Index: test/Plugins/Wti/Wti.IO.Test/PipingSurfaceLinesCsvReaderTest.cs
===================================================================
diff -u -r8fe3ae6f129251f98795abd491315924ca707a76 -rf2284364cde43ab7969dd8f0fb038f846138ec41
--- test/Plugins/Wti/Wti.IO.Test/PipingSurfaceLinesCsvReaderTest.cs	(.../PipingSurfaceLinesCsvReaderTest.cs)	(revision 8fe3ae6f129251f98795abd491315924ca707a76)
+++ test/Plugins/Wti/Wti.IO.Test/PipingSurfaceLinesCsvReaderTest.cs	(.../PipingSurfaceLinesCsvReaderTest.cs)	(revision f2284364cde43ab7969dd8f0fb038f846138ec41)
@@ -5,6 +5,9 @@
 using DelftTools.TestUtils;
 
 using NUnit.Framework;
+
+using Wti.IO.Exceptions;
+
 using IOResources = Wti.IO.Properties.Resources;
 
 namespace Wti.IO.Test
@@ -144,6 +147,50 @@
             }
         }
 
+        [Test]
+        public void GetSurfaceLinesCount_FileCannotBeFound_ThrowCriticalFileReadException()
+        {
+            // Setup
+            string path = Path.Combine(testDataPath, "I_do_not_exist.csv");
+
+            // Precondition
+            Assert.IsFalse(File.Exists(path));
+
+            using (var reader = new PipingSurfaceLinesCsvReader(path))
+            {
+                // Call
+                TestDelegate call = () => reader.GetSurfaceLinesCount();
+
+                // Assert
+                var exception = Assert.Throws<CriticalFileReadException>(call);
+                var expectedMessage = string.Format(IOResources.Error_File_0_does_not_exist, path);
+                Assert.AreEqual(expectedMessage, exception.Message);
+                Assert.IsInstanceOf<FileNotFoundException>(exception.InnerException);
+            }
+        }
+
+        [Test]
+        public void GetSurfaceLinesCount_DirectoryCannotBeFound_ThrowCriticalFileReadException()
+        {
+            // Setup
+            string path = Path.Combine(testDataPath, "..", "this_folder_does_not_exist", "I_do_not_exist.csv");
+
+            // Precondition
+            Assert.IsFalse(File.Exists(path));
+
+            using (var reader = new PipingSurfaceLinesCsvReader(path))
+            {
+                // Call
+                TestDelegate call = () => reader.GetSurfaceLinesCount();
+
+                // Assert
+                var exception = Assert.Throws<CriticalFileReadException>(call);
+                var expectedMessage = string.Format(IOResources.Error_Directory_in_path_0_missing, path);
+                Assert.AreEqual(expectedMessage, exception.Message);
+                Assert.IsInstanceOf<DirectoryNotFoundException>(exception.InnerException);
+            }
+        }
+
         private void DoReadLine_OpenedValidFileWithHeaderAndTwoSurfaceLines_ReturnCreatedSurfaceLine()
         {
             // Setup