Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanSoilLayer.cs
===================================================================
diff -u -r313c23c7b7459821de6fd37e6389fb853c7ce2a4 -r906637928b5acd53b2e45c59ee448c700b03d82a
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanSoilLayer.cs	(.../UpliftVanSoilLayer.cs)	(revision 313c23c7b7459821de6fd37e6389fb853c7ce2a4)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanSoilLayer.cs	(.../UpliftVanSoilLayer.cs)	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -69,6 +69,7 @@
             ShearStrengthRatio = properties.ShearStrengthRatio;
             Pop = properties.Pop;
             DilatancyType = properties.DilatancyType;
+            WaterPressureInterpolationModel = properties.WaterPressureInterpolationModel;
         }
 
         /// <summary>
@@ -141,6 +142,11 @@
         /// </summary>
         public UpliftVanDilatancyType DilatancyType { get; }
 
+        /// <summary>
+        /// Gets the water pressure interpolation model.
+        /// </summary>
+        public UpliftVanWaterPressureInterpolationModel WaterPressureInterpolationModel { get; }
+
         public class ConstructionProperties
         {
             /// <summary>
@@ -158,6 +164,7 @@
                 ShearStrengthRatio = double.NaN;
                 Pop = double.NaN;
                 DilatancyType = UpliftVanDilatancyType.Zero;
+                WaterPressureInterpolationModel = UpliftVanWaterPressureInterpolationModel.Automatic;
             }
 
             /// <summary>
@@ -219,6 +226,11 @@
             /// Gets or sets the dilatancy type.
             /// </summary>
             public UpliftVanDilatancyType DilatancyType { internal get; set; }
+
+            /// <summary>
+            /// Gets or sets the water pressure interpolation model.
+            /// </summary>
+            public UpliftVanWaterPressureInterpolationModel WaterPressureInterpolationModel { internal get; set; }
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModel.cs
===================================================================
diff -u
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModel.cs	(revision 0)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModel.cs	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -0,0 +1,32 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+namespace Ringtoets.MacroStabilityInwards.KernelWrapper.Calculators.UpliftVan.Input
+{
+    /// <summary>
+    /// All water pressure interpolation model types.
+    /// </summary>
+    public enum UpliftVanWaterPressureInterpolationModel
+    {
+        Automatic = 1,
+        Hydrostatic = 2
+    }
+}
\ No newline at end of file
Index: Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Ringtoets.MacroStabilityInwards.KernelWrapper.csproj
===================================================================
diff -u -r313c23c7b7459821de6fd37e6389fb853c7ce2a4 -r906637928b5acd53b2e45c59ee448c700b03d82a
--- Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Ringtoets.MacroStabilityInwards.KernelWrapper.csproj	(.../Ringtoets.MacroStabilityInwards.KernelWrapper.csproj)	(revision 313c23c7b7459821de6fd37e6389fb853c7ce2a4)
+++ Ringtoets/MacroStabilityInwards/src/Ringtoets.MacroStabilityInwards.KernelWrapper/Ringtoets.MacroStabilityInwards.KernelWrapper.csproj	(.../Ringtoets.MacroStabilityInwards.KernelWrapper.csproj)	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -48,6 +48,7 @@
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanPhreaticLineOffsets.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanPreconsolidationStress.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanDilatancyType.cs" />
+    <Compile Include="Calculators\UpliftVan\Input\UpliftVanWaterPressureInterpolationModel.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanShearStrengthModel.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanSoilLayer.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanSoilProfile.cs" />
Index: Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanSoilLayerTest.cs
===================================================================
diff -u -r313c23c7b7459821de6fd37e6389fb853c7ce2a4 -r906637928b5acd53b2e45c59ee448c700b03d82a
--- Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanSoilLayerTest.cs	(.../UpliftVanSoilLayerTest.cs)	(revision 313c23c7b7459821de6fd37e6389fb853c7ce2a4)
+++ Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanSoilLayerTest.cs	(.../UpliftVanSoilLayerTest.cs)	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -108,6 +108,7 @@
             Assert.IsNaN(layer.StrengthIncreaseExponent);
             Assert.IsNaN(layer.Pop);
             Assert.AreEqual(UpliftVanDilatancyType.Zero, layer.DilatancyType);
+            Assert.AreEqual(UpliftVanWaterPressureInterpolationModel.Automatic, layer.WaterPressureInterpolationModel);
         }
 
