diff --git a/ProcessLib/LiquidFlow/Tests.cmake b/ProcessLib/LiquidFlow/Tests.cmake
index b0c7df40850436911324e3ca502db88e3e410ab3..8b394628e147cc9e2b279fa94ebc6d88c81753f3 100644
--- a/ProcessLib/LiquidFlow/Tests.cmake
+++ b/ProcessLib/LiquidFlow/Tests.cmake
@@ -364,3 +364,18 @@ AddTest(
time_dependent_heterogeneous_source_term_pcs_0_ts_120_t_1200.000000.vtu time_dependent_heterogeneous_source_term_pcs_0_ts_120_t_1200.000000.vtu pressure pressure 1e-7 1e-13
time_dependent_heterogeneous_source_term_pcs_0_ts_200_t_2000.000000.vtu time_dependent_heterogeneous_source_term_pcs_0_ts_200_t_2000.000000.vtu pressure pressure 1e-7 1e-13
)
+
+AddTest(
+ NAME LiquidFlow_Flux
+ PATH Parabolic/LiquidFlow/Flux
+ EXECUTABLE ogs
+ EXECUTABLE_ARGS cube_1e3_calculatesurfaceflux.prj
+ WRAPPER time
+ TESTER vtkdiff
+ REQUIREMENTS NOT OGS_USE_MPI
+ DIFF_DATA
+ cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.432000_expected.vtu cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.432000.vtu specific_flux specific_flux 1e-7 1e-13
+ cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.864000_expected.vtu cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.864000.vtu specific_flux specific_flux 1e-7 1e-13
+ LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_1_t_0.432000_expected.vtu LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_1_t_0.432000.vtu pressure pressure 1e-7 1e-13
+ LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_2_t_0.864000_expected.vtu LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_2_t_0.864000.vtu pressure pressure 1e-7 1e-13
+)
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_0_t_0.000000_expected.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_0_t_0.000000_expected.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..1bd0b3bfdf2645457f36b5b7ac66ea7af9677573
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_0_t_0.000000_expected.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3928650be26b5dc4a48e0a635fdfc20eaa912e48c32d6d8c6533c87fee70622b
+size 39859
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_1_t_0.432000_expected.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_1_t_0.432000_expected.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..03b608491d059f3a5df79c37ba27566a2e823c4a
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_1_t_0.432000_expected.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b4b22d3aa39091be0e2b9a1759f9824855175de911f58344b6686f59e43cd6f2
+size 46835
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_2_t_0.864000_expected.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_2_t_0.864000_expected.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..8fff68e1f419f1749e3f9f48de19849d5b2908f4
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/LF_cube_1e3_calculatesurfaceflux_pcs_0_ts_2_t_0.864000_expected.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01b5c7d2ce1ccedbb1a4fbe5a544ad502bf36ef47772db4cec78afc3c8e4f182
+size 46755
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1e3_calculatesurfaceflux.prj b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1e3_calculatesurfaceflux.prj
new file mode 100644
index 0000000000000000000000000000000000000000..b1b890a967422118e6b3d7e74759ff9046dbd1c0
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1e3_calculatesurfaceflux.prj
@@ -0,0 +1,177 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<OpenGeoSysProject>
+ <meshes>
+ <mesh>cube_1x1x1_hex_1e3.vtu</mesh>
+ <mesh>cube_1x1x1_hex_1e3_complete_surface.vtu</mesh>
+ <mesh>cube_1x1x1_hex_1e3_left.vtu</mesh>
+ <mesh>cube_1x1x1_hex_1e3_right.vtu</mesh>
+ </meshes>
+ <processes>
+ <process>
+ <name>LiquidFlow</name>
+ <type>LIQUID_FLOW</type>
+ <integration_order>2</integration_order>
+ <darcy_gravity>
+ <!-- axis_id: 0, 1, or the dimension of space minus one -->
+ <axis_id>0</axis_id>
+ <!-- g>=0. g=0: non gravity term -->
+ <g>0.</g>
+ </darcy_gravity>
+ <process_variables>
+ <process_variable>pressure</process_variable>
+ </process_variables>
+ <secondary_variables>
+ <secondary_variable internal_name="darcy_velocity" output_name="v"/>
+ </secondary_variables>
+ <calculatesurfaceflux>
+ <mesh>cube_1x1x1_hex_1e3_complete_surface</mesh>
+ <property_name>specific_flux</property_name>
+ <output_mesh>cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux.vtu</output_mesh>
+ </calculatesurfaceflux>
+ <material_property>
+ <fluid>
+ <density>
+ <type>Constant</type>
+ <value> 78.68 </value>
+ </density>
+ <viscosity>
+ <type>Constant</type>
+ <value> 1.295e-4 </value>
+ </viscosity>
+ </fluid>
+ <porous_medium>
+ <porous_medium id="0">
+ <permeability>
+ <permeability_tensor_entries>kappa1</permeability_tensor_entries>
+ <type>Constant</type>
+ </permeability>
+ <porosity>
+ <type>Constant</type>
+ <porosity_parameter>constant_porosity_parameter</porosity_parameter>
+ </porosity>
+ <storage>
+ <type>Constant</type>
+ <value> 8.05e-10 </value>
+ </storage>
+ </porous_medium>
+ </porous_medium>
+ </material_property>
+ </process>
+ </processes>
+ <time_loop>
+ <processes>
