that defines the GWF connection number for this multi-aquifer well connection entry. ICONN must be greater than zero and less than or equal to NGWFNODES for multi-aquifer well WELLNO.
GWF	MAW	CONNECTIONDATA	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell. One or more screened intervals can be connected to the same CELLID if CONDEQN for a well is MEAN. The program will terminate with an error if MAW wells using SPECIFIED, THIEM, SKIN, or CUMULATIVE conductance equations have more than one connection to the same CELLID.
GWF	MAW	CONNECTIONDATA	SCRN_TOP	DOUBLE PRECISION	value that defines the top elevation of the screen for the multi-aquifer well connection. If the specified SCRN_TOP is greater than the top of the GWF cell it is set equal to the top of the cell. SCRN_TOP can be any value if CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE and SCRN_TOP is set to the top of the cell.
GWF	MAW	CONNECTIONDATA	SCRN_BOT	DOUBLE PRECISION	value that defines the bottom elevation of the screen for the multi-aquifer well connection. If the specified SCRN_BOT is less than the bottom of the GWF cell it is set equal to the bottom of the cell. SCRN_BOT can be any value if CONDEQN is SPECIFIED, THIEM, SKIN, or COMPOSITE and SCRN_BOT is set to the bottom of the cell.
GWF	MAW	CONNECTIONDATA	HK_SKIN	DOUBLE PRECISION	value that defines the skin (filter pack) hydraulic conductivity (if CONDEQN for the multi-aquifer well is SKIN, CUMULATIVE, or MEAN) or conductance (if CONDEQN for the multi-aquifer well is SPECIFIED) for each GWF node connected to the multi-aquifer well (NGWFNODES). HK_SKIN can be any value if CONDEQN is THIEM.
GWF	MAW	CONNECTIONDATA	RADIUS_SKIN	DOUBLE PRECISION	real value that defines the skin radius (filter pack radius) for the multi-aquifer well. RADIUS_SKIN can be any value if CONDEQN is SPECIFIED or THIEM. Otherwise, RADIUS_SKIN must be greater than RADIUS for the multi-aquifer well.
GWF	MAW	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	MAW	PERIOD	WELLNO	INTEGER	integer value that defines the well number associated with the specified PERIOD data on the line. WELLNO must be greater than zero and less than or equal to NMAWWELLS.
GWF	MAW	PERIOD	MAWSETTING	KEYSTRING	line of information that is parsed into a keyword and values. Keyword values that can be used to start the MAWSETTING string include: STATUS, FLOWING_WELL, RATE, WELL_HEAD, HEAD_LIMIT, SHUT_OFF, RATE_SCALING, and AUXILIARY.
GWF	MAW	PERIOD	STATUS	STRING	keyword option to define well status. STATUS can be ACTIVE, INACTIVE, or CONSTANT. By default, STATUS is ACTIVE.
GWF	MAW	PERIOD	FLOWING_WELL	KEYWORD	keyword to indicate the well is a flowing well. The FLOWING_WELL option can be used to simulate flowing wells when the simulated well head exceeds the specified drainage elevation.
GWF	MAW	PERIOD	FWELEV	DOUBLE PRECISION	elevation used to determine whether or not the well is flowing.
GWF	MAW	PERIOD	FWCOND	DOUBLE PRECISION	conductance used to calculate the discharge of a free flowing well. Flow occurs when the head in the well is above the well top elevation (FWELEV).
GWF	MAW	PERIOD	FWRLEN	DOUBLE PRECISION	length used to reduce the conductance of the flowing well. When the head in the well drops below the well top plus the reduction length, then the conductance is reduced. This reduction length can be used to improve the stability of simulations with flowing wells so that there is not an abrupt change in flowing well rates.
GWF	MAW	PERIOD	RATE	DOUBLE PRECISION	is the volumetric pumping rate for the multi-aquifer well. A positive value indicates recharge and a negative value indicates discharge (pumping). RATE only applies to active (IBOUND $&gt;$ 0) multi-aquifer wells. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. By default, the RATE for each multi-aquifer well is zero.
GWF	MAW	PERIOD	WELL_HEAD	DOUBLE PRECISION	is the head in the multi-aquifer well. WELL_HEAD is only applied to constant head (STATUS is CONSTANT) and inactive (STATUS is INACTIVE) multi-aquifer wells. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	MAW	PERIOD	HEAD_LIMIT	STRING	is the limiting water level (head) in the well, which is the minimum of the well RATE or the well inflow rate from the aquifer. HEAD_LIMIT can be applied to extraction wells (RATE $&lt;$ 0) or injection wells (RATE $&gt;$ 0). HEAD_LIMIT can be deactivated by specifying the text string OFF'. The HEAD\_LIMIT option is based on the HEAD\_LIMIT functionality available in the MNW2~\citep{konikow2009} package for MODFLOW-2005. The HEAD\_LIMIT option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the RATE\_SCALING option instead of the HEAD\_LIMIT option is recommended. By default, HEAD\_LIMIT is OFF'.
GWF	MAW	PERIOD	SHUT_OFF	KEYWORD	keyword for activating well shut off capability. Subsequent values define the minimum and maximum pumping rate that a well must exceed to shutoff or reactivate a well, respectively, during a stress period. SHUT_OFF is only applied to injection wells (RATE$<0$) and if HEAD_LIMIT is specified (not set to `OFF'). If HEAD_LIMIT is specified, SHUT_OFF can be deactivated by specifying a minimum value equal to zero. The SHUT_OFF option is based on the SHUT_OFF functionality available in the MNW2~\citep{konikow2009} package for MODFLOW-2005. The SHUT_OFF option has been included to facilitate backward compatibility with previous versions of MODFLOW but use of the RATE_SCALING option instead of the SHUT_OFF option is recommended. By default, SHUT_OFF is not used.
GWF	MAW	PERIOD	MINRATE	DOUBLE PRECISION	is the minimum rate that a well must exceed to shutoff a well during a stress period. The well will shut down during a time step if the flow rate to the well from the aquifer is less than MINRATE. If a well is shut down during a time step, reactivation of the well cannot occur until the next time step to reduce oscillations. MINRATE must be less than maxrate.
GWF	MAW	PERIOD	MAXRATE	DOUBLE PRECISION	is the maximum rate that a well must exceed to reactivate a well during a stress period. The well will reactivate during a timestep if the well was shutdown during the previous time step and the flow rate to the well from the aquifer exceeds maxrate. Reactivation of the well cannot occur until the next time step if a well is shutdown to reduce oscillations. maxrate must be greater than MINRATE.
GWF	MAW	PERIOD	RATE_SCALING	KEYWORD	activate rate scaling. If RATE_SCALING is specified, both PUMP_ELEVATION and SCALING_LENGTH must be specified. RATE_SCALING cannot be used with HEAD_LIMIT. RATE_SCALING can be used for extraction or injection wells. For extraction wells, the extraction rate will start to decrease once the head in the well lowers to a level equal to the pump elevation plus the scaling length. If the head in the well drops below the pump elevation, then the extraction rate is calculated to be zero. For an injection well, the injection rate will begin to decrease once the head in the well rises above the specified pump elevation. If the head in the well rises above the pump elevation plus the scaling length, then the injection rate will be set to zero.
GWF	MAW	PERIOD	PUMP_ELEVATION	DOUBLE PRECISION	is the elevation of the multi-aquifer well pump (PUMP_ELEVATION). PUMP_ELEVATION should not be less than the bottom elevation (BOTTOM) of the multi-aquifer well.
