Index: Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs
===================================================================
diff -u -rdf9261fbb60c129167c1d6a2ca9aed6dc0885f07 -rebdbf01f6ab35a28b3a306145796ce532920af62
--- Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs	(.../StabilityPointStructuresCalculationService.cs)	(revision df9261fbb60c129167c1d6a2ca9aed6dc0885f07)
+++ Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Service/StabilityPointStructuresCalculationService.cs	(.../StabilityPointStructuresCalculationService.cs)	(revision ebdbf01f6ab35a28b3a306145796ce532920af62)
@@ -25,15 +25,12 @@
 using System.Linq;
 using log4net;
 using Ringtoets.Common.Data.AssessmentSection;
-using Ringtoets.Common.Data.FailureMechanism;
 using Ringtoets.Common.Data.Structures;
 using Ringtoets.Common.IO.HydraRing;
 using Ringtoets.Common.Service;
 using Ringtoets.Common.Service.ValidationRules;
-using Ringtoets.Common.Utils;
 using Ringtoets.HydraRing.Calculation.Calculator;
 using Ringtoets.HydraRing.Calculation.Calculator.Factory;
-using Ringtoets.HydraRing.Calculation.Data;
 using Ringtoets.HydraRing.Calculation.Data.Input.Structures;
 using Ringtoets.HydraRing.Calculation.Exceptions;
 using Ringtoets.StabilityPointStructures.Data;
@@ -290,7 +287,7 @@
                 calculation.InputParameters.StabilityLinearLoadModel.Mean,
                 calculation.InputParameters.StabilityLinearLoadModel.CoefficientOfVariation,
                 calculation.InputParameters.WidthFlowApertures.Mean,
-                calculation.InputParameters.WidthFlowApertures.CoefficientOfVariation);
+                calculation.InputParameters.WidthFlowApertures.StandardDeviation);
 
             return structuresStabilityPointLowSillLinearCalculationInput;
         }
@@ -362,7 +359,7 @@
                 calculation.InputParameters.StabilityQuadraticLoadModel.Mean,
                 calculation.InputParameters.StabilityQuadraticLoadModel.CoefficientOfVariation,
                 calculation.InputParameters.WidthFlowApertures.Mean,
-                calculation.InputParameters.WidthFlowApertures.CoefficientOfVariation);
+                calculation.InputParameters.WidthFlowApertures.StandardDeviation);
 
             return structuresStabilityPointLowSillQuadraticCalculationInput;
         }
@@ -601,8 +598,8 @@
                                      ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FactorStormDurationOpenStructure_DisplayName)),
                 new NumericInputRule(input.StructureNormalOrientation,
                                      ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_StructureNormalOrientation_DisplayName)),
-                new VariationCoefficientNormalDistributionRule(input.WidthFlowApertures,
-                                                               ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_WidthFlowApertures_DisplayName)),
+                new NormalDistributionRule(input.WidthFlowApertures,
+                                           ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_WidthFlowApertures_DisplayName)),
                 new LogNormalDistributionRule(input.FlowWidthAtBottomProtection,
                                               ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FlowWidthAtBottomProtection_DisplayName)),
                 new VariationCoefficientLogNormalDistributionRule(input.StorageStructureArea,
@@ -655,8 +652,8 @@
                                      ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FactorStormDurationOpenStructure_DisplayName)),
                 new NumericInputRule(input.StructureNormalOrientation,
                                      ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_StructureNormalOrientation_DisplayName)),
-                new VariationCoefficientNormalDistributionRule(input.WidthFlowApertures,
-                                                               ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_WidthFlowApertures_DisplayName)),
+                new NormalDistributionRule(input.WidthFlowApertures,
+                                           ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_WidthFlowApertures_DisplayName)),
                 new LogNormalDistributionRule(input.FlowWidthAtBottomProtection,
                                               ParameterNameExtractor.GetFromDisplayName(RingtoetsCommonFormsResources.Structure_FlowWidthAtBottomProtection_DisplayName)),
                 new VariationCoefficientLogNormalDistributionRule(input.StorageStructureArea,