Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Application.Ringtoets.Storage.csproj
===================================================================
diff -u -rfe88135b797eda12b8e4d9b829036d2d7a52b10f -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Application.Ringtoets.Storage.csproj	(.../Application.Ringtoets.Storage.csproj)	(revision fe88135b797eda12b8e4d9b829036d2d7a52b10f)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Application.Ringtoets.Storage.csproj	(.../Application.Ringtoets.Storage.csproj)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -314,6 +314,7 @@
     <Compile Include="Read\DuneErosion\DuneLocationOutputEntityReadExtensions.cs" />
     <Compile Include="Read\ForeshoreProfileEntityReadExtensions.cs" />
     <Compile Include="Read\GrassCoverErosionInwards\GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs" />
+    <Compile Include="Read\GrassCoverErosionInwards\GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensions.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionInwardsFailureMechanismMetaEntityReadExtensions.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionOutwardsHydraulicLocationEntityReadExtensions.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionOutwardsWaveConditionsCalculationEntityReadExtensions.cs" />
Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensions.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensions.cs	(.../DikeHeightAssessmentOutputCreateExtensions.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensions.cs	(.../DikeHeightAssessmentOutputCreateExtensions.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -19,23 +19,34 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using Application.Ringtoets.Storage.DbContext;
 using Ringtoets.GrassCoverErosionInwards.Data;
 
 namespace Application.Ringtoets.Storage.Create.GrassCoverErosionInwards
 {
     /// <summary>
-    /// Extension methods for <see cref="SubCalculationAssessmentOutput"/> related to creating a <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>.
+    /// Extension methods for <see cref="SubCalculationAssessmentOutput"/>
+    /// related to creating a <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>
+    /// or a <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/>.
     /// </summary>
     internal static class DikeHeightAssessmentOutputCreateExtensions
     {
         /// <summary>
-        /// Creates a <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/> based on the information of the <see cref="SubCalculationAssessmentOutput"/>.
+        /// Creates a <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>
+        /// based on the information of the <see cref="SubCalculationAssessmentOutput"/>.
         /// </summary>
         /// <param name="output">The output to create a database entity for.</param>
         /// <returns>A new <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>.</returns>
-        internal static GrassCoverErosionInwardsDikeHeightOutputEntity Create(this SubCalculationAssessmentOutput output)
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="output"/>
+        /// is <c>null</c>.</exception>
+        internal static GrassCoverErosionInwardsDikeHeightOutputEntity CreateDikeHeight(this SubCalculationAssessmentOutput output)
         {
+            if (output == null)
+            {
+                throw new ArgumentNullException(nameof(output));
+            }
+
             return new GrassCoverErosionInwardsDikeHeightOutputEntity
             {
                 DikeHeight = double.IsNaN(output.Result)
@@ -56,5 +67,41 @@
                 CalculationConvergence = (byte) output.CalculationConvergence
             };
         }
+
+        /// <summary>
+        /// Creates a <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/>
+        /// based on the information of the <see cref="SubCalculationAssessmentOutput"/>.
+        /// </summary>
+        /// <param name="output">The output to create a database entity for.</param>
+        /// <returns>A new <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="output"/>
+        /// is <c>null</c>.</exception>
+        internal static GrassCoverErosionInwardsOvertoppingRateOutputEntity CreateOvertoppingRate(this SubCalculationAssessmentOutput output)
+        {
+            if (output == null)
+            {
+                throw new ArgumentNullException(nameof(output));
+            }
+
+            return new GrassCoverErosionInwardsOvertoppingRateOutputEntity
+            {
+                OvertoppingRate = double.IsNaN(output.Result)
+                                 ? (double?) null
+                                 : output.Result,
+                TargetProbability = double.IsNaN(output.TargetProbability)
+                                        ? (double?) null
+                                        : output.TargetProbability,
+                TargetReliability = double.IsNaN(output.TargetReliability)
+                                        ? (double?) null
+                                        : output.TargetReliability,
+                CalculatedProbability = double.IsNaN(output.CalculatedProbability)
+                                            ? (double?) null
+                                            : output.CalculatedProbability,
+                CalculatedReliability = double.IsNaN(output.CalculatedReliability)
+                                            ? (double?) null
+                                            : output.CalculatedReliability,
+                CalculationConvergence = (byte) output.CalculationConvergence
+            };
+        }
     }
 }
\ No newline at end of file
Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensions.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensions.cs	(.../GrassCoverErosionInwardsOutputCreateExtensions.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensions.cs	(.../GrassCoverErosionInwardsOutputCreateExtensions.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -52,17 +52,27 @@
             };
 