GWF	MAW	PERIOD	SCALING_LENGTH	DOUBLE PRECISION	height above the pump elevation (SCALING_LENGTH). If the simulated well head is below this elevation (pump elevation plus the scaling length), then the pumping rate is reduced.
GWF	MAW	PERIOD	AUXILIARY	KEYWORD	keyword for specifying auxiliary variable.
GWF	MAW	PERIOD	AUXNAME	STRING	name for the auxiliary variable to be assigned AUXVAL. AUXNAME must match one of the auxiliary variable names defined in the OPTIONS block. If AUXNAME does not match one of the auxiliary variable names defined in the OPTIONS block the data are ignored.
GWF	MAW	PERIOD	AUXVAL	DOUBLE PRECISION	value for the auxiliary variable. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	SFR	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of stream reach cells.
GWF	SFR	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of stream reach information will be written to the listing file immediately after it is read.
GWF	SFR	OPTIONS	PRINT_STAGE	KEYWORD	keyword to indicate that the list of stream reach stages will be printed to the listing file for every stress period in which ``HEAD PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_STAGE is specified, then stages are printed for the last time step of each stress period.
GWF	SFR	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of stream reach flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	SFR	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that stream reach flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	SFR	OPTIONS	STAGE	KEYWORD	keyword to specify that record corresponds to stage.
GWF	SFR	OPTIONS	STAGEFILE	STRING	name of the binary output file to write stage information.
GWF	SFR	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	SFR	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	SFR	OPTIONS	BUDGETFILE	STRING	name of the binary output file to write budget information.
GWF	SFR	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	SFR	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	SFR	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	SFR	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	SFR	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the SFR package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the SFR package.
GWF	SFR	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the SFR Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	SFR	OPTIONS	MAXIMUM_ITERATIONS	INTEGER	value that defines the maximum number of Streamflow Routing Newton-Raphson iterations allowed for a reach. By default, MAXSFRIT is equal to 100.
GWF	SFR	OPTIONS	MAXIMUM_DEPTH_CHANGE	DOUBLE PRECISION	value that defines the depth closure tolerance. By default, DMAXCHG is equal to $1 \times 10^{-5}$.
GWF	SFR	OPTIONS	UNIT_CONVERSION	DOUBLE PRECISION	value (or conversion factor) that is used in calculating stream depth for stream reach. A constant of 1.486 is used for flow units of cubic feet per second, and a constant of 1.0 is used for units of cubic meters per second. The constant must be multiplied by 86,400 when using time units of days in the simulation.
GWF	SFR	DIMENSIONS	NREACHES	INTEGER	integer value specifying the number of stream reaches. There must be NREACHES entries in the PACKAGEDATA block.
GWF	SFR	PACKAGEDATA	RNO	INTEGER	integer value that defines the reach number associated with the specified PACKAGEDATA data on the line. RNO must be greater than zero and less than or equal to NREACHES. Reach information must be specified for every reach or the program will terminate with an error. The program will also terminate with an error if information for a reach is specified more than once.
GWF	SFR	PACKAGEDATA	CELLID	INTEGER (NCELLDIM)	The keyword NONE' must be specified for reaches that are not connected to an underlying GWF cell. The keyword NONE' is used for reaches that are in cells that have IDOMAIN values less than one or are in areas not covered by the GWF model grid. Reach-aquifer flow is not calculated if the keyword `NONE' is specified.
GWF	SFR	PACKAGEDATA	RLEN	DOUBLE PRECISION	real value that defines the reach length. RLEN must be greater than zero.
GWF	SFR	PACKAGEDATA	RWID	DOUBLE PRECISION	real value that defines the reach width. RWID must be greater than zero.
GWF	SFR	PACKAGEDATA	RGRD	DOUBLE PRECISION	real value that defines the stream gradient (slope) across the reach. RGRD must be greater than zero.
GWF	SFR	PACKAGEDATA	RTP	DOUBLE PRECISION	real value that defines the top elevation of the reach streambed.
GWF	SFR	PACKAGEDATA	RBTH	DOUBLE PRECISION	real value that defines the thickness of the reach streambed. RBTH can be any value if CELLID is `NONE'. Otherwise, RBTH must be greater than zero.
GWF	SFR	PACKAGEDATA	RHK	DOUBLE PRECISION	real value that defines the hydraulic conductivity of the reach streambed. RHK can be any positive value if CELLID is `NONE'. Otherwise, RHK must be greater than zero.
GWF	SFR	PACKAGEDATA	MAN	STRING	real or character value that defines the Manning's roughness coefficient for the reach. MAN must be greater than zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	PACKAGEDATA	NCON	INTEGER	integer value that defines the number of reaches connected to the reach.
GWF	SFR	PACKAGEDATA	USTRF	DOUBLE PRECISION	real value that defines the fraction of upstream flow from each upstream reach that is applied as upstream inflow to the reach. The sum of all USTRF values for all reaches connected to the same upstream reach must be equal to one and USTRF must be greater than or equal to zero.
GWF	SFR	PACKAGEDATA	NDV	INTEGER	integer value that defines the number of downstream diversions for the reach.
GWF	SFR	PACKAGEDATA	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each stream reach. The values of auxiliary variables must be present for each stream reach. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	PACKAGEDATA	BOUNDNAME	STRING	name of the stream reach cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	SFR	CONNECTIONDATA	RNO	INTEGER	integer value that defines the reach number associated with the specified CONNECTIONDATA data on the line. RNO must be greater than zero and less than or equal to NREACHES. Reach connection information must be specified for every reach or the program will terminate with an error. The program will also terminate with an error if connection information for a reach is specified more than once.
GWF	SFR	CONNECTIONDATA	IC	INTEGER (NCON(RNO))	integer value that defines the reach number of the reach connected to the current reach and whether it is connected to the upstream or downstream end of the reach. Negative IC numbers indicate connected reaches are connected to the downstream end of the current reach. Positive IC numbers indicate connected reaches are connected to the upstream end of the current reach. The absolute value of IC must be greater than zero and less than or equal to NREACHES.
GWF	SFR	DIVERSIONS	RNO	INTEGER	integer value that defines the reach number associated with the specified DIVERSIONS data on the line. RNO must be greater than zero and less than or equal to NREACHES. Reach diversion information must be specified for every reach with a NDV value greater than 0 or the program will terminate with an error. The program will also terminate with an error if diversion information for a given reach diversion is specified more than once.
GWF	SFR	DIVERSIONS	IDV	INTEGER	integer value that defines the downstream diversion number for the diversion for reach RNO. IDV must be greater than zero and less than or equal to NDV for reach RNO.
GWF	SFR	DIVERSIONS	ICONR	INTEGER	integer value that defines the downstream reach that will receive the diverted water. IDV must be greater than zero and less than or equal to NREACHES. Furthermore, reach ICONR must be a downstream connection for reach RNO.
