diff --git a/doc/mf6io/mf6ivar/dfn/gwf-drn.dfn b/doc/mf6io/mf6ivar/dfn/gwf-drn.dfn
index c03a1078000..4f5a2ffe90b 100644
--- a/doc/mf6io/mf6ivar/dfn/gwf-drn.dfn
+++ b/doc/mf6io/mf6ivar/dfn/gwf-drn.dfn
@@ -44,6 +44,7 @@ reader urword
 optional true
 longname print input to listing file
 description REPLACE print_input {'{#1}': 'drain'}
+mf6internal iprpak
 
 block options
 name print_flows
@@ -52,6 +53,7 @@ reader urword
 optional true
 longname print calculated flows to listing file
 description REPLACE print_flows {'{#1}': 'drain'}
+mf6internal iprflow
 
 block options
 name save_flows
@@ -60,6 +62,7 @@ reader urword
 optional true
 longname save CHD flows to budget file
 description REPLACE save_flows {'{#1}': 'drain'}
+mf6internal ipakcb
 
 block options
 name ts_filerecord
@@ -145,6 +148,16 @@ optional true
 longname
 description REPLACE mover {'{#1}': 'Drain'}
 
+# dev options
+block options
+name dev_cubic_scaling
+type keyword
+reader urword
+optional true
+longname cubic-scaling
+description cubic-scaling is used to scale the drain conductance
+mf6internal icubicsfac
+
 # --------------------- gwf drn dimensions ---------------------
 
 block dimensions
@@ -178,6 +191,7 @@ shape (maxbound)
 reader urword
 longname
 description
+mf6internal spd
 
 block period
 name cellid
@@ -222,6 +236,7 @@ optional true
 time_series true
 longname auxiliary variables
 description REPLACE aux {'{#1}': 'drain'}
+mf6internal auxvar
 
 block period
 name boundname
diff --git a/make/makefile b/make/makefile
index 82215708a26..64667ddf656 100644
--- a/make/makefile
+++ b/make/makefile
@@ -5,36 +5,36 @@ include ./makedefaults
 
 # Define the source file directories
 SOURCEDIR1=../src
-SOURCEDIR2=../src/Model
-SOURCEDIR3=../src/Model/TransportModel
-SOURCEDIR4=../src/Model/GroundWaterFlow
-SOURCEDIR5=../src/Model/Geometry
+SOURCEDIR2=../src/Exchange
+SOURCEDIR3=../src/Model
+SOURCEDIR4=../src/Model/Geometry
+SOURCEDIR5=../src/Model/TransportModel
 SOURCEDIR6=../src/Model/ModelUtilities
-SOURCEDIR7=../src/Model/GroundWaterTransport
-SOURCEDIR8=../src/Model/Connection
-SOURCEDIR9=../src/Distributed
-SOURCEDIR10=../src/Utilities
-SOURCEDIR11=../src/Utilities/Idm
-SOURCEDIR12=../src/Utilities/Idm/mf6blockfile
-SOURCEDIR13=../src/Utilities/Idm/selector
-SOURCEDIR14=../src/Utilities/Vector
-SOURCEDIR15=../src/Utilities/Matrix
-SOURCEDIR16=../src/Utilities/Observation
-SOURCEDIR17=../src/Utilities/ArrayRead
-SOURCEDIR18=../src/Utilities/OutputControl
-SOURCEDIR19=../src/Utilities/Libraries
-SOURCEDIR20=../src/Utilities/Libraries/blas
-SOURCEDIR21=../src/Utilities/Libraries/rcm
-SOURCEDIR22=../src/Utilities/Libraries/sparsekit
-SOURCEDIR23=../src/Utilities/Libraries/sparskit2
-SOURCEDIR24=../src/Utilities/Libraries/daglib
-SOURCEDIR25=../src/Utilities/Memory
-SOURCEDIR26=../src/Utilities/TimeSeries
-SOURCEDIR27=../src/Timing
-SOURCEDIR28=../src/Solution
-SOURCEDIR29=../src/Solution/PETSc
-SOURCEDIR30=../src/Solution/LinearMethods
-SOURCEDIR31=../src/Exchange
+SOURCEDIR7=../src/Model/Connection
+SOURCEDIR8=../src/Model/GroundWaterTransport
+SOURCEDIR9=../src/Model/GroundWaterFlow
+SOURCEDIR10=../src/Distributed
+SOURCEDIR11=../src/Solution
+SOURCEDIR12=../src/Solution/PETSc
+SOURCEDIR13=../src/Solution/LinearMethods
+SOURCEDIR14=../src/Timing
+SOURCEDIR15=../src/Utilities
+SOURCEDIR16=../src/Utilities/TimeSeries
+SOURCEDIR17=../src/Utilities/Libraries
+SOURCEDIR18=../src/Utilities/Libraries/rcm
+SOURCEDIR19=../src/Utilities/Libraries/sparsekit
+SOURCEDIR20=../src/Utilities/Libraries/sparskit2
+SOURCEDIR21=../src/Utilities/Libraries/blas
+SOURCEDIR22=../src/Utilities/Libraries/daglib
+SOURCEDIR23=../src/Utilities/Idm
+SOURCEDIR24=../src/Utilities/Idm/selector
+SOURCEDIR25=../src/Utilities/Idm/mf6blockfile
+SOURCEDIR26=../src/Utilities/Matrix
+SOURCEDIR27=../src/Utilities/Vector
+SOURCEDIR28=../src/Utilities/Observation
+SOURCEDIR29=../src/Utilities/OutputControl
+SOURCEDIR30=../src/Utilities/Memory
+SOURCEDIR31=../src/Utilities/ArrayRead
 