         [Test]
@@ -127,6 +128,7 @@
             double strengthIncreaseExponent = random.NextDouble();
             double pop = random.NextDouble();
             var dilatancyType = random.NextEnumValue<UpliftVanDilatancyType>();
+            var waterPressureInterpolationModel = random.NextEnumValue<UpliftVanWaterPressureInterpolationModel>();
 
             // Call
             var layer = new UpliftVanSoilLayer(new Point2D[0], new Point2D[0][], new UpliftVanSoilLayer.ConstructionProperties
@@ -142,7 +144,8 @@
                 ShearStrengthRatio = shearStrengthRatio,
                 StrengthIncreaseExponent = strengthIncreaseExponent,
                 Pop = pop,
-                DilatancyType = dilatancyType
+                DilatancyType = dilatancyType,
+                WaterPressureInterpolationModel = waterPressureInterpolationModel
             });
 
             // Assert
@@ -158,6 +161,7 @@
             Assert.AreEqual(strengthIncreaseExponent, layer.StrengthIncreaseExponent);
             Assert.AreEqual(pop, layer.Pop);
             Assert.AreEqual(dilatancyType, layer.DilatancyType);
+            Assert.AreEqual(waterPressureInterpolationModel, layer.WaterPressureInterpolationModel);
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModelTest.cs
===================================================================
diff -u
--- Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModelTest.cs	(revision 0)
+++ Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Calculators/UpliftVan/Input/UpliftVanWaterPressureInterpolationModelTest.cs	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -0,0 +1,40 @@
+// Copyright (C) Stichting Deltares 2017. All rights reserved.
+//
+// This file is part of Ringtoets.
+//
+// Ringtoets is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+//
+// All names, logos, and references to "Deltares" are registered trademarks of
+// Stichting Deltares and remain full property of Stichting Deltares at all times.
+// All rights reserved.
+
+using System;
+using NUnit.Framework;
+using Ringtoets.MacroStabilityInwards.KernelWrapper.Calculators.UpliftVan.Input;
+
+namespace Ringtoets.MacroStabilityInwards.KernelWrapper.Test.Calculators.UpliftVan.Input
+{
+    [TestFixture]
+    public class UpliftVanWaterPressureInterpolationModelTest
+    {
+        [Test]
+        public void Values_ExpectedValues()
+        {
+            // Assert
+            Assert.AreEqual(2, Enum.GetValues(typeof(UpliftVanWaterPressureInterpolationModel)).Length);
+            Assert.AreEqual(1, (int) UpliftVanWaterPressureInterpolationModel.Automatic);
+            Assert.AreEqual(2, (int) UpliftVanWaterPressureInterpolationModel.Hydrostatic);
+        }
+    }
+}
\ No newline at end of file
Index: Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test.csproj
===================================================================
diff -u -r313c23c7b7459821de6fd37e6389fb853c7ce2a4 -r906637928b5acd53b2e45c59ee448c700b03d82a
--- Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test.csproj	(.../Ringtoets.MacroStabilityInwards.KernelWrapper.Test.csproj)	(revision 313c23c7b7459821de6fd37e6389fb853c7ce2a4)
+++ Ringtoets/MacroStabilityInwards/test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test/Ringtoets.MacroStabilityInwards.KernelWrapper.Test.csproj	(.../Ringtoets.MacroStabilityInwards.KernelWrapper.Test.csproj)	(revision 906637928b5acd53b2e45c59ee448c700b03d82a)
@@ -66,6 +66,7 @@
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanPhreaticLineOffsetsTest.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanPreconsolidationStressTest.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanDilatancyTypeTest.cs" />
+    <Compile Include="Calculators\UpliftVan\Input\UpliftVanWaterPressureInterpolationModelTest.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanShearStrengthModelTest.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanSoilLayerTest.cs" />
     <Compile Include="Calculators\UpliftVan\Input\UpliftVanSoilProfileTest.cs" />