GWF	SFR	DIVERSIONS	CPRIOR	STRING	character string value that defines the the prioritization system for the diversion, such as when insufficient water is available to meet all diversion stipulations, and is used in conjunction with the value of FLOW value specified in the STRESS_PERIOD_DATA section. Available diversion options include: (1) CPRIOR = FRACTION', then the amount of the diversion is computed as a fraction of the streamflow leaving reach RNO ($Q_{DS}$); in this case, 0.0 $\le$ DIVFLOW $\le$ 1.0. (2) CPRIOR = EXCESS', a diversion is made only if $Q_{DS}$ for reach RNO exceeds the value of DIVFLOW. If this occurs, then the quantity of water diverted is the excess flow ($Q_{DS} -$ DIVFLOW) and $Q_{DS}$ from reach RNO is set equal to DIVFLOW. This represents a flood-control type of diversion, as described by Danskin and Hanson (2002). (3) CPRIOR = THRESHOLD', then if $Q_{DS}$ in reach RNO is less than the specified diversion flow (DIVFLOW), no water is diverted from reach RNO. If $Q_{DS}$ in reach RNO is greater than or equal to (DIVFLOW), (DIVFLOW) is diverted and $Q_{DS}$ is set to the remainder ($Q_{DS} -$ DIVFLOW)). This approach assumes that once flow in the stream is sufficiently low, diversions from the stream cease, and is the priority' algorithm that originally was programmed into the STR1 Package (Prudic, 1989). (4) CPRIOR = `UPTO' -- if $Q_{DS}$ in reach RNO is greater than or equal to the specified diversion flow (DIVFLOW), $Q_{DS}$ is reduced by DIVFLOW. If $Q_{DS}$ in reach RNO is less than (DIVFLOW), DIVFLOW is set to $Q_{DS}$ and there will be no flow available for reaches connected to downstream end of reach RNO.
GWF	SFR	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	SFR	PERIOD	RNO	INTEGER	integer value that defines the reach number associated with the specified PERIOD data on the line. RNO must be greater than zero and less than or equal to NREACHES.
GWF	SFR	PERIOD	SFRSETTING	KEYSTRING	line of information that is parsed into a keyword and values. Keyword values that can be used to start the SFRSETTING string include: STATUS, MANNING, STAGE, INFLOW, RAINFALL, EVAPORATION, RUNOFF, DIVERSION, UPSTREAM_FRACTION, and AUXILIARY.
GWF	SFR	PERIOD	STATUS	STRING	keyword option to define stream reach status. STATUS can be ACTIVE, INACTIVE, or SIMPLE. The SIMPLE STATUS option simulates streamflow using a user-specified stage for a reach or a stage set to the top of the reach (depth = 0). In cases where the simulated leakage calculated using the specified stage exceeds the sum of inflows to the reach, the stage is set to the top of the reach and leakage is set equal to the sum of inflows. Upstream fractions should be changed using the UPSTREAM_FRACTION SFRSETTING if the status for one or more reaches is changed to ACTIVE or INACTIVE. For example, if one of two downstream connections for a reach is inactivated, the upstream fraction for the active and inactive downstream reach should be changed to 1.0 and 0.0, respectively, to ensure that the active reach receives all of the downstream outflow from the upstream reach. By default, STATUS is ACTIVE.
GWF	SFR	PERIOD	MANNING	STRING	real or character value that defines the Manning's roughness coefficient for the reach. MANNING must be greater than zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	PERIOD	STAGE	STRING	real or character value that defines the stage for the reach. The specified STAGE is only applied if the reach uses the simple routing option. If STAGE is not specified for reaches that use the simple routing option, the specified stage is set to the top of the reach. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	PERIOD	INFLOW	STRING	real or character value that defines the volumetric inflow rate for the streamflow routing reach. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. By default, inflow rates are zero for each reach.
GWF	SFR	PERIOD	RAINFALL	STRING	real or character value that defines the volumetric rate per unit area of water added by precipitation directly on the streamflow routing reach. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. By default, rainfall rates are zero for each reach.
GWF	SFR	PERIOD	EVAPORATION	STRING	real or character value that defines the volumetric rate per unit area of water subtracted by evaporation from the streamflow routing reach. A positive evaporation rate should be provided. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. If the volumetric evaporation rate for a reach exceeds the sources of water to the reach (upstream and specified inflows, rainfall, and runoff but excluding groundwater leakage into the reach) the volumetric evaporation rate is limited to the sources of water to the reach. By default, evaporation rates are zero for each reach.
GWF	SFR	PERIOD	RUNOFF	STRING	real or character value that defines the volumetric rate of diffuse overland runoff that enters the streamflow routing reach. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. If the volumetric runoff rate for a reach is negative and exceeds inflows to the reach (upstream and specified inflows, and rainfall but excluding groundwater leakage into the reach) the volumetric runoff rate is limited to inflows to the reach and the volumetric evaporation rate for the reach is set to zero. By default, runoff rates are zero for each reach.
GWF	SFR	PERIOD	DIVERSION	KEYWORD	keyword to indicate diversion record.
GWF	SFR	PERIOD	IDV	INTEGER	diversion number.
GWF	SFR	PERIOD	DIVRATE	DOUBLE PRECISION	real or character value that defines the volumetric diversion (DIVFLOW) rate for the streamflow routing reach. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	SFR	PERIOD	UPSTREAM_FRACTION	DOUBLE PRECISION	real value that defines the fraction of upstream flow (USTRF) from each upstream reach that is applied as upstream inflow to the reach. The sum of all USTRF values for all reaches connected to the same upstream reach must be equal to one.
GWF	SFR	PERIOD	AUXILIARY	KEYWORD	keyword for specifying auxiliary variable.
GWF	SFR	PERIOD	AUXNAME	STRING	name for the auxiliary variable to be assigned AUXVAL. AUXNAME must match one of the auxiliary variable names defined in the OPTIONS block. If AUXNAME does not match one of the auxiliary variable names defined in the OPTIONS block the data are ignored.
GWF	SFR	PERIOD	AUXVAL	DOUBLE PRECISION	value for the auxiliary variable. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	LAK	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of lake cells.
GWF	LAK	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of lake information will be written to the listing file immediately after it is read.
GWF	LAK	OPTIONS	PRINT_STAGE	KEYWORD	keyword to indicate that the list of lake stages will be printed to the listing file for every stress period in which ``HEAD PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_STAGE is specified, then stages are printed for the last time step of each stress period.
GWF	LAK	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of lake flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	LAK	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that lake flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	LAK	OPTIONS	STAGE	KEYWORD	keyword to specify that record corresponds to stage.
GWF	LAK	OPTIONS	STAGEFILE	STRING	name of the binary output file to write stage information.
GWF	LAK	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	LAK	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	LAK	OPTIONS	BUDGETFILE	STRING	name of the binary output file to write budget information.
GWF	LAK	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	LAK	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	LAK	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	LAK	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	LAK	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the LAK package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the LAK package.
GWF	LAK	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the LAK Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	LAK	OPTIONS	SURFDEP	DOUBLE PRECISION	real value that defines the surface depression depth for VERTICAL lake-GWF connections. If specified, SURFDEP must be greater than or equal to zero. If SURFDEP is not specified, a default value of zero is used for all vertical lake-GWF connections.
GWF	LAK	OPTIONS	TIME_CONVERSION	DOUBLE PRECISION	value that is used in converting outlet flow terms that use Manning's equation or gravitational acceleration to consistent time units. TIME_CONVERSION should be set to 1.0, 60.0, 3,600.0, 86,400.0, and 31,557,600.0 when using time units (TIME_UNITS) of seconds, minutes, hours, days, or years in the simulation, respectively. CONVTIME does not need to be specified if no lake outlets are specified or TIME_UNITS are seconds.