             AddEntityForDikeHeightAssessmentOutput(entity, output.DikeHeightAssessmentOutput);
+            AddEntityForOvertoppingRateAssessmentOutput(entity, output.OvertoppingRateAssessmentOutput);
 
             return entity;
         }
 
-        private static void AddEntityForDikeHeightAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity, SubCalculationAssessmentOutput output)
+        private static void AddEntityForDikeHeightAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity,
+                                                                   SubCalculationAssessmentOutput output)
         {
-            if (output == null)
+            if (output != null)
             {
-                return;
+                entity.GrassCoverErosionInwardsDikeHeightOutputEntities.Add(output.CreateDikeHeight());
             }
-            entity.GrassCoverErosionInwardsDikeHeightOutputEntities.Add(output.Create());
         }
+
+        private static void AddEntityForOvertoppingRateAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity,
+                                                                        SubCalculationAssessmentOutput output)
+        {
+            if (output != null)
+            {
+                entity.GrassCoverErosionInwardsOvertoppingRateOutputEntities.Add(output.CreateOvertoppingRate());
+            }
+        }
     }
 }
\ No newline at end of file
Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs	(.../GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs	(.../GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -19,25 +19,35 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using Application.Ringtoets.Storage.DbContext;
 using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.GrassCoverErosionInwards.Data;
 
 namespace Application.Ringtoets.Storage.Read.GrassCoverErosionInwards
 {
     /// <summary>
-    /// Extension methods for <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/> related to creating 
-    /// a <see cref="SubCalculationAssessmentOutput"/>.
+    /// Extension methods for <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>
+    /// related to creating a <see cref="SubCalculationAssessmentOutput"/>.
     /// </summary>
     internal static class GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensions
     {
         /// <summary>
-        /// Reads the <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/> and use the information to construct a <see cref="SubCalculationAssessmentOutput"/>.
+        /// Reads the <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/> and use
+        /// the information to construct a <see cref="SubCalculationAssessmentOutput"/>.
         /// </summary>
-        /// <param name="entity">The <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/> to create <see cref="SubCalculationAssessmentOutput"/> for.</param>
+        /// <param name="entity">The <see cref="GrassCoverErosionInwardsDikeHeightOutputEntity"/>
+        /// to create <see cref="SubCalculationAssessmentOutput"/> for.</param>
         /// <returns>A new <see cref="SubCalculationAssessmentOutput"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="entity"/>
+        /// is <c>null</c>.</exception>
         internal static SubCalculationAssessmentOutput Read(this GrassCoverErosionInwardsDikeHeightOutputEntity entity)
         {
+            if (entity == null)
+            {
+                throw new ArgumentNullException(nameof(entity));
+            }
+
             return new SubCalculationAssessmentOutput(entity.DikeHeight.ToNullAsNaN(),
                                                   entity.TargetProbability.ToNullAsNaN(),
                                                   entity.TargetReliability.ToNullAsNaN(),
Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputEntityReadExtensions.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputEntityReadExtensions.cs	(.../GrassCoverErosionInwardsOutputEntityReadExtensions.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputEntityReadExtensions.cs	(.../GrassCoverErosionInwardsOutputEntityReadExtensions.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -46,7 +46,7 @@
                                                       Convert.ToBoolean(entity.IsOvertoppingDominant),
                                                       ReadProbabilityAssessmentOutput(entity),
                                                       GetDikeHeightAssessmentOutput(entity),
-                                                      null);
+                                                      GetOvertoppingRateAssessmentOutput(entity));
         }
 