 VPATH = \
 ${SOURCEDIR1} \
@@ -90,14 +90,9 @@ $(OBJDIR)/MemoryHelper.o \
 $(OBJDIR)/CharString.o \
 $(OBJDIR)/Memory.o \
 $(OBJDIR)/List.o \
+$(OBJDIR)/InputDefinition.o \
 $(OBJDIR)/LongLineReader.o \
 $(OBJDIR)/MemoryList.o \
-$(OBJDIR)/TimeSeriesRecord.o \
-$(OBJDIR)/BlockParser.o \
-$(OBJDIR)/MemoryManager.o \
-$(OBJDIR)/InputDefinition.o \
-$(OBJDIR)/TimeSeries.o \
-$(OBJDIR)/ats.o \
 $(OBJDIR)/simnamidm.o \
 $(OBJDIR)/gwt1idm.o \
 $(OBJDIR)/gwt1dsp1idm.o \
@@ -107,10 +102,22 @@ $(OBJDIR)/gwt1dis1idm.o \
 $(OBJDIR)/gwf3wel8idm.o \
 $(OBJDIR)/gwf3npf8idm.o \
 $(OBJDIR)/gwf3idm.o \
+$(OBJDIR)/gwf3drn8idm.o \
 $(OBJDIR)/gwf3disv8idm.o \
 $(OBJDIR)/gwf3disu8idm.o \
 $(OBJDIR)/gwf3dis8idm.o \
 $(OBJDIR)/gwf3chd8idm.o \
+$(OBJDIR)/TimeSeriesRecord.o \
+$(OBJDIR)/BlockParser.o \
+$(OBJDIR)/MemoryManager.o \
+$(OBJDIR)/IdmSimDfnSelector.o \
+$(OBJDIR)/IdmGwtDfnSelector.o \
+$(OBJDIR)/IdmGwfDfnSelector.o \
+$(OBJDIR)/TimeSeries.o \
+$(OBJDIR)/ats.o \
+$(OBJDIR)/IdmDfnSelector.o \
+$(OBJDIR)/TimeArray.o \
+$(OBJDIR)/ArrayReaders.o \
 $(OBJDIR)/TimeSeriesLink.o \
 $(OBJDIR)/TimeSeriesFileList.o \
 $(OBJDIR)/tdis.o \
@@ -118,63 +125,61 @@ $(OBJDIR)/HashTable.o \
 $(OBJDIR)/VectorBase.o \
 $(OBJDIR)/Sparse.o \
 $(OBJDIR)/DisvGeom.o \
-$(OBJDIR)/ArrayReaders.o \
-$(OBJDIR)/IdmSimDfnSelector.o \
-$(OBJDIR)/IdmGwtDfnSelector.o \
-$(OBJDIR)/IdmGwfDfnSelector.o \
+$(OBJDIR)/ArrayReaderBase.o \
+$(OBJDIR)/STLVecInt.o \
+$(OBJDIR)/ModflowInput.o \
+$(OBJDIR)/MemoryManagerExt.o \
+$(OBJDIR)/TimeArraySeries.o \
 $(OBJDIR)/TimeSeriesManager.o \
 $(OBJDIR)/SmoothingFunctions.o \
-$(OBJDIR)/MemoryManagerExt.o \
 $(OBJDIR)/MatrixBase.o \
 $(OBJDIR)/ListReader.o \
 $(OBJDIR)/Connections.o \
-$(OBJDIR)/IdmDfnSelector.o \
-$(OBJDIR)/TimeArray.o \
-$(OBJDIR)/ArrayReaderBase.o \
-$(OBJDIR)/ObsOutput.o \
-$(OBJDIR)/DiscretizationBase.o \
-$(OBJDIR)/STLVecInt.o \
-$(OBJDIR)/ModflowInput.o \
-$(OBJDIR)/TimeArraySeries.o \
 $(OBJDIR)/Integer2dReader.o \
-$(OBJDIR)/ObsOutputList.o \
-$(OBJDIR)/Observe.o \
 $(OBJDIR)/StructVector.o \
 $(OBJDIR)/IdmLogger.o \
 $(OBJDIR)/DefinitionSelect.o \
 $(OBJDIR)/InputLoadType.o \
 $(OBJDIR)/TimeArraySeriesLink.o \
+$(OBJDIR)/DiscretizationBase.o \
 $(OBJDIR)/Integer1dReader.o \
 $(OBJDIR)/Double2dReader.o \
 $(OBJDIR)/Double1dReader.o \
-$(OBJDIR)/ObsUtility.o \
-$(OBJDIR)/ObsContainer.o \
-$(OBJDIR)/BudgetFileReader.o \
 $(OBJDIR)/StructArray.o \
 $(OBJDIR)/BoundInputContext.o \
 $(OBJDIR)/AsciiInputLoadType.o \
 $(OBJDIR)/TimeArraySeriesManager.o \
 $(OBJDIR)/SourceCommon.o \
 $(OBJDIR)/LayeredArrayReader.o \
+$(OBJDIR)/ObsOutput.o \
+$(OBJDIR)/StressListInput.o \
+$(OBJDIR)/StressGridInput.o \
+$(OBJDIR)/LoadMf6File.o \
+$(OBJDIR)/ObsOutputList.o \
+$(OBJDIR)/Observe.o \
+$(OBJDIR)/IdmMf6File.o \
+$(OBJDIR)/sort.o \
+$(OBJDIR)/ObsUtility.o \
+$(OBJDIR)/ObsContainer.o \
+$(OBJDIR)/BudgetFileReader.o \
+$(OBJDIR)/SourceLoad.o \
+$(OBJDIR)/ModelPackageInputs.o \
 $(OBJDIR)/PackageMover.o \
 $(OBJDIR)/Obs3.o \
 $(OBJDIR)/NumericalPackage.o \
 $(OBJDIR)/Budget.o \
 $(OBJDIR)/BudgetTerm.o \
-$(OBJDIR)/StressListInput.o \
-$(OBJDIR)/StressGridInput.o \
-$(OBJDIR)/LoadMf6File.o \
-$(OBJDIR)/sort.o \
 $(OBJDIR)/SfrCrossSectionUtils.o \
-$(OBJDIR)/VirtualBase.o \
+$(OBJDIR)/IdmLoad.o \
 $(OBJDIR)/BoundaryPackage.o \
+$(OBJDIR)/VirtualBase.o \
 $(OBJDIR)/BaseModel.o \
 $(OBJDIR)/PackageBudget.o \
 $(OBJDIR)/HeadFileReader.o \
 $(OBJDIR)/BudgetObject.o \
-$(OBJDIR)/IdmMf6File.o \
 $(OBJDIR)/SfrCrossSectionManager.o \
 $(OBJDIR)/dag_module.o \
+$(OBJDIR)/BoundaryPackageExt.o \
 $(OBJDIR)/VirtualDataLists.o \
 $(OBJDIR)/VirtualDataContainer.o \
 $(OBJDIR)/SimStages.o \
@@ -183,8 +188,6 @@ $(OBJDIR)/FlowModelInterface.o \
 $(OBJDIR)/PrintSaveManager.o \
 $(OBJDIR)/Xt3dAlgorithm.o \
 $(OBJDIR)/gwf3tvbase8.o \
-$(OBJDIR)/SourceLoad.o \
-$(OBJDIR)/ModelPackageInputs.o \
 $(OBJDIR)/gwf3sfr8.o \
 $(OBJDIR)/gwf3riv8.o \
 $(OBJDIR)/gwf3maw8.o \
@@ -202,7 +205,6 @@ $(OBJDIR)/OutputControlData.o \
 $(OBJDIR)/gwf3ic8.o \
 $(OBJDIR)/Xt3dInterface.o \
 $(OBJDIR)/gwf3tvk8.o \
-$(OBJDIR)/IdmLoad.o \
 $(OBJDIR)/gwf3vsc8.o \
 $(OBJDIR)/GwfNpfOptions.o \
 $(OBJDIR)/InterfaceMap.o \
@@ -220,7 +222,6 @@ $(OBJDIR)/gwt1mst1.o \
 $(OBJDIR)/GwtDspOptions.o \
 $(OBJDIR)/gwf3npf8.o \
 $(OBJDIR)/GwtAdvOptions.o \
-$(OBJDIR)/BoundaryPackageExt.o \
 $(OBJDIR)/gwf3tvs8.o \
 $(OBJDIR)/GwfStorageUtils.o \
 $(OBJDIR)/Mover.o \
