Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs
===================================================================
diff -u -rf8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e -ra2353e44937113273f8f48a0823965e79ea537cb
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision f8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision a2353e44937113273f8f48a0823965e79ea537cb)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using System.ComponentModel;
 using Ringtoets.ClosingStructures.Data;
 using Ringtoets.Common.Service;
@@ -44,8 +45,16 @@
                                                                          bool usePreprocessor)
         {
             StructuresClosureCalculationInput input;
-            switch (structureInput.InflowModelType)
+            ClosingStructureInflowModelType closingStructureInflowModelType = structureInput.InflowModelType;
+            if (!Enum.IsDefined(typeof(ClosingStructureInflowModelType), closingStructureInflowModelType))
             {
+                throw new InvalidEnumArgumentException(nameof(structureInput),
+                                                       (int) closingStructureInflowModelType,
+                                                       typeof(ClosingStructureInflowModelType));
+            }
+
+            switch (closingStructureInflowModelType)
+            {
                 case ClosingStructureInflowModelType.VerticalWall:
                     input = CreateClosureVerticalWallCalculationInput(structureInput, generalInput);
                     break;
@@ -56,9 +65,7 @@
                     input = CreateFloodedCulvertCalculationInput(structureInput, generalInput);
                     break;
                 default:
-                    throw new InvalidEnumArgumentException(nameof(structureInput),
-                                                           (int) structureInput.InflowModelType,
-                                                           typeof(ClosingStructureInflowModelType));
+                    throw new NotSupportedException($"The enum value {nameof(ClosingStructureInflowModelType)}.{closingStructureInflowModelType} is not supported.");
             }
 
             HydraRingSettingsDatabaseHelper.AssignSettingsFromDatabase(input, hydraulicBoundaryDatabaseFilePath, usePreprocessor);
Index: Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs
===================================================================
diff -u -r35525b6135cc111e4af3803f7dcce0d7528bbb16 -ra2353e44937113273f8f48a0823965e79ea537cb
--- Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs	(.../StructuresCalculationServiceBase.cs)	(revision 35525b6135cc111e4af3803f7dcce0d7528bbb16)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/Structures/StructuresCalculationServiceBase.cs	(.../StructuresCalculationServiceBase.cs)	(revision a2353e44937113273f8f48a0823965e79ea537cb)
@@ -95,8 +95,8 @@
         /// <param name="assessmentSection">The <see cref="IAssessmentSection"/> for which to validate the values.</param>
         /// <returns><c>true</c> if <paramref name="calculation"/> has no validation errors; <c>false</c> otherwise.</returns>
         /// <exception cref="ArgumentNullException">Thrown when any parameter is <c>null</c>.</exception>
-        /// <exception cref="InvalidEnumArgumentException">Thrown when an unexpected
-        /// enum value is encountered.</exception>
+        /// <exception cref="InvalidEnumArgumentException">Thrown when an invalid enum value is encountered.</exception>
+        /// <exception cref="NotSupportedException">Thrown when an unsupported enum value is encountered.</exception>
         public static bool Validate(StructuresCalculation<TStructureInput> calculation, IAssessmentSection assessmentSection)
         {
             if (calculation == null)
Index: Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs
===================================================================
diff -u -r997a7c7aec4c8fc0466687fe09b09463c4628a6b -ra2353e44937113273f8f48a0823965e79ea537cb
--- Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs	(.../StabilityPointStructuresCalculationService.cs)	(revision 997a7c7aec4c8fc0466687fe09b09463c4628a6b)
+++ Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs	(.../StabilityPointStructuresCalculationService.cs)	(revision a2353e44937113273f8f48a0823965e79ea537cb)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using System.ComponentModel;
 using Ringtoets.Common.Service;
 using Ringtoets.Common.Service.Structures;
@@ -48,56 +49,104 @@
                                                                                 bool usePreprocessor)
         {
             StructuresStabilityPointCalculationInput input;
-            switch (structureInput.InflowModelType)
+            StabilityPointStructureInflowModelType inflowModelType = structureInput.InflowModelType;
+            if (!Enum.IsDefined(typeof(StabilityPointStructureInflowModelType), inflowModelType))
             {
+                throw new InvalidEnumArgumentException(nameof(structureInput),
+                                                       (int)inflowModelType,
+                                                       typeof(StabilityPointStructureInflowModelType));
+            }
+
+            switch (inflowModelType)
+            {
                 case StabilityPointStructureInflowModelType.LowSill:
-                    switch (structureInput.LoadSchematizationType)
-                    {
-                        case LoadSchematizationType.Linear:
-                            input = CreateLowSillLinearCalculationInput(
-                                structureInput,
-                                generalInput);
-                            break;
-                        case LoadSchematizationType.Quadratic:
-                            input = CreateLowSillQuadraticCalculationInput(
-                                structureInput,
-                                generalInput);
-                            break;
-                        default:
-                            throw new InvalidEnumArgumentException(nameof(structureInput),
-                                                                   (int) structureInput.LoadSchematizationType,
-                                                                   typeof(LoadSchematizationType));
-                    }
+                    input = CreateLowSillInput(structureInput, generalInput);
                     break;
                 case StabilityPointStructureInflowModelType.FloodedCulvert:
-                    switch (structureInput.LoadSchematizationType)
-                    {
-                        case LoadSchematizationType.Linear:
-                            input = CreateFloodedCulvertLinearCalculationInput(
-                                structureInput,
-                                generalInput);
-                            break;
-                        case LoadSchematizationType.Quadratic:
-                            input = CreateFloodedCulvertQuadraticCalculationInput(
-                                structureInput,
-                                generalInput);
-                            break;
-                        default:
-                            throw new InvalidEnumArgumentException(nameof(structureInput),
-                                                                   (int) structureInput.LoadSchematizationType,
-                                                                   typeof(LoadSchematizationType));
-                    }
+                    input = CreateFloodedCulvertInput(structureInput, generalInput);
                     break;
                 default:
-                    throw new InvalidEnumArgumentException(nameof(structureInput),
-                                                           (int) structureInput.InflowModelType,
-                                                           typeof(StabilityPointStructureInflowModelType));
+                    throw new NotSupportedException($"The enum value {nameof(StabilityPointStructureInflowModelType)}.{inflowModelType} is not supported.");
             }
 
