Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/DikeProfiles/DikeProfileDataReader.cs
===================================================================
diff -u -rb1ec20c759f606a49e6acdf12c6409e78abcf21b -rb6a73e405591aa848377355d3f2d931cfbb91ff4
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/DikeProfiles/DikeProfileDataReader.cs	(.../DikeProfileDataReader.cs)	(revision b1ec20c759f606a49e6acdf12c6409e78abcf21b)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/DikeProfiles/DikeProfileDataReader.cs	(.../DikeProfileDataReader.cs)	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -74,6 +74,9 @@
         /// <item>A piece of text from the file cannot be converted in the expected variable type.</item>
         /// <item>A converted value is invalid.</item>
         /// <item>The file is incomplete.</item>
+        /// <item>A parameter is defined more then once.</item>
+        /// <item>The geometry points for either the dike or foreshore do not have monotonically
+        /// increasing X-coordinates.</item>
         /// </list></exception>
         public DikeProfileData ReadDikeProfileData(string filePath)
         {
@@ -613,9 +616,13 @@
         /// <param name="lineNumber">The line number.</param>
         /// <returns><c>True</c> if the text matches a DIJK key-value pair and has been
         /// validated successfully; <c>false</c> otherwise.</returns>
-        /// <exception cref="CriticalFileReadException">The value after the DIJK key
-        /// does not represent a valid number or any of read the parameters in the following
-        /// data block is invalid or has already been defined.</exception>
+        /// <exception cref="CriticalFileReadException">When
+        /// <list type="bullet">
+        /// <item>The value after the DIJK key does not represent a valid number.</item>
+        /// <item>Any of read the parameters in the following data block is invalid.</item>
+        /// <item>The parameter has already been defined.</item>
+        /// <item>The X-coordinates of the dike are not monotonically increasing.</item>
+        /// </list></exception>
         private bool TryReadDikeRoughnessPoints(string text, DikeProfileData data, TextReader reader, ref int lineNumber)
         {
             Match dikeGeometryMatch = new Regex(@"^DIJK(\s+(?<dikegeometry>.+?)?)?\s*$").Match(text);
@@ -648,7 +655,15 @@
 
                     RoughnessPoint roughnessPoint = ReadRoughnessPoint(text, lineNumber);
                     data.DikeGeometry[i] = roughnessPoint;
+
+                    if (i > 0)
+                    {
+                        ValidateDikePointsAreMonotonicallyIncreasing(roughnessPoint.Point,
+                                                                     data.DikeGeometry[i - 1].Point,
+                                                                     lineNumber);
+                    }
                 }
+
                 readParameters |= ParametersFoundInFile.DIJK;
                 return true;
             }
@@ -783,18 +798,36 @@
         }
 
         /// <summary>
+        /// Validates that two dike points are monotonically increasing.
+        /// </summary>
+        /// <param name="currentPoint">The current point.</param>
+        /// <param name="previousPoint">The previous point.</param>
+        /// <param name="lineNumber">The line number.</param>
+        /// <exception cref="CriticalFileReadException">When <paramref name="currentPoint"/>
+        /// has an X coordinate before or equal to that of <paramref name="previousPoint"/>.</exception>
+        private void ValidateDikePointsAreMonotonicallyIncreasing(Point2D currentPoint, Point2D previousPoint, int lineNumber)
+        {
+            if (currentPoint.X <= previousPoint.X)
+            {
+                throw CreateCriticalFileReadException(lineNumber, Resources.DikeProfileDataReader_ValidateDikePointsAreMonotonicallyIncreasing_Error_message);
+            }
+        }
+
+        /// <summary>
         /// Attempts to match the given text to a VOORLAND key-value pair. If a match is
         /// found, the data block is being read. If valid, the value is stored.
         /// </summary>
         /// <param name="text">The text of the VOORLAND key-value pair.</param>
         /// <param name="data">The data to be updated.</param>
         /// <param name="reader">The reader of the file.</param>
         /// <param name="lineNumber">The line number.</param>
-        /// <returns><c>True</c> if the text matches a VOORLAND key-value pair and has been
-        /// validated successfully; <c>false</c> otherwise.</returns>
-        /// <exception cref="CriticalFileReadException">The value after the VOORLAND key
-        /// does not represent a valid number or any of read the parameters in the following
-        /// data block is invalid or has already been defined.</exception>
+        /// <exception cref="CriticalFileReadException">When
+        /// <list type="bullet">
+        /// <item>The value after the VOORLAND key does not represent a valid number.</item>
+        /// <item>Any of read the parameters in the following data block is invalid.</item>
+        /// <item>The parameter has already been defined.</item>
+        /// <item>The X-coordinates of the foreshore are not monotonically increasing.</item>
+        /// </list></exception>
         private bool TryReadForeshoreRoughnessPoints(string text, DikeProfileData data, TextReader reader, ref int lineNumber)
         {
             Match foreshoreGeometryMatch = new Regex(@"^VOORLAND(\s+(?<foreshoregeometry>.+?)?)?\s*$").Match(text);
@@ -827,6 +860,13 @@
 
