Index: Riskeer/Integration/src/Riskeer.Integration.Data/AssessmentSection.cs
===================================================================
diff -u -r8339953df3276b6c7b4a3d9f5a278e4c19e85be3 -r7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1
--- Riskeer/Integration/src/Riskeer.Integration.Data/AssessmentSection.cs	(.../AssessmentSection.cs)	(revision 8339953df3276b6c7b4a3d9f5a278e4c19e85be3)
+++ Riskeer/Integration/src/Riskeer.Integration.Data/AssessmentSection.cs	(.../AssessmentSection.cs)	(revision 7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1)
@@ -227,8 +227,6 @@
                 throw new ArgumentNullException(nameof(hydraulicBoundaryLocations));
             }
 
-            ClearHydraulicBoundaryLocationCalculations();
-
             foreach (HydraulicBoundaryLocation hydraulicBoundaryLocation in hydraulicBoundaryLocations)
             {
                 AddHydraulicBoundaryLocationCalculations(hydraulicBoundaryLocation);
Index: Riskeer/Integration/src/Riskeer.Integration.Plugin/Handlers/HydraulicBoundaryDataUpdateHandler.cs
===================================================================
diff -u -r70aabefc8bca8eb959a0909958d4d0465aaed144 -r7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1
--- Riskeer/Integration/src/Riskeer.Integration.Plugin/Handlers/HydraulicBoundaryDataUpdateHandler.cs	(.../HydraulicBoundaryDataUpdateHandler.cs)	(revision 70aabefc8bca8eb959a0909958d4d0465aaed144)
+++ Riskeer/Integration/src/Riskeer.Integration.Plugin/Handlers/HydraulicBoundaryDataUpdateHandler.cs	(.../HydraulicBoundaryDataUpdateHandler.cs)	(revision 7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1)
@@ -116,7 +116,7 @@
 
             hydraulicBoundaryData.Locations.AddRange(newHydraulicBoundaryLocations);
 
-            assessmentSection.SetHydraulicBoundaryLocationCalculations(hydraulicBoundaryData.Locations);
+            assessmentSection.SetHydraulicBoundaryLocationCalculations(newHydraulicBoundaryDatabase.Locations);
             duneLocationsReplacementHandler.Replace(hydraulicBoundaryData.Locations);
 
             var changedObjects = new List<IObservable>();
Index: Riskeer/Integration/test/Riskeer.Integration.Data.Test/AssessmentSectionTest.cs
===================================================================
diff -u -recbba2f636e82f8d94ee7deea09730e39190d2bb -r7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1
--- Riskeer/Integration/test/Riskeer.Integration.Data.Test/AssessmentSectionTest.cs	(.../AssessmentSectionTest.cs)	(revision ecbba2f636e82f8d94ee7deea09730e39190d2bb)
+++ Riskeer/Integration/test/Riskeer.Integration.Data.Test/AssessmentSectionTest.cs	(.../AssessmentSectionTest.cs)	(revision 7fc10264f0bb04fb75b3879b81dcb5ab8e7287f1)
@@ -273,40 +273,6 @@
         }
 
