diff --git a/doc/mf6io/mf6ivar/dfn/gwe-lke.dfn b/doc/mf6io/mf6ivar/dfn/gwe-lke.dfn
index 9372178fa56..1463b9e79fa 100644
--- a/doc/mf6io/mf6ivar/dfn/gwe-lke.dfn
+++ b/doc/mf6io/mf6ivar/dfn/gwe-lke.dfn
@@ -294,7 +294,7 @@ tagged false
 in_record true
 reader urword
 longname boundary thermal conductivity
-description is the thermal conductivity of the interface between the aquifer cell and the lake.  
+description is the thermal conductivity of the material between the aquifer cell and the lake. The thickness of the material is defined by the variable RBTHCND.
 
 block packagedata
 name rbthcnd
diff --git a/doc/mf6io/mf6ivar/dfn/gwe-mwe.dfn b/doc/mf6io/mf6ivar/dfn/gwe-mwe.dfn
index 2aaea0ca537..e08f06ea081 100644
--- a/doc/mf6io/mf6ivar/dfn/gwe-mwe.dfn
+++ b/doc/mf6io/mf6ivar/dfn/gwe-mwe.dfn
@@ -294,7 +294,7 @@ tagged false
 in_record true
 reader urword
 longname thermal conductivity of the feature
-description is the thermal conductivity of the interface between the aquifer cell and the feature.
+description is the thermal conductivity of the material between the aquifer cell and the feature. The thickness of the material is defined by the variable FTHK.
 
 block packagedata
 name fthk
diff --git a/doc/mf6io/mf6ivar/dfn/gwe-sfe.dfn b/doc/mf6io/mf6ivar/dfn/gwe-sfe.dfn
index 3d0466f31ed..a5367c289b1 100644
--- a/doc/mf6io/mf6ivar/dfn/gwe-sfe.dfn
+++ b/doc/mf6io/mf6ivar/dfn/gwe-sfe.dfn
@@ -294,7 +294,7 @@ tagged false
 in_record true
 reader urword
 longname boundary thermal conductivity
-description is the thermal conductivity of the interface between the aquifer cell and the stream reach.  
+description is the thermal conductivity of the material between the aquifer cell and the stream reach. The thickness of the material is defined by the variable RBTHCND.
 
 block packagedata
 name rbthcnd