         private static ProbabilityAssessmentOutput ReadProbabilityAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity)
@@ -61,7 +61,13 @@
         private static SubCalculationAssessmentOutput GetDikeHeightAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity)
         {
             GrassCoverErosionInwardsDikeHeightOutputEntity dikeHeightOutputEntity = entity.GrassCoverErosionInwardsDikeHeightOutputEntities.FirstOrDefault();
-            return dikeHeightOutputEntity != null ? dikeHeightOutputEntity.Read() : null;
+            return dikeHeightOutputEntity?.Read();
         }
+
+        private static SubCalculationAssessmentOutput GetOvertoppingRateAssessmentOutput(GrassCoverErosionInwardsOutputEntity entity)
+        {
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity overtoppingRateOutputEntity = entity.GrassCoverErosionInwardsOvertoppingRateOutputEntities.FirstOrDefault();
+            return overtoppingRateOutputEntity?.Read();
+        }
     }
 }
\ No newline at end of file
Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensions.cs
===================================================================
diff -u
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensions.cs	(revision 0)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensions.cs	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -0,0 +1,59 @@
+// Copyright (C) Stichting Deltares 2016. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using Application.Ringtoets.Storage.DbContext;
+using Ringtoets.Common.Data.Hydraulics;
+using Ringtoets.GrassCoverErosionInwards.Data;
+
+namespace Application.Ringtoets.Storage.Read.GrassCoverErosionInwards
+{
+    /// <summary>
+    /// Extension methods for <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/>
+    /// related to creating a <see cref="SubCalculationAssessmentOutput"/>.
+    /// </summary>
+    internal static class GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensions
+    {
+        /// <summary>
+        /// Reads the <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/> and use
+        /// the information to construct a <see cref="SubCalculationAssessmentOutput"/>.
+        /// </summary>
+        /// <param name="entity">The <see cref="GrassCoverErosionInwardsOvertoppingRateOutputEntity"/>
+        /// to create <see cref="SubCalculationAssessmentOutput"/> for.</param>
+        /// <returns>A new <see cref="SubCalculationAssessmentOutput"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="entity"/>
+        /// is <c>null</c>.</exception>
+        internal static SubCalculationAssessmentOutput Read(this GrassCoverErosionInwardsOvertoppingRateOutputEntity entity)
+        {
+            if (entity == null)
+            {
+                throw new ArgumentNullException(nameof(entity));
+            }
+
+            return new SubCalculationAssessmentOutput(entity.OvertoppingRate.ToNullAsNaN(),
+                                                      entity.TargetProbability.ToNullAsNaN(),
+                                                      entity.TargetReliability.ToNullAsNaN(),
+                                                      entity.CalculatedProbability.ToNullAsNaN(),
+                                                      entity.CalculatedReliability.ToNullAsNaN(),
+                                                      (CalculationConvergence) entity.CalculationConvergence);
+        }
+    }
+}
\ No newline at end of file
Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Application.Ringtoets.Storage.Test.csproj
===================================================================
diff -u -r5c1a60942a2effc207d546054d4832f4aabe8ba5 -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Application.Ringtoets.Storage.Test.csproj	(.../Application.Ringtoets.Storage.Test.csproj)	(revision 5c1a60942a2effc207d546054d4832f4aabe8ba5)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Application.Ringtoets.Storage.Test.csproj	(.../Application.Ringtoets.Storage.Test.csproj)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -112,6 +112,7 @@
     <Compile Include="Read\ForeshoreProfileReadExtensionsTest.cs" />
     <Compile Include="Create\ForeshoreProfileCreateExtensionsTest.cs" />
     <Compile Include="Read\GrassCoverErosionInwards\GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs" />
+    <Compile Include="Read\GrassCoverErosionInwards\GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensionsTest.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionOutwardsHydraulicLocationEntityReadExtensionsTest.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionOutwardsWaveConditionsCalculationEntityReadExtensionsTest.cs" />
     <Compile Include="Read\GrassCoverErosionOutwards\GrassCoverErosionOutwardsWaveConditionsOutputEntityReadExtensionsTest.cs" />
Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensionsTest.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensionsTest.cs	(.../DikeHeightAssessmentOutputCreateExtensionsTest.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/DikeHeightAssessmentOutputCreateExtensionsTest.cs	(.../DikeHeightAssessmentOutputCreateExtensionsTest.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -34,16 +34,30 @@
     public class DikeHeightAssessmentOutputCreateExtensionsTest
     {
         [Test]
-        public void Create_WithValidParameters_ReturnsGrassCoverErosionInwardsDikeHeightOutputEntityWithOutputSet()
+        public void CreateDikeHeight_OutputNull_ThrowArgumentNullException()
         {
             // Setup
+            SubCalculationAssessmentOutput output = null;
+
+            // Call
+            TestDelegate test = () => output.CreateDikeHeight();
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("output", exception.ParamName);
+        }
+
+        [Test]
+        public void CreateDikeHeight_WithValidParameters_ReturnsGrassCoverErosionInwardsDikeHeightOutputEntityWithOutputSet()
+        {
+            // Setup
             var random = new Random(21);
             var output = new SubCalculationAssessmentOutput(
                 random.NextDouble(), random.NextDouble(), random.NextDouble(), random.NextDouble(),
                 random.NextDouble(), random.NextEnumValue<CalculationConvergence>());
 
