Index: Riskeer/Storage/src/Riskeer.Storage.Core/Create/HydraulicBoundaryDatabaseCreateExtensions.cs
===================================================================
diff -u -rfc6767838834f2e37a011e3b441413dec7036301 -r3a18b9a985e7ac9b0c946edd37b1d427fd4aaccd
--- Riskeer/Storage/src/Riskeer.Storage.Core/Create/HydraulicBoundaryDatabaseCreateExtensions.cs	(.../HydraulicBoundaryDatabaseCreateExtensions.cs)	(revision fc6767838834f2e37a011e3b441413dec7036301)
+++ Riskeer/Storage/src/Riskeer.Storage.Core/Create/HydraulicBoundaryDatabaseCreateExtensions.cs	(.../HydraulicBoundaryDatabaseCreateExtensions.cs)	(revision 3a18b9a985e7ac9b0c946edd37b1d427fd4aaccd)
@@ -39,22 +39,38 @@
         /// <param name="hydraulicBoundaryDatabase">The <see cref="HydraulicBoundaryDatabase"/> to create a
         /// <see cref="HydraulicBoundaryDatabaseEntity"/> for.</param>
         /// <param name="order">Index at which this instance resides inside its parent container.</param>
+        /// <param name="registry">The object keeping track of create operations.</param>
         /// <returns>A new <see cref="HydraulicBoundaryDatabaseEntity"/>.</returns>
-        /// <exception cref="ArgumentNullException">Thrown when <paramref name="hydraulicBoundaryDatabase"/> is <c>null</c>.</exception>
-        internal static HydraulicBoundaryDatabaseEntity Create(this HydraulicBoundaryDatabase hydraulicBoundaryDatabase, int order)
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="hydraulicBoundaryDatabase"/>
+        /// or <paramref name="registry"/> is <c>null</c>.</exception>
+        internal static HydraulicBoundaryDatabaseEntity Create(this HydraulicBoundaryDatabase hydraulicBoundaryDatabase,
+                                                               PersistenceRegistry registry, int order)
         {
             if (hydraulicBoundaryDatabase == null)
             {
                 throw new ArgumentNullException(nameof(hydraulicBoundaryDatabase));
             }
 
-            return new HydraulicBoundaryDatabaseEntity
+            if (registry == null)
             {
+                throw new ArgumentNullException(nameof(registry));
+            }
+
+            var entity = new HydraulicBoundaryDatabaseEntity
+            {
                 FilePath = hydraulicBoundaryDatabase.FilePath.DeepClone(),
                 Version = hydraulicBoundaryDatabase.Version.DeepClone(),
                 UsePreprocessorClosure = Convert.ToByte(hydraulicBoundaryDatabase.UsePreprocessorClosure),
                 Order = order
             };
+
+            for (var i = 0; i < hydraulicBoundaryDatabase.Locations.Count; i++)
+            {
+                HydraulicBoundaryLocation location = hydraulicBoundaryDatabase.Locations[i];
+                entity.HydraulicLocationEntities.Add(location.Create(registry, i));
+            }
+
+            return entity;
         }
     }
 }
\ No newline at end of file
Index: Riskeer/Storage/test/Riskeer.Storage.Core.Test/Create/HydraulicBoundaryDatabaseCreateExtensionsTest.cs
===================================================================
diff -u -rfc6767838834f2e37a011e3b441413dec7036301 -r3a18b9a985e7ac9b0c946edd37b1d427fd4aaccd
--- Riskeer/Storage/test/Riskeer.Storage.Core.Test/Create/HydraulicBoundaryDatabaseCreateExtensionsTest.cs	(.../HydraulicBoundaryDatabaseCreateExtensionsTest.cs)	(revision fc6767838834f2e37a011e3b441413dec7036301)
+++ Riskeer/Storage/test/Riskeer.Storage.Core.Test/Create/HydraulicBoundaryDatabaseCreateExtensionsTest.cs	(.../HydraulicBoundaryDatabaseCreateExtensionsTest.cs)	(revision 3a18b9a985e7ac9b0c946edd37b1d427fd4aaccd)
@@ -35,35 +35,56 @@
         public void Create_HydraulicBoundaryDatabaseNull_ThrowsArgumentNullException()
         {
             // Call
-            void Call() => HydraulicBoundaryDatabaseCreateExtensions.Create(null, 0);
+            void Call() => ((HydraulicBoundaryDatabase) null).Create(new PersistenceRegistry(), 0);
 
             // Assert
             var exception = Assert.Throws<ArgumentNullException>(Call);
             Assert.AreEqual("hydraulicBoundaryDatabase", exception.ParamName);
         }
-        
+
         [Test]
+        public void Create_RegistryNull_ThrowsArgumentNullException()
+        {
+            // Setup
+            var hydraulicBoundaryDatabase = new HydraulicBoundaryDatabase();
+
+            // Call
+            void Call() => hydraulicBoundaryDatabase.Create(null, 0);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(Call);
+            Assert.AreEqual("registry", exception.ParamName);
+        }
+
+        [Test]
         public void Create_ValidHydraulicBoundaryDatabase_ReturnsHydraulicBoundaryDatabaseEntity()
         {
             // Setup
             var random = new Random(21);
             int order = random.Next();
-            
+
             var hydraulicBoundaryDatabase = new HydraulicBoundaryDatabase
             {
                 FilePath = "hrdFilePath",
                 Version = "version",
-                UsePreprocessorClosure = random.NextBoolean()
+                UsePreprocessorClosure = random.NextBoolean(),
+                Locations =
+                {
+                    new HydraulicBoundaryLocation(-1, "name", 1, 2)
+                }
             };
 
             // Call
-            HydraulicBoundaryDatabaseEntity entity = hydraulicBoundaryDatabase.Create(order);
-            
+            HydraulicBoundaryDatabaseEntity entity = hydraulicBoundaryDatabase.Create(new PersistenceRegistry(), order);
+
             // Assert
             TestHelper.AssertAreEqualButNotSame(hydraulicBoundaryDatabase.FilePath, entity.FilePath);
             TestHelper.AssertAreEqualButNotSame(hydraulicBoundaryDatabase.Version, entity.Version);
             TestHelper.AssertAreEqualButNotSame(Convert.ToByte(hydraulicBoundaryDatabase.UsePreprocessorClosure), entity.UsePreprocessorClosure);
             TestHelper.AssertAreEqualButNotSame(order, entity.Order);
+
+            int expectedNrOfHydraulicBoundaryLocations = hydraulicBoundaryDatabase.Locations.Count;
+            Assert.AreEqual(expectedNrOfHydraulicBoundaryLocations, entity.HydraulicLocationEntities.Count);
         }
     }
 }
\ No newline at end of file