                     RoughnessPoint roughnessPoint = ReadRoughnessPoint(text, lineNumber);
                     data.ForeshoreGeometry[i] = roughnessPoint;
+
+                    if (i > 0)
+                    {
+                        ValidateForeshorePointsAreMonotonicallyIncreasing(roughnessPoint.Point,
+                                                                          data.ForeshoreGeometry[i - 1].Point,
+                                                                          lineNumber);
+                    }
                 }
                 readParameters |= ParametersFoundInFile.VOORLAND;
                 return true;
@@ -879,6 +919,22 @@
             }
         }
 
+        /// <summary>
+        /// Validates that two foreshore points are monotonically increasing.
+        /// </summary>
+        /// <param name="currentPoint">The current point.</param>
+        /// <param name="previousPoint">The previous point.</param>
+        /// <param name="lineNumber">The line number.</param>
+        /// <exception cref="CriticalFileReadException">When <paramref name="currentPoint"/>
+        /// has an X coordinate before or equal to that of <paramref name="previousPoint"/>.</exception>
+        private void ValidateForeshorePointsAreMonotonicallyIncreasing(Point2D currentPoint, Point2D previousPoint, int lineNumber)
+        {
+            if (currentPoint.X <= previousPoint.X)
+            {
+                throw CreateCriticalFileReadException(lineNumber, Resources.DikeProfileDataReader_ValidateForeshorePointsAreMonotonicallyIncreasing_Error_message);
+            }
+        }
+
         private bool TryReadMemo(string text, DikeProfileData data, StreamReader reader)
         {
             Match memoMatch = new Regex(@"^MEMO\s*$").Match(text);
Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.Designer.cs
===================================================================
diff -u -rb1ec20c759f606a49e6acdf12c6409e78abcf21b -rb6a73e405591aa848377355d3f2d931cfbb91ff4
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision b1ec20c759f606a49e6acdf12c6409e78abcf21b)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -328,6 +328,25 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Dijkgeometrie punten dienen X-coordinaten te hebben die monotoon strict toenemend zijn..
+        /// </summary>
+        internal static string DikeProfileDataReader_ValidateDikePointsAreMonotonicallyIncreasing_Error_message {
+            get {
+                return ResourceManager.GetString("DikeProfileDataReader_ValidateDikePointsAreMonotonicallyIncreasing_Error_message", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Voorlandgeometrie punten dienen X-coordinaten te hebben die monotoon strict toenemend zijn..
+        /// </summary>
+        internal static string DikeProfileDataReader_ValidateForeshorePointsAreMonotonicallyIncreasing_Error_message {
+            get {
+                return ResourceManager.GetString("DikeProfileDataReader_ValidateForeshorePointsAreMonotonicallyIncreasing_Error_mes" +
+                        "sage", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized string similar to De ingelezen Id ({0}) bevat spaties, welke niet zijn toegestaan..
         /// </summary>
         internal static string DikeProfileDataReader_ValidateId_Id_0_has_unsupported_white_space {
Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.resx
===================================================================
diff -u -rb1ec20c759f606a49e6acdf12c6409e78abcf21b -rb6a73e405591aa848377355d3f2d931cfbb91ff4
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.resx	(.../Resources.resx)	(revision b1ec20c759f606a49e6acdf12c6409e78abcf21b)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.IO/Properties/Resources.resx	(.../Resources.resx)	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -252,4 +252,10 @@
   <data name="DikeProfileDataReader_ValidateNoPriorParameterDefinition_Parameter_0_already_defined" xml:space="preserve">
     <value>De parameter {0} is al eerder in het bestand gedefinieerd.</value>
   </data>
+  <data name="DikeProfileDataReader_ValidateDikePointsAreMonotonicallyIncreasing_Error_message" xml:space="preserve">
+    <value>Dijkgeometrie punten dienen X-coordinaten te hebben die monotoon strict toenemend zijn.</value>
+  </data>
+  <data name="DikeProfileDataReader_ValidateForeshorePointsAreMonotonicallyIncreasing_Error_message" xml:space="preserve">
+    <value>Voorlandgeometrie punten dienen X-coordinaten te hebben die monotoon strict toenemend zijn.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/DikeProfiles/DikeProfileDataReaderTest.cs
===================================================================
diff -u -rb1ec20c759f606a49e6acdf12c6409e78abcf21b -rb6a73e405591aa848377355d3f2d931cfbb91ff4
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/DikeProfiles/DikeProfileDataReaderTest.cs	(.../DikeProfileDataReaderTest.cs)	(revision b1ec20c759f606a49e6acdf12c6409e78abcf21b)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/DikeProfiles/DikeProfileDataReaderTest.cs	(.../DikeProfileDataReaderTest.cs)	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -832,6 +832,30 @@
         }
 
