Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.Designer.cs
===================================================================
diff -u -r428346aca4810ed68d8778943246f581cb1a4386 -rbe8c50b3fa0529fda1fe17ddeae50055f958a0bd
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision 428346aca4810ed68d8778943246f581cb1a4386)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.Designer.cs	(.../Resources.Designer.cs)	(revision be8c50b3fa0529fda1fe17ddeae50055f958a0bd)
@@ -1031,6 +1031,16 @@
         }
         
         /// <summary>
+        ///   Looks up a localized string similar to Voor locatie &apos;{0}&apos; is geen toetspeil berekend..
+        /// </summary>
+        public static string PipingInputContextProperties_HydraulicBoundaryLocation_No_design_water_level_calculated {
+            get {
+                return ResourceManager.GetString("PipingInputContextProperties_HydraulicBoundaryLocation_No_design_water_level_calc" +
+                        "ulated", resourceCulture);
+            }
+        }
+        
+        /// <summary>
         ///   Looks up a localized resource of type System.Drawing.Bitmap.
         /// </summary>
         public static System.Drawing.Bitmap PipingInputIcon {
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.resx
===================================================================
diff -u -r428346aca4810ed68d8778943246f581cb1a4386 -rbe8c50b3fa0529fda1fe17ddeae50055f958a0bd
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.resx	(.../Resources.resx)	(revision 428346aca4810ed68d8778943246f581cb1a4386)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Properties/Resources.resx	(.../Resources.resx)	(revision be8c50b3fa0529fda1fe17ddeae50055f958a0bd)
@@ -577,4 +577,7 @@
   <data name="PipingInput_HydraulicBoundaryLocation_DisplayName" xml:space="preserve">
     <value>Locatie met hydraulische randvoorwaarden</value>
   </data>
+  <data name="PipingInputContextProperties_HydraulicBoundaryLocation_No_design_water_level_calculated" xml:space="preserve">
+    <value>Voor locatie '{0}' is geen toetspeil berekend.</value>
+  </data>
 </root>
\ No newline at end of file
Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingInputContextProperties.cs
===================================================================
diff -u -r428346aca4810ed68d8778943246f581cb1a4386 -rbe8c50b3fa0529fda1fe17ddeae50055f958a0bd
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingInputContextProperties.cs	(.../PipingInputContextProperties.cs)	(revision 428346aca4810ed68d8778943246f581cb1a4386)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/PipingInputContextProperties.cs	(.../PipingInputContextProperties.cs)	(revision be8c50b3fa0529fda1fe17ddeae50055f958a0bd)
@@ -201,7 +201,13 @@
             }
             set
             {
+                if (double.IsNaN(value.DesignWaterLevel))
+                {
+                    string message = string.Format(Resources.PipingInputContextProperties_HydraulicBoundaryLocation_No_design_water_level_calculated, value.Name);
+                    throw new ArgumentException(message);
+                }
                 data.WrappedData.HydraulicBoundaryLocation = value;
+                data.WrappedData.AssessmentLevel = value.DesignWaterLevel;
                 data.WrappedData.NotifyObservers();
             }
         }
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingInputContextPropertiesTest.cs
===================================================================
diff -u -r428346aca4810ed68d8778943246f581cb1a4386 -rbe8c50b3fa0529fda1fe17ddeae50055f958a0bd
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingInputContextPropertiesTest.cs	(.../PipingInputContextPropertiesTest.cs)	(revision 428346aca4810ed68d8778943246f581cb1a4386)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/PropertyClasses/PipingInputContextPropertiesTest.cs	(.../PipingInputContextPropertiesTest.cs)	(revision be8c50b3fa0529fda1fe17ddeae50055f958a0bd)
@@ -478,6 +478,82 @@
             mocks.ReplayAll();
         }
 
+        [Test]
+        public void HydraulicBoundaryLocation_DesignWaterLevelIsNaN_ThrowsArgumentException()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSectionMock = mocks.StrictMock<AssessmentSectionBase>();
+            var projectObserver = mocks.StrictMock<IObserver>();
+            mocks.ReplayAll();
+
+            var inputParameters = new PipingInput();
+            inputParameters.Attach(projectObserver);
+
+            var properties = new PipingInputContextProperties
+            {
+                Data = new PipingInputContext(inputParameters,
+                                              Enumerable.Empty<RingtoetsPipingSurfaceLine>(),
+                                              Enumerable.Empty<PipingSoilProfile>(),
+                                              assessmentSectionMock)
+            };
+
+            string testName = "TestName";
+            var hydraulicBoundaryLocation = new HydraulicBoundaryLocation(0, testName, 0, 0)
+            {
+                DesignWaterLevel = double.NaN
+            };
+
+            // Call
+            TestDelegate test = () => properties.HydraulicBoundaryLocation = hydraulicBoundaryLocation;
+
+            // Assert
+            var message = string.Format("Voor locatie '{0}' is geen toetspeil berekend.", testName);
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentException>(test, message);
+
+            Assert.AreEqual(0, properties.AssessmentLevelSellmeijer);
+            Assert.AreEqual(0, properties.AssessmentLevelUplift);
+
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void HydraulicBoundaryLocation_DesignWaterLevelSet_SetsAssessmentLevelToDesignWaterLevelAndNotifiesOnce()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSectionMock = mocks.StrictMock<AssessmentSectionBase>();
+            var projectObserver = mocks.StrictMock<IObserver>();
+            projectObserver.Expect(o => o.UpdateObserver()).Repeat.Times(1);
+            mocks.ReplayAll();
+
+            var inputParameters = new PipingInput();
+            inputParameters.Attach(projectObserver);
+
+            var properties = new PipingInputContextProperties
+            {
+                Data = new PipingInputContext(inputParameters,
+                                              Enumerable.Empty<RingtoetsPipingSurfaceLine>(),
+                                              Enumerable.Empty<PipingSoilProfile>(),
+                                              assessmentSectionMock)
+            };
+
+            double testLevel = new Random(21).NextDouble();
+            var hydraulicBoundaryLocation = new HydraulicBoundaryLocation(0, string.Empty, 0, 0)
+            {
+                DesignWaterLevel = testLevel
+            };
+
+            // Call
+            properties.HydraulicBoundaryLocation = hydraulicBoundaryLocation;
+
+            // Assert
+            Assert.AreEqual(testLevel, properties.AssessmentLevelSellmeijer);
+            Assert.AreEqual(testLevel, properties.AssessmentLevelUplift);
+
+            mocks.VerifyAll();
+        }
+
         private static RingtoetsPipingSurfaceLine ValidSurfaceLine(double xMin, double xMax)
         {
             var surfaceLine = new RingtoetsPipingSurfaceLine();