Index: trunk/resources/data/validator/deprecated.mapcss
===================================================================
--- trunk/resources/data/validator/deprecated.mapcss	(revision 16146)
+++ trunk/resources/data/validator/deprecated.mapcss	(revision 16173)
@@ -1953,2 +1953,10 @@
   group: tr("deprecated tagging");
 }
+
+/* #18951 */
+*[water=riverbank] {
+  throwWarning: tr("{0} is deprecated", "{0.tag}");
+  suggestAlternative: "water=river";
+  group: tr("deprecated tagging");
+  fixAdd: "water=river";
+}