diff --git a/msvs/mf6core.vfproj b/msvs/mf6core.vfproj
index 9786bfb251e..cf6c91bc6eb 100644
--- a/msvs/mf6core.vfproj
+++ b/msvs/mf6core.vfproj
@@ -131,6 +131,7 @@
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3disv8.f90"/>
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3disv8idm.f90"/>
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3drn8.f90"/>
+		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3drn8idm.f90"/>
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3evt8.f90"/>
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3ghb8.f90"/>
 		<File RelativePath="..\src\Model\GroundWaterFlow\gwf3hfb8.f90"/>
diff --git a/src/Model/GroundWaterFlow/gwf3.f90 b/src/Model/GroundWaterFlow/gwf3.f90
index 617287c1d2f..d955ae74b10 100644
--- a/src/Model/GroundWaterFlow/gwf3.f90
+++ b/src/Model/GroundWaterFlow/gwf3.f90
@@ -1296,7 +1296,8 @@ subroutine package_create(this, filtyp, ipakid, ipaknum, pakname, mempath, &
       call wel_create(packobj, ipakid, ipaknum, inunit, iout, this%name, &
                       pakname, mempath)
     case ('DRN6')
-      call drn_create(packobj, ipakid, ipaknum, inunit, iout, this%name, pakname)
+      call drn_create(packobj, ipakid, ipaknum, inunit, iout, this%name, &
+                      pakname, mempath)
     case ('RIV6')
       call riv_create(packobj, ipakid, ipaknum, inunit, iout, this%name, pakname)
     case ('GHB6')
diff --git a/src/Model/GroundWaterFlow/gwf3buy8.f90 b/src/Model/GroundWaterFlow/gwf3buy8.f90
index 39fbdf5629c..2d2e26ef628 100644
--- a/src/Model/GroundWaterFlow/gwf3buy8.f90
+++ b/src/Model/GroundWaterFlow/gwf3buy8.f90
@@ -721,6 +721,7 @@ subroutine buy_cf_drn(packobj, hnew, dense, denseref)
 ! ------------------------------------------------------------------------------
     ! -- modules
     use BndModule, only: BndType
+    use DrnModule, only: DrnType
     class(BndType), pointer :: packobj
     ! -- dummy
     real(DP), intent(in), dimension(:) :: hnew
@@ -737,19 +738,22 @@ subroutine buy_cf_drn(packobj, hnew, dense, denseref)
 ! ------------------------------------------------------------------------------
     !
     ! -- Process density terms for each DRN
-    do n = 1, packobj%nbound
-      node = packobj%nodelist(n)
-      if (packobj%ibound(node) <= 0) cycle
-      rho = dense(node)
-      hbnd = packobj%bound(1, n)
-      cond = packobj%bound(2, n)
-      if (hnew(node) > hbnd) then
-        hcofterm = -cond * (rho / denseref - DONE)
-        rhsterm = hcofterm * hbnd
-        packobj%hcof(n) = packobj%hcof(n) + hcofterm
-        packobj%rhs(n) = packobj%rhs(n) + rhsterm
-      end if
-    end do
+    select type (packobj)
+    type is (DrnType)
+      do n = 1, packobj%nbound
+        node = packobj%nodelist(n)
+        if (packobj%ibound(node) <= 0) cycle
+        rho = dense(node)
+        hbnd = packobj%elev(n)
+        cond = packobj%cond(n)
+        if (hnew(node) > hbnd) then
+          hcofterm = -cond * (rho / denseref - DONE)
+          rhsterm = hcofterm * hbnd
+          packobj%hcof(n) = packobj%hcof(n) + hcofterm
+          packobj%rhs(n) = packobj%rhs(n) + rhsterm
+        end if
+      end do
+    end select
     !
     ! -- Return
     return
diff --git a/src/Model/GroundWaterFlow/gwf3drn8.f90 b/src/Model/GroundWaterFlow/gwf3drn8.f90
index c0b5562c555..7b3090a7f26 100644
--- a/src/Model/GroundWaterFlow/gwf3drn8.f90
+++ b/src/Model/GroundWaterFlow/gwf3drn8.f90
@@ -2,13 +2,14 @@ module DrnModule
   use KindModule, only: DP, I4B
   use ConstantsModule, only: DZERO, DONE, DTWO, &
                              LENFTYPE, LENPACKAGENAME, LENAUXNAME, LINELENGTH
+  use SimVariablesModule, only: errmsg
+  use SimModule, only: count_errors, store_error, store_error_filename
   use MemoryHelperModule, only: create_mem_path
   use SmoothingModule, only: sQSaturation, sQSaturationDerivative, &
                              sQuadraticSaturation
   use BndModule, only: BndType
+  use BndExtModule, only: BndExtType
   use ObsModule, only: DefaultObsIdProcessor
-  use TimeSeriesLinkModule, only: TimeSeriesLinkType, &
-                                  GetTimeSeriesLinkFromList
   use MatrixBaseModule
   !
   implicit none
@@ -20,14 +21,19 @@ module DrnModule
   character(len=LENFTYPE) :: ftype = 'DRN'
   character(len=LENPACKAGENAME) :: text = '             DRN'
   !
-  type, extends(BndType) :: DrnType
+  type, extends(BndExtType) :: DrnType
 
