Index: dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/Deltares.DamPiping.BlighCalculator.csproj
===================================================================
diff -u -r324 -r325
--- dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/Deltares.DamPiping.BlighCalculator.csproj	(.../Deltares.DamPiping.BlighCalculator.csproj)	(revision 324)
+++ dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/Deltares.DamPiping.BlighCalculator.csproj	(.../Deltares.DamPiping.BlighCalculator.csproj)	(revision 325)
@@ -59,6 +59,7 @@
     <EmbeddedResource Include="Properties\Resources.resx">
       <Generator>ResXFileCodeGenerator</Generator>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
+      <SubType>Designer</SubType>
     </EmbeddedResource>
     <EmbeddedResource Include="Properties\Resources.nl-NL.resx" />
   </ItemGroup>
Index: dam failuremechanisms/damPiping/trunk/src/Tests/Deltares.DamPiping.BlighCalculatorTests/PipingCalculatorBlighTests.cs
===================================================================
diff -u -r320 -r325
--- dam failuremechanisms/damPiping/trunk/src/Tests/Deltares.DamPiping.BlighCalculatorTests/PipingCalculatorBlighTests.cs	(.../PipingCalculatorBlighTests.cs)	(revision 320)
+++ dam failuremechanisms/damPiping/trunk/src/Tests/Deltares.DamPiping.BlighCalculatorTests/PipingCalculatorBlighTests.cs	(.../PipingCalculatorBlighTests.cs)	(revision 325)
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using Deltares.DamPiping.BlighCalculator;
+using Deltares.DamPiping.BlighCalculator;
 using NUnit.Framework;
 
 namespace Deltares.DamPiping.BlighCalculatorTests
@@ -29,15 +25,17 @@
         public void TestCalculation()
         {
             const double diff = 0.0001;
-            var bc = new PipingCalculatorBligh();
-            bc.HRiver = 2.0;
-            bc.ModelFactorPiping = 1.0;
-            bc.HExit = 0.0;
-            bc.Rc = 0.3;
-            bc.DTotal = 5.0;
-            bc.SeepageLength = 40.5;
-            //bc.D50 = 2.5e-3; // WTI Test succeeds with CreepFactorWTI todo: remove D50 and CreepFactorWTI?
-            bc.D70 = 180.0; // Dam: set D70 instead of D50
+            var bc = new PipingCalculatorBligh
+            {
+                HRiver = 2.0,
+                ModelFactorPiping = 1.0,
+                HExit = 0.0,
+                Rc = 0.3,
+                DTotal = 5.0,
+                SeepageLength = 40.5,
+                //bc.D50 = 2.5e-3; // WTI Test succeeds with CreepFactorWTI todo: remove D50 and CreepFactorWTI?
+                D70 = 180.0 // Dam: set D70 instead of D50
+            };
             bc.Calculate();
             Assert.AreEqual(4.5, bc.FoSp, diff);
             Assert.AreEqual(2.25, bc.Hc, diff);
@@ -46,5 +44,96 @@
             Assert.AreEqual(3.75, bc.Hcp, diff); // not relevant for Dam todo: remove Hcp?
         }
 
+        [Test]
+        public void TestValidateNaNParameter()
+        {
+            var bc = new PipingCalculatorBligh
+            {
+                HRiver = 2.0,
+                ModelFactorPiping = 1.0,
+                HExit = 0.0,
+                Rc = 0.3,
+                DTotal = 5.0,
+                SeepageLength = 40.5,
+                D70 = 180.0
+            };
+            var originalErrors = bc.Validate();
+
+            bc.HRiver = double.NaN;
+            bc.ModelFactorPiping = double.NaN;
+            bc.HExit = double.NaN;
+            bc.Rc = double.NaN;
+            bc.DTotal = double.NaN;
+            bc.SeepageLength = double.NaN;
+            bc.D70 = double.NaN;
+            var nanErrors = bc.Validate();
+            Assert.AreEqual(originalErrors.Count + 7, nanErrors.Count);
+
+            //  D70 is allowed to be null
+            bc.D70 = null;
+            nanErrors = bc.Validate();
+            Assert.AreEqual(originalErrors.Count + 6, nanErrors.Count);
+        }
+
+        [Test]
+        [SetUICulture("en-US")]
+        public void TestValidateRcLessThan0En()
+        {
+            var calculator = new PipingCalculatorBligh
+            {
+                HRiver = 2.0,
+                ModelFactorPiping = 1.0,
+                HExit = 0.0,
+                Rc = -1e-6,
+                DTotal = 5.0,
+                SeepageLength = 40.5,
+                D70 = 180.0
+            };
+            var errors = calculator.Validate();
+            Assert.AreEqual(1, errors.Count);
+            var expectedMessageEN = "Rc may not be less than 0.";
+            CollectionAssert.AreEqual(new[] {expectedMessageEN}, errors);
+        }
+
+        [Test]
+        [SetUICulture("nl-NL")]
+        public void TestValidateRcLessThan0Nl()
+        {
+            var calculator = new PipingCalculatorBligh
+            {
+                HRiver = 2.0,
+                ModelFactorPiping = 1.0,
+                HExit = 0.0,
+                Rc = -1e-6,
+                DTotal = 5.0,
+                SeepageLength = 40.5,
+                D70 = 180.0
+            };
+            var errors = calculator.Validate();
+            Assert.AreEqual(1, errors.Count);
+            var expectedMessageNL = "De waarde voor de dempingsfactor mag niet lager dan 0 zijn.";
+            CollectionAssert.AreEqual(new[] { expectedMessageNL }, errors);
+        }
+
+        [Test]
+        [SetUICulture("en-US")]
+        public void TestValidateReducedFall()
+        {
+            var calculator = new PipingCalculatorBligh
+            {
+                HRiver = 2.0,
+                ModelFactorPiping = 1.0,
+                HExit = 2.0,
+                Rc = 0,
+                DTotal = 5.0,
+                SeepageLength = 40.5,
+                D70 = 180.0
+            };
+            var errors = calculator.Validate();
+            Assert.AreEqual(1, errors.Count);
+            var expectedMessageEN = "HRiver - HExit - (Rc*DTotal) may not be 0.";
+            CollectionAssert.AreEqual(new[] { expectedMessageEN }, errors);
+        }
+
     }
 }
Index: dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/PipingCalculatorBligh.cs
===================================================================
diff -u -r324 -r325
--- dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/PipingCalculatorBligh.cs	(.../PipingCalculatorBligh.cs)	(revision 324)
+++ dam failuremechanisms/damPiping/trunk/src/Deltares.DamPiping.BlighCalculator/PipingCalculatorBligh.cs	(.../PipingCalculatorBligh.cs)	(revision 325)
@@ -1,7 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using Deltares.DamPiping.BlighCalculator.Properties;
 
 namespace Deltares.DamPiping.BlighCalculator
@@ -284,6 +286,10 @@
             {
                 LogParameterIsNaN(errors, "D50");
             }
+            if (D70 != null && double.IsNaN((double) D70))
+            {
+                LogParameterIsNaN(errors, "D70");
+            }
 
             return errors;
         }