         [Test]
+        [TestCase("faulty_dijkNotMonotonicallyIncreasingX_1.prfl", 20, "Dijk")]
+        [TestCase("faulty_dijkNotMonotonicallyIncreasingX_2.prfl", 18, "Dijk")]
+        [TestCase("faulty_voorlandNotMonotonicallyIncreasingX_1.prfl", 12, "Voorland")]
+        [TestCase("faulty_voorlandNotMonotonicallyIncreasingX_2.prfl", 11, "Voorland")]
+        public void ReadDikeProfileData_FaultyFileWithNotMonotonicallyIncreasingX_ThrowsCriticalFileReadException(
+            string faultyFileName, int expectedLineNumber, string expectedTypePrefix)
+        {
+            // Setup
+            string faultyFilePath = TestHelper.GetTestDataPath(TestDataPath.Ringtoets.GrassCoverErosionInwards.IO,
+                                                               Path.Combine("DikeProfiles", faultyFileName));
+
+            var reader = new DikeProfileDataReader();
+
+            // Call
+            TestDelegate call = () => reader.ReadDikeProfileData(faultyFilePath);
+
+            // Assert
+            string message = Assert.Throws<CriticalFileReadException>(call).Message;
+            string expectedMessage = string.Format("Fout bij het lezen van bestand '{0}' op regel {1}: {2}geometrie punten dienen X-coordinaten te hebben die monotoon strict toenemend zijn.",
+                                                   faultyFilePath, expectedLineNumber, expectedTypePrefix);
+            Assert.AreEqual(expectedMessage, message);
+        }
+
+        [Test]
         [TestCase("faulty_unparsableVoorland.prfl", "oidushp9t8w uyp394hp 983 94")]
         [TestCase("faulty_unparsableVoorland_noValue1.prfl", "")]
         [TestCase("faulty_unparsableVoorland_noValue2.prfl", "")]
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_1.prfl
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_1.prfl	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_1.prfl	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -0,0 +1,27 @@
+VERSIE	4.0
+ID	profiel004
+
+RICHTING	330
+
+DAM	0
+DAMHOOGTE	0.5
+
+VOORLAND	3
+-150.000	-9.000	1.000
+-100.000	-6.000	1.000
+-18.000	-6.000	1.000
+
+DAMWAND	0
+KRUINHOOGTE	6
+DIJK	5
+-18.000	-6.000	1.000
+-2.000	-0.100	0.500
+2.000	0.100	1.000
+2.000	2.300	1.000
+18.000	6.000	1.000
+
+MEMO
+Verkenning prfl format:
+geen dam
+voorland
+talud met (ruwe) berm
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_2.prfl
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_2.prfl	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_dijkNotMonotonicallyIncreasingX_2.prfl	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -0,0 +1,26 @@
+VERSIE	4.0
+ID	profiel004
+
+RICHTING	330
+
+DAM	0
+DAMHOOGTE	0.5
+
+VOORLAND	3
+-150.000	-9.000	1.000
+-100.000	-6.000	1.000
+-18.000	-6.000	1.000
+
+DAMWAND	0
+KRUINHOOGTE	6
+DIJK	4
+18.000	6.000	1.000
+2.000	0.100	1.000
+-2.000	-0.100	0.500
+-18.000	-6.000	1.000
+
+MEMO
+Verkenning prfl format:
+geen dam
+voorland
+talud met (ruwe) berm
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_1.prfl
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_1.prfl	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_1.prfl	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -0,0 +1,27 @@
+VERSIE	4.0
+ID	profiel004
+
+RICHTING	330
+
+DAM	0
+DAMHOOGTE	0.5
+
+VOORLAND	4
+-150.000	-9.000	1.000
+-100.000	-6.000	1.000
+-100.000	-3.000	1.000
+-18.000	-3.000	1.000
+
+DAMWAND	0
+KRUINHOOGTE	6
+DIJK	4
+-18.000	-6.000	1.000
+-2.000	-0.100	0.500
+2.000	0.100	1.000
+18.000	6.000	1.000
+
+MEMO
+Verkenning prfl format:
+geen dam
+voorland
+talud met (ruwe) berm
Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_2.prfl
===================================================================
diff -u
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_2.prfl	(revision 0)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.IO.Test/test-data/DikeProfiles/faulty_voorlandNotMonotonicallyIncreasingX_2.prfl	(revision b6a73e405591aa848377355d3f2d931cfbb91ff4)
@@ -0,0 +1,26 @@
+VERSIE	4.0
+ID	profiel004
+
+RICHTING	330
+
+DAM	0
+DAMHOOGTE	0.5
+
+VOORLAND	3
+-18.000	-6.000	1.000
+-100.000	-6.000	1.000
+-150.000	-9.000	1.000
+
+DAMWAND	0
+KRUINHOOGTE	6
+DIJK	4
+-18.000	-6.000	1.000
+-2.000	-0.100	0.500
+2.000	0.100	1.000
+18.000	6.000	1.000
+
+MEMO
+Verkenning prfl format:
+geen dam
+voorland
+talud met (ruwe) berm