             // Call
-            GrassCoverErosionInwardsDikeHeightOutputEntity entity = output.Create();
+            GrassCoverErosionInwardsDikeHeightOutputEntity entity = output.CreateDikeHeight();
 
             // Assert
             Assert.IsNotNull(entity);
@@ -56,15 +70,15 @@
         }
 
         [Test]
-        public void Create_WithNaNParameters_ReturnsGrassCoverErosionInwardsDikeHeightOutputEntityWithOutputNull()
+        public void CreateDikeHeight_WithNaNParameters_ReturnsGrassCoverErosionInwardsDikeHeightOutputEntityWithOutputNull()
         {
             // Setup
             var random = new Random(21);
             var output = new SubCalculationAssessmentOutput(double.NaN, double.NaN, double.NaN,
-                                                        double.NaN, double.NaN, random.NextEnumValue<CalculationConvergence>());
+                                                            double.NaN, double.NaN, random.NextEnumValue<CalculationConvergence>());
 
             // Call
-            GrassCoverErosionInwardsDikeHeightOutputEntity entity = output.Create();
+            GrassCoverErosionInwardsDikeHeightOutputEntity entity = output.CreateDikeHeight();
 
             // Assert
             Assert.IsNotNull(entity);
@@ -75,5 +89,62 @@
             Assert.IsNull(entity.CalculatedReliability);
             Assert.AreEqual((byte) output.CalculationConvergence, entity.CalculationConvergence);
         }
+
+        [Test]
+        public void CreateOvertoppingRate_OutputNull_ThrowArgumentNullException()
+        {
+            // Setup
+            SubCalculationAssessmentOutput output = null;
+
+            // Call
+            TestDelegate test = () => output.CreateOvertoppingRate();
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("output", exception.ParamName);
+        }
+
+        [Test]
+        public void CreateOvertoppingRate_WithValidParameters_ReturnsGrassCoverErosionInwardsOvertoppingRateOutputEntityWithOutputSet()
+        {
+            // Setup
+            var random = new Random(21);
+            var output = new SubCalculationAssessmentOutput(
+                random.NextDouble(), random.NextDouble(), random.NextDouble(), random.NextDouble(),
+                random.NextDouble(), random.NextEnumValue<CalculationConvergence>());
+
+            // Call
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity entity = output.CreateOvertoppingRate();
+
+            // Assert
+            Assert.IsNotNull(entity);
+            Assert.AreEqual(output.Result, entity.OvertoppingRate, output.Result.GetAccuracy());
+            Assert.AreEqual(output.TargetProbability, entity.TargetProbability);
+            Assert.AreEqual(output.TargetReliability, entity.TargetReliability, output.TargetReliability.GetAccuracy());
+            Assert.AreEqual(output.CalculatedProbability, entity.CalculatedProbability);
+            Assert.AreEqual(output.CalculatedReliability, entity.CalculatedReliability, output.CalculatedReliability.GetAccuracy());
+            Assert.AreEqual((byte) output.CalculationConvergence, entity.CalculationConvergence);
+        }
+
+        [Test]
+        public void CreateOvertoppingRate_WithNaNParameters_ReturnsGrassCoverErosionInwardsOvertoppingRateOutputEntityWithOutputNull()
+        {
+            // Setup
+            var random = new Random(21);
+            var output = new SubCalculationAssessmentOutput(double.NaN, double.NaN, double.NaN,
+                                                            double.NaN, double.NaN, random.NextEnumValue<CalculationConvergence>());
+
+            // Call
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity entity = output.CreateOvertoppingRate();
+
+            // Assert
+            Assert.IsNotNull(entity);
+            Assert.IsNull(entity.OvertoppingRate);
+            Assert.IsNull(entity.TargetProbability);
+            Assert.IsNull(entity.TargetReliability);
+            Assert.IsNull(entity.CalculatedProbability);
+            Assert.IsNull(entity.CalculatedReliability);
+            Assert.AreEqual((byte) output.CalculationConvergence, entity.CalculationConvergence);
+        }
     }
 }
\ No newline at end of file
Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensionsTest.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensionsTest.cs	(.../GrassCoverErosionInwardsOutputCreateExtensionsTest.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Create/GrassCoverErosionInwards/GrassCoverErosionInwardsOutputCreateExtensionsTest.cs	(.../GrassCoverErosionInwardsOutputCreateExtensionsTest.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -23,6 +23,7 @@
 using System.Linq;
 using Application.Ringtoets.Storage.Create.GrassCoverErosionInwards;
 using Application.Ringtoets.Storage.DbContext;
+using Core.Common.TestUtil;
 using NUnit.Framework;
 using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.Common.Data.Probability;
@@ -43,11 +44,16 @@
             var probabilityAssessmentOutput = new ProbabilityAssessmentOutput(random.NextDouble(), random.NextDouble(),
                                                                               random.NextDouble(), random.NextDouble(),
                                                                               random.NextDouble());
-            var dikeHeightConvergence = (CalculationConvergence) random.Next(1, Enum.GetValues(typeof(CalculationConvergence)).Length + 1);
+            var dikeHeightConvergence = random.NextEnumValue<CalculationConvergence>();
+            var overtoppingRateConvergence = random.NextEnumValue<CalculationConvergence>();
             var dikeHeightAssessmentOutput = new SubCalculationAssessmentOutput(random.NextDouble(), random.NextDouble(),
-                                                                            random.NextDouble(), random.NextDouble(),
-                                                                            random.NextDouble(), dikeHeightConvergence);
-            var output = new GrassCoverErosionInwardsOutput(random.NextDouble(), false, probabilityAssessmentOutput, dikeHeightAssessmentOutput, null);
+                                                                                random.NextDouble(), random.NextDouble(),
+                                                                                random.NextDouble(), dikeHeightConvergence);
+            var overtoppingRateAssessmentOutput = new SubCalculationAssessmentOutput(random.NextDouble(), random.NextDouble(),
+                                                                                     random.NextDouble(), random.NextDouble(),
+                                                                                     random.NextDouble(), overtoppingRateConvergence);
+            var output = new GrassCoverErosionInwardsOutput(random.NextDouble(), false, probabilityAssessmentOutput,
+                                                            dikeHeightAssessmentOutput, overtoppingRateAssessmentOutput);
 
