Index: DamEngine/trunk/src/Deltares.DamEngine.Data.Tests/Geotechnics/SoilProfile2DSurfaceLineHelperTests.cs
===================================================================
diff -u -r5127 -r5261
--- DamEngine/trunk/src/Deltares.DamEngine.Data.Tests/Geotechnics/SoilProfile2DSurfaceLineHelperTests.cs	(.../SoilProfile2DSurfaceLineHelperTests.cs)	(revision 5127)
+++ DamEngine/trunk/src/Deltares.DamEngine.Data.Tests/Geotechnics/SoilProfile2DSurfaceLineHelperTests.cs	(.../SoilProfile2DSurfaceLineHelperTests.cs)	(revision 5261)
@@ -544,4 +544,20 @@
                                                                        c.HeadPoint.X.IsNearEqual(curve.EndPoint.X) && c.HeadPoint.Z.IsNearEqual(curve.EndPoint.Z)));
 
     }
+    
+    [TestCase (0.0, 0, true)]
+    [TestCase (0.0, 3, false)]
+    [TestCase (1.0, 0, false)]
+    [Test]
+    public void TestIsLayerAboveOriginalSurfaceLine(double surfaceZ, int layer, bool expectedLayerAbove)
+    {
+        // Given
+        SurfaceLine2 surfaceLine = FactoryForSurfaceLines.CreateHorizontalSurfaceLine(surfaceZ, -50.0, 60.0);
+        SoilProfile2D soilProfile = FactoryForSoilProfiles.CreateSoilProfile2DWithSixSurfacesFormingTwoLayers();
+        soilProfile.Geometry.RegenerateGeometry();
+        // When
+        bool result = SoilProfile2DSurfaceLineHelper.IsLayerAboveOriginalSurfaceLine(soilProfile.Surfaces[layer], surfaceLine.Geometry);
+        // Then
+        Assert.That(result, Is.EqualTo(expectedLayerAbove));
+    }
 }
\ No newline at end of file
Index: DamEngine/trunk/src/Deltares.DamEngine.TestHelpers/Factories/FactoryForSurfaceLines.cs
===================================================================
diff -u -r5238 -r5261
--- DamEngine/trunk/src/Deltares.DamEngine.TestHelpers/Factories/FactoryForSurfaceLines.cs	(.../FactoryForSurfaceLines.cs)	(revision 5238)
+++ DamEngine/trunk/src/Deltares.DamEngine.TestHelpers/Factories/FactoryForSurfaceLines.cs	(.../FactoryForSurfaceLines.cs)	(revision 5261)
@@ -313,15 +313,15 @@
     /// Creates a horizontal surface line.
     /// </summary>
     /// <returns>surface line</returns>
-    public static SurfaceLine2 CreateHorizontalSurfaceLine(double level)
+    public static SurfaceLine2 CreateHorizontalSurfaceLine(double level, double left = -10, double right = 10)
     {
         var surfaceLine = new SurfaceLine2
         {
             Name = "HorizontalLine"
         };
 
-        surfaceLine.EnsurePointOfType(-10, level, CharacteristicPointType.SurfaceLevelOutside);
-        surfaceLine.EnsurePointOfType(10, level, CharacteristicPointType.SurfaceLevelInside);
+        surfaceLine.EnsurePointOfType(left, level, CharacteristicPointType.SurfaceLevelOutside);
+        surfaceLine.EnsurePointOfType(right, level, CharacteristicPointType.SurfaceLevelInside);
 
         surfaceLine.Geometry.SyncCalcPoints();
         return surfaceLine;
Index: DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilProfile2DSurfaceLineHelper.cs
===================================================================
diff -u -r5260 -r5261
--- DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilProfile2DSurfaceLineHelper.cs	(.../SoilProfile2DSurfaceLineHelper.cs)	(revision 5260)
+++ DamEngine/trunk/src/Deltares.DamEngine.Data/Geotechnics/SoilProfile2DSurfaceLineHelper.cs	(.../SoilProfile2DSurfaceLineHelper.cs)	(revision 5261)
@@ -343,7 +343,7 @@
         }
     }
 
-    private static bool IsLayerAboveOriginalSurfaceLine(SoilLayer2D layer, GeometryPointString surfaceLine)
+    internal static bool IsLayerAboveOriginalSurfaceLine(SoilLayer2D layer, GeometryPointString surfaceLine)
     {
         if (layer == null || surfaceLine == null)
         {