Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs
===================================================================
diff -u -re460b2bfa0cbeee7fb326bc1cae370719bb7cc8b -r34ba2c960e26c2b6acaddae12e7fcbe6f581f9bb
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision e460b2bfa0cbeee7fb326bc1cae370719bb7cc8b)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision 34ba2c960e26c2b6acaddae12e7fcbe6f581f9bb)
@@ -270,7 +270,6 @@
             {
                 validationResults.Add(RingtoetsCommonServiceResources.CalculationService_ValidateInput_No_hydraulic_boundary_location_selected);
             }
-            //TODO: Validate all the input parameters here, see WTI-926
 
             if (inputParameters.Structure == null)
             {
@@ -286,6 +285,9 @@
                     case ClosingStructureInflowModelType.LowSill:
                         validationResults.AddRange(ValidateLowSillCalculationInput(inputParameters));
                         break;
+                    case ClosingStructureInflowModelType.FloodedCulvert:
+                        validationResults.AddRange(ValidateFloodedCulverCalculationInput(inputParameters));
+                        break;
                     default:
                         throw new InvalidEnumArgumentException("inputParameters",
                                                                (int) inputParameters.InflowModelType,
@@ -344,10 +346,8 @@
 
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.StormDuration,
                                                                                    ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_StormDuration_DisplayName)));
-
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.InsideWaterLevel,
-                                                                                  ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_InsideWaterLevel_DisplayName)));
-
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_InsideWaterLevel_DisplayName)));
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.ModelFactorSuperCriticalFlow,
                                                                                    ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_ModelFactorSuperCriticalFlow_DisplayName)));
 
@@ -359,7 +359,6 @@
 
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.WidthFlowApertures,
                                                                                    ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_WidthFlowApertures_DisplayName)));
-
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.FlowWidthAtBottomProtection,
                                                                                    ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FlowWidthAtBottomProtection_DisplayName)));
             validationResults.AddRange(DistributionValidation.ValidateDistribution(input.StorageStructureArea,
@@ -373,6 +372,36 @@
             return validationResults;
         }
 
+        private static IEnumerable<string> ValidateFloodedCulverCalculationInput(ClosingStructuresInput input)
+        {
+            var validationResults = new List<string>();
+
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.StormDuration,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_StormDuration_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.InsideWaterLevel,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_InsideWaterLevel_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.DrainCoefficient,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_DrainCoefficient_DisplayName)));
+
+            if (IsInvalidNumber(input.FactorStormDurationOpenStructure))
+            {
+                validationResults.Add(string.Format(RingtoetsCommonServiceResources.Validation_ValidateInput_No_value_entered_for_ParameterName_0_,
+                                                    ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FactorStormDurationOpenStructure_DisplayName)));
+            }
+
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.AreaFlowApertures,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_AreaFlowApertures_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.FlowWidthAtBottomProtection,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FlowWidthAtBottomProtection_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.StorageStructureArea,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_StorageStructureArea_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.AllowedLevelIncreaseStorage,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_AllowedLevelIncreaseStorage_DisplayName)));
+            validationResults.AddRange(DistributionValidation.ValidateDistribution(input.CriticalOvertoppingDischarge,
+                                                                                   ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_CriticalOvertoppingDischarge_DisplayName)));
+            return validationResults;
+        }
+
         private static bool IsInvalidNumber(RoundedDouble value)
         {
             return double.IsNaN(value) || double.IsInfinity(value);