             // Call
             GrassCoverErosionInwardsOutputEntity entity = output.Create();
@@ -62,13 +68,21 @@
             Assert.AreEqual(probabilityAssessmentOutput.RequiredProbability, entity.RequiredProbability);
             Assert.AreEqual(probabilityAssessmentOutput.RequiredReliability.Value, entity.RequiredReliability);
 
-            var dikeHeightEntity = entity.GrassCoverErosionInwardsDikeHeightOutputEntities.First();
+            GrassCoverErosionInwardsDikeHeightOutputEntity dikeHeightEntity = entity.GrassCoverErosionInwardsDikeHeightOutputEntities.First();
             Assert.AreEqual(dikeHeightAssessmentOutput.Result, dikeHeightEntity.DikeHeight, dikeHeightAssessmentOutput.Result.GetAccuracy());
             Assert.AreEqual(dikeHeightAssessmentOutput.TargetProbability, dikeHeightEntity.TargetProbability);
             Assert.AreEqual(dikeHeightAssessmentOutput.TargetReliability, dikeHeightEntity.TargetReliability, dikeHeightAssessmentOutput.TargetReliability.GetAccuracy());
             Assert.AreEqual(dikeHeightAssessmentOutput.CalculatedProbability, dikeHeightEntity.CalculatedProbability);
             Assert.AreEqual(dikeHeightAssessmentOutput.CalculatedReliability, dikeHeightEntity.CalculatedReliability, dikeHeightAssessmentOutput.CalculatedReliability.GetAccuracy());
             Assert.AreEqual((byte) dikeHeightAssessmentOutput.CalculationConvergence, dikeHeightEntity.CalculationConvergence);
+
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity overtoppingRateEntity = entity.GrassCoverErosionInwardsOvertoppingRateOutputEntities.First();
+            Assert.AreEqual(overtoppingRateAssessmentOutput.Result, overtoppingRateEntity.OvertoppingRate, overtoppingRateAssessmentOutput.Result.GetAccuracy());
+            Assert.AreEqual(overtoppingRateAssessmentOutput.TargetProbability, overtoppingRateEntity.TargetProbability);
+            Assert.AreEqual(overtoppingRateAssessmentOutput.TargetReliability, overtoppingRateEntity.TargetReliability, overtoppingRateAssessmentOutput.TargetReliability.GetAccuracy());
+            Assert.AreEqual(overtoppingRateAssessmentOutput.CalculatedProbability, overtoppingRateEntity.CalculatedProbability);
+            Assert.AreEqual(overtoppingRateAssessmentOutput.CalculatedReliability, overtoppingRateEntity.CalculatedReliability, overtoppingRateAssessmentOutput.CalculatedReliability.GetAccuracy());
+            Assert.AreEqual((byte) overtoppingRateAssessmentOutput.CalculationConvergence, overtoppingRateEntity.CalculationConvergence);
         }
 