+ <process ref="LiquidFlow">
+ <nonlinear_solver>basic_picard</nonlinear_solver>
+ <convergence_criterion>
+ <type>DeltaX</type>
+ <norm_type>NORM2</norm_type>
+ <abstol>1.e-10</abstol>
+ </convergence_criterion>
+ <time_discretization>
+ <type>BackwardEuler</type>
+ </time_discretization>
+ <time_stepping>
+ <type>FixedTimeStepping</type>
+ <t_initial> 0.0 </t_initial>
+ <t_end> 0.864 </t_end>
+ <timesteps>
+ <pair>
+ <repeat>2</repeat>
+ <delta_t>0.432</delta_t>
+ </pair>
+ </timesteps>
+ </time_stepping>
+ </process>
+ </processes>
+ <output>
+ <type>VTK</type>
+ <prefix>LF_cube_1e3_calculatesurfaceflux</prefix>
+ <timesteps>
+ <pair>
+ <repeat> 1 </repeat>
+ <each_steps> 1 </each_steps>
+ </pair>
+ </timesteps>
+ <variables>
+ <variable> pressure </variable>
+ <variable> v </variable>
+ </variables>
+ </output>
+ </time_loop>
+ <parameters>
+ <parameter>
+ <name>p0</name>
+ <type>Constant</type>
+ <value>5e6</value>
+ </parameter>
+ <parameter>
+ <name>p_Dirichlet_left</name>
+ <type>Constant</type>
+ <value>1e7</value>
+ </parameter>
+ <parameter>
+ <name>p_Dirichlet_right</name>
+ <type>Constant</type>
+ <value>1e6</value>
+ </parameter>
+ <parameter>
+ <name>constant_porosity_parameter</name>
+ <type>Constant</type>
+ <value>1</value>
+ </parameter>
+ <parameter>
+ <name>kappa1</name>
+ <type>Constant</type>
+ <values>9.2e-12 0 0 0 9.2e-12 0 0 0 9.2e-12</values>
+ </parameter>
+ <parameter>
+ <name>p_spatial</name>
+ <type>Constant</type>
+ <value>1</value>
+ </parameter>
+ </parameters>
+ <process_variables>
+ <process_variable>
+ <name>pressure</name>
+ <components>1</components>
+ <order>1</order>
+ <initial_condition>p0</initial_condition>
+ <boundary_conditions>
+ <boundary_condition>
+ <mesh>cube_1x1x1_hex_1e3_left</mesh>
+ <type>Dirichlet</type>
+ <parameter>p_Dirichlet_left</parameter>
+ </boundary_condition>
+ <boundary_condition>
+ <mesh>cube_1x1x1_hex_1e3_right</mesh>
+ <type>Dirichlet</type>
+ <parameter>p_Dirichlet_right</parameter>
+ </boundary_condition>
+ </boundary_conditions>
+ </process_variable>
+ </process_variables>
+ <nonlinear_solvers>
+ <nonlinear_solver>
+ <name>basic_picard</name>
+ <type>Picard</type>
+ <max_iter>10</max_iter>
+ <linear_solver>general_linear_solver</linear_solver>
+ </nonlinear_solver>
+ </nonlinear_solvers>
+ <linear_solvers>
+ <linear_solver>
+ <name>general_linear_solver</name>
+ <lis>-i cg -p jacobi -tol 1e-16 -maxiter 10000</lis>
+ <eigen>
+ <solver_type>CG</solver_type>
+ <precon_type>DIAGONAL</precon_type>
+ <max_iteration_step>10000</max_iteration_step>
+ <error_tolerance>1e-16</error_tolerance>
+ </eigen>
+ <petsc>
+ <prefix>lf</prefix>
+ <parameters>-lf_ksp_type cg -lf_pc_type bjacobi -lf_ksp_rtol 1e-16 -lf_ksp_max_it 10000</parameters>
+ </petsc>
+ </linear_solver>
+ </linear_solvers>
+</OpenGeoSysProject>
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..500d9f815a5726e303aa4f8c220220c9bb517c7d
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f3e77b980dc0a4cefc19ba02eca4ad07ded3dc97497a01f169c719fc738a6bc9
+size 23197
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..303a9f426e18ba598faa5a55f8538f6f5d306b24
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4f405c070ea2cab30321345825eff7421fb1a5401cc2887a68da26e4e04d0b70
+size 65673
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.432000_expected.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.432000_expected.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..d2018339442f61f182df59373021b6109e692dfa
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.432000_expected.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c40d5de97b2704c8260f3afec3d5d381b6614b3b6121518535a90ec738764cac
+size 79556
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.864000_expected.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.864000_expected.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..4b51b65f9ec78cd50e344735f893baf7e1ec2932
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_complete_surface_left_right_dirichlet_specific_flux_t_0.864000_expected.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2e2fb642aa3ca416db53112da6cbceed72e2a74369297c48bd26964ee95dcdb6
+size 79556
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_left.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_left.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..0c67788fb0ebf2ae70ceb7434487759729ccbb57
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_left.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3b76bf4e7791dcd0431554367369cd2c49fd24c6d0784b73d55333667b73d1bc
+size 12897
diff --git a/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_right.vtu b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_right.vtu
new file mode 100644
index 0000000000000000000000000000000000000000..cb08cfb5227fb22b26a87ee682d0ba2e5a4f393a
--- /dev/null
+++ b/Tests/Data/Parabolic/LiquidFlow/Flux/cube_1x1x1_hex_1e3_right.vtu
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:efcc5a635b6616ee00d7f8df481c3dfedbab2984a2e5ffb317386095681d19e4
+size 12898