Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.CalculatedInput/WaternetCalculationService.cs
===================================================================
diff -u -r68f204f50eaf5f1e881c18fb2d878a17c722f75a -re77815b31b213789da306754de0867d6cb2de105
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.CalculatedInput/WaternetCalculationService.cs	(.../WaternetCalculationService.cs)	(revision 68f204f50eaf5f1e881c18fb2d878a17c722f75a)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.CalculatedInput/WaternetCalculationService.cs	(.../WaternetCalculationService.cs)	(revision e77815b31b213789da306754de0867d6cb2de105)
@@ -20,6 +20,7 @@
 // All rights reserved.
 
 using System;
+using Core.Common.Base.Data;
 using Ringtoets.MacroStabilityInwards.CalculatedInput.Converters;
 using Ringtoets.MacroStabilityInwards.KernelWrapper.Calculators;
 using Ringtoets.MacroStabilityInwards.KernelWrapper.Calculators.Input;
@@ -42,12 +43,13 @@
         /// of the <see cref="IMacroStabilityInwardsWaternetInput"/>.
         /// </summary>
         /// <param name="input">The input to get the values from.</param>
+        /// <param name="assessmentLevel">The assessment level to use.</param>
         /// <returns>A calculated <see cref="MacroStabilityInwardsWaternet"/>,
         /// or an empty <see cref="MacroStabilityInwardsWaternet"/> when the Waternet
         /// could not be calculated.</returns>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="input"/>
         /// is <c>null</c>.</exception>
-        public static MacroStabilityInwardsWaternet CalculateExtreme(IMacroStabilityInwardsWaternetInput input)
+        public static MacroStabilityInwardsWaternet CalculateExtreme(IMacroStabilityInwardsWaternetInput input, RoundedDouble assessmentLevel)
         {
             if (input == null)
             {
@@ -56,7 +58,7 @@
 
             IWaternetCalculator calculator = MacroStabilityInwardsCalculatorFactory.Instance
                                                                                    .CreateWaternetExtremeCalculator(
-                                                                                       CreateExtremeCalculatorInput(input),
+                                                                                       CreateExtremeCalculatorInput(input, assessmentLevel),
                                                                                        MacroStabilityInwardsKernelWrapperFactory.Instance);
 
             try
@@ -116,11 +118,11 @@
             return new WaternetCalculatorInput(properties);
         }
 
-        private static WaternetCalculatorInput CreateExtremeCalculatorInput(IMacroStabilityInwardsWaternetInput input)
+        private static WaternetCalculatorInput CreateExtremeCalculatorInput(IMacroStabilityInwardsWaternetInput input, RoundedDouble assessmentLevel)
         {
             WaternetCalculatorInput.ConstructionProperties properties = CreateCalculatorInputConstructionProperties(input);
             properties.PhreaticLineOffsets = PhreaticLineOffsetsConverter.Convert(input.LocationInputExtreme);
-            properties.AssessmentLevel = input.AssessmentLevel;
+            properties.AssessmentLevel = assessmentLevel;
             properties.WaterLevelPolder = input.LocationInputExtreme.WaterLevelPolder;
             properties.PenetrationLength = input.LocationInputExtreme.PenetrationLength;
 
Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Primitives/IMacroStabilityInwardsWaternetInput.cs
===================================================================
diff -u -r90a9502badff5788374461a1b2179a5dd0e866a2 -re77815b31b213789da306754de0867d6cb2de105
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Primitives/IMacroStabilityInwardsWaternetInput.cs	(.../IMacroStabilityInwardsWaternetInput.cs)	(revision 90a9502badff5788374461a1b2179a5dd0e866a2)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.Primitives/IMacroStabilityInwardsWaternetInput.cs	(.../IMacroStabilityInwardsWaternetInput.cs)	(revision e77815b31b213789da306754de0867d6cb2de105)
@@ -35,12 +35,6 @@
         MacroStabilityInwardsSurfaceLine SurfaceLine { get; }
 
         /// <summary>
-        /// Gets the outside high water level.
-        /// [m+NAP]
-        /// </summary>
-        RoundedDouble AssessmentLevel { get; }
-
-        /// <summary>
         /// Gets the profile which contains a 2 dimensional definition of soil layers with properties.
         /// </summary>
         IMacroStabilityInwardsSoilProfileUnderSurfaceLine SoilProfileUnderSurfaceLine { get; }