         [Test]
@@ -92,13 +106,21 @@
             Assert.IsNull(entity.RequiredProbability);
             Assert.IsNull(entity.RequiredReliability);
 
-            var dikeHeightEntity = entity.GrassCoverErosionInwardsDikeHeightOutputEntities.First();
+            GrassCoverErosionInwardsDikeHeightOutputEntity dikeHeightEntity = entity.GrassCoverErosionInwardsDikeHeightOutputEntities.First();
             Assert.IsNull(dikeHeightEntity.DikeHeight);
             Assert.IsNull(dikeHeightEntity.TargetProbability);
             Assert.IsNull(dikeHeightEntity.TargetReliability);
             Assert.IsNull(dikeHeightEntity.CalculatedProbability);
             Assert.IsNull(dikeHeightEntity.CalculatedReliability);
             Assert.AreEqual((byte) dikeHeightAssessmentOutput.CalculationConvergence, dikeHeightEntity.CalculationConvergence);
+
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity overtoppingRateEntity = entity.GrassCoverErosionInwardsOvertoppingRateOutputEntities.First();
+            Assert.IsNull(overtoppingRateEntity.OvertoppingRate);
+            Assert.IsNull(overtoppingRateEntity.TargetProbability);
+            Assert.IsNull(overtoppingRateEntity.TargetReliability);
+            Assert.IsNull(overtoppingRateEntity.CalculatedProbability);
+            Assert.IsNull(overtoppingRateEntity.CalculatedReliability);
+            Assert.AreEqual((byte) overtoppingRateAssessmentOutput.CalculationConvergence, overtoppingRateEntity.CalculationConvergence);
         }
 