         [Test]
-        public void SetHydraulicBoundaryLocationCalculations_Always_PreviousCalculationsCleared()
-        {
-            // Setup
-            var random = new Random(21);
-            var assessmentSection = new AssessmentSection(random.NextEnumValue<AssessmentSectionComposition>());
-
-            var waterLevelCalculationsForTargetProbability = new HydraulicBoundaryLocationCalculationsForTargetProbability(0.1);
-            assessmentSection.WaterLevelCalculationsForUserDefinedTargetProbabilities.Add(waterLevelCalculationsForTargetProbability);
-
-            var waveHeightCalculationsForTargetProbability = new HydraulicBoundaryLocationCalculationsForTargetProbability(0.01);
-            assessmentSection.WaveHeightCalculationsForUserDefinedTargetProbabilities.Add(waveHeightCalculationsForTargetProbability);
-
-            assessmentSection.SetHydraulicBoundaryLocationCalculations(new HydraulicBoundaryLocation[]
-            {
-                new TestHydraulicBoundaryLocation()
-            });
-
-            // Precondition
-            CollectionAssert.IsNotEmpty(assessmentSection.WaterLevelCalculationsForSignalFloodingProbability);
-            CollectionAssert.IsNotEmpty(assessmentSection.WaterLevelCalculationsForMaximumAllowableFloodingProbability);
-            CollectionAssert.IsNotEmpty(waterLevelCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations);
-            CollectionAssert.IsNotEmpty(waveHeightCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations);
-
-            // Call
-            assessmentSection.SetHydraulicBoundaryLocationCalculations(Enumerable.Empty<HydraulicBoundaryLocation>());
-
-            // Assert
-            CollectionAssert.IsEmpty(assessmentSection.WaterLevelCalculationsForSignalFloodingProbability);
-            CollectionAssert.IsEmpty(assessmentSection.WaterLevelCalculationsForMaximumAllowableFloodingProbability);
-            CollectionAssert.IsEmpty(waterLevelCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations);
-            CollectionAssert.IsEmpty(waveHeightCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations);
-        }
-
-        [Test]
         public void SetHydraulicBoundaryLocationCalculations_MultipleHydraulicBoundaryLocations_SetsExpectedCalculations()
         {
             // Setup
@@ -333,6 +299,43 @@
             AssertDefaultHydraulicBoundaryLocationCalculations(assessmentSection, 1, hydraulicBoundaryLocation2);
         }
 
+        [Test]
+        public void GivenAssessmentSectionWithHydraulicBoundaryLocationCalculations_WhenSetHydraulicBoundaryLocationCalculations_ThenCalculationsAdded()
+        {
+            // Given
+            var random = new Random(21);
+            var assessmentSection = new AssessmentSection(random.NextEnumValue<AssessmentSectionComposition>());
+
+            var waterLevelCalculationsForTargetProbability = new HydraulicBoundaryLocationCalculationsForTargetProbability(0.1);
+            assessmentSection.WaterLevelCalculationsForUserDefinedTargetProbabilities.Add(waterLevelCalculationsForTargetProbability);
+
+            var waveHeightCalculationsForTargetProbability = new HydraulicBoundaryLocationCalculationsForTargetProbability(0.01);
+            assessmentSection.WaveHeightCalculationsForUserDefinedTargetProbabilities.Add(waveHeightCalculationsForTargetProbability);
+
+            assessmentSection.SetHydraulicBoundaryLocationCalculations(new HydraulicBoundaryLocation[]
+            {
+                new TestHydraulicBoundaryLocation()
+            });
+
+            // Precondition
+            Assert.AreEqual(1, assessmentSection.WaterLevelCalculationsForSignalFloodingProbability.Count());
+            Assert.AreEqual(1, assessmentSection.WaterLevelCalculationsForMaximumAllowableFloodingProbability.Count());
+            Assert.AreEqual(1, waterLevelCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations.Count);
+            Assert.AreEqual(1, waveHeightCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations.Count);
+
+            // When
+            assessmentSection.SetHydraulicBoundaryLocationCalculations(new HydraulicBoundaryLocation[]
+            {
+                new TestHydraulicBoundaryLocation()
+            });
+
+            // Then
+            Assert.AreEqual(2, assessmentSection.WaterLevelCalculationsForSignalFloodingProbability.Count());
+            Assert.AreEqual(2, assessmentSection.WaterLevelCalculationsForMaximumAllowableFloodingProbability.Count());
+            Assert.AreEqual(2, waterLevelCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations.Count);
+            Assert.AreEqual(2, waveHeightCalculationsForTargetProbability.HydraulicBoundaryLocationCalculations.Count);
+        }
+
         private static IEnumerable<TestCaseData> GetFailureMechanismInAssemblyStates()
         {
             yield return new TestCaseData(AssessmentSectionComposition.Dike, new[]