+    real(DP), dimension(:), pointer, contiguous :: elev => null() !< DRN elevation
+    real(DP), dimension(:), pointer, contiguous :: cond => null() !< DRN conductance at aquifer interface
     integer(I4B), pointer :: iauxddrncol => null()
     integer(I4B), pointer :: icubic_scaling => null()
 
   contains
     procedure :: allocate_scalars => drn_allocate_scalars
-    procedure :: bnd_options => drn_options
+    procedure :: allocate_arrays => drn_allocate_arrays
+    procedure :: source_options => drn_options
+    procedure :: log_drn_options
+    procedure :: bnd_rp => drn_rp
     procedure :: bnd_ck => drn_ck
     procedure :: bnd_cf => drn_cf
     procedure :: bnd_fc => drn_fc
@@ -36,16 +42,18 @@ module DrnModule
     procedure :: define_listlabel
     procedure :: get_drain_elevations
     procedure :: get_drain_factor
+    procedure :: bound_value => drn_bound_value
+    procedure :: cond_mult
     ! -- methods for observations
     procedure, public :: bnd_obs_supported => drn_obs_supported
     procedure, public :: bnd_df_obs => drn_df_obs
-    ! -- method for time series
-    procedure, public :: bnd_rp_ts => drn_rp_ts
+    procedure, public :: drn_store_user_cond
   end type DrnType
 
 contains
 
-  subroutine drn_create(packobj, id, ibcnum, inunit, iout, namemodel, pakname)
+  subroutine drn_create(packobj, id, ibcnum, inunit, iout, namemodel, pakname, &
+                        mempath)
 ! ******************************************************************************
 ! drn_create -- Create a New Drn Package
 ! Subroutine: (1) create new-style package
@@ -62,6 +70,7 @@ subroutine drn_create(packobj, id, ibcnum, inunit, iout, namemodel, pakname)
     integer(I4B), intent(in) :: iout
     character(len=*), intent(in) :: namemodel
     character(len=*), intent(in) :: pakname
+    character(len=*), intent(in) :: mempath
     ! -- local
     type(DrnType), pointer :: drnobj
 ! ------------------------------------------------------------------------------
@@ -71,7 +80,7 @@ subroutine drn_create(packobj, id, ibcnum, inunit, iout, namemodel, pakname)
     packobj => drnobj
     !
     ! -- create name and memory path
-    call packobj%set_names(ibcnum, namemodel, pakname, ftype)
+    call packobj%set_names(ibcnum, namemodel, pakname, ftype, mempath)
     packobj%text = text
     !
     ! -- allocate scalars
@@ -107,12 +116,16 @@ subroutine drn_da(this)
 ! ------------------------------------------------------------------------------
     !
     ! -- Deallocate parent package
-    call this%BndType%bnd_da()
+    call this%BndExtType%bnd_da()
     !
     ! -- scalars
     call mem_deallocate(this%iauxddrncol)
     call mem_deallocate(this%icubic_scaling)
     !
+    ! -- arrays
+    call mem_deallocate(this%elev, 'ELEV', this%memoryPath)
+    call mem_deallocate(this%cond, 'COND', this%memoryPath)
+    !
     ! -- return
     return
   end subroutine drn_da
@@ -129,8 +142,8 @@ subroutine drn_allocate_scalars(this)
     class(DrnType) :: this
 ! ------------------------------------------------------------------------------
     !
-    ! -- call standard BndType allocate scalars
-    call this%BndType%allocate_scalars()
+    ! -- call base type allocate scalars
+    call this%BndExtType%allocate_scalars()
     !
     ! -- allocate the object and assign values to object variables
     call mem_allocate(this%iauxddrncol, 'IAUXDDRNCOL', this%memoryPath)
@@ -148,56 +161,101 @@ subroutine drn_allocate_scalars(this)
     return
   end subroutine drn_allocate_scalars
 
