Index: DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryHelper.cs
===================================================================
diff -u -r5046 -r5058
--- DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryHelper.cs	(.../GeometryHelper.cs)	(revision 5046)
+++ DamEngine/trunk/src/Deltares.DamEngine.Data/Geometry/GeometryHelper.cs	(.../GeometryHelper.cs)	(revision 5058)
@@ -277,8 +277,7 @@
         List<GeometryCurve> geometryCurveList = new List<GeometryCurve>();
         foreach (GeometryCurve curve in outerLoop.CurveList)
         {
-            if (((curve.SurfaceAtLeft == null ? (true ? 1 : 0) : (curve.SurfaceAtLeft == aData ? 1 : 0)) & 
-                 (curve.SurfaceAtRight == null ? 1 : (curve.SurfaceAtRight == aData ? 1 : 0))) != 0)
+            if (IsCurveAnExistingCurve(curve, aData))
                 geometryCurveList.Add(curve);
             else
                 geometry.NewlyEffectedCurves.Add(curve);
@@ -289,7 +288,13 @@
         geometry.Remove( aSurface, false);
         geometry.NewlyEffectedCurves.Clear();
     }
-    
+
+    private static bool IsCurveAnExistingCurve(GeometryCurve curve, GeometrySurface aData)
+    {
+        return ((curve.SurfaceAtLeft == null ? (true ? 1 : 0) : (curve.SurfaceAtLeft == aData ? 1 : 0)) & 
+                (curve.SurfaceAtRight == null ? 1 : (curve.SurfaceAtRight == aData ? 1 : 0))) != 0;
+    }
+
     /// <summary>
     /// Gets the intersection curve which is a vertical helper line which can be used to find all intersections at a given x.
     /// </summary>