         [Test]
@@ -114,5 +136,19 @@
             // Assert
             Assert.IsFalse(entity.GrassCoverErosionInwardsDikeHeightOutputEntities.Any());
         }
+
+        [Test]
+        public void Create_OvertoppingRateAssessmentOutputIsNull_NoOvertoppingRateOutputEntityCreated()
+        {
+            // Setup
+            var probabilityAssessmentOutput = new ProbabilityAssessmentOutput(1, 1, 1, 1, 1);
+            var output = new GrassCoverErosionInwardsOutput(1, true, probabilityAssessmentOutput, null, null);
+
+            // Call
+            GrassCoverErosionInwardsOutputEntity entity = output.Create();
+
+            // Assert
+            Assert.IsFalse(entity.GrassCoverErosionInwardsOvertoppingRateOutputEntities.Any());
+        }
     }
 }
\ No newline at end of file
Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs
===================================================================
diff -u -r8cb270db5fbcb82f19d6f3a390f083e9e0516d8c -reec680fe322aea5d1ecf8fdf1f14a273afdf6c53
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs	(.../GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs)	(revision 8cb270db5fbcb82f19d6f3a390f083e9e0516d8c)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs	(.../GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest.cs)	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -34,6 +34,20 @@
     public class GrassCoverErosionInwardsDikeHeightOutputEntityReadExtensionsTest
     {
         [Test]
+        public void Read_EntityNull_ThrowArgumentNullException()
+        {
+            // Setup
+            GrassCoverErosionInwardsDikeHeightOutputEntity entity = null;
+
+            // Call
+            TestDelegate test = () => entity.Read();
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("entity", exception.ParamName);
+        }
+
+        [Test]
         public void Read_ValidParameters_ReturnsDikeHeightAssessmentOutput()
         {
             // Setup
@@ -43,7 +57,7 @@
             double targetReliability = random.NextDouble();
             double calculatedProbability = random.NextDouble();
             double calculatedReliability = random.NextDouble();
-            CalculationConvergence convergence = random.NextEnumValue<CalculationConvergence>();
+            var convergence = random.NextEnumValue<CalculationConvergence>();
             var entity = new GrassCoverErosionInwardsDikeHeightOutputEntity
             {
                 DikeHeight = dikeHeight,
@@ -71,7 +85,7 @@
         {
             // Setup
             var random = new Random(22);
-            CalculationConvergence convergence = random.NextEnumValue<CalculationConvergence>();
+            var convergence = random.NextEnumValue<CalculationConvergence>();
             var entity = new GrassCoverErosionInwardsDikeHeightOutputEntity
             {
                 CalculationConvergence = (byte) convergence
Index: Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensionsTest.cs
===================================================================
diff -u
--- Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensionsTest.cs	(revision 0)
+++ Application/Ringtoets/test/Application.Ringtoets.Storage.Test/Read/GrassCoverErosionInwards/GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensionsTest.cs	(revision eec680fe322aea5d1ecf8fdf1f14a273afdf6c53)
@@ -0,0 +1,106 @@
+// Copyright (C) Stichting Deltares 2016. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using Application.Ringtoets.Storage.DbContext;
+using Application.Ringtoets.Storage.Read.GrassCoverErosionInwards;
+using Core.Common.TestUtil;
+using NUnit.Framework;
+using Ringtoets.Common.Data.Hydraulics;
+using Ringtoets.Common.Data.TestUtil;
+using Ringtoets.GrassCoverErosionInwards.Data;
+
+namespace Application.Ringtoets.Storage.Test.Read.GrassCoverErosionInwards
+{
+    [TestFixture]
+    public class GrassCoverErosionInwardsOvertoppingRateOutputEntityReadExtensionsTest
+    {
+        [Test]
+        public void Read_EntityNull_ThrowArgumentNullException()
+        {
+            // Setup
+            GrassCoverErosionInwardsOvertoppingRateOutputEntity entity = null;
+
+            // Call
+            TestDelegate test = () => entity.Read();
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("entity", exception.ParamName);
+        }
+
+        [Test]
+        public void Read_ValidParameters_ReturnsOvertoppingRateAssessmentOutput()
+        {
+            // Setup
+            var random = new Random(22);
+            double overtoppingRate = random.NextDouble();
+            double targetProbability = random.NextDouble();
+            double targetReliability = random.NextDouble();
+            double calculatedProbability = random.NextDouble();
+            double calculatedReliability = random.NextDouble();
+            var convergence = random.NextEnumValue<CalculationConvergence>();
+            var entity = new GrassCoverErosionInwardsOvertoppingRateOutputEntity
+            {
+                OvertoppingRate = overtoppingRate,
+                TargetProbability = targetProbability,
+                TargetReliability = targetReliability,
+                CalculatedProbability = calculatedProbability,
+                CalculatedReliability = calculatedReliability,
+                CalculationConvergence = (byte) convergence
+            };
+
+            // Call
+            SubCalculationAssessmentOutput output = entity.Read();
+
+            // Assert
+            Assert.AreEqual(overtoppingRate, output.Result, output.Result.GetAccuracy());
+            Assert.AreEqual(targetProbability, output.TargetProbability);
+            Assert.AreEqual(targetReliability, output.TargetReliability, output.TargetReliability.GetAccuracy());
+            Assert.AreEqual(calculatedProbability, output.CalculatedProbability);
+            Assert.AreEqual(calculatedReliability, output.CalculatedReliability, output.CalculatedReliability.GetAccuracy());
+            Assert.AreEqual(convergence, output.CalculationConvergence);
+        }
+
+        [Test]
+        public void Read_NullParameters_ReturnsOvertoppingRateAssessmentOutputWithNaN()
+        {
+            // Setup
+            var random = new Random(22);
+            var convergence = random.NextEnumValue<CalculationConvergence>();
+            var entity = new GrassCoverErosionInwardsOvertoppingRateOutputEntity
+            {
+                CalculationConvergence = (byte) convergence
+            };
+
+            // Call
+            SubCalculationAssessmentOutput output = entity.Read();
+
+            // Assert
+            Assert.IsNaN(output.Result);
+            Assert.IsNaN(output.TargetProbability);
+            Assert.IsNaN(output.TargetReliability);
+            Assert.IsNaN(output.CalculatedProbability);
+            Assert.IsNaN(output.CalculatedReliability);
+            Assert.AreEqual(convergence, output.CalculationConvergence);
+        }
+    }
+}
\ No newline at end of file