-  subroutine drn_options(this, option, found)
+  subroutine drn_allocate_arrays(this, nodelist, auxvar)
+! ******************************************************************************
+! drn_allocate_arrays -- allocate arrays
 ! ******************************************************************************
-! drn_options -- set options specific to DrnType
 !
-! drn_options overrides BndType%bnd_options
+!    SPECIFICATIONS:
+! ------------------------------------------------------------------------------
+    ! -- modules
+    use MemoryManagerModule, only: mem_allocate, mem_setptr, mem_checkin
+    ! -- dummy
+    class(DrnType) :: this
+    integer(I4B), dimension(:), pointer, contiguous, optional :: nodelist
+    real(DP), dimension(:, :), pointer, contiguous, optional :: auxvar
+    ! -- local
+! ------------------------------------------------------------------------------
+    !
+    ! -- call base type allocate arrays
+    call this%BndExtType%allocate_arrays(nodelist, auxvar)
+    !
+    ! -- set drn input context pointers
+    call mem_setptr(this%elev, 'ELEV', this%input_mempath)
+    call mem_setptr(this%cond, 'COND', this%input_mempath)
+    !
+    ! --checkin drn input context pointers
+    call mem_checkin(this%elev, 'ELEV', this%memoryPath, &
+                     'ELEV', this%input_mempath)
+    call mem_checkin(this%cond, 'COND', this%memoryPath, &
+                     'COND', this%input_mempath)
+    !
+    ! -- return
+    return
+  end subroutine drn_allocate_arrays
+
+  subroutine drn_rp(this)
+! ******************************************************************************
+! drn_rp -- Read and prepare
+! ******************************************************************************
+!
+!    SPECIFICATIONS:
+! ------------------------------------------------------------------------------
+    use TdisModule, only: kper
+    ! -- dummy
+    class(DrnType), intent(inout) :: this
+    ! -- local
+! ------------------------------------------------------------------------------
+    if (this%iper /= kper) return
+    !
+    ! -- Call the parent class read and prepare
+    call this%BndExtType%bnd_rp()
+    !
+    ! -- store user cond
+    if (this%ivsc == 1) then
+      call this%drn_store_user_cond()
+    end if
+    !
+    ! -- Write the list to iout if requested
+    if (this%iprpak /= 0) then
+      call this%write_list()
+    end if
+    !
+    ! -- return
+    return
+  end subroutine drn_rp
+
+  subroutine drn_options(this)
+! ******************************************************************************
+! drn_options -- source options specific to DrnType
 ! ******************************************************************************
 !
 !    SPECIFICATIONS:
 ! ------------------------------------------------------------------------------
     use InputOutputModule, only: urword
-    use SimModule, only: store_error
+    use MemoryManagerExtModule, only: mem_set_value
+    use CharacterStringModule, only: CharacterStringType
+    use GwfDrnInputModule, only: GwfDrnParamFoundType
     ! -- dummy
     class(DrnType), intent(inout) :: this
-    character(len=*), intent(inout) :: option
-    logical, intent(inout) :: found
     ! -- local
-    character(len=LINELENGTH) :: errmsg
+    type(GwfDrnParamFoundType) :: found
     character(len=LENAUXNAME) :: ddrnauxname
     integer(I4B) :: n
 ! ------------------------------------------------------------------------------
     !
-    found = .true.
-    select case (option)
-    case ('MOVER')
-      this%imover = 1
-      write (this%iout, '(4x,A)') 'MOVER OPTION ENABLED'
-    case ('AUXDEPTHNAME')
-      call this%parser%GetStringCaps(ddrnauxname)
-      this%iauxddrncol = -1
-      write (this%iout, '(4x,a,a)') &
-        'AUXILIARY DRAIN DEPTH NAME: ', trim(ddrnauxname)
-      !
-      ! -- right now these are options that are only available in the
-      !    development version and are not included in the documentation.
-      !    These options are only available when IDEVELOPMODE in
-      !    constants module is set to 1
-    case ('DEV_CUBIC_SCALING')
-      call this%parser%DevOpt()
-      this%icubic_scaling = 1
-      write (this%iout, '(4x,a,1x,a)') &
-        'CUBIC SCALING will be used for drains with non-zero DDRN values', &
-        'even if the NEWTON-RAPHSON method is not being used.'
-    case default
-      !
-      ! -- No options found
-      found = .false.
-    end select
+    ! -- source base class options
+    call this%BndExtType%source_options()
+    !
+    ! -- source drain options
+    call mem_set_value(this%imover, 'MOVER', this%input_mempath, found%mover)
+    call mem_set_value(ddrnauxname, 'AUXDEPTHNAME', this%input_mempath, &
+                       found%auxdepthname)
+    call mem_set_value(this%icubic_scaling, 'ICUBICSFAC', this%input_mempath, &
+                       found%icubicsfac)
     !
-    ! -- DDRN was specified, so find column of auxvar that will be used
-    if (this%iauxddrncol < 0) then
+    if (found%auxdepthname) then
+      this%iauxddrncol = -1
       !
       ! -- Error if no aux variable specified
       if (this%naux == 0) then
@@ -225,10 +283,50 @@ subroutine drn_options(this, option, found)
       end if
     end if
     !
+    if (found%icubicsfac) then
+      call this%parser%DevOpt()
+    end if
+    !
+    ! -- log DRN specific options
+    call this%log_drn_options(found)
+    !
     ! -- return
     return
   end subroutine drn_options
 
+  !> @ brief Log DRN specific package options
+  !<
+  subroutine log_drn_options(this, found)
+    ! -- modules
+    use GwfDrnInputModule, only: GwfDrnParamFoundType
+    ! -- dummy variables
+    class(DrnType), intent(inout) :: this !< BndExtType object
+    type(GwfDrnParamFoundType), intent(in) :: found
+    ! -- local variables
+    ! -- format
+    !
+    ! -- log found options
+    write (this%iout, '(/1x,a)') 'PROCESSING '//trim(adjustl(this%text)) &
+      //' OPTIONS'
+    !
+    if (found%mover) then
+      write (this%iout, '(4x,A)') 'MOVER OPTION ENABLED'
+    end if
+    !
+    if (found%icubicsfac) then
+      write (this%iout, '(4x,a,1x,a)') &
+        'CUBIC SCALING will be used for drains with non-zero DDRN values', &
+        'even if the NEWTON-RAPHSON method is not being used.'
+    end if
+    !
+    ! -- close logging block
+    write (this%iout, '(1x,a)') &
+      'END OF '//trim(adjustl(this%text))//' OPTIONS'
+    !
+    ! -- return
+    return
+  end subroutine log_drn_options
+
   subroutine drn_ck(this)
 ! ******************************************************************************
 ! drn_ck -- Check drain boundary condition data
@@ -237,12 +335,9 @@ subroutine drn_ck(this)
 !    SPECIFICATIONS:
 ! ------------------------------------------------------------------------------
     ! -- modules
-    use ConstantsModule, only: LINELENGTH
-    use SimModule, only: store_error, count_errors, store_error_unit
     ! -- dummy
     class(DrnType), intent(inout) :: this
     ! -- local
-    character(len=LINELENGTH) :: errmsg
     integer(I4B) :: i
     integer(I4B) :: node
     real(DP) :: bt
@@ -280,7 +375,7 @@ subroutine drn_ck(this)
     !
     ! -- write summary of drain package error messages
     if (count_errors() > 0) then
-      call store_error_unit(this%inunit)
+      call store_error_filename(this%input_fname)
     end if
     !
     ! -- return
@@ -328,7 +423,8 @@ subroutine drn_cf(this, reset_mover)
       end if
       !
       ! -- set local variables for this drain
-      cdrn = this%bound(2, i)
+      cdrn = this%cond_mult(i)
+
       !
       ! -- calculate the drainage scaling factor
       call this%get_drain_factor(i, fact, drnbot)
@@ -383,7 +479,7 @@ subroutine drn_fc(this, rhs, ia, idxglo, matrix_sln)
       ! -- If mover is active and this drain is discharging,
       !    store available water (as positive value).
       if (this%imover == 1 .and. fact > DZERO) then
-        drncond = this%bound(2, i)
+        drncond = this%cond_mult(i)
         qdrn = fact * drncond * (this%xnew(n) - drnbot)
         call this%pakmvrobj%accumulate_qformvr(i, qdrn)
       end if
@@ -431,7 +527,7 @@ subroutine drn_fn(this, rhs, ia, idxglo, matrix_sln)
         end if
         !
         ! -- set local variables for this drain
-        cdrn = this%bound(2, i)
+        cdrn = this%cond_mult(i)
         xnew = this%xnew(node)
         !
         ! -- calculate the drainage depth and the top and bottom of
@@ -510,7 +606,7 @@ subroutine get_drain_elevations(this, i, drndepth, drntop, drnbot)
     !
     ! -- initialize dummy and local variables
     drndepth = DZERO
-    drnelev = this%bound(1, i)
+    drnelev = this%elev(i)
     !
     ! -- set the drain depth
     if (this%iauxddrncol > 0) then
@@ -630,33 +726,71 @@ subroutine drn_df_obs(this)
     return
   end subroutine drn_df_obs
 