             HydraRingSettingsDatabaseHelper.AssignSettingsFromDatabase(input, hydraulicBoundaryDatabaseFilePath, usePreprocessor);
             return input;
         }
 
+        /// <summary>
+        /// Creates calculation input based on the <paramref name="structureInput"/> and <paramref name="generalInput"/>
+        /// for flooded culvert calculations.
+        /// </summary>
+        /// <param name="structureInput">The <see cref="StabilityPointStructuresInput"/> to base the calculation on.</param>
+        /// <param name="generalInput">The <see cref="GeneralStabilityPointStructuresInput"/> to base the calculation on.</param>
+        /// <returns>A configured <see cref="StructuresStabilityPointCalculationInput"/>.</returns>
+        /// <exception cref="InvalidEnumArgumentException">Thrown when <paramref name="structureInput"/> contains
+        /// an invalid value of <see cref="LoadSchematizationType"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when<paramref name="structureInput"/> contains
+        /// an unsupported value of <see cref="LoadSchematizationType"/> </exception>
+        private static StructuresStabilityPointCalculationInput CreateFloodedCulvertInput(StabilityPointStructuresInput structureInput,
+                                                                                          GeneralStabilityPointStructuresInput generalInput)
+        {
+            LoadSchematizationType loadSchematizationType = structureInput.LoadSchematizationType;
+            if (!Enum.IsDefined(typeof(LoadSchematizationType), loadSchematizationType))
+            {
+                throw new InvalidEnumArgumentException(nameof(structureInput),
+                                                       (int)loadSchematizationType,
+                                                       typeof(LoadSchematizationType));
+            }
+
+            switch (structureInput.LoadSchematizationType)
+            {
+                case LoadSchematizationType.Linear:
+                    return CreateFloodedCulvertLinearCalculationInput(
+                        structureInput,
+                        generalInput);
+                case LoadSchematizationType.Quadratic:
+                    return CreateFloodedCulvertQuadraticCalculationInput(
+                        structureInput,
+                        generalInput);
+                default:
+                    throw new NotSupportedException($"The enum value {nameof(LoadSchematizationType)}.{loadSchematizationType} is not supported.");
+            }
+        }
+
+        /// <summary>
+        /// Creates calculation input based on the <paramref name="structureInput"/> and <paramref name="generalInput"/>
+        /// for low sill calculations.
+        /// </summary>
+        /// <param name="structureInput">The <see cref="StabilityPointStructuresInput"/> to base the calculation on.</param>
+        /// <param name="generalInput">The <see cref="GeneralStabilityPointStructuresInput"/> to base the calculation on.</param>
+        /// <returns>A configured <see cref="StructuresStabilityPointCalculationInput"/>.</returns>
+        /// <exception cref="InvalidEnumArgumentException">Thrown when <paramref name="structureInput"/> contains
+        /// an invalid value of <see cref="LoadSchematizationType"/>.</exception>
+        /// <exception cref="NotSupportedException">Thrown when<paramref name="structureInput"/> contains
+        /// an unsupported value of <see cref="LoadSchematizationType"/> </exception>
+        private static StructuresStabilityPointCalculationInput CreateLowSillInput(StabilityPointStructuresInput structureInput,
+                                                                                   GeneralStabilityPointStructuresInput generalInput)
+        {
+            LoadSchematizationType loadSchematizationType = structureInput.LoadSchematizationType;
+            if (!Enum.IsDefined(typeof(LoadSchematizationType), loadSchematizationType))
+            {
+                throw new InvalidEnumArgumentException(nameof(structureInput),
+                                                       (int) loadSchematizationType,
+                                                       typeof(LoadSchematizationType));
+            }
+
+            switch (loadSchematizationType)
+            {
+                case LoadSchematizationType.Linear:
+                    return CreateLowSillLinearCalculationInput(
+                        structureInput,
+                        generalInput);
+                case LoadSchematizationType.Quadratic:
+                    return CreateLowSillQuadraticCalculationInput(
+                        structureInput,
+                        generalInput);
+                default:
+                    throw new NotSupportedException($"The enum value {nameof(LoadSchematizationType)}.{loadSchematizationType} is not supported.");
+            }
+        }
+
         private static StructuresStabilityPointLowSillLinearCalculationInput CreateLowSillLinearCalculationInput(
             StabilityPointStructuresInput structureInput,
             GeneralStabilityPointStructuresInput generalInput)