diff --git a/models/MRTModel.cpp b/models/MRTModel.cpp
index d4413b1b..86afd647 100644
--- a/models/MRTModel.cpp
+++ b/models/MRTModel.cpp
@@ -285,9 +285,9 @@ void ScaLBL_MRTModel::Run(){
 			As=sumReduce( Dm->Comm, As);
 			Hs=sumReduce( Dm->Comm, Hs);
 			Xs=sumReduce( Dm->Comm, Xs);
+			double h = Dm->voxel_length;
+			double absperm = h*h*mu*Mask->Porosity()*flow_rate / force_mag;
 			if (rank==0) {
-				double h = Dm->voxel_length;
-				double absperm = h*h*mu*Mask->Porosity()*flow_rate / force_mag;
 				printf("     %f\n",absperm);
 				FILE * log_file = fopen("Permeability.csv","a");
 				fprintf(log_file,"%i %.8g %.8g %.8g %.8g %.8g %.8g %.8g %.8g %.8g %.8g %.8g %.8g\n",timestep, Fx, Fy, Fz, mu,