-  ! -- Procedure related to time series
-
-  subroutine drn_rp_ts(this)
-    ! -- Assign tsLink%Text appropriately for
-    !    all time series in use by package.
-    !    In DRN package variables ELEV and COND
-    !    can be controlled by time series.
-    ! -- dummy
-    class(DrnType), intent(inout) :: this
-    ! -- local
-    integer(I4B) :: i, nlinks
-    type(TimeSeriesLinkType), pointer :: tslink => null()
-    !
-    nlinks = this%TsManager%boundtslinks%Count()
-    do i = 1, nlinks
-      tslink => GetTimeSeriesLinkFromList(this%TsManager%boundtslinks, i)
-      if (associated(tslink)) then
-        select case (tslink%JCol)
-        case (1)
-          tslink%Text = 'ELEV'
-        case (2)
-          tslink%Text = 'COND'
-        end select
-      end if
+  subroutine drn_store_user_cond(this)
+    ! -- modules
+    ! -- dummy variables
+    class(DrnType), intent(inout) :: this !< BndExtType object
+    ! -- local variables
+    integer(I4B) :: n
+    !
+    ! -- store backup copy of conductance values
+    do n = 1, this%nbound
+      this%condinput(n) = this%cond_mult(n)
     end do
     !
+    ! -- return
+    return
+  end subroutine drn_store_user_cond
+
+  function cond_mult(this, row) result(cond)
+    ! -- modules
+    use ConstantsModule, only: DZERO
+    ! -- dummy variables
+    class(DrnType), intent(inout) :: this !< BndExtType object
+    integer(I4B), intent(in) :: row
+    ! -- result
+    real(DP) :: cond
+    !
+    if (this%iauxmultcol > 0) then
+      cond = this%cond(row) * this%auxvar(this%iauxmultcol, row)
+    else
+      cond = this%cond(row)
+    end if
+    !
+    ! -- return
+    return
+  end function cond_mult
+
+! ******************************************************************************
+! drn_bound_value -- return requested boundary value
+! ******************************************************************************
+!
+!    SPECIFICATIONS:
+! ------------------------------------------------------------------------------
+  function drn_bound_value(this, col, row) result(bndval)
+    ! -- modules
+    use ConstantsModule, only: DZERO
+    ! -- dummy variables
+    class(DrnType), intent(inout) :: this !< BndExtType object
+    integer(I4B), intent(in) :: col
+    integer(I4B), intent(in) :: row
+    ! -- result
+    real(DP) :: bndval
+    !
+    select case (col)
+    case (1)
+      bndval = this%elev(row)
+    case (2)
+      bndval = this%cond_mult(row)
+    case default
+      errmsg = 'Programming error. DRN bound value requested column '&
+               &'outside range of ncolbnd (2).'
+      call store_error(errmsg)
+      call store_error_filename(this%input_fname)
+    end select
+    !
+    ! -- return
     return
-  end subroutine drn_rp_ts
+  end function drn_bound_value
 
