Index: DamEngine/trunk/xsd/DamLocation.xsd
===================================================================
diff -u -r2522 -r2567
--- DamEngine/trunk/xsd/DamLocation.xsd	(.../DamLocation.xsd)	(revision 2522)
+++ DamEngine/trunk/xsd/DamLocation.xsd	(.../DamLocation.xsd)	(revision 2567)
@@ -95,10 +95,10 @@
                 <xs:attribute name="RiverLevel" type="xs:double" use="required" />
                 <xs:attribute name="RiverLevelLow" type="xs:double" use="optional" />
                 <xs:attribute name="DikeTableHeight" type="xs:double" use="optional" />
-                <xs:attribute name="PlLineOffsetBelowDikeTopAtRiver" type="xs:double" use="optional" />
-                <xs:attribute name="PlLineOffsetBelowDikeTopAtPolder" type="xs:double" use="optional" />
-                <xs:attribute name="PlLineOffsetBelowShoulderBaseInside" type="xs:double" use="optional" />
-                <xs:attribute name="PlLineOffsetBelowDikeToeAtPolder" type="xs:double" use="optional" />
+                <xs:attribute name="PlLineOffsetBelowDikeTopAtRiver" type="xs:double" use="required" />
+                <xs:attribute name="PlLineOffsetBelowDikeTopAtPolder" type="xs:double" use="required" />
+                <xs:attribute name="PlLineOffsetBelowShoulderBaseInside" type="xs:double" use="required" />
+                <xs:attribute name="PlLineOffsetBelowDikeToeAtPolder" type="xs:double" use="required" />
                 <xs:attribute name="PlLineOffsetBelowDikeCrestMiddle" type="xs:double" use="optional" />
                 <xs:attribute name="PlLineOffsetFactorBelowShoulderCrest" type="xs:double" use="optional" />
                 <xs:attribute name="HeadPl3" type="xs:double" use="optional" />