GWF	LAK	OPTIONS	LENGTH_CONVERSION	DOUBLE PRECISION	real value that is used in converting outlet flow terms that use Manning's equation or gravitational acceleration to consistent length units. LENGTH_CONVERSION should be set to 3.28081, 1.0, and 100.0 when using length units (LENGTH_UNITS) of feet, meters, or centimeters in the simulation, respectively. LENGTH_CONVERSION does not need to be specified if no lake outlets are specified or LENGTH_UNITS are meters.
GWF	LAK	DIMENSIONS	NLAKES	INTEGER	value specifying the number of lakes that will be simulated for all stress periods.
GWF	LAK	DIMENSIONS	NOUTLETS	INTEGER	value specifying the number of outlets that will be simulated for all stress periods. If NOUTLETS is not specified, a default value of zero is used.
GWF	LAK	DIMENSIONS	NTABLES	INTEGER	value specifying the number of lakes tables that will be used to define the lake stage, volume relation, and surface area. If NTABLES is not specified, a default value of zero is used.
GWF	LAK	PACKAGEDATA	LAKENO	INTEGER	integer value that defines the lake number associated with the specified PACKAGEDATA data on the line. LAKENO must be greater than zero and less than or equal to NLAKES. Lake information must be specified for every lake or the program will terminate with an error. The program will also terminate with an error if information for a lake is specified more than once.
GWF	LAK	PACKAGEDATA	STRT	DOUBLE PRECISION	real value that defines the starting stage for the lake.
GWF	LAK	PACKAGEDATA	NLAKECONN	INTEGER	integer value that defines the number of GWF cells connected to this (LAKENO) lake. There can only be one vertical lake connection to each GWF cell. NLAKECONN must be greater than zero.
GWF	LAK	PACKAGEDATA	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each lake. The values of auxiliary variables must be present for each lake. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PACKAGEDATA	BOUNDNAME	STRING	name of the lake cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	LAK	CONNECTIONDATA	LAKENO	INTEGER	integer value that defines the lake number associated with the specified CONNECTIONDATA data on the line. LAKENO must be greater than zero and less than or equal to NLAKES. Lake connection information must be specified for every lake connection to the GWF model (NLAKECONN) or the program will terminate with an error. The program will also terminate with an error if connection information for a lake connection to the GWF model is specified more than once.
GWF	LAK	CONNECTIONDATA	ICONN	INTEGER	integer value that defines the GWF connection number for this lake connection entry. ICONN must be greater than zero and less than or equal to NLAKECONN for lake LAKENO.
GWF	LAK	CONNECTIONDATA	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	LAK	CONNECTIONDATA	CLAKTYPE	STRING	character string that defines the lake-GWF connection type for the lake connection. Possible lake-GWF connection type strings include: VERTICAL--character keyword to indicate the lake-GWF connection is vertical and connection conductance calculations use the hydraulic conductivity corresponding to the $K_{33}$ tensor component defined for CELLID in the NPF package. HORIZONTAL--character keyword to indicate the lake-GWF connection is horizontal and connection conductance calculations use the hydraulic conductivity corresponding to the $K_{11}$ tensor component defined for CELLID in the NPF package. EMBEDDEDH--character keyword to indicate the lake-GWF connection is embedded in a single cell and connection conductance calculations use the hydraulic conductivity corresponding to the $K_{11}$ tensor component defined for CELLID in the NPF package. EMBEDDEDV--character keyword to indicate the lake-GWF connection is embedded in a single cell and connection conductance calculations use the hydraulic conductivity corresponding to the $K_{33}$ tensor component defined for CELLID in the NPF package. Embedded lakes can only be connected to a single cell (NLAKECONN = 1) and there must be a lake table associated with each embedded lake.
GWF	LAK	CONNECTIONDATA	BEDLEAK	DOUBLE PRECISION	character string or real value that defines the bed leakance for the lake-GWF connection. BEDLEAK must be greater than or equal to zero or specified to be NONE. If BEDLEAK is specified to be NONE, the lake-GWF connection conductance is solely a function of aquifer properties in the connected GWF cell and lakebed sediments are assumed to be absent.
GWF	LAK	CONNECTIONDATA	BELEV	DOUBLE PRECISION	real value that defines the bottom elevation for a HORIZONTAL lake-GWF connection. Any value can be specified if CLAKTYPE is VERTICAL, EMBEDDEDH, or EMBEDDEDV. If CLAKTYPE is HORIZONTAL and BELEV is not equal to TELEV, BELEV must be greater than or equal to the bottom of the GWF cell CELLID. If BELEV is equal to TELEV, BELEV is reset to the bottom of the GWF cell CELLID.
GWF	LAK	CONNECTIONDATA	TELEV	DOUBLE PRECISION	real value that defines the top elevation for a HORIZONTAL lake-GWF connection. Any value can be specified if CLAKTYPE is VERTICAL, EMBEDDEDH, or EMBEDDEDV. If CLAKTYPE is HORIZONTAL and TELEV is not equal to BELEV, TELEV must be less than or equal to the top of the GWF cell CELLID. If TELEV is equal to BELEV, TELEV is reset to the top of the GWF cell CELLID.
GWF	LAK	CONNECTIONDATA	CONNLEN	DOUBLE PRECISION	real value that defines the distance between the connected GWF CELLID node and the lake for a HORIZONTAL, EMBEDDEDH, or EMBEDDEDV lake-GWF connection. CONLENN must be greater than zero for a HORIZONTAL, EMBEDDEDH, or EMBEDDEDV lake-GWF connection. Any value can be specified if CLAKTYPE is VERTICAL.
GWF	LAK	CONNECTIONDATA	CONNWIDTH	DOUBLE PRECISION	real value that defines the connection face width for a HORIZONTAL lake-GWF connection. CONNWIDTH must be greater than zero for a HORIZONTAL lake-GWF connection. Any value can be specified if CLAKTYPE is VERTICAL, EMBEDDEDH, or EMBEDDEDV.
GWF	LAK	TABLES	LAKENO	INTEGER	integer value that defines the lake number associated with the specified TABLES data on the line. LAKENO must be greater than zero and less than or equal to NLAKES. The program will terminate with an error if table information for a lake is specified more than once or the number of specified tables is less than NTABLES.
GWF	LAK	TABLES	TAB6	KEYWORD	keyword to specify that record corresponds to a table file.
GWF	LAK	TABLES	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	LAK	TABLES	TAB6_FILENAME	STRING	character string that defines the path and filename for the file containing lake table data for the lake connection. The CTABNAME file includes the number of entries in the file and the relation between stage, surface area, and volume for each entry in the file. Lake table files for EMBEDDEDH and EMBEDDEDV lake-GWF connections also include lake-GWF exchange area data for each entry in the file. Input instructions for the CTABNAME file is included at the LAK package lake table file input instructions section.
GWF	LAK	OUTLETS	OUTLETNO	INTEGER	integer value that defines the outlet number associated with the specified OUTLETS data on the line. OUTLETNO must be greater than zero and less than or equal to NOUTLETS. Outlet information must be specified for every outlet or the program will terminate with an error. The program will also terminate with an error if information for a outlet is specified more than once.
GWF	LAK	OUTLETS	LAKEIN	INTEGER	integer value that defines the lake number that outlet is connected to. LAKEIN must be greater than zero and less than or equal to NLAKES.