 end module DrnModule
diff --git a/src/Model/GroundWaterFlow/gwf3drn8idm.f90 b/src/Model/GroundWaterFlow/gwf3drn8idm.f90
new file mode 100644
index 00000000000..f9865faa74d
--- /dev/null
+++ b/src/Model/GroundWaterFlow/gwf3drn8idm.f90
@@ -0,0 +1,490 @@
+! ** Do Not Modify! MODFLOW 6 system generated file. **
+module GwfDrnInputModule
+  use ConstantsModule, only: LENVARNAME
+  use InputDefinitionModule, only: InputParamDefinitionType, &
+                                   InputBlockDefinitionType
+  private
+  public gwf_drn_param_definitions
+  public gwf_drn_aggregate_definitions
+  public gwf_drn_block_definitions
+  public GwfDrnParamFoundType
+  public gwf_drn_multi_package
+  public gwf_drn_aux_sfac_param
+
+  type GwfDrnParamFoundType
+    logical :: auxiliary = .false.
+    logical :: auxmultname = .false.
+    logical :: auxdepthname = .false.
+    logical :: boundnames = .false.
+    logical :: iprpak = .false.
+    logical :: iprflow = .false.
+    logical :: ipakcb = .false.
+    logical :: ts_filerecord = .false.
+    logical :: ts6 = .false.
+    logical :: filein = .false.
+    logical :: ts6_filename = .false.
+    logical :: obs_filerecord = .false.
+    logical :: obs6 = .false.
+    logical :: obs6_filename = .false.
+    logical :: mover = .false.
+    logical :: icubicsfac = .false.
+    logical :: maxbound = .false.
+    logical :: cellid = .false.
+    logical :: elev = .false.
+    logical :: cond = .false.
+    logical :: auxvar = .false.
+    logical :: boundname = .false.
+  end type GwfDrnParamFoundType
+
+  logical :: gwf_drn_multi_package = .true.
+
+  character(len=LENVARNAME) :: gwf_drn_aux_sfac_param = ''
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_auxiliary = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'AUXILIARY', & ! tag name
+    'AUXILIARY', & ! fortran variable
+    'STRING', & ! type
+    'NAUX', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_auxmultname = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'AUXMULTNAME', & ! tag name
+    'AUXMULTNAME', & ! fortran variable
+    'STRING', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_auxdepthname = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'AUXDEPTHNAME', & ! tag name
+    'AUXDEPTHNAME', & ! fortran variable
+    'STRING', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_boundnames = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'BOUNDNAMES', & ! tag name
+    'BOUNDNAMES', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_iprpak = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'PRINT_INPUT', & ! tag name
+    'IPRPAK', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_iprflow = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'PRINT_FLOWS', & ! tag name
+    'IPRFLOW', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_ipakcb = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'SAVE_FLOWS', & ! tag name
+    'IPAKCB', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_ts_filerecord = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'TS_FILERECORD', & ! tag name
+    'TS_FILERECORD', & ! fortran variable
+    'RECORD TS6 FILEIN TS6_FILENAME', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_ts6 = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'TS6', & ! tag name
+    'TS6', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_filein = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'FILEIN', & ! tag name
+    'FILEIN', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_ts6_filename = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'TS6_FILENAME', & ! tag name
+    'TS6_FILENAME', & ! fortran variable
+    'STRING', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .true., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_obs_filerecord = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'OBS_FILERECORD', & ! tag name
+    'OBS_FILERECORD', & ! fortran variable
+    'RECORD OBS6 FILEIN OBS6_FILENAME', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_obs6 = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'OBS6', & ! tag name
+    'OBS6', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_obs6_filename = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'OBS6_FILENAME', & ! tag name
+    'OBS6_FILENAME', & ! fortran variable
+    'STRING', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .true., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_mover = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'MOVER', & ! tag name
+    'MOVER', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_icubicsfac = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'OPTIONS', & ! block
+    'DEV_CUBIC_SCALING', & ! tag name
+    'ICUBICSFAC', & ! fortran variable
+    'KEYWORD', & ! type
+    '', & ! shape
+    .false., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_maxbound = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'DIMENSIONS', & ! block
+    'MAXBOUND', & ! tag name
+    'MAXBOUND', & ! fortran variable
+    'INTEGER', & ! type
+    '', & ! shape
+    .true., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_cellid = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'CELLID', & ! tag name
+    'CELLID', & ! fortran variable
+    'INTEGER1D', & ! type
+    'NCELLDIM', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_elev = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'ELEV', & ! tag name
+    'ELEV', & ! fortran variable
+    'DOUBLE', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .true. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_cond = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'COND', & ! tag name
+    'COND', & ! fortran variable
+    'DOUBLE', & ! type
+    '', & ! shape
+    .true., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .true. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_auxvar = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'AUX', & ! tag name
+    'AUXVAR', & ! fortran variable
+    'DOUBLE1D', & ! type
+    'NAUX', & ! shape
+    .false., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .true. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_boundname = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'BOUNDNAME', & ! tag name
+    'BOUNDNAME', & ! fortran variable
+    'STRING', & ! type
+    '', & ! shape
+    .false., & ! required
+    .true., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwf_drn_param_definitions(*) = &
+    [ &
+    gwfdrn_auxiliary, &
+    gwfdrn_auxmultname, &
+    gwfdrn_auxdepthname, &
+    gwfdrn_boundnames, &
+    gwfdrn_iprpak, &
+    gwfdrn_iprflow, &
+    gwfdrn_ipakcb, &
+    gwfdrn_ts_filerecord, &
+    gwfdrn_ts6, &
+    gwfdrn_filein, &
+    gwfdrn_ts6_filename, &
+    gwfdrn_obs_filerecord, &
+    gwfdrn_obs6, &
+    gwfdrn_obs6_filename, &
+    gwfdrn_mover, &
+    gwfdrn_icubicsfac, &
+    gwfdrn_maxbound, &
+    gwfdrn_cellid, &
+    gwfdrn_elev, &
+    gwfdrn_cond, &
+    gwfdrn_auxvar, &
+    gwfdrn_boundname &
+    ]
+
+  type(InputParamDefinitionType), parameter :: &
+    gwfdrn_spd = InputParamDefinitionType &
+    ( &
+    'GWF', & ! component
+    'DRN', & ! subcomponent
+    'PERIOD', & ! block
+    'STRESS_PERIOD_DATA', & ! tag name
+    'SPD', & ! fortran variable
+    'RECARRAY CELLID ELEV COND AUX BOUNDNAME', & ! type
+    'MAXBOUND', & ! shape
+    .true., & ! required
+    .false., & ! multi-record
+    .false., & ! preserve case
+    .false., & ! layered
+    .false. & ! timeseries
