Index: Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs
===================================================================
diff -u -rab5044d23f83bbc1b8906f23a2a541162c6e6464 -r376859993eadc6d75eea3e97d624b83a24e922b6
--- Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationService.cs)	(revision ab5044d23f83bbc1b8906f23a2a541162c6e6464)
+++ Ringtoets/GrassCoverErosionOutwards/src/Ringtoets.GrassCoverErosionOutwards.Service/GrassCoverErosionOutwardsWaveConditionsCalculationService.cs	(.../GrassCoverErosionOutwardsWaveConditionsCalculationService.cs)	(revision 376859993eadc6d75eea3e97d624b83a24e922b6)
@@ -127,14 +127,17 @@
                 failureMechanism.Contribution,
                 failureMechanism.GeneralInput.N);
             string preprocessorDirectory = assessmentSection.HydraulicBoundaryDatabase.EffectivePreprocessorDirectory();
-            RoundedDouble normativeAssessmentLevel = calculation.InputParameters.HydraulicBoundaryLocation?.DesignWaterLevelCalculation1.Output?.Result ?? RoundedDouble.NaN;
 
-            TotalWaterLevelCalculations = calculation.InputParameters.GetWaterLevels(normativeAssessmentLevel).Count();
+            RoundedDouble assessmentLevel = failureMechanism.GetAssessmentLevel(assessmentSection,
+                                                                                calculation.InputParameters.HydraulicBoundaryLocation,
+                                                                                calculation.InputParameters.CategoryType);
 
+            TotalWaterLevelCalculations = calculation.InputParameters.GetWaterLevels(assessmentLevel).Count();
+
             try
             {
                 IEnumerable<WaveConditionsOutput> outputs = CalculateWaveConditions(calculation.InputParameters,
-                                                                                    normativeAssessmentLevel,
+                                                                                    assessmentLevel,
                                                                                     a,
                                                                                     b,
                                                                                     c,