GWF	LAK	OUTLETS	LAKEOUT	INTEGER	integer value that defines the lake number that outlet discharge from lake outlet OUTLETNO is routed to. LAKEOUT must be greater than or equal to zero and less than or equal to NLAKES. If LAKEOUT is zero, outlet discharge from lake outlet OUTLETNO is discharged to an external boundary.
GWF	LAK	OUTLETS	COUTTYPE	STRING	character string that defines the outlet type for the outlet OUTLETNO. Possible COUTTYPE strings include: SPECIFIED--character keyword to indicate the outlet is defined as a specified flow. MANNING--character keyword to indicate the outlet is defined using Manning's equation. WEIR--character keyword to indicate the outlet is defined using a sharp weir equation.
GWF	LAK	OUTLETS	INVERT	DOUBLE PRECISION	real value that defines the invert elevation for the lake outlet. Any value can be specified if COUTTYPE is SPECIFIED. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	OUTLETS	WIDTH	DOUBLE PRECISION	real value that defines the width of the lake outlet. Any value can be specified if COUTTYPE is SPECIFIED. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	OUTLETS	ROUGH	DOUBLE PRECISION	real value that defines the roughness coefficient for the lake outlet. Any value can be specified if COUTTYPE is not MANNING. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	OUTLETS	SLOPE	DOUBLE PRECISION	real value that defines the bed slope for the lake outlet. Any value can be specified if COUTTYPE is not MANNING. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	LAK	PERIOD	LAKENO	INTEGER	integer value that defines the lake number associated with the specified PERIOD data on the line. LAKENO must be greater than zero and less than or equal to NLAKES.
GWF	LAK	PERIOD	LAKSETTING	KEYSTRING	line of information that is parsed into a keyword and values. Keyword values that can be used to start the LAKSETTING string include: STATUS, STAGE, RAINFALL, EVAPORATION, RUNOFFON, WITHDRAWAL, and AUXILIARY.
GWF	LAK	PERIOD	STATUS	STRING	keyword option to define lake status. STATUS can be ACTIVE, INACTIVE, or CONSTANT. By default, STATUS is ACTIVE.
GWF	LAK	PERIOD	STAGE	STRING	real or character value that defines the stage for the lake. The specified STAGE is only applied if the lake is a constant stage lake. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	RAINFALL	STRING	real or character value that defines the rainfall rate $(LT^{-1})$ for the lake. Value must be greater than or equal to zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	EVAPORATION	STRING	real or character value that defines the maximum evaporation rate $(LT^{-1})$ for the lake. Value must be greater than or equal to zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	RUNOFF	STRING	real or character value that defines the runoff rate $(L^3 T^{-1})$ for the lake. Value must be greater than or equal to zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	WITHDRAWAL	STRING	real or character value that defines the maximum withdrawal rate $(L^3 T^{-1})$ for the lake. Value must be greater than or equal to zero. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	AUXILIARY	KEYWORD	keyword for specifying auxiliary variable.
GWF	LAK	PERIOD	AUXNAME	STRING	name for the auxiliary variable to be assigned AUXVAL. AUXNAME must match one of the auxiliary variable names defined in the OPTIONS block. If AUXNAME does not match one of the auxiliary variable names defined in the OPTIONS block the data are ignored.
GWF	LAK	PERIOD	AUXVAL	DOUBLE PRECISION	value for the auxiliary variable. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	OUTLETNO	INTEGER	integer value that defines the outlet number associated with the specified PERIOD data on the line. OUTLETNO must be greater than zero and less than or equal to NOUTLETS.
GWF	LAK	PERIOD	OUTLETSETTING	KEYSTRING	line of information that is parsed into a keyword and values. Keyword values that can be used to start the OUTLETSETTING string include: RATE, INVERT, WIDTH, SLOPE, and ROUGH.
GWF	LAK	PERIOD	RATE	STRING	real or character value that defines the extraction rate for the lake outflow. A positive value indicates inflow and a negative value indicates outflow from the lake. RATE only applies to active (IBOUND $&gt;$ 0) lakes. A specified RATE is only applied if COUTTYPE for the OUTLETNO is SPECIFIED. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value. By default, the RATE for each SPECIFIED lake outlet is zero.
GWF	LAK	PERIOD	INVERT	STRING	real or character value that defines the invert elevation for the lake outlet. A specified INVERT value is only used for active lakes if COUTTYPE for lake outlet OUTLETNO is not SPECIFIED. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	ROUGH	STRING	real value that defines the roughness coefficient for the lake outlet. Any value can be specified if COUTTYPE is not MANNING. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	WIDTH	STRING	real or character value that defines the width of the lake outlet. A specified WIDTH value is only used for active lakes if COUTTYPE for lake outlet OUTLETNO is not SPECIFIED. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	LAK	PERIOD	SLOPE	STRING	real or character value that defines the bed slope for the lake outlet. A specified SLOPE value is only used for active lakes if COUTTYPE for lake outlet OUTLETNO is MANNING. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	OPTIONS	AUXILIARY	STRING (NAUX)	defines an array of one or more auxiliary variable names. There is no limit on the number of auxiliary variables that can be provided on this line; however, lists of information provided in subsequent blocks must have a column of data for each auxiliary variable name defined here. The number of auxiliary variables detected on this line determines the value for naux. Comments cannot be provided anywhere on this line as they will be interpreted as auxiliary variable names. Auxiliary variables may not be used by the package, but they will be available for use by other parts of the program. The program will terminate with an error if auxiliary variables are specified on more than one line in the options block.
GWF	UZF	OPTIONS	AUXMULTNAME	STRING	name of auxiliary variable to be used as multiplier of GWF cell area used by UZF cell.
GWF	UZF	OPTIONS	BOUNDNAMES	KEYWORD	keyword to indicate that boundary names may be provided with the list of UZF cells.
GWF	UZF	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of UZF information will be written to the listing file immediately after it is read.
GWF	UZF	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of UZF flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	UZF	OPTIONS	SAVE_FLOWS	KEYWORD	keyword to indicate that UZF flow terms will be written to the file specified with ``BUDGET FILEOUT'' in Output Control.
GWF	UZF	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	UZF	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	UZF	OPTIONS	BUDGETFILE	STRING	name of the binary output file to write budget information.
GWF	UZF	OPTIONS	TS6	KEYWORD	keyword to specify that record corresponds to a time-series file.
GWF	UZF	OPTIONS	FILEIN	KEYWORD	keyword to specify that an input filename is expected next.
GWF	UZF	OPTIONS	TS6_FILENAME	STRING	defines a time-series file defining time series that can be used to assign time-varying values. See the ``Time-Variable Input'' section for instructions on using the time-series capability.
GWF	UZF	OPTIONS	OBS6	KEYWORD	keyword to specify that record corresponds to an observations file.
GWF	UZF	OPTIONS	OBS6_FILENAME	STRING	name of input file to define observations for the UZF package. See the ``Observation utility'' section for instructions for preparing observation input files. Table \ref{table:obstype} lists observation type(s) supported by the UZF package.
GWF	UZF	OPTIONS	MOVER	KEYWORD	keyword to indicate that this instance of the UZF Package can be used with the Water Mover (MVR) Package. When the MOVER option is specified, additional memory is allocated within the package to store the available, provided, and received water.
