Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverterTests.cs
===================================================================
diff -u -r2961 -r2962
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverterTests.cs	(.../PlLinesToWaternetConverterTests.cs)	(revision 2961)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators.Tests/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverterTests.cs	(.../PlLinesToWaternetConverterTests.cs)	(revision 2962)
@@ -1,4 +1,5 @@
-using System.Data;
+using System;
+using System.Data;
 using Deltares.DamEngine.Data.General;
 using Deltares.DamEngine.Data.General.PlLines;
 using Deltares.DamEngine.Calculators.KernelWrappers.MacroStabilityCommon;
@@ -10,6 +11,49 @@
     public class PlLinesToWaternetConverterTests
     {
         [Test]
+        [TestCase(0)]
+        [TestCase(0.01)]
+        [TestCase(10)]
+        public void ConvertPlLineToWaternet_PlLinesFullyDefinedAtOrBelowSoil1DProfile_ReturnsExpectedWaternet(double offsetFromBottomOfProfile)
+        {
+            // Setup
+            var random = new Random(21);
+            double leftCoordinate = random.NextDouble();
+            double rightCoordinate = leftCoordinate + 1;
+            var penetrationLength = random.NextDouble();
+            
+            SoilProfile1D soilProfile = CreateSoilProfile1DForTest();
+            double bottomLevel = soilProfile.BottomLevel;
+            double plLineZCoordinate = bottomLevel - offsetFromBottomOfProfile;
+
+            var plLines = new PlLines();
+            PlLine plLine = plLines.Lines[PlLineType.Pl1];
+            plLine.Points.Add(new PlLinePoint(leftCoordinate, plLineZCoordinate));
+            plLine.Points.Add(new PlLinePoint(rightCoordinate, plLineZCoordinate));
+
+            plLine = plLines.Lines[PlLineType.Pl2];
+            plLine.Points.Add(new PlLinePoint(leftCoordinate, plLineZCoordinate));
+            plLine.Points.Add(new PlLinePoint(rightCoordinate, plLineZCoordinate));
+            
+            plLine = plLines.Lines[PlLineType.Pl3];
+            plLine.Points.Add(new PlLinePoint(leftCoordinate, plLineZCoordinate));
+            plLine.Points.Add(new PlLinePoint(rightCoordinate, plLineZCoordinate));
+
+            plLine = plLines.Lines[PlLineType.Pl4];
+            plLine.Points.Add(new PlLinePoint(leftCoordinate, plLineZCoordinate));
+            plLine.Points.Add(new PlLinePoint(rightCoordinate, plLineZCoordinate));
+
+            // Call
+            var waternet = PlLinesToWaternetConverter.ConvertPlLineToWaternet(plLines, soilProfile, penetrationLength, leftCoordinate, rightCoordinate);
+
+            // Assert
+            Assert.IsNull(waternet.PhreaticLine);
+            CollectionAssert.IsEmpty(waternet.HeadLineList);
+            CollectionAssert.IsEmpty(waternet.WaternetLineList);
+        }
+
+
+        [Test]
         public void TestConvertPlLinesToWaternet()
         {
             const double cDif = 0.0001;
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs
===================================================================
diff -u -r2961 -r2962
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs	(.../PlLinesToWaternetConverter.cs)	(revision 2961)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/PlLinesToWaternetConverter.cs	(.../PlLinesToWaternetConverter.cs)	(revision 2962)
@@ -24,19 +24,22 @@
             ThrowWhenSoilProfile1DIsNull(soilProfile1D);
             var waternet = new Waternet
             {
-                IsGenerated = false,
+                IsGenerated = false
             };
 
             var plLine1 = plLines.Lines[PlLineType.Pl1];
-            waternet.PhreaticLine = new PhreaticLine();
-            foreach (var plLinePoint in plLine1.Points)
+            if (plLine1 != null && !IsBelowSoilProfile(soilProfile1D, plLine1))
             {
-                waternet.PhreaticLine.Points.Add(plLinePoint);
+                waternet.PhreaticLine = new PhreaticLine();
+                foreach (var plLinePoint in plLine1.Points)
+                {
+                    waternet.PhreaticLine.Points.Add(plLinePoint);
+                }
             }
 
             var plLine = plLines.Lines[PlLineType.Pl2];
             var headLine = ConvertPlLineToHeadLine(plLine);
-            if (headLine != null)
+            if (headLine != null && !IsBelowSoilProfile(soilProfile1D, plLine))
             {
                 waternet.HeadLineList.Add(headLine);
                 if (soilProfile1D.BottomAquiferLayer != null)
@@ -50,7 +53,7 @@
 
             plLine = plLines.Lines[PlLineType.Pl3];
             headLine = ConvertPlLineToHeadLine(plLine);
-            if (headLine != null)
+            if (headLine != null && !IsBelowSoilProfile(soilProfile1D, plLine))
             {
                 waternet.HeadLineList.Add(headLine);
                 if (soilProfile1D.BottomAquiferLayer != null)
@@ -64,7 +67,7 @@
 
             plLine = plLines.Lines[PlLineType.Pl4];
             headLine = ConvertPlLineToHeadLine(plLine);
-            if (headLine != null)
+            if (headLine != null && !IsBelowSoilProfile(soilProfile1D, plLine))
             {
                 waternet.HeadLineList.Add(headLine);
                 if (soilProfile1D.InBetweenAquiferLayer != null)
@@ -79,6 +82,21 @@
             return waternet;
         }
 
+        private static bool IsBelowSoilProfile(SoilProfile1D soilProfile, PlLine line)
+        {
+            double bottomSoilProfileLevel = soilProfile.BottomLevel;
+
+            foreach (PlLinePoint point in line.Points)
+            {
+                if (point.Z <= bottomSoilProfileLevel)
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         internal static HeadLine ConvertPlLineToHeadLine(PlLine plLine)
         {
             HeadLine headLine = null;
@@ -129,7 +147,5 @@
                 throw new NoNullAllowedException(Resources.PlLinesToWaternetConverter_NoPlLinesDefined);
             }
         }
-
-
     }
 }