+    )
+
+  type(InputParamDefinitionType), parameter :: &
+    gwf_drn_aggregate_definitions(*) = &
+    [ &
+    gwfdrn_spd &
+    ]
+
+  type(InputBlockDefinitionType), parameter :: &
+    gwf_drn_block_definitions(*) = &
+    [ &
+    InputBlockDefinitionType( &
+    'OPTIONS', & ! blockname
+    .false., & ! required
+    .false., & ! aggregate
+    .false. & ! block_variable
+    ), &
+    InputBlockDefinitionType( &
+    'DIMENSIONS', & ! blockname
+    .true., & ! required
+    .false., & ! aggregate
+    .false. & ! block_variable
+    ), &
+    InputBlockDefinitionType( &
+    'PERIOD', & ! blockname
+    .true., & ! required
+    .true., & ! aggregate
+    .true. & ! block_variable
+    ) &
+    ]
+
+end module GwfDrnInputModule
diff --git a/src/Model/GroundWaterFlow/gwf3vsc8.f90 b/src/Model/GroundWaterFlow/gwf3vsc8.f90
index 01a767c41bc..ef8f55d4026 100644
--- a/src/Model/GroundWaterFlow/gwf3vsc8.f90
+++ b/src/Model/GroundWaterFlow/gwf3vsc8.f90
@@ -519,6 +519,7 @@ subroutine vsc_ad_standard_bnd(packobj, hnew, visc, viscref, locelev, &
                                  ivisc, a2, a3, a4, ctemp)
     ! -- modules
     use BndModule, only: BndType
+    use DrnModule, only: DrnType
     class(BndType), pointer :: packobj
     ! -- dummy
     real(DP), intent(in), dimension(:) :: hnew
@@ -551,8 +552,17 @@ subroutine vsc_ad_standard_bnd(packobj, hnew, visc, viscref, locelev, &
                                    packobj%auxvar)
       !
       ! -- update boundary conductance based on viscosity effects
-      packobj%bound(2, n) = update_bnd_cond(viscbnd, viscref, &
+      select case (packobj%filtyp)
+      case ('DRN')
+        select type (packobj)
+        type is (DrnType)
+          packobj%cond(n) = update_bnd_cond(viscbnd, viscref, &
                                             packobj%condinput(n))
+        end select
+      case default
+        packobj%bound(2, n) = update_bnd_cond(viscbnd, viscref, &
+                                              packobj%condinput(n))
+      end select
       !
     end do
     !
diff --git a/src/Utilities/Idm/selector/IdmGwfDfnSelector.f90 b/src/Utilities/Idm/selector/IdmGwfDfnSelector.f90
index bde123809aa..c9c15d09b60 100644
--- a/src/Utilities/Idm/selector/IdmGwfDfnSelector.f90
+++ b/src/Utilities/Idm/selector/IdmGwfDfnSelector.f90
@@ -9,6 +9,7 @@ module IdmGwfDfnSelectorModule
   use GwfDisInputModule
   use GwfDisuInputModule
   use GwfDisvInputModule
+  use GwfDrnInputModule
   use GwfNpfInputModule
   use GwfWelInputModule
   use GwfNamInputModule
@@ -77,6 +78,11 @@ module IdmGwfDfnSelectorModule
     logical :: ncvert = .false.
     logical :: icvert = .false.
     logical :: ncpl = .false.
+    logical :: auxdepthname = .false.
+    logical :: mover = .false.
+    logical :: icubicsfac = .false.
+    logical :: elev = .false.
+    logical :: cond = .false.
     logical :: cellavg = .false.
     logical :: ithickstrt = .false.
     logical :: cvoptions = .false.
@@ -115,7 +121,6 @@ module IdmGwfDfnSelectorModule
     logical :: afrcsv = .false.
     logical :: fileout = .false.
     logical :: afrcsvfile = .false.
-    logical :: mover = .false.
     logical :: q = .false.
     logical :: list = .false.
     logical :: print_input = .false.
@@ -156,6 +161,8 @@ function gwf_param_definitions(subcomponent) result(input_definition)
       call set_param_pointer(input_definition, gwf_disu_param_definitions)
     case ('DISV')
       call set_param_pointer(input_definition, gwf_disv_param_definitions)
+    case ('DRN')
+      call set_param_pointer(input_definition, gwf_drn_param_definitions)
     case ('NPF')
       call set_param_pointer(input_definition, gwf_npf_param_definitions)
     case ('WEL')
@@ -180,6 +187,8 @@ function gwf_aggregate_definitions(subcomponent) result(input_definition)
       call set_param_pointer(input_definition, gwf_disu_aggregate_definitions)
     case ('DISV')
       call set_param_pointer(input_definition, gwf_disv_aggregate_definitions)
+    case ('DRN')
+      call set_param_pointer(input_definition, gwf_drn_aggregate_definitions)
     case ('NPF')
       call set_param_pointer(input_definition, gwf_npf_aggregate_definitions)
     case ('WEL')
@@ -204,6 +213,8 @@ function gwf_block_definitions(subcomponent) result(input_definition)
       call set_block_pointer(input_definition, gwf_disu_block_definitions)
     case ('DISV')
       call set_block_pointer(input_definition, gwf_disv_block_definitions)
+    case ('DRN')
+      call set_block_pointer(input_definition, gwf_drn_block_definitions)
     case ('NPF')
       call set_block_pointer(input_definition, gwf_npf_block_definitions)
     case ('WEL')
@@ -227,6 +238,8 @@ function gwf_idm_multi_package(subcomponent) result(multi_package)
       multi_package = gwf_disu_multi_package
     case ('DISV')
       multi_package = gwf_disv_multi_package
+    case ('DRN')
+      multi_package = gwf_drn_multi_package
     case ('NPF')
       multi_package = gwf_npf_multi_package
     case ('WEL')
@@ -253,6 +266,8 @@ function gwf_idm_sfac_param(subcomponent) result(sfac_param)
       sfac_param = gwf_disu_aux_sfac_param
     case ('DISV')
       sfac_param = gwf_disv_aux_sfac_param
+    case ('DRN')
+      sfac_param = gwf_drn_aux_sfac_param
     case ('NPF')
       sfac_param = gwf_npf_aux_sfac_param
     case ('WEL')
@@ -280,6 +295,8 @@ function gwf_idm_integrated(subcomponent) result(integrated)
       integrated = .true.
     case ('DISV')
       integrated = .true.
+    case ('DRN')
+      integrated = .true.
     case ('NPF')
       integrated = .true.
     case ('WEL')
diff --git a/src/meson.build b/src/meson.build
index 95ddd9532ba..83fc181b801 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -59,6 +59,7 @@ modflow_sources = files(
     'Model' / 'GroundWaterFlow' / 'gwf3disv8.f90',
     'Model' / 'GroundWaterFlow' / 'gwf3disv8idm.f90',
     'Model' / 'GroundWaterFlow' / 'gwf3drn8.f90',
+    'Model' / 'GroundWaterFlow' / 'gwf3drn8idm.f90',
     'Model' / 'GroundWaterFlow' / 'gwf3evt8.f90',
     'Model' / 'GroundWaterFlow' / 'gwf3ghb8.f90',
     'Model' / 'GroundWaterFlow' / 'gwf3hfb8.f90',
diff --git a/utils/idmloader/scripts/dfn2f90.py b/utils/idmloader/scripts/dfn2f90.py
index 905094238d6..1b8d67f3264 100644
--- a/utils/idmloader/scripts/dfn2f90.py
+++ b/utils/idmloader/scripts/dfn2f90.py
@@ -984,6 +984,10 @@ def _write_master_component(self, fh=None):
             Path("../../../doc/mf6io/mf6ivar/dfn", "gwf-disv.dfn"),
             Path("../../../src/Model/GroundWaterFlow", "gwf3disv8idm.f90"),
         ],
+        [
+            Path("../../../doc/mf6io/mf6ivar/dfn", "gwf-drn.dfn"),
+            Path("../../../src/Model/GroundWaterFlow", "gwf3drn8idm.f90"),
+        ],
         [
             Path("../../../doc/mf6io/mf6ivar/dfn", "gwf-npf.dfn"),
             Path("../../../src/Model/GroundWaterFlow", "gwf3npf8idm.f90"),
diff --git a/utils/mf5to6/make/makefile b/utils/mf5to6/make/makefile
index 61d820da428..6aeb41e0a59 100644
--- a/utils/mf5to6/make/makefile
+++ b/utils/mf5to6/make/makefile
@@ -5,10 +5,10 @@ include ./makedefaults
 
 # Define the source file directories
 SOURCEDIR1=../src
-SOURCEDIR2=../src/MF2005
-SOURCEDIR3=../src/NWT
-SOURCEDIR4=../src/LGR
-SOURCEDIR5=../src/Preproc
+SOURCEDIR2=../src/LGR
+SOURCEDIR3=../src/Preproc
+SOURCEDIR4=../src/MF2005
+SOURCEDIR5=../src/NWT
 SOURCEDIR6=../../../src/Utilities/Memory
 SOURCEDIR7=../../../src/Utilities/TimeSeries
 SOURCEDIR8=../../../src/Utilities