GWF	UZF	OPTIONS	SIMULATE_ET	KEYWORD	keyword specifying that ET in the unsaturated (UZF) and saturated zones (GWF) will be simulated. ET can be simulated in the UZF cell and not the GWF cell by omitting keywords LINEAR_GWET and SQUARE_GWET.
GWF	UZF	OPTIONS	LINEAR_GWET	KEYWORD	keyword specifying that groundwater ET will be simulated using the original ET formulation of MODFLOW-2005.
GWF	UZF	OPTIONS	SQUARE_GWET	KEYWORD	keyword specifying that groundwater ET will be simulated by assuming a constant ET rate for groundwater levels between land surface (TOP) and land surface minus the ET extinction depth (TOP-EXTDP). Groundwater ET is smoothly reduced from the PET rate to zero over a nominal interval at TOP-EXTDP.
GWF	UZF	OPTIONS	SIMULATE_GWSEEP	KEYWORD	keyword specifying that groundwater discharge (GWSEEP) to land surface will be simulated. Groundwater discharge is nonzero when groundwater head is greater than land surface.
GWF	UZF	OPTIONS	UNSAT_ETWC	KEYWORD	keyword specifying that ET in the unsaturated zone will be simulated as a function of the specified PET rate while the water content (THETA) is greater than the ET extinction water content (EXTWC).
GWF	UZF	OPTIONS	UNSAT_ETAE	KEYWORD	keyword specifying that ET in the unsaturated zone will be simulated simulated using a capillary pressure based formulation. Capillary pressure is calculated using the Brooks-Corey retention function.
GWF	UZF	DIMENSIONS	NUZFCELLS	INTEGER	is the number of UZF cells. More than one UZF cell can be assigned to a GWF cell; however, only one GWF cell can be assigned to a single UZF cell. If more than one UZF cell is assigned to a GWF cell, then an auxiliary variable should be used to reduce the surface area of the UZF cell with the AUXMULTNAME option.
GWF	UZF	DIMENSIONS	NTRAILWAVES	INTEGER	is the number of trailing waves. A recommended value of 7 can be used for NTRAILWAVES. This value can be increased to lower mass balance error in the unsaturated zone.
GWF	UZF	DIMENSIONS	NWAVESETS	INTEGER	is the number of wave sets. A recommended value of 40 can be used for NWAVESETS. This value can be increased if more waves are required to resolve variations in water content within the unsaturated zone.
GWF	UZF	PACKAGEDATA	IUZNO	INTEGER	integer value that defines the UZF cell number associated with the specified PACKAGEDATA data on the line. IUZNO must be greater than zero and less than or equal to NUZFCELLS. UZF information must be specified for every UZF cell or the program will terminate with an error. The program will also terminate with an error if information for a UZF cell is specified more than once.
GWF	UZF	PACKAGEDATA	CELLID	INTEGER (NCELLDIM)	is the cell identifier, and depends on the type of grid that is used for the simulation. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column. For a grid that uses the DISV input file, CELLID is the layer and CELL2D number. If the model uses the unstructured discretization (DISU) input file, CELLID is the node number for the cell.
GWF	UZF	PACKAGEDATA	LANDFLAG	INTEGER	integer value set to one for land surface cells indicating that boundary conditions can be applied and data can be specified in the PERIOD block. A value of 0 specifies a non-land surface cell.
GWF	UZF	PACKAGEDATA	IVERTCON	INTEGER	integer value set to specify underlying UZF cell that receives water flowing to bottom of cell. If unsaturated zone flow reaches the water table before the cell bottom, then water is added to the GWF cell instead of flowing to the underlying UZF cell. A value of 0 indicates the UZF cell is not connected to an underlying UZF cell.
GWF	UZF	PACKAGEDATA	SURFDEP	DOUBLE PRECISION	is the surface depression depth of the UZF cell.
GWF	UZF	PACKAGEDATA	VKS	DOUBLE PRECISION	is the vertical saturated hydraulic conductivity of the UZF cell.
GWF	UZF	PACKAGEDATA	THTR	DOUBLE PRECISION	is the residual (irreducible) water content of the UZF cell.
GWF	UZF	PACKAGEDATA	THTS	DOUBLE PRECISION	is the saturated water content of the UZF cell.
GWF	UZF	PACKAGEDATA	THTI	DOUBLE PRECISION	is the initial water content of the UZF cell.
GWF	UZF	PACKAGEDATA	EPS	DOUBLE PRECISION	is the epsilon exponent of the UZF cell.
GWF	UZF	PACKAGEDATA	BOUNDNAME	STRING	name of the UZF cell cell. BOUNDNAME is an ASCII character variable that can contain as many as 40 characters. If BOUNDNAME contains spaces in it, then the entire name must be enclosed within single quotes.
GWF	UZF	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	UZF	PERIOD	IUZNO	INTEGER	integer value that defines the UZF cell number associated with the specified PERIOD data on the line.
GWF	UZF	PERIOD	FINF	STRING	real or character value that defines the applied infiltration rate of the UZF cell ($LT^{-1}$). If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	PET	STRING	real or character value that defines the potential evapotranspiration rate of the UZF cell and specified GWF cell. Evapotranspiration is first removed from the unsaturated zone and any remaining potential evapotranspiration is applied to the saturated zone. If IVERTCON is greater than zero then residual potential evapotranspiration not satisfied in the UZF cell is applied to the underlying UZF and GWF cells. PET is always specified, but is only used if SIMULATE_ET is specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	EXTDP	STRING	real or character value that defines the evapotranspiration extinction depth of the UZF cell. If IVERTCON is greater than zero and EXTDP extends below the GWF cell bottom then remaining potential evapotranspiration is applied to the underlying UZF and GWF cells. EXTDP is always specified, but is only used if SIMULATE_ET is specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	EXTWC	STRING	real or character value that defines the evapotranspiration extinction water content of the UZF cell. EXTWC is always specified, but is only used if SIMULATE_ET and UNSAT_ETWC are specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	HA	STRING	real or character value that defines the air entry potential (head) of the UZF cell. HA is always specified, but is only used if SIMULATE_ET and UNSAT_ETAE are specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	HROOT	STRING	real or character value that defines the root potential (head) of the UZF cell. HROOT is always specified, but is only used if SIMULATE_ET and UNSAT_ETAE are specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	ROOTACT	STRING	real or character value that defines the root activity function of the UZF cell. ROOTACT is the length of roots in a given volume of soil divided by that volume. Values range from 0 to about 3 $cm^{-2}$, depending on the plant community and its stage of development. ROOTACT is always specified, but is only used if SIMULATE_ET and UNSAT_ETAE are specified in the OPTIONS block. If the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	UZF	PERIOD	AUX	DOUBLE PRECISION (NAUX)	represents the values of the auxiliary variables for each UZF. The values of auxiliary variables must be present for each UZF. The values must be specified in the order of the auxiliary variables specified in the OPTIONS block. If the package supports time series and the Options block includes a TIMESERIESFILE entry (see the ``Time-Variable Input'' section), values can be obtained from a time series by entering the time-series name in place of a numeric value.
GWF	MVR	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of MVR information will be written to the listing file immediately after it is read.
GWF	MVR	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of MVR flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	MVR	OPTIONS	MODELNAMES	KEYWORD	keyword to indicate that all package names will be preceded by the model name for the package. Model names are required when the Mover Package is used with a GWF-GWF Exchange. The MODELNAME keyword should not be used for a Mover Package that is for a single GWF Model.
GWF	MVR	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	MVR	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	MVR	OPTIONS	BUDGETFILE	STRING	name of the output file to write budget information.
GWF	MVR	DIMENSIONS	MAXMVR	INTEGER	integer value specifying the maximum number of water mover entries that will specified for any stress period.
GWF	MVR	DIMENSIONS	MAXPACKAGES	INTEGER	integer value specifying the number of unique packages that are included in this water mover input file.
GWF	MVR	PACKAGES	MNAME	STRING	name of model containing the package. Model names are assigned by the user in the simulation name file.
GWF	MVR	PACKAGES	PNAME	STRING	is the name of a package that may be included in a subsequent stress period block. The package name is assigned in the name file for the GWF Model. Package names are optionally provided in the name file. If they are not provided by the user, then packages are assigned a default value, which is the package acronym followed by a hyphen and the package number. For example, the first Drain Package is named DRN-1. The second Drain Package is named DRN-2, and so forth.
GWF	MVR	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	MVR	PERIOD	MNAME1	STRING	name of model containing the package, PNAME1.
GWF	MVR	PERIOD	PNAME1	STRING	is the package name for the provider. The package PNAME1 must be designated to provide water through the MVR Package by specifying the keyword ``MOVER'' in its OPTIONS block.
GWF	MVR	PERIOD	ID1	INTEGER	is the identifier for the provider. For the standard boundary packages, the provider identifier is the number of the boundary as it is listed in the package input file. (Note that the order of these boundaries may change by stress period, which must be accounted for in the Mover Package.) So the first well has an identifier of one. The second is two, and so forth. For the advanced packages, the identifier is the reach number (SFR Package), well number (MAW Package), or UZF cell number. For the Lake Package, ID1 is the lake outlet number. Thus, outflows from a single lake can be routed to different streams, for example.
GWF	MVR	PERIOD	MNAME2	STRING	name of model containing the package, PNAME2.
GWF	MVR	PERIOD	PNAME2	STRING	is the package name for the receiver. The package PNAME2 must be designated to receive water from the MVR Package by specifying the keyword ``MOVER'' in its OPTIONS block.
GWF	MVR	PERIOD	ID2	INTEGER	is the identifier for the receiver. The receiver identifier is the reach number (SFR Package), Lake number (LAK Package), well number (MAW Package), or UZF cell number.
GWF	MVR	PERIOD	MVRTYPE	STRING	is the character string signifying the method for determining how much water will be moved. Supported values are FACTOR'' EXCESS'' THRESHOLD'' and UPTO''. These four options determine how the receiver flow rate, $Q_R$, is calculated. These options are based the options available in the SFR2 Package for diverting stream flow.
GWF	MVR	PERIOD	VALUE	DOUBLE PRECISION	is the value to be used in the equation for calculating the amount of water to move. For the ``FACTOR'' option, VALUE is the $\alpha$ factor. For the remaining options, VALUE is the specified flow rate, $Q_S$.
GWF	GNC	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of GNC information will be written to the listing file immediately after it is read.
GWF	GNC	OPTIONS	PRINT_FLOWS	KEYWORD	keyword to indicate that the list of GNC flow rates will be printed to the listing file for every stress period time step in which BUDGET PRINT'' is specified in Output Control. If there is no Output Control option and PRINT_FLOWS'' is specified, then flow rates are printed for the last time step of each stress period.
GWF	GNC	OPTIONS	EXPLICIT	KEYWORD	keyword to indicate that the ghost node correction is applied in an explicit manner on the right-hand side of the matrix. The explicit approach will likely require additional outer iterations. If the keyword is not specified, then the correction will be applied in an implicit manner on the left-hand side. The implicit approach will likely converge better, but may require additional memory. If the EXPLICIT keyword is not specified, then the BICGSTAB linear acceleration option should be specified within the LINEAR block of the Sparse Matrix Solver.
GWF	GNC	DIMENSIONS	NUMGNC	INTEGER	is the number of GNC entries.
GWF	GNC	DIMENSIONS	NUMALPHAJ	INTEGER	is the number of contributing factors.
GWF	GNC	GNCDATA	CELLIDN	INTEGER	is the cellid of the cell, $n$, in which the ghost node is located. For a structured grid that uses the DIS input file, CELLIDN is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLIDN is the layer number and CELL2D number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLIDN is the node number for the cell.
GWF	GNC	GNCDATA	CELLIDM	INTEGER	is the cellid of the connecting cell, $m$, to which flow occurs from the ghost node. For a structured grid that uses the DIS input file, CELLIDM is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLIDM is the layer number and CELL2D number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLIDM is the node number for the cell.
GWF	GNC	GNCDATA	CELLIDSJ	INTEGER (NUMALPHAJ)	is the array of CELLIDS for the contributing j cells, which contribute to the interpolated head value at the ghost node. This item contains one CELLID for each of the contributing cells of the ghost node. Note that if the number of actual contributing cells needed by the user is less than NUMALPHAJ for any ghost node, then a dummy CELLID of zero(s) should be inserted with an associated contributing factor of zero. For a structured grid that uses the DIS input file, CELLID is the layer, row, and column numbers of the cell. For a grid that uses the DISV input file, CELLID is the layer number and cell2d number for the two cells. If the model uses the unstructured discretization (DISU) input file, then CELLID is the node number for the cell.
GWF	GNC	GNCDATA	ALPHASJ	DOUBLE PRECISION (NUMALPHAJ)	is the contributing factors for each contributing node in CELLIDSJ. Note that if the number of actual contributing cells is less than NUMALPHAJ for any ghost node, then dummy CELLIDS should be inserted with an associated contributing factor of zero. The sum of ALPHASJ should be less than one. This is because one minus the sum of ALPHASJ is equal to the alpha term (alpha n in equation 4-61 of the GWF Model report) that is multiplied by the head in cell n.
GWF	OC	OPTIONS	BUDGET	KEYWORD	keyword to specify that record corresponds to the budget.
GWF	OC	OPTIONS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
GWF	OC	OPTIONS	BUDGETFILE	STRING	name of the output file to write budget information.
GWF	OC	OPTIONS	HEAD	KEYWORD	keyword to specify that record corresponds to head.
GWF	OC	OPTIONS	HEADFILE	STRING	name of the output file to write head information.
GWF	OC	OPTIONS	PRINT_FORMAT	KEYWORD	keyword to specify format for printing to the listing file.
GWF	OC	OPTIONS	COLUMNS	INTEGER	number of columns for writing data.
GWF	OC	OPTIONS	WIDTH	INTEGER	width for writing each number.
GWF	OC	OPTIONS	DIGITS	INTEGER	number of digits to use for writing a number.
GWF	OC	OPTIONS	FORMAT	STRING	write format can be EXPONENTIAL, FIXED, GENERAL, or SCIENTIFIC.
GWF	OC	PERIOD	IPER	INTEGER	integer value specifying the starting stress period number for which the data specified in the PERIOD block apply. IPER must be less than or equal to NPER in the TDIS Package and greater than zero. The IPER value assigned to a stress period block must be greater than the IPER value assigned for the previous PERIOD block. The information specified in the PERIOD block will continue to apply for all subsequent stress periods, unless the program encounters another PERIOD block.
GWF	OC	PERIOD	SAVE	KEYWORD	keyword to indicate that information will be saved this stress period.
GWF	OC	PERIOD	PRINT	KEYWORD	keyword to indicate that information will be printed this stress period.
GWF	OC	PERIOD	RTYPE	STRING	type of information to save or print. Can be BUDGET or HEAD.
GWF	OC	PERIOD	OCSETTING	KEYSTRING	specifies the steps for which the data will be saved.
GWF	OC	PERIOD	ALL	KEYWORD	keyword to indicate save for all time steps in period.
GWF	OC	PERIOD	FIRST	KEYWORD	keyword to indicate save for first step in period. This keyword may be used in conjunction with other keywords to print or save results for multiple time steps.
GWF	OC	PERIOD	LAST	KEYWORD	keyword to indicate save for last step in period. This keyword may be used in conjunction with other keywords to print or save results for multiple time steps.
GWF	OC	PERIOD	FREQUENCY	INTEGER	save at the specified time step frequency. This keyword may be used in conjunction with other keywords to print or save results for multiple time steps.
GWF	OC	PERIOD	STEPS	INTEGER (<NSTP)	save for each step specified in STEPS. This keyword may be used in conjunction with other keywords to print or save results for multiple time steps.
UTL	LAK	DIMENSIONS	NROW	INTEGER	integer value specifying the number of rows in the lake table. There must be NROW rows of data in the TABLE block.
UTL	LAK	DIMENSIONS	NCOL	INTEGER	integer value specifying the number of columns in the lake table. There must be NCOL columns of data in the TABLE block. For lakes with HORIZONTAL and/or VERTICAL CTYPE connections, NCOL must be equal to 3. For lakes with EMBEDDEDH or EMBEDDEDV CTYPE connections, NCOL must be equal to 4.
UTL	LAK	TABLE	STAGE	DOUBLE PRECISION	real value that defines the stage corresponding to the remaining data on the line.
UTL	LAK	TABLE	VOLUME	DOUBLE PRECISION	real value that defines the lake volume corresponding to the stage specified on the line.
UTL	LAK	TABLE	SAREA	DOUBLE PRECISION	real value that defines the lake surface area corresponding to the stage specified on the line.
UTL	LAK	TABLE	BAREA	DOUBLE PRECISION	real value that defines the lake-GWF exchange area corresponding to the stage specified on the line. BAREA is only specified if the CLAKTYPE for the lake is EMBEDDEDH or EMBEDDEDV.
UTL	OBS	OPTIONS	DIGITS	INTEGER	Keyword and an integer digits specifier used for conversion of simulated values to text on output. The default is 5 digits. When simulated values are written to a file specified as file type DATA in the Name File, the digits specifier controls the number of significant digits with which simulated values are written to the output file. The digits specifier has no effect on the number of significant digits with which the simulation time is written for continuous observations.
UTL	OBS	OPTIONS	PRINT_INPUT	KEYWORD	keyword to indicate that the list of observation information will be written to the listing file immediately after it is read.
UTL	OBS	CONTINUOUS	FILEOUT	KEYWORD	keyword to specify that an output filename is expected next.
UTL	OBS	CONTINUOUS	OBS_OUTPUT_FILE_NAME	STRING	Name of a file to which simulated values corresponding to observations in the block are to be written. The file name can be an absolute or relative path name. A unique output file must be specified for each SINGLE or CONTINUOUS block. If the BINARY'' option is used, output is written in binary form. By convention, text output files have the extension csv'' (for Comma-Separated Values'') and binary output files have the extension bsv'' (for ``Binary Simulated Values'').
UTL	OBS	CONTINUOUS	BINARY	KEYWORD	an optional keyword used to indicate that the output file should be written in binary (unformatted) form.
UTL	OBS	CONTINUOUS	OBSNAME	STRING	string of 1 to 40 nonblank characters used to identify the observation. The identifier need not be unique; however, identification and post-processing of observations in the output files are facilitated if each observation is given a unique name.
UTL	OBS	CONTINUOUS	OBSTYPE	STRING	a string of characters used to identify the observation type.
UTL	OBS	CONTINUOUS	ID	STRING	Text identifying cell where observation is located. For packages other than NPF, if boundary names are defined in the corresponding package input file, ID can be a boundary name. Otherwise ID is a cellid. If the model discretization is type DIS, cellid is three integers (layer, row, column). If the discretization is DISV, cellid is two integers (layer, cell number). If the discretization is DISU, cellid is one integer (node number).
UTL	OBS	CONTINUOUS	ID2	STRING	Text identifying cell adjacent to cell identified by ID. The form of ID2 is as described for ID. ID2 is used for intercell-flow observations of a GWF model, for three observation types of the LAK Package, for two observation types of the MAW Package, and one observation type of the UZF Package.
UTL	TS	ATTRIBUTES	NAMES	KEYWORD	xxx
UTL	TS	ATTRIBUTES	TIME_SERIES_NAMES	STRING ANY1D	Name by which a package references a particular time-array series. The name must be unique among all time-array series used in a package.
UTL	TS	ATTRIBUTES	METHODS	KEYWORD	xxx
UTL	TS	ATTRIBUTES	INTERPOLATION_METHOD	STRING TIME_SERIES_NAMES	Interpolation method, which is either STEPWISE or LINEAR.
UTL	TS	ATTRIBUTES	METHOD	KEYWORD	xxx
UTL	TS	ATTRIBUTES	INTERPOLATION_METHOD_SINGLE	STRING	Interpolation method, which is either STEPWISE or LINEAR.
UTL	TS	ATTRIBUTES	SFACS	KEYWORD	xxx
UTL	TS	ATTRIBUTES	SFACVAL	DOUBLE PRECISION <TIME_SERIES_NAME	Scale factor, which will multiply all array values in time series. SFAC is an optional attribute; if omitted, SFAC = 1.0.
UTL	TS	ATTRIBUTES	SFAC	KEYWORD	xxx
UTL	TS	TIMESERIES	TS_TIME	DOUBLE PRECISION	A numeric time relative to the start of the simulation, in the time unit used in the simulation. Times must be strictly increasing.
UTL	TS	TIMESERIES	TS_ARRAY	DOUBLE PRECISION TIME_SERIES_NAMES	A 2-D array of numeric, floating-point values, or a constant value, readable by the U2DREL array-reading utility.
UTL	TAS	ATTRIBUTES	NAME	KEYWORD	xxx
UTL	TAS	ATTRIBUTES	TIME_SERIES_NAME	STRING ANY1D	Name by which a package references a particular time-array series. The name must be unique among all time-array series used in a package.
UTL	TAS	ATTRIBUTES	METHOD	KEYWORD	xxx
UTL	TAS	ATTRIBUTES	INTERPOLATION_METHOD	STRING	Interpolation method, which is either STEPWISE or LINEAR.
UTL	TAS	ATTRIBUTES	SFAC	KEYWORD	xxx
UTL	TAS	ATTRIBUTES	SFACVAL	DOUBLE PRECISION TIME_SERIES_NAME	Scale factor, which will multiply all array values in time series. SFAC is an optional attribute; if omitted, SFAC = 1.0.
UTL	TAS	TIME	TIME_FROM_MODEL_START	DOUBLE PRECISION	A numeric time relative to the start of the simulation, in the time unit used in the simulation. Times must be strictly increasing.
UTL	TAS	TIME	TAS_ARRAY	DOUBLE PRECISION (UNKNOWN)	An array of numeric, floating-point values, or a constant value, readable by the U2DREL array-reading utility.